From: Peter Zijlstra <peterz@infradead.org>
To: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>,
linux-kernel@vger.kernel.org, acme@redhat.com,
kirill.shutemov@linux.intel.com, Borislav Petkov <bp@alien8.de>,
rric@kernel.org
Subject: Re: [RFC PATCH 07/17] perf: Add pmu_info to user page
Date: Tue, 3 Oct 2017 16:40:34 +0200 [thread overview]
Message-ID: <20171003144034.um4fjtxza2qb42ei@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20170905133026.13689-8-alexander.shishkin@linux.intel.com>
On Tue, Sep 05, 2017 at 04:30:16PM +0300, Alexander Shishkin wrote:
> Allow PMUs to supply additional static information that may be required
> by their decoders. Most of what Intel PT driver exports as capability
> attributes (timing packet freqencies, frequency ratios etc), its decoder
> needs to be able to correctly decode its binary stream. However, when
> decoding Intel PT stream from a core dump, we can't rely on the sysfs
> attributes, so we need to pack this information into the perf buffer,
> so that the resulting core dump is self-contained.
>
> In order to do this, we append a PMU-specific structure to the user
> page. Such structures will include size, for versioning.
>
> @@ -508,6 +513,18 @@ struct perf_addr_filters_head {
> unsigned int nr_file_filters;
> };
>
> +struct pmu_info {
> + /*
> + * Size of this structure, for versioning.
> + */
> + u32 note_size;
> +
> + /*
> + * Size of the container structure, not including this one
> + */
> + u32 pmu_descsz;
> +};
> +
> /**
> * enum perf_event_active_state - the states of a event
> */
> diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h
> index 3d64d9ea80..4cdd4fab9d 100644
> --- a/include/uapi/linux/perf_event.h
> +++ b/include/uapi/linux/perf_event.h
> @@ -599,6 +599,16 @@ struct perf_event_mmap_page {
> __u64 aux_tail;
> __u64 aux_offset;
> __u64 aux_size;
> +
> + /*
> + * PMU data: static info that (AUX) decoder wants to know in order to
> + * decode correctly:
> + *
> + * pmu_offset >= sizeof(struct perf_event_mmap_page)
> + * pmu_offset + pmu_size <= PAGE_SIZE
> + */
> + __u64 pmu_offset;
> + __u64 pmu_size;
> };
Why like this? Why not dump the data as part of
PERF_RECORD_ITRACE_START/PERF_RECORD_AUX ?
next prev parent reply other threads:[~2017-10-03 14:40 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-05 13:30 [RFC PATCH 00/17] perf: Detached events Alexander Shishkin
2017-09-05 13:30 ` [RFC PATCH 01/17] perf: Allow mmapping only user page Alexander Shishkin
2017-09-06 16:28 ` Borislav Petkov
2017-09-13 11:35 ` Alexander Shishkin
2017-09-13 12:58 ` Borislav Petkov
2017-09-05 13:30 ` [RFC PATCH 02/17] perf: Factor out mlock accounting Alexander Shishkin
2017-09-05 13:30 ` [RFC PATCH 03/17] tracefs: De-globalize instances' callbacks Alexander Shishkin
2018-01-24 18:54 ` Steven Rostedt
2017-09-05 13:30 ` [RFC PATCH 04/17] tracefs: Add ->unlink callback to tracefs_dir_ops Alexander Shishkin
2017-09-05 13:30 ` [RFC PATCH 05/17] perf: Introduce detached events Alexander Shishkin
2017-10-03 14:34 ` Peter Zijlstra
2017-10-06 11:23 ` Alexander Shishkin
2017-09-05 13:30 ` [RFC PATCH 06/17] perf: Add buffers to the " Alexander Shishkin
2017-10-03 14:36 ` Peter Zijlstra
2017-09-05 13:30 ` [RFC PATCH 07/17] perf: Add pmu_info to user page Alexander Shishkin
2017-10-03 14:40 ` Peter Zijlstra [this message]
2017-09-05 13:30 ` [RFC PATCH 08/17] perf: Allow inheritance for detached events Alexander Shishkin
2017-10-03 14:42 ` Peter Zijlstra
2017-10-06 11:40 ` Alexander Shishkin
2017-09-05 13:30 ` [RFC PATCH 09/17] perf: Use shmemfs pages for userspace-only per-thread " Alexander Shishkin
2017-10-03 14:43 ` Peter Zijlstra
2017-10-06 11:52 ` Alexander Shishkin
2017-09-05 13:30 ` [RFC PATCH 10/17] perf: Implement pinning and scheduling for SHMEM events Alexander Shishkin
2017-09-05 13:30 ` [RFC PATCH 11/17] perf: Implement mlock accounting for shmem ring buffers Alexander Shishkin
2017-09-05 13:30 ` [RFC PATCH 12/17] perf: Track pinned events per user Alexander Shishkin
2017-09-05 13:30 ` [RFC PATCH 13/17] perf: Re-inject shmem buffers after exec Alexander Shishkin
2017-09-05 13:30 ` [RFC PATCH 14/17] perf: Add ioctl(REATTACH) for detached events Alexander Shishkin
2017-10-03 14:50 ` Peter Zijlstra
2017-09-05 13:30 ` [RFC PATCH 15/17] perf: Allow controlled non-root access to " Alexander Shishkin
2017-10-03 14:53 ` Peter Zijlstra
2017-09-05 13:30 ` [RFC PATCH 16/17] perf/x86/intel/pt: Add PMU info Alexander Shishkin
2017-09-05 13:30 ` [RFC PATCH 17/17] perf/x86/intel/bts: " Alexander Shishkin
2017-09-06 16:24 ` [RFC PATCH 00/17] perf: Detached events Borislav Petkov
2017-09-13 11:54 ` Alexander Shishkin
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