[tip:perf/core] perf/x86: Fix Userspace RDPMC switch

From: tip-bot for Peter Zijlstra
Date: Mon Feb 10 2014 - 08:29:29 EST


Commit-ID: 0e9f2204cfa6d79abe3e525ddf7c4ab5792cc751
Gitweb: http://git.kernel.org/tip/0e9f2204cfa6d79abe3e525ddf7c4ab5792cc751
Author: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
AuthorDate: Wed, 5 Feb 2014 11:19:56 +0100
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Sun, 9 Feb 2014 13:08:25 +0100

perf/x86: Fix Userspace RDPMC switch

The current code forgets to change the CR4 state on the current CPU.
Use on_each_cpu() instead of smp_call_function().

Reported-by: Mark Davies <junk@xxxxxxxxxxx>
Suggested-by: Mark Davies <junk@xxxxxxxxxxx>
Signed-off-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: fweisbec@xxxxxxxxx
Link: http://lkml.kernel.org/n/tip-69efsat90ibhnd577zy3z9gh@xxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
arch/x86/kernel/cpu/perf_event.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index 1246b85..895604f 100644
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -1826,7 +1826,7 @@ static ssize_t set_attr_rdpmc(struct device *cdev,

if (!!val != !!x86_pmu.attr_rdpmc) {
x86_pmu.attr_rdpmc = !!val;
- smp_call_function(change_rdpmc, (void *)val, 1);
+ on_each_cpu(change_rdpmc, (void *)val, 1);
}

return count;
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