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authorPeter Zijlstra <peterz@infradead.org>2012-03-22 17:26:36 +0100
committerIngo Molnar <mingo@kernel.org>2012-03-23 09:52:16 +0100
commitc7206205d00ab375839bd6c7ddb247d600693c09 (patch)
tree24b9d66a5eaef77c1fc40bc8f6f28acfd167bf5b /arch
parentc5bc437702b24817cabd65a6a57971ff91a7712c (diff)
downloadop-kernel-dev-c7206205d00ab375839bd6c7ddb247d600693c09.zip
op-kernel-dev-c7206205d00ab375839bd6c7ddb247d600693c09.tar.gz
perf: Fix mmap_page capabilities and docs
Complete the syscall-less self-profiling feature and address all complaints, namely: - capabilities, so we can detect what is actually available at runtime Add a capabilities field to perf_event_mmap_page to indicate what is actually available for use. - on x86: RDPMC weirdness due to being 40/48 bits and not sign-extending properly. - ABI documentation as to how all this stuff works. Also improve the documentation for the new features. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Stephane Eranian <eranian@google.com> Cc: Vince Weaver <vweaver1@eecs.utk.edu> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Jiri Olsa <jolsa@redhat.com> Link: http://lkml.kernel.org/r/1332433596.2487.33.camel@twins Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kernel/cpu/perf_event.c10
1 files changed, 9 insertions, 1 deletions
diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index 453ac94..4ef8104 100644
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -1622,6 +1622,9 @@ static int x86_pmu_event_idx(struct perf_event *event)
{
int idx = event->hw.idx;
+ if (!x86_pmu.attr_rdpmc)
+ return 0;
+
if (x86_pmu.num_counters_fixed && idx >= X86_PMC_IDX_FIXED) {
idx -= X86_PMC_IDX_FIXED;
idx |= 1 << 30;
@@ -1706,14 +1709,19 @@ static struct pmu pmu = {
.flush_branch_stack = x86_pmu_flush_branch_stack,
};
-void perf_update_user_clock(struct perf_event_mmap_page *userpg, u64 now)
+void arch_perf_update_userpage(struct perf_event_mmap_page *userpg, u64 now)
{
+ userpg->cap_usr_time = 0;
+ userpg->cap_usr_rdpmc = x86_pmu.attr_rdpmc;
+ userpg->pmc_width = x86_pmu.cntval_bits;
+
if (!boot_cpu_has(X86_FEATURE_CONSTANT_TSC))
return;
if (!boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
return;
+ userpg->cap_usr_time = 1;
userpg->time_mult = this_cpu_read(cyc2ns);
userpg->time_shift = CYC2NS_SCALE_FACTOR;
userpg->time_offset = this_cpu_read(cyc2ns_offset) - now;
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