From: Alexey Budankov <alexey.budankov@linux.intel.com>
To: Alexander Shishkin <alexander.shishkin@linux.intel.com>,
Peter Zijlstra <peterz@infradead.org>,
mingo@kernel.org
Cc: linux-kernel@vger.kernel.org, acme@kernel.org, jolsa@redhat.com,
songliubraving@fb.com, eranian@google.com, tglx@linutronix.de,
mark.rutland@arm.com, megha.dey@intel.com, frederic@kernel.org
Subject: Re: [RFC][PATCH] perf: Rewrite core context handling
Date: Wed, 17 Oct 2018 18:58:59 +0300 [thread overview]
Message-ID: <9052ed5a-207f-3be4-6a03-8a23ac358c74@linux.intel.com> (raw)
In-Reply-To: <871s8o62if.fsf@ashishki-desk.ger.corp.intel.com>
Hi Alex,
On 17.10.2018 18:01, Alexander Shishkin wrote:
> Alexey Budankov <alexey.budankov@linux.intel.com> writes:
>
>> Since it reduces to single cpu context (and single task context) at all times,
>> ideally, it would probably be coded as simple as this:
>>
>> perf_rotate_context()
>> {
>> cpu = this_cpu_ptr(&cpu_context)
>> for_every_pmu(pmu, cpu)
>> for_every_event_ctx(event_ctx, pmu)
>> rotate(event_ctx, pmu)
>> }
>>
>> so rotate(event_ctx, pmu) would operate on common events objects semantics
>> and memory layout, and PMU specific code handle SW/HW programming differences.
>
> Ok, what's event_ctx and how does that simplify things?
Currently, rotate_ctx() is called twice from perf_rotate_context()
for cpu and task contexts:
struct perf_cpu_context {
struct perf_event_context ctx;
struct perf_event_context *task_ctx;
If it would be implemented in a loop that could, probably, reduce
complexity of perf_rotate_context(), partly pushing the complexity
*down* to SW/HW pmu specific code and perf_rotate_context() would
become scalable for any number of contexts.
Thanks,
Alexey
>
> Regards,
> --
> Alex
>
next prev parent reply other threads:[~2018-10-17 15:59 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-10 10:45 [RFC][PATCH] perf: Rewrite core context handling Peter Zijlstra
2018-10-11 7:50 ` Song Liu
2018-10-11 9:29 ` Peter Zijlstra
2018-10-11 22:37 ` Song Liu
2018-10-12 9:50 ` Peter Zijlstra
2018-10-12 14:25 ` Peter Zijlstra
2018-10-13 8:31 ` Song Liu
2018-10-16 9:50 ` Peter Zijlstra
2018-10-16 16:34 ` Song Liu
2018-10-16 18:10 ` Peter Zijlstra
2018-10-16 18:24 ` Song Liu
2018-10-12 7:04 ` Alexey Budankov
2018-10-12 11:54 ` Peter Zijlstra
2018-10-15 7:26 ` Alexey Budankov
2018-10-15 8:34 ` Peter Zijlstra
2018-10-15 8:53 ` Peter Zijlstra
2018-10-15 17:29 ` Alexey Budankov
2018-10-15 18:31 ` Stephane Eranian
2018-10-16 6:39 ` Alexey Budankov
2018-10-16 9:32 ` Peter Zijlstra
2018-10-15 22:09 ` Song Liu
2018-10-16 18:28 ` Song Liu
2018-10-17 11:06 ` Peter Zijlstra
2018-10-17 16:43 ` Song Liu
2018-10-17 17:19 ` Peter Zijlstra
2018-10-17 18:33 ` Peter Zijlstra
2018-10-17 18:57 ` Song Liu
2018-10-16 16:26 ` Mark Rutland
2018-10-16 18:07 ` Peter Zijlstra
2018-10-17 8:57 ` Alexey Budankov
2018-10-17 15:01 ` Alexander Shishkin
2018-10-17 15:58 ` Alexey Budankov [this message]
2018-10-17 16:30 ` Peter Zijlstra
2018-10-18 7:05 ` Alexey Budankov
2018-10-22 13:26 ` Alexander Shishkin
2018-10-23 6:13 ` Song Liu
2018-10-23 6:55 ` Peter Zijlstra
2019-05-15 11:17 ` Alexander Shishkin
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