From: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
To: andrea@betterlinux.com
Cc: akpm@linux-foundation.org, minchan.kim@gmail.com,
riel@redhat.com, peterz@infradead.org, hannes@cmpxchg.org,
kamezawa.hiroyu@jp.fujitsu.com, aarcange@redhat.com,
hughd@google.com, jamesjer@betterlinux.com, marcus@bluehost.com,
matt@bluehost.com, tytso@mit.edu, shaohua.li@intel.com,
P@draigBrady.com, linux-mm@kvack.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 0/2] fadvise: support POSIX_FADV_NOREUSE
Date: Mon, 27 Jun 2011 16:42:39 +0900 [thread overview]
Message-ID: <4E08346F.3070203@jp.fujitsu.com> (raw)
In-Reply-To: <20110627071139.GC1247@thinkpad>
>>> POSIX_FADV_DONTNEED = drop page cache if possible
>>> POSIX_FADV_NOREUSE = reduce page cache eligibility
>>
>> Eeek.
>>
>> Your POSIX_FADV_NOREUSE is very different from POSIX definition.
>> POSIX says,
>>
>> POSIX_FADV_NOREUSE
>> Specifies that the application expects to access the specified data once and then
>> not reuse it thereafter.
>>
>> IfI understand correctly, it designed for calling _before_ data access
>> and to be expected may prevent lru activation. But your NORESE is designed
>> for calling _after_ data access. Big difference might makes a chance of
>> portability issue.
>
> You're right. NOREUSE is designed to implement drop behind policy.
>
> I'll post a new patch that will plug this logic in DONTNEED (like the
> presious version), but without breaking the old /proc/sys/vm/drop_caches
> behavior.
Great!
thanks.
--
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/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2011-06-27 7:43 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-06-24 13:49 Andrea Righi
2011-06-24 13:49 ` [PATCH v3 1/2] mm: introduce __invalidate_mapping_pages() Andrea Righi
2011-06-26 22:46 ` Rik van Riel
2011-06-27 7:05 ` Andrea Righi
2011-06-24 13:49 ` [PATCH v3 2/2] fadvise: implement POSIX_FADV_NOREUSE Andrea Righi
2011-06-26 22:47 ` Rik van Riel
2011-06-27 7:05 ` Andrea Righi
2011-06-27 3:04 ` [PATCH v3 0/2] fadvise: support POSIX_FADV_NOREUSE KOSAKI Motohiro
2011-06-27 7:11 ` Andrea Righi
2011-06-27 7:42 ` KOSAKI Motohiro [this message]
2011-06-27 10:17 ` Pádraig Brady
2011-06-27 10:29 ` Andrea Righi
2011-06-27 11:53 ` Pádraig Brady
2011-06-27 12:39 ` Andrea Righi
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=4E08346F.3070203@jp.fujitsu.com \
--to=kosaki.motohiro@jp.fujitsu.com \
--cc=P@draigBrady.com \
--cc=aarcange@redhat.com \
--cc=akpm@linux-foundation.org \
--cc=andrea@betterlinux.com \
--cc=hannes@cmpxchg.org \
--cc=hughd@google.com \
--cc=jamesjer@betterlinux.com \
--cc=kamezawa.hiroyu@jp.fujitsu.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=marcus@bluehost.com \
--cc=matt@bluehost.com \
--cc=minchan.kim@gmail.com \
--cc=peterz@infradead.org \
--cc=riel@redhat.com \
--cc=shaohua.li@intel.com \
--cc=tytso@mit.edu \
/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