From: Andrew Morton <akpm@linux-foundation.org>
To: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Tejun Heo <tj@kernel.org>,
Christoph Lameter <cl@linux-foundation.org>,
Al Viro <viro@zeniv.linux.org.uk>,
Eric Dumazet <eric.dumazet@gmail.com>,
Ric Mason <ric.masonn@gmail.com>,
Simon Jeons <simon.jeons@gmail.com>,
Dave Hansen <dave.hansen@intel.com>,
Andi Kleen <ak@linux.intel.com>,
linux-kernel <linux-kernel@vger.kernel.org>,
linux-mm <linux-mm@kvack.org>
Subject: Re: [PATCH v2 1/2] Make the batch size of the percpu_counter configurable
Date: Wed, 29 May 2013 12:26:05 -0700 [thread overview]
Message-ID: <20130529122605.082cbb1ad8f5cbc9e82e7b16@linux-foundation.org> (raw)
In-Reply-To: <1369265838.27102.351.camel@schen9-DESK>
On Wed, 22 May 2013 16:37:18 -0700 Tim Chen <tim.c.chen@linux.intel.com> wrote:
> Currently the per cpu counter's batch size for memory accounting is
> configured as twice the number of cpus in the system. However,
> for system with very large memory, it is more appropriate to make it
> proportional to the memory size per cpu in the system.
>
> For example, for a x86_64 system with 64 cpus and 128 GB of memory,
> the batch size is only 2*64 pages (0.5 MB). So any memory accounting
> changes of more than 0.5MB will overflow the per cpu counter into
> the global counter. Instead, for the new scheme, the batch size
> is configured to be 0.4% of the memory/cpu = 8MB (128 GB/64 /256),
> which is more inline with the memory size.
I renamed the patch to "mm: tune vm_committed_as percpu_counter
batching size".
Do we have any performance testing results? They're pretty important
for a performance-improvement patch ;)
next prev parent reply other threads:[~2013-05-29 19:26 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-05-03 10:10 Tim Chen
2013-05-03 10:10 ` [PATCH v2 2/2] Make batch size for memory accounting configured according to size of memory Tim Chen
2013-05-21 20:41 ` [PATCH v2 1/2] Make the batch size of the percpu_counter configurable Andrew Morton
2013-05-21 23:27 ` Tim Chen
2013-05-21 23:41 ` Andrew Morton
2013-05-22 0:43 ` Tim Chen
2013-05-22 7:20 ` Andrew Morton
2013-05-22 23:37 ` Tim Chen
2013-05-29 19:26 ` Andrew Morton [this message]
2013-05-29 21:20 ` Tim Chen
2013-05-29 21:34 ` Andrew Morton
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