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| author | Alexandre Truong <alexandre.truong@arm.com> | 2021-12-17 18:45:18 +0300 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2021-12-22 00:35:44 +0300 |
| commit | aa8db3e41dae953b636ff68e944479900d149a37 (patch) | |
| tree | 20d2c8e5e4cb9e27ef0c5f4e8f3e8dcabed8230b /tools/perf/util/callchain.c | |
| parent | ab23692134489f0f563168449fc27bfb5d6b04dd (diff) | |
| download | linux-aa8db3e41dae953b636ff68e944479900d149a37.tar.xz | |
perf callchain: Enable dwarf_callchain_users on arm64
Enable dwarf_callchain_users on arm64 which will be needed to do a
DWARF unwind in order to get the caller of the leaf frame.
Reviewed-by: James Clark <james.clark@arm.com>
Signed-off-by: Alexandre Truong <alexandre.truong@arm.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: John Garry <john.garry@huawei.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20211217154521.80603-5-german.gomez@arm.com
Signed-off-by: German Gomez <german.gomez@arm.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/util/callchain.c')
| -rw-r--r-- | tools/perf/util/callchain.c | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/tools/perf/util/callchain.c b/tools/perf/util/callchain.c index 8e2777133bd9..131207b91d15 100644 --- a/tools/perf/util/callchain.c +++ b/tools/perf/util/callchain.c @@ -1600,7 +1600,7 @@ void callchain_cursor_reset(struct callchain_cursor *cursor) map__zput(node->ms.map); } -void callchain_param_setup(u64 sample_type) +void callchain_param_setup(u64 sample_type, const char *arch) { if (symbol_conf.use_callchain || symbol_conf.cumulate_callchain) { if ((sample_type & PERF_SAMPLE_REGS_USER) && @@ -1612,6 +1612,18 @@ void callchain_param_setup(u64 sample_type) else callchain_param.record_mode = CALLCHAIN_FP; } + + /* + * It's necessary to use libunwind to reliably determine the caller of + * a leaf function on aarch64, as otherwise we cannot know whether to + * start from the LR or FP. + * + * Always starting from the LR can result in duplicate or entirely + * erroneous entries. Always skipping the LR and starting from the FP + * can result in missing entries. + */ + if (callchain_param.record_mode == CALLCHAIN_FP && !strcmp(arch, "arm64")) + dwarf_callchain_users = true; } static bool chain_match(struct callchain_list *base_chain, |