Commit-ID: bf92b1feb658f6a262daf3a87d790997a1dca0ff Gitweb: http://git.kernel.org/tip/bf92b1feb658f6a262daf3a87d790997a1dca0ff Author: Davidlohr Bueso <dave@xxxxxxxxxxxx> AuthorDate: Wed, 6 Apr 2016 10:05:15 +0200 Committer: Ingo Molnar <mingo@xxxxxxxxxx> CommitDate: Wed, 13 Apr 2016 10:54:23 +0200 x86/mce: Remove explicit smp_rmb() when starting CPUs sync mce_start() has an explicit smp_wmb() to serialize writes to global_nwo and mce_callin. However, atomic_inc_return() implies barriers on both sides of the call, as such simply rely on this full SMP barrier. Signed-off-by: Davidlohr Bueso <dbueso@xxxxxxx> Signed-off-by: Borislav Petkov <bp@xxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Tony Luck <tony.luck@xxxxxxxxx> Cc: linux-edac <linux-edac@xxxxxxxxxxxxxxx> Link: http://lkml.kernel.org/r/1458602396-840-1-git-send-email-dave@xxxxxxxxxxxx Link: http://lkml.kernel.org/r/1459929916-12852-3-git-send-email-bp@xxxxxxxxx Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> --- arch/x86/kernel/cpu/mcheck/mce.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c index f0c921b..6b7039c 100644 --- a/arch/x86/kernel/cpu/mcheck/mce.c +++ b/arch/x86/kernel/cpu/mcheck/mce.c @@ -830,9 +830,9 @@ static int mce_start(int *no_way_out) atomic_add(*no_way_out, &global_nwo); /* - * global_nwo should be updated before mce_callin + * Rely on the implied barrier below, such that global_nwo + * is updated before mce_callin. */ - smp_wmb(); order = atomic_inc_return(&mce_callin); /* -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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