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| author | Ahmed S. Darwish <a.darwish@linutronix.de> | 2020-07-20 17:55:19 +0200 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2020-07-29 16:14:26 +0200 |
| commit | b75058614fdd3140074a640b514f6a0b4d485a2d (patch) | |
| tree | c395cef190fc9a9a1501432222b6cdd87af06ccd /init | |
| parent | cd29f22019ec4ab998d2e1e8c831c7c42db4aa7d (diff) | |
| download | lwn-b75058614fdd3140074a640b514f6a0b4d485a2d.tar.gz lwn-b75058614fdd3140074a640b514f6a0b4d485a2d.zip | |
sched: tasks: Use sequence counter with associated spinlock
A sequence counter write side critical section must be protected by some
form of locking to serialize writers. A plain seqcount_t does not
contain the information of which lock must be held when entering a write
side critical section.
Use the new seqcount_spinlock_t data type, which allows to associate a
spinlock with the sequence counter. This enables lockdep to verify that
the spinlock used for writer serialization is held when the write side
critical section is entered.
If lockdep is disabled this lock association is compiled out and has
neither storage size nor runtime overhead.
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200720155530.1173732-14-a.darwish@linutronix.de
Diffstat (limited to 'init')
| -rw-r--r-- | init/init_task.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/init/init_task.c b/init/init_task.c index 15089d15010a..94fe3ba1bb60 100644 --- a/init/init_task.c +++ b/init/init_task.c @@ -154,7 +154,8 @@ struct task_struct init_task .trc_holdout_list = LIST_HEAD_INIT(init_task.trc_holdout_list), #endif #ifdef CONFIG_CPUSETS - .mems_allowed_seq = SEQCNT_ZERO(init_task.mems_allowed_seq), + .mems_allowed_seq = SEQCNT_SPINLOCK_ZERO(init_task.mems_allowed_seq, + &init_task.alloc_lock), #endif #ifdef CONFIG_RT_MUTEXES .pi_waiters = RB_ROOT_CACHED, |