Messages in this thread | | | Subject | Re: [PATCH v4 4/6] perf tools: enable dwarf_callchain_users on arm64 | From | German Gomez <> | Date | Fri, 17 Dec 2021 12:08:59 +0000 |
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On 15/12/2021 16:37, Mark Rutland wrote: > On Wed, Dec 15, 2021 at 03:11:36PM +0000, German Gomez wrote: >> [...] >> >> + >> + /* >> + * It's possible to determine the caller of leaf frames with omitted >> + * frame pointers on aarch64 using libunwind, so enable it. >> + */ > I reckon it's worth mentioning *why* we need to do this; how about: > > /* > * 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. > */ > > Other than that, this looks fine to me! > > Thanks, > Mark.
Ack, I will update this
Thanks, German
> >> + if (callchain_param.record_mode == CALLCHAIN_FP && !strcmp(arch, "arm64")) >> + dwarf_callchain_users = true; >> } >> >> static bool chain_match(struct callchain_list *base_chain, >> diff --git a/tools/perf/util/callchain.h b/tools/perf/util/callchain.h >> index 77fba053c677..d95615daed73 100644 >> --- a/tools/perf/util/callchain.h >> +++ b/tools/perf/util/callchain.h >> @@ -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); >> -- >> 2.25.1 >>
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