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authorWang Nan <wangnan0@huawei.com>2016-05-20 16:38:23 +0000
committerArnaldo Carvalho de Melo <acme@redhat.com>2016-05-20 14:54:23 -0300
commitb90dc17a5d14a881f9bb3b58edb3d71075d58afb (patch)
treee621aa3d42c009475f758375b76d4ef755520bd6 /tools/perf/util/evsel.c
parentMerge tag 'perf-core-for-mingo-20160520' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent (diff)
downloadlinux-dev-b90dc17a5d14a881f9bb3b58edb3d71075d58afb.tar.xz
linux-dev-b90dc17a5d14a881f9bb3b58edb3d71075d58afb.zip
perf evsel: Add overwrite attribute and check write_backward
Add 'overwrite' attribute to evsel to mark whether this event is overwritable. The following commits will support syntax like: # perf record -e cycles/overwrite/ ... An overwritable evsel requires kernel support for the perf_event_attr.write_backward ring buffer feature. Add it to perf_missing_feature. Signed-off-by: Wang Nan <wangnan0@huawei.com> Cc: He Kuang <hekuang@huawei.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1463762315-155689-2-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/util/evsel.c')
-rw-r--r--tools/perf/util/evsel.c13
1 files changed, 13 insertions, 0 deletions
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 964c7c3602c0..02c177d14c8d 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -37,6 +37,7 @@ static struct {
bool clockid;
bool clockid_wrong;
bool lbr_flags;
+ bool write_backward;
} perf_missing_features;
static clockid_t clockid;
@@ -1376,6 +1377,8 @@ fallback_missing_features:
if (perf_missing_features.lbr_flags)
evsel->attr.branch_sample_type &= ~(PERF_SAMPLE_BRANCH_NO_FLAGS |
PERF_SAMPLE_BRANCH_NO_CYCLES);
+ if (perf_missing_features.write_backward)
+ evsel->attr.write_backward = false;
retry_sample_id:
if (perf_missing_features.sample_id_all)
evsel->attr.sample_id_all = 0;
@@ -1438,6 +1441,12 @@ retry_open:
err = -EINVAL;
goto out_close;
}
+
+ if (evsel->overwrite &&
+ perf_missing_features.write_backward) {
+ err = -EINVAL;
+ goto out_close;
+ }
}
}
@@ -1500,6 +1509,10 @@ try_fallback:
PERF_SAMPLE_BRANCH_NO_FLAGS))) {
perf_missing_features.lbr_flags = true;
goto fallback_missing_features;
+ } else if (!perf_missing_features.write_backward &&
+ evsel->attr.write_backward) {
+ perf_missing_features.write_backward = true;
+ goto fallback_missing_features;
}
out_close: