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authorArnaldo Carvalho de Melo <acme@redhat.com>2016-05-10 18:08:32 -0300
committerArnaldo Carvalho de Melo <acme@redhat.com>2016-05-16 23:11:51 -0300
commit3b1fff08038bd0792b1aa1e9703b2dd0512a3fd0 (patch)
tree894e513ec904c0b4249917b64adac9d5bda162b5 /kernel/events/callchain.c
parentperf core: Pass max stack as a perf_callchain_entry context (diff)
downloadlinux-dev-3b1fff08038bd0792b1aa1e9703b2dd0512a3fd0.tar.xz
linux-dev-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/events/callchain.c')
-rw-r--r--kernel/events/callchain.c3
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)