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author | Peter Zijlstra <peterz@infradead.org> | 2016-07-18 11:41:10 -0700 |
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committer | Ingo Molnar <mingo@kernel.org> | 2016-07-20 09:48:40 +0200 |
commit | 08e237fa56a1d95c1372033bc29c4a2517b3c0fa (patch) | |
tree | 516f04cfcd11fafd8d801c7ce0ed60ca660d26d0 /arch/x86/kernel/process.c | |
parent | 4fffe71dd913cca5532da594e2f48a0db6b494dc (diff) | |
download | op-kernel-dev-08e237fa56a1d95c1372033bc29c4a2517b3c0fa.zip op-kernel-dev-08e237fa56a1d95c1372033bc29c4a2517b3c0fa.tar.gz |
x86/cpu: Add workaround for MONITOR instruction erratum on Goldmont based CPUs
Monitored cached line may not wake up from mwait on certain
Goldmont based CPUs. This patch will avoid calling
current_set_polling_and_test() and thereby not set the TIF_ flag.
The result is that we'll always send IPIs for wakeups.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1468867270-18493-1-git-send-email-jacob.jun.pan@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel/process.c')
-rw-r--r-- | arch/x86/kernel/process.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index 96becbb..59f68f1 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -404,7 +404,7 @@ static int prefer_mwait_c1_over_halt(const struct cpuinfo_x86 *c) if (c->x86_vendor != X86_VENDOR_INTEL) return 0; - if (!cpu_has(c, X86_FEATURE_MWAIT)) + if (!cpu_has(c, X86_FEATURE_MWAIT) || static_cpu_has_bug(X86_BUG_MONITOR)) return 0; return 1; |