The following commit has been merged into the sched/urgent branch of tip: Commit-ID: 09554009c0cad4cb2223dd943c813c9257c6883a Gitweb: https://git.kernel.org/tip/09554009c0cad4cb2223dd943c813c9257c6883a Author: Mathieu Desnoyers <mathieu.desnoy...@efficios.com> AuthorDate: Thu, 19 Sep 2019 13:37:00 -04:00 Committer: Ingo Molnar <mi...@kernel.org> CommitterDate: Wed, 25 Sep 2019 17:42:30 +02:00
sched/membarrier: Remove redundant check Checking that the number of threads is 1 is redundant with checking mm_users == 1. No change in functionality intended. Suggested-by: Oleg Nesterov <o...@redhat.com> Signed-off-by: Mathieu Desnoyers <mathieu.desnoy...@efficios.com> Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org> Cc: Chris Metcalf <cmetc...@ezchip.com> Cc: Christoph Lameter <c...@linux.com> Cc: Eric W. Biederman <ebied...@xmission.com> Cc: Kirill Tkhai <tk...@yandex.ru> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Mike Galbraith <efa...@gmx.de> Cc: Paul E. McKenney <paul...@linux.ibm.com> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Russell King - ARM Linux admin <li...@armlinux.org.uk> Cc: Thomas Gleixner <t...@linutronix.de> Link: https://lkml.kernel.org/r/20190919173705.2181-3-mathieu.desnoy...@efficios.com Signed-off-by: Ingo Molnar <mi...@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 d48b95f..7ccbd0e 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.
