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* locking/ww_mutex: Remove the __ww_mutex_lock*() inline wrappersNicolai Hähnle2017-01-142-22/+12Star
| | | | | | | | | | | | | | | | | | | | | Keep the documentation in the header file since there is no good place for it in mutex.c: there are two rather different implementations with different EXPORT_SYMBOLs for each function. Signed-off-by: Nicolai Hähnle <nicolai.haehnle@amd.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: =?UTF-8?q?Nicolai=20H=C3=A4hnle?= <Nicolai.Haehnle@amd.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Maarten Lankhorst <dev@mblankhorst.nl> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dri-devel@lists.freedesktop.org Link: http://lkml.kernel.org/r/1482346000-9927-6-git-send-email-nhaehnle@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* locking/ww_mutex: Set use_ww_ctx even when locking without a contextNicolai Hähnle2017-01-142-21/+19Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | We will add a new field to struct mutex_waiter. This field must be initialized for all waiters if any waiter uses the ww_use_ctx path. So there is a trade-off: Keep ww_mutex locking without a context on the faster non-use_ww_ctx path, at the cost of adding the initialization to all mutex locks (including non-ww_mutexes), or avoid the additional cost for non-ww_mutex locks, at the cost of adding additional checks to the use_ww_ctx path. We take the latter choice. It may be worth eliminating the users of ww_mutex_lock(lock, NULL), but there are a lot of them. Signed-off-by: Nicolai Hähnle <Nicolai.Haehnle@amd.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Maarten Lankhorst <dev@mblankhorst.nl> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dri-devel@lists.freedesktop.org Link: http://lkml.kernel.org/r/1482346000-9927-5-git-send-email-nhaehnle@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* locking/ww_mutex: Extract stamp comparison to __ww_mutex_stamp_after()Nicolai Hähnle2017-01-141-2/+8
| | | | | | | | | | | | | | | | | | The function will be re-used in subsequent patches. Signed-off-by: Nicolai Hähnle <Nicolai.Haehnle@amd.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Maarten Lankhorst <dev@mblankhorst.nl> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dri-devel@lists.freedesktop.org Link: http://lkml.kernel.org/r/1482346000-9927-4-git-send-email-nhaehnle@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* locking/mutex: Fix mutex handoffPeter Zijlstra2017-01-143-59/+57Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While reviewing the ww_mutex patches, I noticed that it was still possible to (incorrectly) succeed for (incorrect) code like: mutex_lock(&a); mutex_lock(&a); This was possible if the second mutex_lock() would block (as expected) but then receive a spurious wakeup. At that point it would find itself at the front of the queue, request a handoff and instantly claim ownership and continue, since owner would point to itself. Avoid this scenario and simplify the code by introducing a third low bit to signal handoff pickup. So once we request handoff, unlock clears the handoff bit and sets the pickup bit along with the new owner. This also removes the need for the .handoff argument to __mutex_trylock(), since that becomes superfluous with PICKUP. In order to guarantee enough low bits, ensure task_struct alignment is at least L1_CACHE_BYTES (which seems a good ideal regardless). Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 9d659ae14b54 ("locking/mutex: Add lock handoff to avoid starvation") Signed-off-by: Ingo Molnar <mingo@kernel.org>
* locking/percpu-rwsem: Replace waitqueue with rcuwaitDavidlohr Bueso2017-01-142-8/+7Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | The use of any kind of wait queue is an overkill for pcpu-rwsems. While one option would be to use the less heavy simple (swait) flavor, this is still too much for what pcpu-rwsems needs. For one, we do not care about any sort of queuing in that the only (rare) time writers (and readers, for that matter) are queued is when trying to acquire the regular contended rw_sem. There cannot be any further queuing as writers are serialized by the rw_sem in the first place. Given that percpu_down_write() must not be called after exit_notify(), we can replace the bulky waitqueue with rcuwait such that a writer can wait for its turn to take the lock. As such, we can avoid the queue handling and locking overhead. Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dave@stgolabs.net Link: http://lkml.kernel.org/r/1484148146-14210-3-git-send-email-dave@stgolabs.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
* sched/wait, RCU: Introduce rcuwait machineryDavidlohr Bueso2017-01-142-0/+93
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | rcuwait provides support for (single) RCU-safe task wait/wake functionality, with the caveat that it must not be called after exit_notify(), such that we avoid racing with rcu delayed_put_task_struct callbacks, task_struct being rcu unaware in this context -- for which we similarly have task_rcu_dereference() magic, but with different return semantics, which can conflict with the wakeup side. The interfaces are quite straightforward: rcuwait_wait_event() rcuwait_wake_up() More details are in the comments, but it's perhaps worth mentioning at least, that users must provide proper serialization when waiting on a condition, and avoid corrupting a concurrent waiter. Also care must be taken between the task and the condition for when calling the wakeup -- we cannot miss wakeups. When porting users, this is for example, a given when using waitqueues in that everything is done under the q->lock. As such, it can remove sources of non preemptable unbounded work for realtime. Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dave@stgolabs.net Link: http://lkml.kernel.org/r/1484148146-14210-2-git-send-email-dave@stgolabs.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
* sched/core: Remove set_task_state()Davidlohr Bueso2017-01-1412-51/+26Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is a nasty interface and setting the state of a foreign task must not be done. As of the following commit: be628be0956 ("bcache: Make gc wakeup sane, remove set_task_state()") ... everyone in the kernel calls set_task_state() with current, allowing the helper to be removed. However, as the comment indicates, it is still around for those archs where computing current is more expensive than using a pointer, at least in theory. An important arch that is affected is arm64, however this has been addressed now [1] and performance is up to par making no difference with either calls. Of all the callers, if any, it's the locking bits that would care most about this -- ie: we end up passing a tsk pointer to a lot of the lock slowpath, and setting ->state on that. The following numbers are based on two tests: a custom ad-hoc microbenchmark that just measures latencies (for ~65 million calls) between get_task_state() vs get_current_state(). Secondly for a higher overview, an unlink microbenchmark was used, which pounds on a single file with open, close,unlink combos with increasing thread counts (up to 4x ncpus). While the workload is quite unrealistic, it does contend a lot on the inode mutex or now rwsem. [1] https://lkml.kernel.org/r/1483468021-8237-1-git-send-email-mark.rutland@arm.com == 1. x86-64 == Avg runtime set_task_state(): 601 msecs Avg runtime set_current_state(): 552 msecs vanilla dirty Hmean unlink1-processes-2 36089.26 ( 0.00%) 38977.33 ( 8.00%) Hmean unlink1-processes-5 28555.01 ( 0.00%) 29832.55 ( 4.28%) Hmean unlink1-processes-8 37323.75 ( 0.00%) 44974.57 ( 20.50%) Hmean unlink1-processes-12 43571.88 ( 0.00%) 44283.01 ( 1.63%) Hmean unlink1-processes-21 34431.52 ( 0.00%) 38284.45 ( 11.19%) Hmean unlink1-processes-30 34813.26 ( 0.00%) 37975.17 ( 9.08%) Hmean unlink1-processes-48 37048.90 ( 0.00%) 39862.78 ( 7.59%) Hmean unlink1-processes-79 35630.01 ( 0.00%) 36855.30 ( 3.44%) Hmean unlink1-processes-110 36115.85 ( 0.00%) 39843.91 ( 10.32%) Hmean unlink1-processes-141 32546.96 ( 0.00%) 35418.52 ( 8.82%) Hmean unlink1-processes-172 34674.79 ( 0.00%) 36899.21 ( 6.42%) Hmean unlink1-processes-203 37303.11 ( 0.00%) 36393.04 ( -2.44%) Hmean unlink1-processes-224 35712.13 ( 0.00%) 36685.96 ( 2.73%) == 2. ppc64le == Avg runtime set_task_state(): 938 msecs Avg runtime set_current_state: 940 msecs vanilla dirty Hmean unlink1-processes-2 19269.19 ( 0.00%) 30704.50 ( 59.35%) Hmean unlink1-processes-5 20106.15 ( 0.00%) 21804.15 ( 8.45%) Hmean unlink1-processes-8 17496.97 ( 0.00%) 17243.28 ( -1.45%) Hmean unlink1-processes-12 14224.15 ( 0.00%) 17240.21 ( 21.20%) Hmean unlink1-processes-21 14155.66 ( 0.00%) 15681.23 ( 10.78%) Hmean unlink1-processes-30 14450.70 ( 0.00%) 15995.83 ( 10.69%) Hmean unlink1-processes-48 16945.57 ( 0.00%) 16370.42 ( -3.39%) Hmean unlink1-processes-79 15788.39 ( 0.00%) 14639.27 ( -7.28%) Hmean unlink1-processes-110 14268.48 ( 0.00%) 14377.40 ( 0.76%) Hmean unlink1-processes-141 14023.65 ( 0.00%) 16271.69 ( 16.03%) Hmean unlink1-processes-172 13417.62 ( 0.00%) 16067.55 ( 19.75%) Hmean unlink1-processes-203 15293.08 ( 0.00%) 15440.40 ( 0.96%) Hmean unlink1-processes-234 13719.32 ( 0.00%) 16190.74 ( 18.01%) Hmean unlink1-processes-265 16400.97 ( 0.00%) 16115.22 ( -1.74%) Hmean unlink1-processes-296 14388.60 ( 0.00%) 16216.13 ( 12.70%) Hmean unlink1-processes-320 15771.85 ( 0.00%) 15905.96 ( 0.85%) x86-64 (known to be fast for get_current()/this_cpu_read_stable() caching) and ppc64 (with paca) show similar improvements in the unlink microbenches. The small delta for ppc64 (2ms), does not represent the gains on the unlink runs. In the case of x86, there was a decent amount of variation in the latency runs, but always within a 20 to 50ms increase), ppc was more constant. Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dave@stgolabs.net Cc: mark.rutland@arm.com Link: http://lkml.kernel.org/r/1483479794-14013-5-git-send-email-dave@stgolabs.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
* kernel/locking: Compute 'current' directlyDavidlohr Bueso2017-01-144-29/+22Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch effectively replaces the tsk pointer dereference (which is obviously == current), to directly use get_current() macro. This is to make the removal of setting foreign task states smoother and painfully obvious. Performance win on some archs such as x86-64 and ppc64. On a microbenchmark that calls set_task_state() vs set_current_state() and an inode rwsem pounding benchmark doing unlink: == 1. x86-64 == Avg runtime set_task_state(): 601 msecs Avg runtime set_current_state(): 552 msecs vanilla dirty Hmean unlink1-processes-2 36089.26 ( 0.00%) 38977.33 ( 8.00%) Hmean unlink1-processes-5 28555.01 ( 0.00%) 29832.55 ( 4.28%) Hmean unlink1-processes-8 37323.75 ( 0.00%) 44974.57 ( 20.50%) Hmean unlink1-processes-12 43571.88 ( 0.00%) 44283.01 ( 1.63%) Hmean unlink1-processes-21 34431.52 ( 0.00%) 38284.45 ( 11.19%) Hmean unlink1-processes-30 34813.26 ( 0.00%) 37975.17 ( 9.08%) Hmean unlink1-processes-48 37048.90 ( 0.00%) 39862.78 ( 7.59%) Hmean unlink1-processes-79 35630.01 ( 0.00%) 36855.30 ( 3.44%) Hmean unlink1-processes-110 36115.85 ( 0.00%) 39843.91 ( 10.32%) Hmean unlink1-processes-141 32546.96 ( 0.00%) 35418.52 ( 8.82%) Hmean unlink1-processes-172 34674.79 ( 0.00%) 36899.21 ( 6.42%) Hmean unlink1-processes-203 37303.11 ( 0.00%) 36393.04 ( -2.44%) Hmean unlink1-processes-224 35712.13 ( 0.00%) 36685.96 ( 2.73%) == 2. ppc64le == Avg runtime set_task_state(): 938 msecs Avg runtime set_current_state: 940 msecs vanilla dirty Hmean unlink1-processes-2 19269.19 ( 0.00%) 30704.50 ( 59.35%) Hmean unlink1-processes-5 20106.15 ( 0.00%) 21804.15 ( 8.45%) Hmean unlink1-processes-8 17496.97 ( 0.00%) 17243.28 ( -1.45%) Hmean unlink1-processes-12 14224.15 ( 0.00%) 17240.21 ( 21.20%) Hmean unlink1-processes-21 14155.66 ( 0.00%) 15681.23 ( 10.78%) Hmean unlink1-processes-30 14450.70 ( 0.00%) 15995.83 ( 10.69%) Hmean unlink1-processes-48 16945.57 ( 0.00%) 16370.42 ( -3.39%) Hmean unlink1-processes-79 15788.39 ( 0.00%) 14639.27 ( -7.28%) Hmean unlink1-processes-110 14268.48 ( 0.00%) 14377.40 ( 0.76%) Hmean unlink1-processes-141 14023.65 ( 0.00%) 16271.69 ( 16.03%) Hmean unlink1-processes-172 13417.62 ( 0.00%) 16067.55 ( 19.75%) Hmean unlink1-processes-203 15293.08 ( 0.00%) 15440.40 ( 0.96%) Hmean unlink1-processes-234 13719.32 ( 0.00%) 16190.74 ( 18.01%) Hmean unlink1-processes-265 16400.97 ( 0.00%) 16115.22 ( -1.74%) Hmean unlink1-processes-296 14388.60 ( 0.00%) 16216.13 ( 12.70%) Hmean unlink1-processes-320 15771.85 ( 0.00%) 15905.96 ( 0.85%) Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dave@stgolabs.net Cc: mark.rutland@arm.com Link: http://lkml.kernel.org/r/1483479794-14013-4-git-send-email-dave@stgolabs.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
* drivers/tty: Compute 'current' directlyDavidlohr Bueso2017-01-141-10/+8Star
| | | | | | | | | | | | | | | | | | | | This patch effectively replaces the tsk pointer dereference (which is obviously == current), to directly use get_current() macro. This is to make the removal of setting foreign task states smoother and painfully obvious. Performance win on some archs such as x86-64 and ppc64 -- arm64 is no longer an issue. Signed-off-by: Davidlohr Bueso <dave@stgolabs.net> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: mark.rutland@arm.com Link: http://lkml.kernel.org/r/1483479794-14013-3-git-send-email-dave@stgolabs.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
* kernel/exit: Compute 'current' directlyDavidlohr Bueso2017-01-141-11/+11
| | | | | | | | | | | | | | | | | | | | This patch effectively replaces the tsk pointer dereference (which is obviously == current), to directly use get_current() macro. In this case, do_exit() always passes current to exit_mm(), hence we can simply get rid of the argument. This is also a performance win on some archs such as x86-64 and ppc64 -- arm64 is no longer an issue. Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dave@stgolabs.net Cc: mark.rutland@arm.com Link: http://lkml.kernel.org/r/1483479794-14013-2-git-send-email-dave@stgolabs.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
* locking/spinlocks/x86, paravirt: Remove paravirt_ticketlocks_enabledWaiman Long2017-01-144-39/+0Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is a follow-up of commit: cfd8983f03c7b2 ("x86, locking/spinlocks: Remove ticket (spin)lock implementation") The static_key structure 'paravirt_ticketlocks_enabled' is now removed as it is no longer used. As a result, the init functions kvm_spinlock_init_jump() and xen_init_spinlocks_jump() are also removed. A simple build and boot test was done to verify it. Signed-off-by: Waiman Long <longman@redhat.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Alok Kataria <akataria@vmware.com> Cc: Chris Wright <chrisw@sous-sol.org> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: kvm@vger.kernel.org Cc: linux-arch@vger.kernel.org Cc: virtualization@lists.linux-foundation.org Cc: xen-devel@lists.xenproject.org Link: http://lkml.kernel.org/r/1484252878-1962-1-git-send-email-longman@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* locking/jump_labels: Update bug_at() boot messageAndy Shevchenko2017-01-121-2/+1Star
| | | | | | | | | | | | | | | First of all, %*ph specifier allows to dump data in hex format using the pointer to a buffer. This is suitable to use here. Besides that Thomas suggested to move it to critical level and replace __FILE__ by explicit mention of "jumplabel". Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20170110164354.47372-1-andriy.shevchenko@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* locking/pvqspinlock: Don't wait if vCPU is preemptedPan Xinhui2017-01-121-1/+1
| | | | | | | | | | | | | | If prev node is not in running state or its vCPU is preempted, we can give up our vCPU slices in pv_wait_node() ASAP. Signed-off-by: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: longman@redhat.com Link: http://lkml.kernel.org/r/1484035006-6787-1-git-send-email-xinhui.pan@linux.vnet.ibm.com [ Fixed typos in the changelog, removed ugly linebreak from the code. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
* locking/spinlocks: Remove the unused spin_lock_bh_nested() APIWaiman Long2017-01-124-19/+0Star
| | | | | | | | | | | | | The spin_lock_bh_nested() API is defined but is not used anywhere in the kernel. So all spin_lock_bh_nested() and related APIs are now removed. Signed-off-by: Waiman Long <longman@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1483975612-16447-1-git-send-email-longman@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* Merge branch 'akpm' (patches from Andrew)Linus Torvalds2017-01-1139-182/+355
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge fixes from Andrew Morton: "27 fixes. There are three patches that aren't actually fixes. They're simple function renamings which are nice-to-have in mainline as ongoing net development depends on them." * akpm: (27 commits) timerfd: export defines to userspace mm/hugetlb.c: fix reservation race when freeing surplus pages mm/slab.c: fix SLAB freelist randomization duplicate entries zram: support BDI_CAP_STABLE_WRITES zram: revalidate disk under init_lock mm: support anonymous stable page mm: add documentation for page fragment APIs mm: rename __page_frag functions to __page_frag_cache, drop order from drain mm: rename __alloc_page_frag to page_frag_alloc and __free_page_frag to page_frag_free mm, memcg: fix the active list aging for lowmem requests when memcg is enabled mm: don't dereference struct page fields of invalid pages mailmap: add codeaurora.org names for nameless email commits signal: protect SIGNAL_UNKILLABLE from unintentional clearing. mm: pmd dirty emulation in page fault handler ipc/sem.c: fix incorrect sem_lock pairing lib/Kconfig.debug: fix frv build failure mm: get rid of __GFP_OTHER_NODE mm: fix remote numa hits statistics mm: fix devm_memremap_pages crash, use mem_hotplug_{begin, done} ocfs2: fix crash caused by stale lvb with fsdlm plugin ...
| * timerfd: export defines to userspaceMike Frysinger2017-01-113-19/+38
| | | | | | | | | | | | | | | | | | | | | | | | Since userspace is expected to call timerfd syscalls directly with these flags/ioctls, make sure we export them so they don't have to duplicate the values themselves. Link: http://lkml.kernel.org/r/20161219064052.7196-1-vapier@gentoo.org Signed-off-by: Mike Frysinger <vapier@gentoo.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm/hugetlb.c: fix reservation race when freeing surplus pagesMike Kravetz2017-01-111-9/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | return_unused_surplus_pages() decrements the global reservation count, and frees any unused surplus pages that were backing the reservation. Commit 7848a4bf51b3 ("mm/hugetlb.c: add cond_resched_lock() in return_unused_surplus_pages()") added a call to cond_resched_lock in the loop freeing the pages. As a result, the hugetlb_lock could be dropped, and someone else could use the pages that will be freed in subsequent iterations of the loop. This could result in inconsistent global hugetlb page state, application api failures (such as mmap) failures or application crashes. When dropping the lock in return_unused_surplus_pages, make sure that the global reservation count (resv_huge_pages) remains sufficiently large to prevent someone else from claiming pages about to be freed. Analyzed by Paul Cassella. Fixes: 7848a4bf51b3 ("mm/hugetlb.c: add cond_resched_lock() in return_unused_surplus_pages()") Link: http://lkml.kernel.org/r/1483991767-6879-1-git-send-email-mike.kravetz@oracle.com Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Reported-by: Paul Cassella <cassella@cray.com> Suggested-by: Michal Hocko <mhocko@kernel.org> Cc: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: <stable@vger.kernel.org> [3.15+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm/slab.c: fix SLAB freelist randomization duplicate entriesJohn Sperbeck2017-01-111-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch fixes a bug in the freelist randomization code. When a high random number is used, the freelist will contain duplicate entries. It will result in different allocations sharing the same chunk. It will result in odd behaviours and crashes. It should be uncommon but it depends on the machines. We saw it happening more often on some machines (every few hours of running tests). Fixes: c7ce4f60ac19 ("mm: SLAB freelist randomization") Link: http://lkml.kernel.org/r/20170103181908.143178-1-thgarnie@google.com Signed-off-by: John Sperbeck <jsperbeck@google.com> Signed-off-by: Thomas Garnier <thgarnie@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * zram: support BDI_CAP_STABLE_WRITESMinchan Kim2017-01-111-2/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | zram has used per-cpu stream feature from v4.7. It aims for increasing cache hit ratio of scratch buffer for compressing. Downside of that approach is that zram should ask memory space for compressed page in per-cpu context which requires stricted gfp flag which could be failed. If so, it retries to allocate memory space out of per-cpu context so it could get memory this time and compress the data again, copies it to the memory space. In this scenario, zram assumes the data should never be changed but it is not true without stable page support. So, If the data is changed under us, zram can make buffer overrun so that zsmalloc free object chain is broken so system goes crash like below https://bugzilla.suse.com/show_bug.cgi?id=997574 This patch adds BDI_CAP_STABLE_WRITES to zram for declaring "I am block device needing *stable write*". Fixes: da9556a2367c ("zram: user per-cpu compression streams") Link: http://lkml.kernel.org/r/1482366980-3782-4-git-send-email-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Takashi Iwai <tiwai@suse.de> Cc: Hyeoncheol Lee <cheol.lee@lge.com> Cc: <yjay.kim@lge.com> Cc: Sangseok Lee <sangseok.lee@lge.com> Cc: Hugh Dickins <hughd@google.com> Cc: Darrick J. Wong <darrick.wong@oracle.com> Cc: <stable@vger.kernel.org> [4.7+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * zram: revalidate disk under init_lockMinchan Kim2017-01-111-7/+1Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit b4c5c60920e3 ("zram: avoid lockdep splat by revalidate_disk") moved revalidate_disk call out of init_lock to avoid lockdep false-positive splat. However, commit 08eee69fcf6b ("zram: remove init_lock in zram_make_request") removed init_lock in IO path so there is no worry about lockdep splat. So, let's restore it. This patch is needed to set BDI_CAP_STABLE_WRITES atomically in next patch. Fixes: da9556a2367c ("zram: user per-cpu compression streams") Link: http://lkml.kernel.org/r/1482366980-3782-3-git-send-email-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Takashi Iwai <tiwai@suse.de> Cc: Hyeoncheol Lee <cheol.lee@lge.com> Cc: <yjay.kim@lge.com> Cc: Sangseok Lee <sangseok.lee@lge.com> Cc: Hugh Dickins <hughd@google.com> Cc: Darrick J. Wong <darrick.wong@oracle.com> Cc: <stable@vger.kernel.org> [4.7+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm: support anonymous stable pageMinchan Kim2017-01-112-2/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | During developemnt for zram-swap asynchronous writeback, I found strange corruption of compressed page, resulting in: Modules linked in: zram(E) CPU: 3 PID: 1520 Comm: zramd-1 Tainted: G E 4.8.0-mm1-00320-ge0d4894c9c38-dirty #3274 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 task: ffff88007620b840 task.stack: ffff880078090000 RIP: set_freeobj.part.43+0x1c/0x1f RSP: 0018:ffff880078093ca8 EFLAGS: 00010246 RAX: 0000000000000018 RBX: ffff880076798d88 RCX: ffffffff81c408c8 RDX: 0000000000000018 RSI: 0000000000000000 RDI: 0000000000000246 RBP: ffff880078093cb0 R08: 0000000000000000 R09: 0000000000000000 R10: ffff88005bc43030 R11: 0000000000001df3 R12: ffff880076798d88 R13: 000000000005bc43 R14: ffff88007819d1b8 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff88007e380000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc934048f20 CR3: 0000000077b01000 CR4: 00000000000406e0 Call Trace: obj_malloc+0x22b/0x260 zs_malloc+0x1e4/0x580 zram_bvec_rw+0x4cd/0x830 [zram] page_requests_rw+0x9c/0x130 [zram] zram_thread+0xe6/0x173 [zram] kthread+0xca/0xe0 ret_from_fork+0x25/0x30 With investigation, it reveals currently stable page doesn't support anonymous page. IOW, reuse_swap_page can reuse the page without waiting writeback completion so it can overwrite page zram is compressing. Unfortunately, zram has used per-cpu stream feature from v4.7. It aims for increasing cache hit ratio of scratch buffer for compressing. Downside of that approach is that zram should ask memory space for compressed page in per-cpu context which requires stricted gfp flag which could be failed. If so, it retries to allocate memory space out of per-cpu context so it could get memory this time and compress the data again, copies it to the memory space. In this scenario, zram assumes the data should never be changed but it is not true unless stable page supports. So, If the data is changed under us, zram can make buffer overrun because second compression size could be bigger than one we got in previous trial and blindly, copy bigger size object to smaller buffer which is buffer overrun. The overrun breaks zsmalloc free object chaining so system goes crash like above. I think below is same problem. https://bugzilla.suse.com/show_bug.cgi?id=997574 Unfortunately, reuse_swap_page should be atomic so that we cannot wait on writeback in there so the approach in this patch is simply return false if we found it needs stable page. Although it increases memory footprint temporarily, it happens rarely and it should be reclaimed easily althoug it happened. Also, It would be better than waiting of IO completion, which is critial path for application latency. Fixes: da9556a2367c ("zram: user per-cpu compression streams") Link: http://lkml.kernel.org/r/20161120233015.GA14113@bbox Link: http://lkml.kernel.org/r/1482366980-3782-2-git-send-email-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Acked-by: Hugh Dickins <hughd@google.com> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Darrick J. Wong <darrick.wong@oracle.com> Cc: Takashi Iwai <tiwai@suse.de> Cc: Hyeoncheol Lee <cheol.lee@lge.com> Cc: <yjay.kim@lge.com> Cc: Sangseok Lee <sangseok.lee@lge.com> Cc: <stable@vger.kernel.org> [4.7+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm: add documentation for page fragment APIsAlexander Duyck2017-01-111-0/+42
| | | | | | | | | | | | | | | | | | | | | | | | | | This is a first pass at trying to add documentation for the page_frag APIs. They may still change over time but for now I thought I would try to get these documented so that as more network drivers and stack calls make use of them we have one central spot to document how they are meant to be used. Link: http://lkml.kernel.org/r/20170104024157.13451.6758.stgit@localhost.localdomain Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm: rename __page_frag functions to __page_frag_cache, drop order from drainAlexander Duyck2017-01-113-11/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch does two things. First it goes through and renames the __page_frag prefixed functions to __page_frag_cache so that we can be clear that we are draining or refilling the cache, not the frags themselves. Second we drop the order parameter from __page_frag_cache_drain since we don't actually need to pass it since all fragments are either order 0 or must be a compound page. Link: http://lkml.kernel.org/r/20170104023954.13451.5678.stgit@localhost.localdomain Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm: rename __alloc_page_frag to page_frag_alloc and __free_page_frag to ↵Alexander Duyck2017-01-114-13/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | page_frag_free Patch series "Page fragment updates", v4. This patch series takes care of a few cleanups for the page fragments API. First we do some renames so that things are much more consistent. First we move the page_frag_ portion of the name to the front of the functions names. Secondly we split out the cache specific functions from the other page fragment functions by adding the word "cache" to the name. Finally I added a bit of documentation that will hopefully help to explain some of this. I plan to revisit this later as we get things more ironed out in the near future with the changes planned for the DMA setup to support eXpress Data Path. This patch (of 3): This patch renames the page frag functions to be more consistent with other APIs. Specifically we place the name page_frag first in the name and then have either an alloc or free call name that we append as the suffix. This makes it a bit clearer in terms of naming. In addition we drop the leading double underscores since we are technically no longer a backing interface and instead the front end that is called from the networking APIs. Link: http://lkml.kernel.org/r/20170104023854.13451.67390.stgit@localhost.localdomain Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm, memcg: fix the active list aging for lowmem requests when memcg is enabledMichal Hocko2017-01-114-24/+49
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Nils Holland and Klaus Ethgen have reported unexpected OOM killer invocations with 32b kernel starting with 4.8 kernels kworker/u4:5 invoked oom-killer: gfp_mask=0x2400840(GFP_NOFS|__GFP_NOFAIL), nodemask=0, order=0, oom_score_adj=0 kworker/u4:5 cpuset=/ mems_allowed=0 CPU: 1 PID: 2603 Comm: kworker/u4:5 Not tainted 4.9.0-gentoo #2 [...] Mem-Info: active_anon:58685 inactive_anon:90 isolated_anon:0 active_file:274324 inactive_file:281962 isolated_file:0 unevictable:0 dirty:649 writeback:0 unstable:0 slab_reclaimable:40662 slab_unreclaimable:17754 mapped:7382 shmem:202 pagetables:351 bounce:0 free:206736 free_pcp:332 free_cma:0 Node 0 active_anon:234740kB inactive_anon:360kB active_file:1097296kB inactive_file:1127848kB unevictable:0kB isolated(anon):0kB isolated(file):0kB mapped:29528kB dirty:2596kB writeback:0kB shmem:0kB shmem_thp: 0kB shmem_pmdmapped: 184320kB anon_thp: 808kB writeback_tmp:0kB unstable:0kB pages_scanned:0 all_unreclaimable? no DMA free:3952kB min:788kB low:984kB high:1180kB active_anon:0kB inactive_anon:0kB active_file:7316kB inactive_file:0kB unevictable:0kB writepending:96kB present:15992kB managed:15916kB mlocked:0kB slab_reclaimable:3200kB slab_unreclaimable:1408kB kernel_stack:0kB pagetables:0kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB lowmem_reserve[]: 0 813 3474 3474 Normal free:41332kB min:41368kB low:51708kB high:62048kB active_anon:0kB inactive_anon:0kB active_file:532748kB inactive_file:44kB unevictable:0kB writepending:24kB present:897016kB managed:836248kB mlocked:0kB slab_reclaimable:159448kB slab_unreclaimable:69608kB kernel_stack:1112kB pagetables:1404kB bounce:0kB free_pcp:528kB local_pcp:340kB free_cma:0kB lowmem_reserve[]: 0 0 21292 21292 HighMem free:781660kB min:512kB low:34356kB high:68200kB active_anon:234740kB inactive_anon:360kB active_file:557232kB inactive_file:1127804kB unevictable:0kB writepending:2592kB present:2725384kB managed:2725384kB mlocked:0kB slab_reclaimable:0kB slab_unreclaimable:0kB kernel_stack:0kB pagetables:0kB bounce:0kB free_pcp:800kB local_pcp:608kB free_cma:0kB the oom killer is clearly pre-mature because there there is still a lot of page cache in the zone Normal which should satisfy this lowmem request. Further debugging has shown that the reclaim cannot make any forward progress because the page cache is hidden in the active list which doesn't get rotated because inactive_list_is_low is not memcg aware. The code simply subtracts per-zone highmem counters from the respective memcg's lru sizes which doesn't make any sense. We can simply end up always seeing the resulting active and inactive counts 0 and return false. This issue is not limited to 32b kernels but in practice the effect on systems without CONFIG_HIGHMEM would be much harder to notice because we do not invoke the OOM killer for allocations requests targeting < ZONE_NORMAL. Fix the issue by tracking per zone lru page counts in mem_cgroup_per_node and subtract per-memcg highmem counts when memcg is enabled. Introduce helper lruvec_zone_lru_size which redirects to either zone counters or mem_cgroup_get_zone_lru_size when appropriate. We are losing empty LRU but non-zero lru size detection introduced by ca707239e8a7 ("mm: update_lru_size warn and reset bad lru_size") because of the inherent zone vs. node discrepancy. Fixes: f8d1a31163fc ("mm: consider whether to decivate based on eligible zones inactive ratio") Link: http://lkml.kernel.org/r/20170104100825.3729-1-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Reported-by: Nils Holland <nholland@tisys.org> Tested-by: Nils Holland <nholland@tisys.org> Reported-by: Klaus Ethgen <Klaus@Ethgen.de> Acked-by: Minchan Kim <minchan@kernel.org> Acked-by: Mel Gorman <mgorman@suse.de> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: <stable@vger.kernel.org> [4.8+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm: don't dereference struct page fields of invalid pagesArd Biesheuvel2017-01-111-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The VM_BUG_ON() check in move_freepages() checks whether the node id of a page matches the node id of its zone. However, it does this before having checked whether the struct page pointer refers to a valid struct page to begin with. This is guaranteed in most cases, but may not be the case if CONFIG_HOLES_IN_ZONE=y. So reorder the VM_BUG_ON() with the pfn_valid_within() check. Link: http://lkml.kernel.org/r/1481706707-6211-2-git-send-email-ard.biesheuvel@linaro.org Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Will Deacon <will.deacon@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Hanjun Guo <hanjun.guo@linaro.org> Cc: Yisheng Xie <xieyisheng1@huawei.com> Cc: Robert Richter <rrichter@cavium.com> Cc: James Morse <james.morse@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mailmap: add codeaurora.org names for nameless email commitsStephen Boyd2017-01-111-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Some codeaurora.org emails have crept in but the names don't exist for them. Add the names for the emails so git can match everyone up. Link: http://lkml.kernel.org/r/20170104194611.25933-1-sboyd@codeaurora.org Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Sarangdhar Joshi <spjoshi@codeaurora.org> Cc: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org> Cc: Subhash Jadavani <subhashj@codeaurora.org> Cc: Thomas Pedersen <twp@codeaurora.org> Cc: Andy Gross <andy.gross@linaro.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * signal: protect SIGNAL_UNKILLABLE from unintentional clearing.Jamie Iles2017-01-112-2/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since commit 00cd5c37afd5 ("ptrace: permit ptracing of /sbin/init") we can now trace init processes. init is initially protected with SIGNAL_UNKILLABLE which will prevent fatal signals such as SIGSTOP, but there are a number of paths during tracing where SIGNAL_UNKILLABLE can be implicitly cleared. This can result in init becoming stoppable/killable after tracing. For example, running: while true; do kill -STOP 1; done & strace -p 1 and then stopping strace and the kill loop will result in init being left in state TASK_STOPPED. Sending SIGCONT to init will resume it, but init will now respond to future SIGSTOP signals rather than ignoring them. Make sure that when setting SIGNAL_STOP_CONTINUED/SIGNAL_STOP_STOPPED that we don't clear SIGNAL_UNKILLABLE. Link: http://lkml.kernel.org/r/20170104122017.25047-1-jamie.iles@oracle.com Signed-off-by: Jamie Iles <jamie.iles@oracle.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm: pmd dirty emulation in page fault handlerMinchan Kim2017-01-111-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Andreas reported [1] made a test in jemalloc hang in THP mode in arm64: http://lkml.kernel.org/r/mvmmvfy37g1.fsf@hawking.suse.de The problem is currently page fault handler doesn't supports dirty bit emulation of pmd for non-HW dirty-bit architecture so that application stucks until VM marked the pmd dirty. How the emulation work depends on the architecture. In case of arm64, when it set up pte firstly, it sets pte PTE_RDONLY to get a chance to mark the pte dirty via triggering page fault when store access happens. Once the page fault occurs, VM marks the pmd dirty and arch code for setting pmd will clear PTE_RDONLY for application to proceed. IOW, if VM doesn't mark the pmd dirty, application hangs forever by repeated fault(i.e., store op but the pmd is PTE_RDONLY). This patch enables pmd dirty-bit emulation for those architectures. [1] b8d3c4c3009d, mm/huge_memory.c: don't split THP page when MADV_FREE syscall is called Fixes: b8d3c4c3009d ("mm/huge_memory.c: don't split THP page when MADV_FREE syscall is called") Link: http://lkml.kernel.org/r/1482506098-6149-1-git-send-email-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Reported-by: Andreas Schwab <schwab@suse.de> Tested-by: Andreas Schwab <schwab@suse.de> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Jason Evans <je@fb.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: <stable@vger.kernel.org> [4.5+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * ipc/sem.c: fix incorrect sem_lock pairingManfred Spraul2017-01-111-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Based on the syzcaller test case from dvyukov: https://gist.githubusercontent.com/dvyukov/d0e5efefe4d7d6daed829f5c3ca26a40/raw/08d0a261fe3c987bed04fbf267e08ba04bd533ea/gistfile1.txt The slow (i.e.: failure to acquire) syscall exit from semtimedop() incorrectly assumed that the the same lock is acquired as it was at the initial syscall entry. This is wrong: - thread A: single semop semop(), sleeps - thread B: multi semop semop(), sleeps - thread A: woken up by signal/timeout With this sequence, the initial sem_lock() call locks the per-semaphore spinlock, and it is unlocked with sem_unlock(). The call at the syscall return locks the global spinlock. Because locknum is not updated, the following sem_unlock() call unlocks the per-semaphore spinlock, which is actually not locked. The fix is trivial: Use the return value from sem_lock. Fixes: 370b262c896e ("ipc/sem: avoid idr tree lookup for interrupted semop") Link: http://lkml.kernel.org/r/1482215645-22328-1-git-send-email-manfred@colorfullife.com Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Reported-by: Johanna Abrahamsson <johanna@mjao.org> Tested-by: Johanna Abrahamsson <johanna@mjao.org> Acked-by: Davidlohr Bueso <dave@stgolabs.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * lib/Kconfig.debug: fix frv build failureSudip Mukherjee2017-01-111-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The build of frv allmodconfig was failing with the errors like: /tmp/cc0JSPc3.s: Assembler messages: /tmp/cc0JSPc3.s:1839: Error: symbol `.LSLT0' is already defined /tmp/cc0JSPc3.s:1842: Error: symbol `.LASLTP0' is already defined /tmp/cc0JSPc3.s:1969: Error: symbol `.LELTP0' is already defined /tmp/cc0JSPc3.s:1970: Error: symbol `.LELT0' is already defined Commit 866ced950bcd ("kbuild: Support split debug info v4") introduced splitting the debug info and keeping that in a separate file. Somehow, the frv-linux gcc did not like that and I am guessing that instead of splitting it started copying. The first report about this is at: https://lists.01.org/pipermail/kbuild-all/2015-July/010527.html. I will try and see if this can work with frv and if still fails I will open a bug report with gcc. But meanwhile this is the easiest option to solve build failure of frv. Fixes: 866ced950bcd ("kbuild: Support split debug info v4") Link: http://lkml.kernel.org/r/1482062348-5352-1-git-send-email-sudipm.mukherjee@gmail.com Signed-off-by: Sudip Mukherjee <sudip.mukherjee@codethink.co.uk> Reported-by: Fengguang Wu <fengguang.wu@intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm: get rid of __GFP_OTHER_NODEMichal Hocko2017-01-116-21/+9Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The flag was introduced by commit 78afd5612deb ("mm: add __GFP_OTHER_NODE flag") to allow proper accounting of remote node allocations done by kernel daemons on behalf of a process - e.g. khugepaged. After "mm: fix remote numa hits statistics" we do not need and actually use the flag so we can safely remove it because all allocations which are satisfied from their "home" node are accounted properly. [mhocko@suse.com: fix build] Link: http://lkml.kernel.org/r/20170106122225.GK5556@dhcp22.suse.cz Link: http://lkml.kernel.org/r/20170102153057.9451-3-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Mel Gorman <mgorman@suse.de> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Taku Izumi <izumi.taku@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm: fix remote numa hits statisticsMichal Hocko2017-01-111-11/+4Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Jia He has noticed that commit b9f00e147f27 ("mm, page_alloc: reduce branches in zone_statistics") has an unintentional side effect that remote node allocation requests are accounted as NUMA_MISS rathat than NUMA_HIT and NUMA_OTHER if such a request doesn't use __GFP_OTHER_NODE. There are many of these potentially because the flag is used very rarely while we have many users of __alloc_pages_node. Fix this by simply ignoring __GFP_OTHER_NODE (it can be removed in a follow up patch) and treat all allocations that were satisfied from the preferred zone's node as NUMA_HITS because this is the same node we requested the allocation from in most cases. If this is not the local node then we just account it as NUMA_OTHER rather than NUMA_LOCAL. One downsize would be that an allocation request for a node which is outside of the mempolicy nodemask would be reported as a hit which is a bit weird but that was the case before b9f00e147f27 already. Fixes: b9f00e147f27 ("mm, page_alloc: reduce branches in zone_statistics") Link: http://lkml.kernel.org/r/20170102153057.9451-2-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Reported-by: Jia He <hejianet@gmail.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> # with cbmc[1] superpowers Acked-by: Mel Gorman <mgorman@suse.de> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Taku Izumi <izumi.taku@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm: fix devm_memremap_pages crash, use mem_hotplug_{begin, done}Dan Williams2017-01-111-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Both arch_add_memory() and arch_remove_memory() expect a single threaded context. For example, arch/x86/mm/init_64.c::kernel_physical_mapping_init() does not hold any locks over this check and branch: if (pgd_val(*pgd)) { pud = (pud_t *)pgd_page_vaddr(*pgd); paddr_last = phys_pud_init(pud, __pa(vaddr), __pa(vaddr_end), page_size_mask); continue; } pud = alloc_low_page(); paddr_last = phys_pud_init(pud, __pa(vaddr), __pa(vaddr_end), page_size_mask); The result is that two threads calling devm_memremap_pages() simultaneously can end up colliding on pgd initialization. This leads to crash signatures like the following where the loser of the race initializes the wrong pgd entry: BUG: unable to handle kernel paging request at ffff888ebfff0000 IP: memcpy_erms+0x6/0x10 PGD 2f8e8fc067 PUD 0 /* <---- Invalid PUD */ Oops: 0000 [#1] SMP DEBUG_PAGEALLOC CPU: 54 PID: 3818 Comm: systemd-udevd Not tainted 4.6.7+ #13 task: ffff882fac290040 ti: ffff882f887a4000 task.ti: ffff882f887a4000 RIP: memcpy_erms+0x6/0x10 [..] Call Trace: ? pmem_do_bvec+0x205/0x370 [nd_pmem] ? blk_queue_enter+0x3a/0x280 pmem_rw_page+0x38/0x80 [nd_pmem] bdev_read_page+0x84/0xb0 Hold the standard memory hotplug mutex over calls to arch_{add,remove}_memory(). Fixes: 41e94a851304 ("add devm_memremap_pages") Link: http://lkml.kernel.org/r/148357647831.9498.12606007370121652979.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> Cc: Christoph Hellwig <hch@lst.de> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * ocfs2: fix crash caused by stale lvb with fsdlm pluginEric Ren2017-01-113-0/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The crash happens rather often when we reset some cluster nodes while nodes contend fiercely to do truncate and append. The crash backtrace is below: dlm: C21CBDA5E0774F4BA5A9D4F317717495: dlm_recover_grant 1 locks on 971 resources dlm: C21CBDA5E0774F4BA5A9D4F317717495: dlm_recover 9 generation 5 done: 4 ms ocfs2: Begin replay journal (node 318952601, slot 2) on device (253,18) ocfs2: End replay journal (node 318952601, slot 2) on device (253,18) ocfs2: Beginning quota recovery on device (253,18) for slot 2 ocfs2: Finishing quota recovery on device (253,18) for slot 2 (truncate,30154,1):ocfs2_truncate_file:470 ERROR: bug expression: le64_to_cpu(fe->i_size) != i_size_read(inode) (truncate,30154,1):ocfs2_truncate_file:470 ERROR: Inode 290321, inode i_size = 732 != di i_size = 937, i_flags = 0x1 ------------[ cut here ]------------ kernel BUG at /usr/src/linux/fs/ocfs2/file.c:470! invalid opcode: 0000 [#1] SMP Modules linked in: ocfs2_stack_user(OEN) ocfs2(OEN) ocfs2_nodemanager ocfs2_stackglue(OEN) quota_tree dlm(OEN) configfs fuse sd_mod iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi af_packet iscsi_ibft iscsi_boot_sysfs softdog xfs libcrc32c ppdev parport_pc pcspkr parport joydev virtio_balloon virtio_net i2c_piix4 acpi_cpufreq button processor ext4 crc16 jbd2 mbcache ata_generic cirrus virtio_blk ata_piix drm_kms_helper ahci syscopyarea libahci sysfillrect sysimgblt fb_sys_fops ttm floppy libata drm virtio_pci virtio_ring uhci_hcd virtio ehci_hcd usbcore serio_raw usb_common sg dm_multipath dm_mod scsi_dh_rdac scsi_dh_emc scsi_dh_alua scsi_mod autofs4 Supported: No, Unsupported modules are loaded CPU: 1 PID: 30154 Comm: truncate Tainted: G OE N 4.4.21-69-default #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.8.1-0-g4adadbd-20151112_172657-sheep25 04/01/2014 task: ffff88004ff6d240 ti: ffff880074e68000 task.ti: ffff880074e68000 RIP: 0010:[<ffffffffa05c8c30>] [<ffffffffa05c8c30>] ocfs2_truncate_file+0x640/0x6c0 [ocfs2] RSP: 0018:ffff880074e6bd50 EFLAGS: 00010282 RAX: 0000000000000074 RBX: 000000000000029e RCX: 0000000000000000 RDX: 0000000000000001 RSI: 0000000000000246 RDI: 0000000000000246 RBP: ffff880074e6bda8 R08: 000000003675dc7a R09: ffffffff82013414 R10: 0000000000034c50 R11: 0000000000000000 R12: ffff88003aab3448 R13: 00000000000002dc R14: 0000000000046e11 R15: 0000000000000020 FS: 00007f839f965700(0000) GS:ffff88007fc80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 00007f839f97e000 CR3: 0000000036723000 CR4: 00000000000006e0 Call Trace: ocfs2_setattr+0x698/0xa90 [ocfs2] notify_change+0x1ae/0x380 do_truncate+0x5e/0x90 do_sys_ftruncate.constprop.11+0x108/0x160 entry_SYSCALL_64_fastpath+0x12/0x6d Code: 24 28 ba d6 01 00 00 48 c7 c6 30 43 62 a0 8b 41 2c 89 44 24 08 48 8b 41 20 48 c7 c1 78 a3 62 a0 48 89 04 24 31 c0 e8 a0 97 f9 ff <0f> 0b 3d 00 fe ff ff 0f 84 ab fd ff ff 83 f8 fc 0f 84 a2 fd ff RIP [<ffffffffa05c8c30>] ocfs2_truncate_file+0x640/0x6c0 [ocfs2] It's because ocfs2_inode_lock() get us stale LVB in which the i_size is not equal to the disk i_size. We mistakenly trust the LVB because the underlaying fsdlm dlm_lock() doesn't set lkb_sbflags with DLM_SBF_VALNOTVALID properly for us. But, why? The current code tries to downconvert lock without DLM_LKF_VALBLK flag to tell o2cb don't update RSB's LVB if it's a PR->NULL conversion, even if the lock resource type needs LVB. This is not the right way for fsdlm. The fsdlm plugin behaves different on DLM_LKF_VALBLK, it depends on DLM_LKF_VALBLK to decide if we care about the LVB in the LKB. If DLM_LKF_VALBLK is not set, fsdlm will skip recovering RSB's LVB from this lkb and set the right DLM_SBF_VALNOTVALID appropriately when node failure happens. The following diagram briefly illustrates how this crash happens: RSB1 is inode metadata lock resource with LOCK_TYPE_USES_LVB; The 1st round: Node1 Node2 RSB1: PR RSB1(master): NULL->EX ocfs2_downconvert_lock(PR->NULL, set_lvb==0) ocfs2_dlm_lock(no DLM_LKF_VALBLK) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - dlm_lock(no DLM_LKF_VALBLK) convert_lock(overwrite lkb->lkb_exflags with no DLM_LKF_VALBLK) RSB1: NULL RSB1: EX reset Node2 dlm_recover_rsbs() recover_lvb() /* The LVB is not trustable if the node with EX fails and * no lock >= PR is left. We should set RSB_VALNOTVALID for RSB1. */ if(!(kb_exflags & DLM_LKF_VALBLK)) /* This means we miss the chance to return; * to invalid the LVB here. */ The 2nd round: Node 1 Node2 RSB1(become master from recovery) ocfs2_setattr() ocfs2_inode_lock(NULL->EX) /* dlm_lock() return the stale lvb without setting DLM_SBF_VALNOTVALID */ ocfs2_meta_lvb_is_trustable() return 1 /* so we don't refresh inode from disk */ ocfs2_truncate_file() mlog_bug_on_msg(disk isize != i_size_read(inode)) /* crash! */ The fix is quite straightforward. We keep to set DLM_LKF_VALBLK flag for dlm_lock() if the lock resource type needs LVB and the fsdlm plugin is uesed. Link: http://lkml.kernel.org/r/1481275846-6604-1-git-send-email-zren@suse.com Signed-off-by: Eric Ren <zren@suse.com> Reviewed-by: Joseph Qi <jiangqi903@gmail.com> Cc: Mark Fasheh <mfasheh@versity.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * bpf: do not use KMALLOC_SHIFT_MAXMichal Hocko2017-01-112-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 01b3f52157ff ("bpf: fix allocation warnings in bpf maps and integer overflow") has added checks for the maximum allocateable size. It (ab)used KMALLOC_SHIFT_MAX for that purpose. While this is not incorrect it is not very clean because we already have KMALLOC_MAX_SIZE for this very reason so let's change both checks to use KMALLOC_MAX_SIZE instead. The original motivation for using KMALLOC_SHIFT_MAX was to work around an incorrect KMALLOC_MAX_SIZE which could lead to allocation warnings but it is no longer needed since "slab: make sure that KMALLOC_MAX_SIZE will fit into MAX_ORDER". Link: http://lkml.kernel.org/r/20161220130659.16461-3-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Christoph Lameter <cl@linux.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm, slab: make sure that KMALLOC_MAX_SIZE will fit into MAX_ORDERMichal Hocko2017-01-111-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Andrey Konovalov has reported the following warning triggered by the syzkaller fuzzer. WARNING: CPU: 1 PID: 9935 at mm/page_alloc.c:3511 __alloc_pages_nodemask+0x159c/0x1e20 Kernel panic - not syncing: panic_on_warn set ... CPU: 1 PID: 9935 Comm: syz-executor0 Not tainted 4.9.0-rc7+ #34 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Call Trace: __alloc_pages_slowpath mm/page_alloc.c:3511 __alloc_pages_nodemask+0x159c/0x1e20 mm/page_alloc.c:3781 alloc_pages_current+0x1c7/0x6b0 mm/mempolicy.c:2072 alloc_pages include/linux/gfp.h:469 kmalloc_order+0x1f/0x70 mm/slab_common.c:1015 kmalloc_order_trace+0x1f/0x160 mm/slab_common.c:1026 kmalloc_large include/linux/slab.h:422 __kmalloc+0x210/0x2d0 mm/slub.c:3723 kmalloc include/linux/slab.h:495 ep_write_iter+0x167/0xb50 drivers/usb/gadget/legacy/inode.c:664 new_sync_write fs/read_write.c:499 __vfs_write+0x483/0x760 fs/read_write.c:512 vfs_write+0x170/0x4e0 fs/read_write.c:560 SYSC_write fs/read_write.c:607 SyS_write+0xfb/0x230 fs/read_write.c:599 entry_SYSCALL_64_fastpath+0x1f/0xc2 The issue is caused by a lack of size check for the request size in ep_write_iter which should be fixed. It, however, points to another problem, that SLUB defines KMALLOC_MAX_SIZE too large because the its KMALLOC_SHIFT_MAX is (MAX_ORDER + PAGE_SHIFT) which means that the resulting page allocator request might be MAX_ORDER which is too large (see __alloc_pages_slowpath). The same applies to the SLOB allocator which allows even larger sizes. Make sure that they are capped properly and never request more than MAX_ORDER order. Link: http://lkml.kernel.org/r/20161220130659.16461-2-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Reported-by: Andrey Konovalov <andreyknvl@google.com> Acked-by: Christoph Lameter <cl@linux.com> Cc: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * dax: wrprotect pmd_t in dax_mapping_entry_mkcleanRoss Zwisler2017-01-113-19/+38
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently dax_mapping_entry_mkclean() fails to clean and write protect the pmd_t of a DAX PMD entry during an *sync operation. This can result in data loss in the following sequence: 1) mmap write to DAX PMD, dirtying PMD radix tree entry and making the pmd_t dirty and writeable 2) fsync, flushing out PMD data and cleaning the radix tree entry. We currently fail to mark the pmd_t as clean and write protected. 3) more mmap writes to the PMD. These don't cause any page faults since the pmd_t is dirty and writeable. The radix tree entry remains clean. 4) fsync, which fails to flush the dirty PMD data because the radix tree entry was clean. 5) crash - dirty data that should have been fsync'd as part of 4) could still have been in the processor cache, and is lost. Fix this by marking the pmd_t clean and write protected in dax_mapping_entry_mkclean(), which is called as part of the fsync operation 2). This will cause the writes in step 3) above to generate page faults where we'll re-dirty the PMD radix tree entry, resulting in flushes in the fsync that happens in step 4). Fixes: 4b4bb46d00b3 ("dax: clear dirty entry tags on cache flush") Link: http://lkml.kernel.org/r/1482272586-21177-3-git-send-email-ross.zwisler@linux.intel.com Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Jan Kara <jack@suse.cz> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Dave Hansen <dave.hansen@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm: add follow_pte_pmd()Ross Zwisler2017-01-112-7/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "Write protect DAX PMDs in *sync path". Currently dax_mapping_entry_mkclean() fails to clean and write protect the pmd_t of a DAX PMD entry during an *sync operation. This can result in data loss, as detailed in patch 2. This series is based on Dan's "libnvdimm-pending" branch, which is the current home for Jan's "dax: Page invalidation fixes" series. You can find a working tree here: https://git.kernel.org/cgit/linux/kernel/git/zwisler/linux.git/log/?h=dax_pmd_clean This patch (of 2): Similar to follow_pte(), follow_pte_pmd() allows either a PTE leaf or a huge page PMD leaf to be found and returned. Link: http://lkml.kernel.org/r/1482272586-21177-2-git-send-email-ross.zwisler@linux.intel.com Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Suggested-by: Dave Hansen <dave.hansen@intel.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Jan Kara <jack@suse.cz> Cc: Matthew Wilcox <mawilcox@microsoft.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm/thp/pagecache/collapse: free the pte page table on collapse for thp page ↵Aneesh Kumar K.V2017-01-111-19/+2Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | cache. With THP page cache, when trying to build a huge page from regular pte pages, we just clear the pmd entry. We will take another fault and at that point we will find the huge page in the radix tree, thereby using the huge page to complete the page fault The second fault path will allocate the needed pgtable_t page for archs like ppc64. So no need to deposit the same in collapse path. Depositing them in the collapse path resulting in a pgtable_t memory leak also giving errors like BUG: non-zero nr_ptes on freeing mm: 3 Fixes: 953c66c2b22a ("mm: THP page cache support for ppc64") Link: http://lkml.kernel.org/r/20161212163428.6780-2-aneesh.kumar@linux.vnet.ibm.com Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * dax: fix deadlock with DAX 4k holesRoss Zwisler2017-01-111-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently in DAX if we have three read faults on the same hole address we can end up with the following: Thread 0 Thread 1 Thread 2 -------- -------- -------- dax_iomap_fault grab_mapping_entry lock_slot <locks empty DAX entry> dax_iomap_fault grab_mapping_entry get_unlocked_mapping_entry <sleeps on empty DAX entry> dax_iomap_fault grab_mapping_entry get_unlocked_mapping_entry <sleeps on empty DAX entry> dax_load_hole find_or_create_page ... page_cache_tree_insert dax_wake_mapping_entry_waiter <wakes one sleeper> __radix_tree_replace <swaps empty DAX entry with 4k zero page> <wakes> get_page lock_page ... put_locked_mapping_entry unlock_page put_page <sleeps forever on the DAX wait queue> The crux of the problem is that once we insert a 4k zero page, all locking from then on is done in terms of that 4k zero page and any additional threads sleeping on the empty DAX entry will never be woken. Fix this by waking all sleepers when we replace the DAX radix tree entry with a 4k zero page. This will allow all sleeping threads to successfully transition from locking based on the DAX empty entry to locking on the 4k zero page. With the test case reported by Xiong this happens very regularly in my test setup, with some runs resulting in 9+ threads in this deadlocked state. With this fix I've been able to run that same test dozens of times in a loop without issue. Fixes: ac401cc78242 ("dax: New fault locking") Link: http://lkml.kernel.org/r/1483479365-13607-1-git-send-email-ross.zwisler@linux.intel.com Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Reported-by: Xiong Zhou <xzhou@redhat.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: <stable@vger.kernel.org> [4.7+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * MAINTAINERS: remove duplicate bug filling descriptionVlastimil Babka2017-01-111-1/+0Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I have noticed that two different descriptions for B: entries in MAINTAINERS were merged: commit 686564434e88 ("MAINTAINERS: Add bug tracking system location entry type") and 2de2bd95f456 ("MAINTAINERS: add "B:" for URI where to file bugs"). This patch keeps the description from 2de2bd95f456. There has been a discussion [1] about whether this more detailed description is useful and what it exactly implies. I find it more useful and general, and the author of 686564434e88 agreed in the end that either is fine. [1] https://lkml.org/lkml/2016/12/8/71 Link: http://lkml.kernel.org/r/20161219085158.12114-1-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds2017-01-1131-121/+243
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull networking fixes from David Miller: 1) Fix rtlwifi crash, from Larry Finger. 2) Memory disclosure in appletalk ipddp routing code, from Vlad Tsyrklevich. 3) r8152 can erroneously split an RX packet into multiple URBs if the Rx FIFO is not empty when we suspend. Fix this by waiting for the FIFO to empty before suspending. From Hayes Wang. 4) Two GRO fixes (enter slow path when not enough SKB tail room exists, disable frag0 optimizations when there are IPV6 extension headers) from Eric Dumazet and Herbert Xu. 5) A series of mlx5e bug fixes (do source udp port offloading for tunnels properly, Ip fragment matching fixes, handling firmware errors properly when installing TC rules, etc.) from Saeed Mahameed, Or Gerlitz, Roi Dayan, Hadar Hen Zion, Gil Rockah, and Daniel Jurgens. 6) Two VRF fixes from David Ahern (don't skip multipath selection for VRF paths, disallow VRF to be configured with table ID 0). * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (35 commits) net: vrf: do not allow table id 0 net: phy: marvell: fix Marvell 88E1512 used in SGMII mode sctp: Fix spelling mistake: "Atempt" -> "Attempt" net: ipv4: Fix multipath selection with vrf cgroup: move CONFIG_SOCK_CGROUP_DATA to init/Kconfig gro: use min_t() in skb_gro_reset_offset() net/mlx5: Only cancel recovery work when cleaning up device net/mlx5e: Remove WARN_ONCE from adaptive moderation code net/mlx5e: Un-register uplink representor on nic_disable net/mlx5e: Properly handle FW errors while adding TC rules net/mlx5e: Fix kbuild warnings for uninitialized parameters net/mlx5e: Set inline mode requirements for matching on IP fragments net/mlx5e: Properly get address type of encapsulation IP headers net/mlx5e: TC ipv4 tunnel encap offload error flow fixes net/mlx5e: Warn when rejecting offload attempts of IP tunnels net/mlx5e: Properly handle offloading of source udp port for IP tunnels gro: Disable frag0 optimization on IPv6 ext headers gro: Enter slow-path if there is no tailroom mlx4: Return EOPNOTSUPP instead of ENOTSUPP net/af_iucv: don't use paged skbs for TX on HiperSockets ...
| * | net: vrf: do not allow table id 0David Ahern2017-01-111-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Frank reported that vrf devices can be created with a table id of 0. This breaks many of the run time table id checks and should not be allowed. Detect this condition at create time and fail with EINVAL. Fixes: 193125dbd8eb ("net: Introduce VRF device driver") Reported-by: Frank Kellermann <frank.kellermann@atos.net> Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * | net: phy: marvell: fix Marvell 88E1512 used in SGMII modeRussell King2017-01-111-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When an Marvell 88E1512 PHY is connected to a nic in SGMII mode, the fiber page is used for the SGMII host-side connection. The PHY driver notices that SUPPORTED_FIBRE is set, so it tries reading the fiber page for the link status, and ends up reading the MAC-side status instead of the outgoing (copper) link. This leads to incorrect results reported via ethtool. If the PHY is connected via SGMII to the host, ignore the fiber page. However, continue to allow the existing power management code to suspend and resume the fiber page. Fixes: 6cfb3bcc0641 ("Marvell phy: check link status in case of fiber link.") Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
| * | sctp: Fix spelling mistake: "Atempt" -> "Attempt"Colin Ian King2017-01-111-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | Trivial fix to spelling mistake in WARN_ONCE message Signed-off-by: Colin Ian King <colin.king@canonical.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * | net: ipv4: Fix multipath selection with vrfDavid Ahern2017-01-112-2/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | fib_select_path does not call fib_select_multipath if oif is set in the flow struct. For VRF use cases oif is always set, so multipath route selection is bypassed. Use the FLOWI_FLAG_SKIP_NH_OIF to skip the oif check similar to what is done in fib_table_lookup. Add saddr and proto to the flow struct for the fib lookup done by the VRF driver to better match hash computation for a flow. Fixes: 613d09b30f8b ("net: Use VRF device index for lookups on TX") Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * | cgroup: move CONFIG_SOCK_CGROUP_DATA to init/KconfigArnd Bergmann2017-01-112-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We now 'select SOCK_CGROUP_DATA' but Kconfig complains that this is not right when CONFIG_NET is disabled and there is no socket interface: warning: (CGROUP_BPF) selects SOCK_CGROUP_DATA which has unmet direct dependencies (NET) I don't know what the correct solution for this is, but simply removing the dependency on NET from SOCK_CGROUP_DATA by moving it out of the 'if NET' section avoids the warning and does not produce other build errors. Fixes: 483c4933ea09 ("cgroup: Fix CGROUP_BPF config") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: David S. Miller <davem@davemloft.net>
| * | gro: use min_t() in skb_gro_reset_offset()Eric Dumazet2017-01-111-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On 32bit arches, (skb->end - skb->data) is not 'unsigned int', so we shall use min_t() instead of min() to avoid a compiler error. Fixes: 1272ce87fa01 ("gro: Enter slow-path if there is no tailroom") Reported-by: kernel test robot <fengguang.wu@intel.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * | Merge branch 'mlx5-fixes'David S. Miller2017-01-114-44/+75
| |\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Saeed Mahameed says: ==================== Mellanox mlx5 fixes and cleanups 2017-01-10 This series includes some mlx5e general cleanups from Daniel, Gil, Hadar and myself. Also it includes some critical mlx5e TC offloads fixes from Or Gerlitz. For -stable: - net/mlx5e: Remove WARN_ONCE from adaptive moderation code Although this fix doesn't affect any functionality, I thought it is better to clean this -WARN_ONCE- up for -stable in case someone hits such corner case. Please apply and let me know if there's any problem. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>