Messages in this thread | | | Subject | Re: [PATCH V6 03/16] perf/core: Add support for PERF_SAMPLE_CODE_PAGE_SIZE | From | "Liang, Kan" <> | Date | Mon, 10 Aug 2020 18:37:08 -0400 |
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On 8/10/2020 5:41 PM, Peter Zijlstra wrote: > On Mon, Aug 10, 2020 at 02:24:23PM -0700, Kan Liang wrote: >> From: Stephane Eranian <eranian@google.com> >> >> When studying code layout, it is useful to capture the page size of the >> sampled code address. >> >> Add a new sample type for code page size. >> The new sample type requires collecting the ip. The code page size can >> be calculated from the IRQ-safe perf_get_page_size(). >> >> Only the generic support is covered. The large PEBS will be disabled >> with this sample type. > > -ENOREASON
I think the reason is similar to PERF_SAMPLE_DATA_PAGE_SIZE. For large PEBS, the mapping could be gone for the earlier PEBS records. Invalid page size may be retrieved. I will update the commit message.
Thanks, Kan
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