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* perf_counter: Provide a way to enable counters on execPaul Mackerras2009-06-301-0/+50
| | | | | | | | | | | | | | | This provides a way to mark a counter to be enabled on the next exec. This is useful for measuring the total activity of a program without including overhead from the process that launches it. This also changes the perf stat command to use this new facility. Signed-off-by: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <19017.43927.838745.689203@cargo.ozlabs.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf_counter: Complete counter swapPeter Zijlstra2009-06-261-1/+6
| | | | | | | | | | Complete the counter swap by indeed switching the times too and updating the userpage after modifying the counter values. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> LKML-Reference: <1246014623.31755.195.camel@twins> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf_counter: Rework the sample ABIPeter Zijlstra2009-06-251-21/+15Star
| | | | | | | | | | | | | | | | | The PERF_EVENT_READ implementation made me realize we don't actually need the sample_type int the output sample, since we already have that in the perf_counter_attr information. Therefore, remove the PERF_EVENT_MISC_OVERFLOW bit and the event->type overloading, and imply put counter overflow samples in a PERF_EVENT_SAMPLE type. This also fixes the issue that event->type was only 32-bit and sample_type had 64 usable bits. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf_counter: Implement more accurate per task statisticsPeter Zijlstra2009-06-251-3/+80
| | | | | | | | | | | | | | | | | | | | With the introduction of PERF_EVENT_READ we have the possibility to provide accurate counter values for individual tasks in a task hierarchy. However, due to the lazy context switching used for similar counter contexts our current per task counts are way off. In order to maintain some of the lazy switch benefits we don't disable it out-right, but simply iterate the active counters and flip the values between the contexts. This only reads the counters but does not need to reprogram the full PMU. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf_counter: Add PERF_EVENT_READPeter Zijlstra2009-06-251-4/+68
| | | | | | | | | | | | | | Provide a read() like event which can be used to log the counter value at specific sites such as child->parent folding on exit. In order to be useful, we log the counter parent ID, not the actual counter ID, since userspace can only relate parent IDs to perf_counter_attr constructs. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf_counter, x86: Add mmap counter read supportPeter Zijlstra2009-06-251-1/+9
| | | | | | | | | Update the mmap control page with the needed information to use the userspace RDPMC instruction for self monitoring. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf_counter: Add scale information to the mmap control pagePeter Zijlstra2009-06-251-0/+6
| | | | | | | | Add the needed time scale to the self-profile mmap information. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf_counter: Optimize perf_counter_alloc()'s inherit casePeter Zijlstra2009-06-231-12/+20
| | | | | | | | | | | | | We don't need to add usage counts for swcounter and attr usage models for inherited counters since the parent counter will always have one, which suffices to generate the needed output. This avoids up to 3 global atomic increments per inherited counter. LKML-Reference: <new-submission> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf_counter: Push inherit into perf_counter_alloc()Peter Zijlstra2009-06-231-8/+6Star
| | | | | | | | | | | | | | | | Teach perf_counter_alloc() about inheritance so that we can optimize the inherit path in the next patch. Remove the child_counter->atrr.inherit = 1 line because the only way to get there is if parent_counter->attr.inherit == 1 and we copy the attrs. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf_counter: Optimize perf_swcounter_event()Peter Zijlstra2009-06-231-3/+15
| | | | | | | | | | | | | | | Similar to tracepoints, use an enable variable to reduce overhead when unused. Only look for a counter of a particular event type when we know there is at least one in the system. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf_counter: Push perf_sample_data through the swcounter codePeter Zijlstra2009-06-201-26/+29
| | | | | | | | | Push the perf_sample_data further outwards to the swcounter interface, to abstract it away some more. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf_counter: Close race in perf_lock_task_context()Peter Zijlstra2009-06-191-6/+5Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | perf_lock_task_context() is buggy because it can return a dead context. the RCU read lock in perf_lock_task_context() only guarantees the memory won't get freed, it doesn't guarantee the object is valid (in our case refcount > 0). Therefore we can return a locked object that can get freed the moment we release the rcu read lock. perf_pin_task_context() then increases the refcount and does an unlock on freed memory. That increased refcount will cause a double free, in case it started out with 0. Ammend this by including the get_ctx() functionality in perf_lock_task_context() (all users already did this later anyway), and return a NULL context when the found one is already dead. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf_counter: Simplify and fix task migration countingPeter Zijlstra2009-06-191-22/+1Star
| | | | | | | | | | | | | | | | | | | | | | | | | The task migrations counter was causing rare and hard to decypher memory corruptions under load. After a day of debugging and bisection we found that the problem was introduced with: 3f731ca: perf_counter: Fix cpu migration counter Turning them off fixes the crashes. Incidentally, the whole perf_counter_task_migration() logic can be done simpler as well, by injecting a proper sw-counter event. This cleanup also fixed the crashes. The precise failure mode is not completely clear yet, but we are clearly not unhappy about having a fix ;-) Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf_counter: Add event overlow handlingPeter Zijlstra2009-06-181-55/+130
| | | | | | | | | | | | | | | | | | | | | Alternative method of mmap() data output handling that provides better overflow management and a more reliable data stream. Unlike the previous method, that didn't have any user->kernel feedback and relied on userspace keeping up, this method relies on userspace writing its last read position into the control page. It will ensure new output doesn't overwrite not-yet read events, new events for which there is no space left are lost and the overflow counter is incremented, providing exact event loss numbers. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf_counter: Fix ctx->mutex vs counter->mutex inversionPeter Zijlstra2009-06-151-23/+11Star
| | | | | | | | | | | | | | Simon triggered a lockdep inversion report about us taking ctx->mutex vs counter->mutex in inverse orders. Fix that up. Reported-by: Simon Holm Thøgersen <odie@cs.aau.dk> Tested-by: Simon Holm Thøgersen <odie@cs.aau.dk> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf_counter: Fix stack corruption in perf_read_hwMarti Raudsepp2009-06-131-1/+1
| | | | | | | | | | | With PERF_FORMAT_ID, perf_read_hw now needs space for up to 4 values. Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf_counter: Fix atomic_set vs. atomic64_t type mismatchPaul Mackerras2009-06-131-1/+1
| | | | | | | | | | | Using atomic_set on an atomic64_t variable gives a compiler warning on powerpc, and won't give the desired result at runtime. This fixes an instance of this error in the perf_counter code. Signed-off-by: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <18995.20490.979429.244883@cargo.ozlabs.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf_counter: Add forward/backward attribute ABI compatibilityPeter Zijlstra2009-06-121-3/+86
| | | | | | | | | | | | | | | | | | | | | | | | | | | Provide for means of extending the perf_counter_attr in a 'natural' way. We allow growing the structure by appending fields at the end by specifying the full structure size inside it. When a new kernel sees a smaller (old) structure, it will 0 pad the tail. When an old kernel sees a larger (new) structure, it will verify the tail consists of 0s, otherwise fail. If we fail due to a size-mismatch, we return -E2BIG and write the kernel's native attribe size back into the provided structure. Furthermore, add some attribute verification, so that we'll fail counter creation when unknown bits are present (PERF_SAMPLE, PERF_FORMAT, or in the __reserved fields). (This ABI detail is introduced while keeping the existing syscall ABI.) Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf_counter: Remove PERF_TYPE_RAW special casingPeter Zijlstra2009-06-121-5/+1Star
| | | | | | | | | | | | | | The PERF_TYPE_RAW special case seems superfluous these days. Remove it and add it to the switch() stmt like the others. [ Impact: cleanup ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf_counter: Add counter->id to the throttle eventPeter Zijlstra2009-06-111-1/+3
| | | | | | | | | | | So as to be able to distuinguish between multiple counters. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf_counter: Standardize event namesPeter Zijlstra2009-06-111-10/+10
| | | | | | | | | | | Pure renames only, to PERF_COUNT_HW_* and PERF_COUNT_SW_*. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf_counter: Rename enumsPeter Zijlstra2009-06-111-3/+3
| | | | | | | | | | | | Rename the perf enums to be in the 'perf_' namespace and strictly enumerate the ABI bits. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf_counter: Rename perf_counter_limit sysctlPeter Zijlstra2009-06-111-8/+19
| | | | | | | | | | | | | Rename perf_counter_limit to perf_counter_max_sample_rate and prohibit creation of counters with a known higher sample frequency. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf_counter: More paranoia settingsPeter Zijlstra2009-06-111-2/+23
| | | | | | | | | | | | | | | | Rename the perf_counter_priv knob to perf_counter_paranoia (because priv can be read as private, as opposed to privileged) and provide one more level: 0 - permissive 1 - restrict cpu counters to privilidged contexts 2 - restrict kernel-mode code counting and profiling Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf_counter: Accurate period dataPeter Zijlstra2009-06-111-3/+6
| | | | | | | | | | | | | | | | | We currently log hw.sample_period for PERF_SAMPLE_PERIOD, however this is incorrect. When we adjust the period, it will only take effect the next cycle but report it for the current cycle. So when we adjust the period for every cycle, we're always wrong. Solve this by keeping track of the last_period. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf_counter: Introduce struct for sample dataPeter Zijlstra2009-06-111-16/+22
| | | | | | | | | | | | For easy extension of the sample data, put it in a structure. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf_counter: Annotate exit ctx recursionPeter Zijlstra2009-06-111-1/+12
| | | | | | | | | | | | Ever since Paul fixed it to unclone the context before taking the ctx->lock this became a false positive, annotate it away. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf_counter: More aggressive frequency adjustmentPeter Zijlstra2009-06-101-42/+88
| | | | | | | | | | | | | | | | | | Also employ the overflow handler to adjust the frequency, this results in a stable frequency in about 40~50 samples, instead of that many ticks. This also means we can start sampling at a sample period of 1 without running head-first into the throttle. It relies on sched_clock() to accurately measure the time difference between the overflow NMIs. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf_counter: Implement generalized cache event typesIngo Molnar2009-06-061-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Extend generic event enumeration with the PERF_TYPE_HW_CACHE method. This is a 3-dimensional space: { L1-D, L1-I, L2, ITLB, DTLB, BPU } x { load, store, prefetch } x { accesses, misses } User-space passes in the 3 coordinates and the kernel provides a counter. (if the hardware supports that type and if the combination makes sense.) Combinations that make no sense produce a -EINVAL. Combinations that are not supported by the hardware produce -ENOTSUP. Extend the tools to deal with this, and rewrite the event symbol parsing code with various popular aliases for the units and access methods above. So 'l1-cache-miss' and 'l1d-read-ops' are both valid aliases. ( x86 is supported for now, with the Nehalem event table filled in, and with Core2 and Atom having placeholder tables. ) Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf_counter: Separate out attr->type from attr->configIngo Molnar2009-06-061-8/+6Star
| | | | | | | | | | | | | | | | | | | | | | | | | Counter type is a frequently used value and we do a lot of bit juggling by encoding and decoding it from attr->config. Clean this up by creating a separate attr->type field. Also clean up the various similarly complex user-space bits all around counter attribute management. The net improvement is significant, and it will be easier to add a new major type (which is what triggered this cleanup). (This changes the ABI, all tools are adapted.) (PowerPC build-tested.) Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf_counter: Fix frequency adjustment for < HZPeter Zijlstra2009-06-051-7/+25
| | | | | | | | | Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf_counter: Add PERF_SAMPLE_PERIODPeter Zijlstra2009-06-051-0/+10
| | | | | | | | | | | | In order to allow easy tracking of the period, also provide means of adding it to the sample data. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf_counter: Change PERF_SAMPLE_CONFIG into PERF_SAMPLE_IDPeter Zijlstra2009-06-051-4/+4
| | | | | | | | | | | | The purpose of PERF_SAMPLE_CONFIG was to identify the counters, since then we've added counter ids, use those instead. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf_counter: Generate mmap events for install_special_mapping()Peter Zijlstra2009-06-051-12/+22
| | | | | | | | | | | | In order to track the vdso also generate mmap events for install_special_mapping(). Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf_counter: Fix lockup with interrupting countersPaul Mackerras2009-06-051-1/+1
| | | | | | | | | | | | | | | | | | | | | | Commit 8e3747c1 ("perf_counter: Change data head from u32 to u64") changed the type of 'head' in struct perf_mmap_data from atomic_t to atomic_long_t, but missed converting one use of atomic_read on it to atomic_long_read. The effect of using atomic_read rather than atomic_long_read on powerpc (and other big-endian architectures) is that we get the high half of the 64-bit quantity, resulting in the cmpxchg retry loop in perf_output_begin spinning forever as soon as data->head becomes non-zero. On little-endian architectures such as x86 we would get the low half, resulting in a lockup once data->head becomes greater than 4G. This fixes it by using atomic_long_read rather than atomic_read. [ Impact: fix perfcounter lockup on PowerPC / big-endian systems ] Signed-off-by: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <18984.33964.21541.743096@cargo.ozlabs.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf_counter: Remove munmap stuffPeter Zijlstra2009-06-041-35/+3Star
| | | | | | | | | | | | In name of keeping it simple, only track mmap events. Userspace will have to remove old overlapping maps when it encounters them. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf_counter: Add fork eventPeter Zijlstra2009-06-041-17/+114
| | | | | | | | | | | | Create a fork event so that we can easily clone the comm and dso maps without having to generate all those events. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf_counter: Fix throttling lock-upIngo Molnar2009-06-031-5/+14
| | | | | | | | | | | | | | | | | | | | | Throttling logic is broken and we can lock up with too small hw sampling intervals. Make the throttling code more robust: disable counters even if we already disabled them. ( Also clean up whitespace damage i noticed while reading various pieces of code related to throttling. ) Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf_counter: Fix race in counter initializationPeter Zijlstra2009-06-031-11/+14
| | | | | | | | | | | | | | | | | | | | We need the PID namespace and counter ID available when the counter overflows and we need to generate a sample event. [ Impact: fix kernel crash with high-frequency sampling ] Reported-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: John Kacur <jkacur@redhat.com> LKML-Reference: <new-submission> [ fixed a further crash and cleaned up the initialization a bit ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf_counter: Rename perf_counter_hw_event => perf_counter_attrPeter Zijlstra2009-06-021-58/+58
| | | | | | | | | | | | | | | | | The structure isn't hw only and when I read event, I think about those things that fall out the other end. Rename the thing. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: John Kacur <jkacur@redhat.com> Cc: Stephane Eranian <eranian@googlemail.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf_counter: Add ioctl for changing the sample period/frequencyPeter Zijlstra2009-06-021-0/+41
| | | | | | | | | | | | | | Reported-by: Stephane Eranian <eranian@googlemail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: John Kacur <jkacur@redhat.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf_counter: Change data head from u32 to u64Peter Zijlstra2009-06-021-7/+8
| | | | | | | | | | | Since some people worried that 4G might not be a large enough as an mmap data window, extend it to 64 bit for capable platforms. Reported-by: Stephane Eranian <eranian@googlemail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf_counter: Rename various fieldsPeter Zijlstra2009-06-021-52/+52
| | | | | | | | | | | | | | | | | | | | | | | A few renames: s/irq_period/sample_period/ s/irq_freq/sample_freq/ s/PERF_RECORD_/PERF_SAMPLE_/ s/record_type/sample_type/ And change both the new sample_type and read_format to u64. Reported-by: Stephane Eranian <eranian@googlemail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: John Kacur <jkacur@redhat.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf_counter: Add unique counter idPeter Zijlstra2009-06-021-2/+7
| | | | | | | | | | | | | | | | | | | | | Stephan raised the issue that we currently cannot distinguish between similar counters within a group (PERF_RECORD_GROUP uses the config value as identifier). Therefore, generate a new ID for each counter using a global u64 sequence counter. Reported-by: Stephane Eranian <eranian@googlemail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: John Kacur <jkacur@redhat.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf_counter: Use PID namespaces properlyPeter Zijlstra2009-06-021-8/+34
| | | | | | | | | | | | | | | | | | | | Stop using task_struct::pid and start using PID namespaces. PIDs will be reported in the PID namespace of the monitoring task at the moment of counter creation. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: John Kacur <jkacur@redhat.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf_counter: Remove unused prev_state fieldPaul Mackerras2009-06-021-4/+0Star
| | | | | | | | | | | | | | | | | This removes the prev_state field of struct perf_counter since it is now unused. It was only used by the cpu migration counter, which doesn't use it any more. Signed-off-by: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: John Kacur <jkacur@redhat.com> LKML-Reference: <18979.35052.915728.626374@cargo.ozlabs.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf_counter: Fix cpu migration counterPaul Mackerras2009-06-021-53/+21Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This fixes the cpu migration software counter to count correctly even when contexts get swapped from one task to another. Previously the cpu migration counts reported by perf stat were bogus, ranging from negative to several thousand for a single "lat_ctx 2 8 32" run. With this patch the cpu migration count reported for "lat_ctx 2 8 32" is almost always between 35 and 44. This fixes the problem by adding a call into the perf_counter code from set_task_cpu when tasks are migrated. This enables us to use the generic swcounter code (with some modifications) for the cpu migration counter. This modifies the swcounter code to allow a NULL regs pointer to be passed in to perf_swcounter_ctx_event() etc. The cpu migration counter does this because there isn't necessarily a pt_regs struct for the task available. In this case, the counter will not have interrupt capability - but the migration counter didn't have interrupt capability before, so this is no loss. Signed-off-by: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: John Kacur <jkacur@redhat.com> LKML-Reference: <18979.35006.819769.416327@cargo.ozlabs.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf_counter: Initialize per-cpu context earlier on cpu upPaul Mackerras2009-06-021-0/+4
| | | | | | | | | | | | | | | | | | | | | | This arranges for perf_counter's notifier for cpu hotplug operations to be called earlier than the migration notifier in sched.c by increasing its priority to 20, compared to the 10 for the migration notifier. The reason for doing this is that a subsequent commit to convert the cpu migration counter to use the generic swcounter infrastructure will add a call into the perf_counter subsystem when tasks get migrated. Therefore the perf_counter subsystem needs a chance to initialize its per-cpu data for the new cpu before it can get called from the migration code. This also adds a comment to the migration notifier noting that its priority needs to be lower than that of the perf_counter notifier. Signed-off-by: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <18981.1900.792795.836858@cargo.ozlabs.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf_counter: Tidy up style detailsIngo Molnar2009-06-011-18/+21
| | | | | | | | | | | | | | | | | | - whitespace fixlets - make local variable definitions more consistent [ Impact: cleanup ] Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: John Kacur <jkacur@redhat.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf_counter: Allow software counters to count while task is not runningPaul Mackerras2009-06-011-6/+42
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This changes perf_swcounter_match() so that per-task software counters can count events that occur while their associated task is not running. This will allow us to use the generic software counter code for counting task migrations, which can occur while the task is not scheduled in. To do this, we have to distinguish between the situations where the counter is inactive because its task has been scheduled out, and those where the counter is inactive because it is part of a group that was not able to go on the PMU. In the former case we want the counter to count, but not in the latter case. If the context is active, we have the latter case. If the context is inactive then we need to know whether the counter was counting when the context was last active, which we can determine by comparing its ->tstamp_stopped timestamp with the context's timestamp. This also folds three checks in perf_swcounter_match, checking perf_event_raw(), perf_event_type() and perf_event_id() individually, into a single 64-bit comparison on counter->hw_event.config, as an optimization. Signed-off-by: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: John Kacur <jkacur@redhat.com> LKML-Reference: <18979.34810.259718.955621@cargo.ozlabs.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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