* [PATCH] perf, tools: Disable branch flags/cycles for --callgraph lbr
@ 2015-12-12 0:12 Andi Kleen
2015-12-14 9:55 ` Jiri Olsa
2015-12-18 8:46 ` [tip:perf/core] perf evsel: Disable branch flags/ cycles " tip-bot for Andi Kleen
0 siblings, 2 replies; 4+ messages in thread
From: Andi Kleen @ 2015-12-12 0:12 UTC (permalink / raw)
To: acme; +Cc: jolsa, mingo, linux-kernel, Andi Kleen
From: Andi Kleen <ak@linux.intel.com>
[The kernel patch needed for this is in tip now
(b16a5b52eb9 perf/x86: Add option to disable ...)
So this user tools patch to make use of it should be merged now]
Automatically disable collecting branch flags and cycles with
--call-graph lbr. This allows avoiding a bunch of extra MSR
reads in the PMI on Skylake.
When the kernel doesn't support the new flags they are automatically
cleared in the fallback code.
v2: Switch to use branch_sample_type instead of sample_type.
Adjust description.
Fix the fallback logic.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
---
tools/perf/util/evsel.c | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 47f0330..544e440 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -36,6 +36,7 @@ static struct {
bool cloexec;
bool clockid;
bool clockid_wrong;
+ bool lbr_flags;
} perf_missing_features;
static clockid_t clockid;
@@ -574,7 +575,9 @@ perf_evsel__config_callgraph(struct perf_evsel *evsel,
} else {
perf_evsel__set_sample_bit(evsel, BRANCH_STACK);
attr->branch_sample_type = PERF_SAMPLE_BRANCH_USER |
- PERF_SAMPLE_BRANCH_CALL_STACK;
+ PERF_SAMPLE_BRANCH_CALL_STACK |
+ PERF_SAMPLE_BRANCH_NO_CYCLES |
+ PERF_SAMPLE_BRANCH_NO_FLAGS;
}
} else
pr_warning("Cannot use LBR callstack with branch stack. "
@@ -1337,6 +1340,9 @@ fallback_missing_features:
evsel->attr.mmap2 = 0;
if (perf_missing_features.exclude_guest)
evsel->attr.exclude_guest = evsel->attr.exclude_host = 0;
+ if (perf_missing_features.lbr_flags)
+ evsel->attr.branch_sample_type &= ~(PERF_SAMPLE_BRANCH_NO_FLAGS |
+ PERF_SAMPLE_BRANCH_NO_CYCLES);
retry_sample_id:
if (perf_missing_features.sample_id_all)
evsel->attr.sample_id_all = 0;
@@ -1455,6 +1461,12 @@ try_fallback:
} else if (!perf_missing_features.sample_id_all) {
perf_missing_features.sample_id_all = true;
goto retry_sample_id;
+ } else if (!perf_missing_features.lbr_flags &&
+ (evsel->attr.branch_sample_type &
+ (PERF_SAMPLE_BRANCH_NO_CYCLES |
+ PERF_SAMPLE_BRANCH_NO_FLAGS))) {
+ perf_missing_features.lbr_flags = true;
+ goto fallback_missing_features;
}
out_close:
--
2.4.3
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] perf, tools: Disable branch flags/cycles for --callgraph lbr
2015-12-12 0:12 [PATCH] perf, tools: Disable branch flags/cycles for --callgraph lbr Andi Kleen
@ 2015-12-14 9:55 ` Jiri Olsa
2015-12-14 15:12 ` Arnaldo Carvalho de Melo
2015-12-18 8:46 ` [tip:perf/core] perf evsel: Disable branch flags/ cycles " tip-bot for Andi Kleen
1 sibling, 1 reply; 4+ messages in thread
From: Jiri Olsa @ 2015-12-14 9:55 UTC (permalink / raw)
To: Andi Kleen; +Cc: acme, jolsa, mingo, linux-kernel, Andi Kleen
On Fri, Dec 11, 2015 at 04:12:24PM -0800, Andi Kleen wrote:
> From: Andi Kleen <ak@linux.intel.com>
>
> [The kernel patch needed for this is in tip now
> (b16a5b52eb9 perf/x86: Add option to disable ...)
> So this user tools patch to make use of it should be merged now]
>
> Automatically disable collecting branch flags and cycles with
> --call-graph lbr. This allows avoiding a bunch of extra MSR
> reads in the PMI on Skylake.
>
> When the kernel doesn't support the new flags they are automatically
> cleared in the fallback code.
>
> v2: Switch to use branch_sample_type instead of sample_type.
> Adjust description.
> Fix the fallback logic.
> Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
thanks,
jirka
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] perf, tools: Disable branch flags/cycles for --callgraph lbr
2015-12-14 9:55 ` Jiri Olsa
@ 2015-12-14 15:12 ` Arnaldo Carvalho de Melo
0 siblings, 0 replies; 4+ messages in thread
From: Arnaldo Carvalho de Melo @ 2015-12-14 15:12 UTC (permalink / raw)
To: Jiri Olsa; +Cc: Andi Kleen, jolsa, mingo, linux-kernel, Andi Kleen
Em Mon, Dec 14, 2015 at 10:55:38AM +0100, Jiri Olsa escreveu:
> On Fri, Dec 11, 2015 at 04:12:24PM -0800, Andi Kleen wrote:
> > From: Andi Kleen <ak@linux.intel.com>
> >
> > [The kernel patch needed for this is in tip now
> > (b16a5b52eb9 perf/x86: Add option to disable ...)
> > So this user tools patch to make use of it should be merged now]
> >
> > Automatically disable collecting branch flags and cycles with
> > --call-graph lbr. This allows avoiding a bunch of extra MSR
> > reads in the PMI on Skylake.
> >
> > When the kernel doesn't support the new flags they are automatically
> > cleared in the fallback code.
> >
> > v2: Switch to use branch_sample_type instead of sample_type.
> > Adjust description.
> > Fix the fallback logic.
> > Signed-off-by: Andi Kleen <ak@linux.intel.com>
>
> Acked-by: Jiri Olsa <jolsa@kernel.org>
Thanks, applied to perf/core.
- Arnaldo
^ permalink raw reply [flat|nested] 4+ messages in thread
* [tip:perf/core] perf evsel: Disable branch flags/ cycles for --callgraph lbr
2015-12-12 0:12 [PATCH] perf, tools: Disable branch flags/cycles for --callgraph lbr Andi Kleen
2015-12-14 9:55 ` Jiri Olsa
@ 2015-12-18 8:46 ` tip-bot for Andi Kleen
1 sibling, 0 replies; 4+ messages in thread
From: tip-bot for Andi Kleen @ 2015-12-18 8:46 UTC (permalink / raw)
To: linux-tip-commits; +Cc: hpa, tglx, mingo, linux-kernel, ak, acme, jolsa
Commit-ID: bd0f889536f80630c1c4a414f2de90744d2c87d0
Gitweb: http://git.kernel.org/tip/bd0f889536f80630c1c4a414f2de90744d2c87d0
Author: Andi Kleen <ak@linux.intel.com>
AuthorDate: Fri, 11 Dec 2015 16:12:24 -0800
Committer: Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Mon, 14 Dec 2015 12:11:22 -0300
perf evsel: Disable branch flags/cycles for --callgraph lbr
[The kernel patch needed for this is in tip now (b16a5b52eb9 perf/x86:
Add option to disable ...) So this user tools patch to make use of it
should be merged now]
Automatically disable collecting branch flags and cycles with
--call-graph lbr. This allows avoiding a bunch of extra MSR
reads in the PMI on Skylake.
When the kernel doesn't support the new flags they are automatically
cleared in the fallback code.
v2: Switch to use branch_sample_type instead of sample_type.
Adjust description.
Fix the fallback logic.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/1449879144-29074-1-git-send-email-andi@firstfloor.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/perf/util/evsel.c | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 47f0330..544e440 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -36,6 +36,7 @@ static struct {
bool cloexec;
bool clockid;
bool clockid_wrong;
+ bool lbr_flags;
} perf_missing_features;
static clockid_t clockid;
@@ -574,7 +575,9 @@ perf_evsel__config_callgraph(struct perf_evsel *evsel,
} else {
perf_evsel__set_sample_bit(evsel, BRANCH_STACK);
attr->branch_sample_type = PERF_SAMPLE_BRANCH_USER |
- PERF_SAMPLE_BRANCH_CALL_STACK;
+ PERF_SAMPLE_BRANCH_CALL_STACK |
+ PERF_SAMPLE_BRANCH_NO_CYCLES |
+ PERF_SAMPLE_BRANCH_NO_FLAGS;
}
} else
pr_warning("Cannot use LBR callstack with branch stack. "
@@ -1337,6 +1340,9 @@ fallback_missing_features:
evsel->attr.mmap2 = 0;
if (perf_missing_features.exclude_guest)
evsel->attr.exclude_guest = evsel->attr.exclude_host = 0;
+ if (perf_missing_features.lbr_flags)
+ evsel->attr.branch_sample_type &= ~(PERF_SAMPLE_BRANCH_NO_FLAGS |
+ PERF_SAMPLE_BRANCH_NO_CYCLES);
retry_sample_id:
if (perf_missing_features.sample_id_all)
evsel->attr.sample_id_all = 0;
@@ -1455,6 +1461,12 @@ try_fallback:
} else if (!perf_missing_features.sample_id_all) {
perf_missing_features.sample_id_all = true;
goto retry_sample_id;
+ } else if (!perf_missing_features.lbr_flags &&
+ (evsel->attr.branch_sample_type &
+ (PERF_SAMPLE_BRANCH_NO_CYCLES |
+ PERF_SAMPLE_BRANCH_NO_FLAGS))) {
+ perf_missing_features.lbr_flags = true;
+ goto fallback_missing_features;
}
out_close:
^ permalink raw reply related [flat|nested] 4+ messages in thread
end of thread, other threads:[~2015-12-18 8:47 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2015-12-12 0:12 [PATCH] perf, tools: Disable branch flags/cycles for --callgraph lbr Andi Kleen
2015-12-14 9:55 ` Jiri Olsa
2015-12-14 15:12 ` Arnaldo Carvalho de Melo
2015-12-18 8:46 ` [tip:perf/core] perf evsel: Disable branch flags/ cycles " tip-bot for Andi Kleen
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