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authorAhmed S. Darwish <a.darwish@linutronix.de>2020-07-20 17:55:19 +0200
committerPeter Zijlstra <peterz@infradead.org>2020-07-29 16:14:26 +0200
commitb75058614fdd3140074a640b514f6a0b4d485a2d (patch)
treec395cef190fc9a9a1501432222b6cdd87af06ccd /init
parentcd29f22019ec4ab998d2e1e8c831c7c42db4aa7d (diff)
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.c3
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,