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Subject[RFC PATCH for 5.4 2/7] Cleanup: sched/membarrier: Remove redundant check
Date
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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