diff options
author | Suresh Siddha <suresh.b.siddha@intel.com> | 2009-03-17 14:16:54 -0400 |
---|---|---|
committer | Ingo Molnar <mingo@elte.hu> | 2009-03-18 04:36:14 -0400 |
commit | ce4e240c279a31096f74afa6584a62d64a1ba8c8 (patch) | |
tree | 2b5f7bdf6dc058c09257977929d8f622e6c09466 /arch/x86/mm/tlb.c | |
parent | fa4b57cc045d6134b9862b2873f9c8ba9ed53ffe (diff) |
x86: add x2apic_wrmsr_fence() to x2apic flush tlb paths
Impact: optimize APIC IPI related barriers
Uncached MMIO accesses for xapic are inherently serializing and hence
we don't need explicit barriers for xapic IPI paths.
x2apic MSR writes/reads don't have serializing semantics and hence need
a serializing instruction or mfence, to make all the previous memory
stores globally visisble before the x2apic msr write for IPI.
Add x2apic_wrmsr_fence() in flush tlb path to x2apic specific paths.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: "steiner@sgi.com" <steiner@sgi.com>
Cc: Nick Piggin <npiggin@suse.de>
LKML-Reference: <1237313814.27006.203.camel@localhost.localdomain>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/mm/tlb.c')
-rw-r--r-- | arch/x86/mm/tlb.c | 5 |
1 files changed, 0 insertions, 5 deletions
diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c index a654d59e4483..821e97017e95 100644 --- a/arch/x86/mm/tlb.c +++ b/arch/x86/mm/tlb.c | |||
@@ -187,11 +187,6 @@ static void flush_tlb_others_ipi(const struct cpumask *cpumask, | |||
187 | cpumask, cpumask_of(smp_processor_id())); | 187 | cpumask, cpumask_of(smp_processor_id())); |
188 | 188 | ||
189 | /* | 189 | /* |
190 | * Make the above memory operations globally visible before | ||
191 | * sending the IPI. | ||
192 | */ | ||
193 | smp_mb(); | ||
194 | /* | ||
195 | * We have to send the IPI only to | 190 | * We have to send the IPI only to |
196 | * CPUs affected. | 191 | * CPUs affected. |
197 | */ | 192 | */ |