From: Alexander Shishkin <alexander.shishkin@linux.intel.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>,
linux-kernel@vger.kernel.org, Robert Richter <rric@kernel.org>,
Frederic Weisbecker <fweisbec@gmail.com>,
Mike Galbraith <efault@gmx.de>, Paul Mackerras <paulus@samba.org>,
Stephane Eranian <eranian@google.com>,
Andi Kleen <ak@linux.intel.com>
Subject: Re: [RFC v2 6/7] perf: add api for pmus to write to AUX space
Date: Wed, 25 Jun 2014 14:24:51 +0300 [thread overview]
Message-ID: <87fvitxmd8.fsf@ashishki-desk.ger.corp.intel.com> (raw)
In-Reply-To: <20140624172723.GS3213@twins.programming.kicks-ass.net>
Peter Zijlstra <peterz@infradead.org> writes:
> On Wed, Jun 11, 2014 at 06:41:49PM +0300, Alexander Shishkin wrote:
>> +void perf_aux_output_end(struct perf_output_handle *handle, unsigned long size,
>> + bool truncated)
>> +{
>> + struct ring_buffer *rb = handle->rb;
>> + unsigned long aux_head;
>> +
>> + aux_head = local_read(&rb->aux_head);
>> + local_add(size, &rb->aux_head);
>> +
>> + rb->user_page->aux_head = local_read(&rb->aux_head);
>> + smp_wmb();
>> +
>> + perf_output_wakeup(handle);
>> + handle->event = NULL;
>> +
>> + ring_buffer_put(rb);
>> +}
>
> This thing is distinctly less complex than perf_output_put_handle().. ?
This one doesn't support nested writers, but there shouldn't be any
either. But I notice now that the barrier is misplaced. Wakeup watermark
is not yet taken care of, but will be. Anything else I'm missing?
Regards,
--
Alex
next prev parent reply other threads:[~2014-06-25 11:24 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-06-11 15:41 [RFC v2 0/7] perf: perf: add AUX space to ring_buffer Alexander Shishkin
2014-06-11 15:41 ` [RFC v2 1/7] perf: add data_{offset,size} to user_page Alexander Shishkin
2014-06-13 13:51 ` Robert Richter
2014-06-11 15:41 ` [RFC v2 2/7] perf: add AUX area to ring buffer for raw data streams Alexander Shishkin
2014-06-24 17:19 ` Peter Zijlstra
2014-06-25 11:09 ` Alexander Shishkin
2014-06-25 12:11 ` Peter Zijlstra
2014-06-11 15:41 ` [RFC v2 3/7] perf: support high-order allocations for AUX space Alexander Shishkin
2014-06-11 15:41 ` [RFC v2 4/7] perf: add a capability for AUX_NO_SG pmus to do software double buffering Alexander Shishkin
2014-06-11 15:41 ` [RFC v2 5/7] perf: add a pmu capability for "exclusive" events Alexander Shishkin
2014-06-24 17:18 ` Peter Zijlstra
2014-06-25 11:12 ` Alexander Shishkin
2014-06-11 15:41 ` [RFC v2 6/7] perf: add api for pmus to write to AUX space Alexander Shishkin
2014-06-24 17:27 ` Peter Zijlstra
2014-06-25 11:24 ` Alexander Shishkin [this message]
2014-06-25 12:12 ` Peter Zijlstra
2014-06-11 15:41 ` [RFC v2 7/7] perf: add AUX record Alexander Shishkin
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