From: Peter Zijlstra <peterz@infradead.org>
To: kan.liang@intel.com
Cc: linux-kernel@vger.kernel.org, mingo@redhat.com,
alexander.shishkin@linux.intel.com, eranian@google.com,
ak@linux.intel.com
Subject: Re: [PATCH 2/2] perf,core: use parent avg sample period as child initial period
Date: Wed, 25 Jan 2017 16:33:01 +0100 [thread overview]
Message-ID: <20170125153301.GQ6500@twins.programming.kicks-ass.net> (raw)
In-Reply-To: <1484745662-15928-3-git-send-email-kan.liang@intel.com>
On Wed, Jan 18, 2017 at 08:21:02AM -0500, kan.liang@intel.com wrote:
> From: Kan Liang <kan.liang@intel.com>
>
> perf brings additional overhead when monitoring the task which
> frequently generates child task.
>
> When inheriting a event from parent task to child task, the
> sample_period of original parent event (parent_event->parent) will be
> assigned to child event as its initial period, which is usually the
> default sample_period 1.
Why is that mostly 1? I would expect the parent event's sample_period to
ramp up as well.
next prev parent reply other threads:[~2017-01-25 15:33 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-01-18 13:21 [PATCH 0/2] patches to reduce perf overhead kan.liang
2017-01-18 13:21 ` [PATCH 1/2] perf,core: try parent pmu first when init child event kan.liang
2017-01-30 11:59 ` [tip:perf/core] perf/core: Try parent PMU first when initializing a " tip-bot for Kan Liang
2017-01-18 13:21 ` [PATCH 2/2] perf,core: use parent avg sample period as child initial period kan.liang
2017-01-25 15:33 ` Peter Zijlstra [this message]
2017-01-29 15:24 ` Liang, Kan
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