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author | Arnaldo Carvalho de Melo <acme@redhat.com> | 2016-05-10 23:08:32 +0200 |
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committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2016-05-17 04:11:51 +0200 |
commit | 3b1fff08038bd0792b1aa1e9703b2dd0512a3fd0 (patch) | |
tree | 894e513ec904c0b4249917b64adac9d5bda162b5 /kernel | |
parent | perf core: Pass max stack as a perf_callchain_entry context (diff) | |
download | linux-3b1fff08038bd0792b1aa1e9703b2dd0512a3fd0.tar.xz linux-3b1fff08038bd0792b1aa1e9703b2dd0512a3fd0.zip |
perf core: Add a 'nr' field to perf_event_callchain_context
We will use it to count how many addresses are in the entry->ip[] array,
excluding PERF_CONTEXT_{KERNEL,USER,etc} entries, so that we can really
return the number of entries specified by the user via the relevant
sysctl, kernel.perf_event_max_contexts, or via the per event
perf_event_attr.sample_max_stack knob.
This way we keep the perf_sample->ip_callchain->nr meaning, that is the
number of entries, be it real addresses or PERF_CONTEXT_ entries, while
honouring the max_stack knobs, i.e. the end result will be max_stack
entries if we have at least that many entries in a given stack trace.
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-s8teto51tdqvlfhefndtat9r@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/events/callchain.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/kernel/events/callchain.c b/kernel/events/callchain.c index af95ad92893a..8774ff86debb 100644 --- a/kernel/events/callchain.c +++ b/kernel/events/callchain.c @@ -196,8 +196,7 @@ get_perf_callchain(struct pt_regs *regs, u32 init_nr, bool kernel, bool user, ctx.entry = entry; ctx.max_stack = max_stack; - - entry->nr = init_nr; + ctx.nr = entry->nr = init_nr; if (kernel && !user_mode(regs)) { if (add_mark) |