diff options
| author | Arnaldo Carvalho de Melo <acme@redhat.com> | 2016-04-27 10:16:24 -0300 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2016-04-27 10:29:07 -0300 |
| commit | 4cb93446c587d56e2a54f4f83113daba2c0b6dee (patch) | |
| tree | a251b1d510831dc071eadbbbe3e38a85fe643365 /tools/perf/util/machine.c | |
| parent | c5dfd78eb79851e278b7973031b9ca363da87a7e (diff) | |
perf tools: Set the maximum allowed stack from /proc/sys/kernel/perf_event_max_stack
There is an upper limit to what tooling considers a valid callchain,
and it was tied to the hardcoded value in the kernel,
PERF_MAX_STACK_DEPTH (127), now that this can be tuned via a sysctl,
make it read it and use that as the upper limit, falling back to
PERF_MAX_STACK_DEPTH for kernels where this sysctl isn't present.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-yjqsd30nnkogvj5oyx9ghir9@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/util/machine.c')
| -rw-r--r-- | tools/perf/util/machine.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c index 656c1d7ee7d4..2cb95bbf9ea6 100644 --- a/tools/perf/util/machine.c +++ b/tools/perf/util/machine.c @@ -1764,7 +1764,7 @@ static int resolve_lbr_callchain_sample(struct thread *thread, */ int mix_chain_nr = i + 1 + lbr_nr + 1; - if (mix_chain_nr > PERF_MAX_STACK_DEPTH + PERF_MAX_BRANCH_DEPTH) { + if (mix_chain_nr > (int)sysctl_perf_event_max_stack + PERF_MAX_BRANCH_DEPTH) { pr_warning("corrupted callchain. skipping...\n"); return 0; } @@ -1825,7 +1825,7 @@ static int thread__resolve_callchain_sample(struct thread *thread, * Based on DWARF debug information, some architectures skip * a callchain entry saved by the kernel. */ - if (chain->nr < PERF_MAX_STACK_DEPTH) + if (chain->nr < sysctl_perf_event_max_stack) skip_idx = arch_skip_callchain_idx(thread, chain); /* @@ -1886,7 +1886,7 @@ static int thread__resolve_callchain_sample(struct thread *thread, } check_calls: - if (chain->nr > PERF_MAX_STACK_DEPTH && (int)chain->nr > max_stack) { + if (chain->nr > sysctl_perf_event_max_stack && (int)chain->nr > max_stack) { pr_warning("corrupted callchain. skipping...\n"); return 0; } |