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perf callchain: Enable dwarf_callchain_users on arm64

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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>
This commit is contained in:
Alexandre Truong 2021-12-17 15:45:18 +00:00 committed by Arnaldo Carvalho de Melo
parent ab23692134
commit aa8db3e41d
4 changed files with 18 additions and 6 deletions
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4
tools/perf/builtin-report.c
View File

@ -410,7 +410,7 @@ static int report__setup_sample_type(struct report *rep)
}
}
callchain_param_setup(sample_type);
callchain_param_setup(sample_type, perf_env__arch(&rep->session->header.env));
if (rep->stitch_lbr && (callchain_param.record_mode != CALLCHAIN_LBR)) {
ui__warning("Can't find LBR callchain. Switch off --stitch-lbr.\n"
@ -1127,7 +1127,7 @@ static int process_attr(struct perf_tool *tool __maybe_unused,
* on events sample_type.
*/
sample_type = evlist__combined_sample_type(*pevlist);
callchain_param_setup(sample_type);
callchain_param_setup(sample_type, perf_env__arch((*pevlist)->env));
return 0;
}

4
tools/perf/builtin-script.c
View File

@ -2318,7 +2318,7 @@ static int process_attr(struct perf_tool *tool, union perf_event *event,
* on events sample_type.
*/
sample_type = evlist__combined_sample_type(evlist);
callchain_param_setup(sample_type);
callchain_param_setup(sample_type, perf_env__arch((*pevlist)->env));
/* Enable fields for callchain entries */
if (symbol_conf.use_callchain &&
@ -3468,7 +3468,7 @@ static void script__setup_sample_type(struct perf_script *script)
struct perf_session *session = script->session;
u64 sample_type = evlist__combined_sample_type(session->evlist);
callchain_param_setup(sample_type);
callchain_param_setup(sample_type, perf_env__arch(session->machines.host.env));
if (script->stitch_lbr && (callchain_param.record_mode != CALLCHAIN_LBR)) {
pr_warning("Can't find LBR callchain. Switch off --stitch-lbr.\n"

14
tools/perf/util/callchain.c
View File

@ -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,

2
tools/perf/util/callchain.h
View File

@ -300,7 +300,7 @@ int callchain_branch_counts(struct callchain_root *root,
u64 *branch_count, u64 *predicted_count,
u64 *abort_count, u64 *cycles_count);
void callchain_param_setup(u64 sample_type);
void callchain_param_setup(u64 sample_type, const char *arch);
bool callchain_cnode_matched(struct callchain_node *base_cnode,
struct callchain_node *pair_cnode);