From: Fengguang Wu <fengguang.wu@intel.com>
To: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
linux-arch@vger.kernel.org
Subject: Re: [PATCH] mm: create a separate slab for page->ptl allocation
Date: Tue, 22 Oct 2013 13:55:12 +0100 [thread overview]
Message-ID: <20131022125512.GA24418@localhost> (raw)
In-Reply-To: <1382442839-7458-1-git-send-email-kirill.shutemov@linux.intel.com>
On Tue, Oct 22, 2013 at 02:53:59PM +0300, Kirill A. Shutemov wrote:
> If DEBUG_SPINLOCK and DEBUG_LOCK_ALLOC are enabled spinlock_t on x86_64
> is 72 bytes. For page->ptl they will be allocated from kmalloc-96 slab,
> so we loose 24 on each. An average system can easily allocate few tens
> thousands of page->ptl and overhead is significant.
>
> Let's create a separate slab for page->ptl allocation to solve this.
Tested-by: Fengguang Wu <fengguang.wu@intel.com>
In a 4p server, we noticed up to +469.1% increase in will-it-scale page_fault3
test case and +199.8% in vm-scalability case-shm-pread-seq-mt.
5c02216ce3110aab070d 5a58baaa0a1af0a43d7c
------------------------ ------------------------
300409.00 +440.2% 1622770.80 TOTAL will-it-scale.page_fault3.90.threads
5c02216ce3110aab070d 5a58baaa0a1af0a43d7c
------------------------ ------------------------
291257.80 +469.1% 1657582.20 TOTAL will-it-scale.page_fault3.120.threads
...
5c02216ce3110aab070d 5a58baaa0a1af0a43d7c
------------------------ ------------------------
4034831.40 +199.8% 12095649.80 TOTAL vm-scalability.throughput
Thanks,
Fengguang
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2013-10-22 12:55 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-22 11:53 [PATCH] mm: create a separate slab for page->ptl allocation Kirill A. Shutemov
2013-10-22 12:55 ` Fengguang Wu [this message]
2013-11-04 10:42 ` Kirill A. Shutemov
2013-11-05 23:01 ` Andrew Morton
2013-11-05 22:42 ` Kirill A. Shutemov
2013-11-05 23:56 ` Andrew Morton
2013-11-05 23:13 ` Kirill A. Shutemov
2013-11-06 0:43 ` Andrew Morton
2013-11-06 9:31 ` Peter Zijlstra
2013-11-06 11:18 ` Peter Zijlstra
2013-11-06 13:31 ` lockref: Use bloated_spinlocks to avoid explicit config dependencies Kirill A. Shutemov
2013-11-06 14:32 ` Peter Zijlstra
2013-11-06 13:21 ` [PATCH] mm: create a separate slab for page->ptl allocation Kirill A. Shutemov
2013-11-06 14:30 ` Peter Zijlstra
2013-11-06 10:34 ` Will Deacon
2013-11-06 10:49 ` Geert Uytterhoeven
2013-11-06 11:02 ` Peter Zijlstra
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20131022125512.GA24418@localhost \
--to=fengguang.wu@intel.com \
--cc=akpm@linux-foundation.org \
--cc=kirill.shutemov@linux.intel.com \
--cc=linux-arch@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mingo@redhat.com \
--cc=peterz@infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).