Messages in this thread | | | Subject | Re: [PATCH v5 6/6] perf arm64: inject missing frames if perf-record used "--call-graph=fp" | From | German Gomez <> | Date | Mon, 10 Jan 2022 10:48:57 +0000 |
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Hi Jiri,
On 21/12/2021 09:32, Jiri Olsa wrote: > On Fri, Dec 17, 2021 at 03:45:20PM +0000, German Gomez wrote: > > SNIP > >> +} >> + >> +u64 get_leaf_frame_caller_aarch64(struct perf_sample *sample, struct thread *thread, int usr_idx) >> +{ >> + int ret; >> + struct entries entries = {}; >> + struct regs_dump old_regs = sample->user_regs; >> + >> + if (!get_leaf_frame_caller_enabled(sample)) >> + return 0; >> + >> + /* >> + * If PC and SP are not recorded, get the value of PC from the stack >> + * and set its mask. SP is not used when doing the unwinding but it >> + * still needs to be set to prevent failures. >> + */ >> + >> + if (!(sample->user_regs.mask & SMPL_REG_MASK(PERF_REG_ARM64_PC))) { >> + sample->user_regs.cache_mask |= SMPL_REG_MASK(PERF_REG_ARM64_PC); >> + sample->user_regs.cache_regs[PERF_REG_ARM64_PC] = sample->callchain->ips[usr_idx+1]; >> + } >> + >> + if (!(sample->user_regs.mask & SMPL_REG_MASK(PERF_REG_ARM64_SP))) { >> + sample->user_regs.cache_mask |= SMPL_REG_MASK(PERF_REG_ARM64_SP); >> + sample->user_regs.cache_regs[PERF_REG_ARM64_SP] = 0; >> + } >> + >> + ret = unwind__get_entries(add_entry, &entries, thread, sample, 2); > just curious, did you try this with both unwinders libunwind/libdw?
Yes I did,
This is the program I was using:
int a = 0;
void leaf() { for (int i = 0; i < 10000000; i++) a *= a; }
void parent() { leaf(); }
int main() { parent(); }
... compiled with "gcc -O0 -fno-omit-frame-pointer -fno-inline program.c"
> > any chance you could add arm specific test for this?
I don't see a reason not to. I'll make a note for a separate patch.
> > otherwise it looks good to me > > Acked-by: Jiri Olsa <jolsa@kernel.org>
Thanks for the review, German
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