From: Michal Hocko <mhocko@kernel.org>
To: Rik van Riel <riel@surriel.com>
Cc: Janani Ravichandran <janani.rvchndrn@gmail.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
akpm@linux-foundation.org, hannes@compxchg.org,
vdavydov@virtuozzo.com, vbabka@suse.cz,
mgorman@techsingularity.net, kirill.shutemov@linux.intel.com,
bywxiaobai@163.com, rostedt@goodmis.org
Subject: Re: [PATCH 1/2] mm: page_alloc.c: Add tracepoints for slowpath
Date: Wed, 27 Jul 2016 20:44:45 +0200 [thread overview]
Message-ID: <20160727184445.GG21859@dhcp22.suse.cz> (raw)
In-Reply-To: <1469643382.10218.20.camel@surriel.com>
On Wed 27-07-16 14:16:22, Rik van Riel wrote:
> On Wed, 2016-07-27 at 18:33 +0200, Michal Hocko wrote:
> > On Wed 27-07-16 10:47:59, Janani Ravichandran wrote:
> > >
> > > Add tracepoints to the slowpath code to gather some information.
> > > The tracepoints can also be used to find out how much time was
> > > spent in
> > > the slowpath.
> > I do not think this is a right thing to measure.
> > __alloc_pages_slowpath
> > is more a code organization thing. The fast path might perform an
> > expensive operations like zone reclaim (if node_reclaim_mode > 0) so
> > these trace point would miss it.
>
> It doesn't look like it does. The fast path either
> returns an allocated page to the caller, or calls
> into the slow path.
I must be missing something here but what prevents
__alloc_pages_nodemask->get_page_from_freelist from doing zone_reclaim?
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2016-07-27 18:44 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-07-27 14:43 [PATCH 0/2] New tracepoints for slowpath and memory compaction Janani Ravichandran
2016-07-27 14:47 ` [PATCH 1/2] mm: page_alloc.c: Add tracepoints for slowpath Janani Ravichandran
2016-07-27 15:23 ` Steven Rostedt
2016-07-27 17:20 ` Dave Hansen
2016-07-27 17:30 ` Steven Rostedt
2016-07-28 20:11 ` Janani Ravichandran
2016-08-04 15:19 ` Steven Rostedt
2016-08-05 16:03 ` Janani Ravichandran
2016-08-05 16:30 ` Steven Rostedt
2016-08-07 10:36 ` Janani Ravichandran
2016-07-27 16:33 ` Michal Hocko
2016-07-27 18:16 ` Rik van Riel
2016-07-27 18:28 ` Steven Rostedt
2016-07-27 18:44 ` Michal Hocko [this message]
2016-07-27 18:57 ` Rik van Riel
2016-07-27 14:51 ` [PATCH 2/2] mm: compaction.c: Add/Modify direct compaction tracepoints Janani Ravichandran
2016-07-27 15:24 ` Steven Rostedt
2016-08-01 13:25 ` Vlastimil Babka
2016-08-07 12:32 ` Janani Ravichandran
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