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author | David S. Miller | 2018-05-21 22:01:54 +0200 |
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committer | David S. Miller | 2018-05-21 22:01:54 +0200 |
commit | 6f6e434aa267a6030477876d89444fe3a6b7a48d (patch) | |
tree | 67755c422f1e85451aa646eae21d4c6f3f389d9f /include/linux/sched.h | |
parent | vmcore: move get_vmcore_size out of __init (diff) | |
parent | Merge tag 'mips_fixes_4.17_2' of git://git.kernel.org/pub/scm/linux/kernel/gi... (diff) | |
download | kernel-qcow2-linux-6f6e434aa267a6030477876d89444fe3a6b7a48d.tar.gz kernel-qcow2-linux-6f6e434aa267a6030477876d89444fe3a6b7a48d.tar.xz kernel-qcow2-linux-6f6e434aa267a6030477876d89444fe3a6b7a48d.zip |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
S390 bpf_jit.S is removed in net-next and had changes in 'net',
since that code isn't used any more take the removal.
TLS data structures split the TX and RX components in 'net-next',
put the new struct members from the bug fix in 'net' into the RX
part.
The 'net-next' tree had some reworking of how the ERSPAN code works in
the GRE tunneling code, overlapping with a one-line headroom
calculation fix in 'net'.
Overlapping changes in __sock_map_ctx_update_elem(), keep the bits
that read the prog members via READ_ONCE() into local variables
before using them.
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/linux/sched.h')
-rw-r--r-- | include/linux/sched.h | 50 |
1 files changed, 45 insertions, 5 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h index b3d697f3b573..c2413703f45d 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -112,17 +112,36 @@ struct task_group; #ifdef CONFIG_DEBUG_ATOMIC_SLEEP +/* + * Special states are those that do not use the normal wait-loop pattern. See + * the comment with set_special_state(). + */ +#define is_special_task_state(state) \ + ((state) & (__TASK_STOPPED | __TASK_TRACED | TASK_DEAD)) + #define __set_current_state(state_value) \ do { \ + WARN_ON_ONCE(is_special_task_state(state_value));\ current->task_state_change = _THIS_IP_; \ current->state = (state_value); \ } while (0) + #define set_current_state(state_value) \ do { \ + WARN_ON_ONCE(is_special_task_state(state_value));\ current->task_state_change = _THIS_IP_; \ smp_store_mb(current->state, (state_value)); \ } while (0) +#define set_special_state(state_value) \ + do { \ + unsigned long flags; /* may shadow */ \ + WARN_ON_ONCE(!is_special_task_state(state_value)); \ + raw_spin_lock_irqsave(¤t->pi_lock, flags); \ + current->task_state_change = _THIS_IP_; \ + current->state = (state_value); \ + raw_spin_unlock_irqrestore(¤t->pi_lock, flags); \ + } while (0) #else /* * set_current_state() includes a barrier so that the write of current->state @@ -144,8 +163,8 @@ struct task_group; * * The above is typically ordered against the wakeup, which does: * - * need_sleep = false; - * wake_up_state(p, TASK_UNINTERRUPTIBLE); + * need_sleep = false; + * wake_up_state(p, TASK_UNINTERRUPTIBLE); * * Where wake_up_state() (and all other wakeup primitives) imply enough * barriers to order the store of the variable against wakeup. @@ -154,12 +173,33 @@ struct task_group; * once it observes the TASK_UNINTERRUPTIBLE store the waking CPU can issue a * TASK_RUNNING store which can collide with __set_current_state(TASK_RUNNING). * - * This is obviously fine, since they both store the exact same value. + * However, with slightly different timing the wakeup TASK_RUNNING store can + * also collide with the TASK_UNINTERRUPTIBLE store. Loosing that store is not + * a problem either because that will result in one extra go around the loop + * and our @cond test will save the day. * * Also see the comments of try_to_wake_up(). */ -#define __set_current_state(state_value) do { current->state = (state_value); } while (0) -#define set_current_state(state_value) smp_store_mb(current->state, (state_value)) +#define __set_current_state(state_value) \ + current->state = (state_value) + +#define set_current_state(state_value) \ + smp_store_mb(current->state, (state_value)) + +/* + * set_special_state() should be used for those states when the blocking task + * can not use the regular condition based wait-loop. In that case we must + * serialize against wakeups such that any possible in-flight TASK_RUNNING stores + * will not collide with our state change. + */ +#define set_special_state(state_value) \ + do { \ + unsigned long flags; /* may shadow */ \ + raw_spin_lock_irqsave(¤t->pi_lock, flags); \ + current->state = (state_value); \ + raw_spin_unlock_irqrestore(¤t->pi_lock, flags); \ + } while (0) + #endif /* Task command name length: */ |