Messages in this thread Patch in this message | | | From | Mathieu Desnoyers <> | Subject | [RFC PATCH 2/4] Cleanup: sched/membarrier: remove redundant check | Date | Thu, 5 Sep 2019 23:12:58 -0400 |
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Checking that the number of threads is 1 is redundant with checking mm_users == 1.
Suggested-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: "Paul E. McKenney" <paulmck@linux.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Russell King - ARM Linux admin <linux@armlinux.org.uk> Cc: Chris Metcalf <cmetcalf@ezchip.com> Cc: Christoph Lameter <cl@linux.com> Cc: Kirill Tkhai <tkhai@yandex.ru> Cc: Mike Galbraith <efault@gmx.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> --- kernel/sched/membarrier.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/kernel/sched/membarrier.c b/kernel/sched/membarrier.c index 5110d91b1b0e..7e0a0d6535f3 100644 --- a/kernel/sched/membarrier.c +++ b/kernel/sched/membarrier.c @@ -186,7 +186,7 @@ static int membarrier_register_global_expedited(void) MEMBARRIER_STATE_GLOBAL_EXPEDITED_READY) return 0; atomic_or(MEMBARRIER_STATE_GLOBAL_EXPEDITED, &mm->membarrier_state); - if (atomic_read(&mm->mm_users) == 1 && get_nr_threads(p) == 1) { + if (atomic_read(&mm->mm_users) == 1) { /* * For single mm user, single threaded process, we can * simply issue a memory barrier after setting @@ -232,7 +232,7 @@ static int membarrier_register_private_expedited(int flags) if (flags & MEMBARRIER_FLAG_SYNC_CORE) atomic_or(MEMBARRIER_STATE_PRIVATE_EXPEDITED_SYNC_CORE, &mm->membarrier_state); - if (!(atomic_read(&mm->mm_users) == 1 && get_nr_threads(p) == 1)) { + if (atomic_read(&mm->mm_users) != 1) { /* * Ensure all future scheduler executions will observe the * new thread flag state for this process. -- 2.17.1
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