From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail6.bemta12.messagelabs.com (mail6.bemta12.messagelabs.com [216.82.250.247]) by kanga.kvack.org (Postfix) with ESMTP id 471599000BD for ; Mon, 27 Jun 2011 03:43:00 -0400 (EDT) Received: from m1.gw.fujitsu.co.jp (unknown [10.0.50.71]) by fgwmail6.fujitsu.co.jp (Postfix) with ESMTP id 5B5D23EE0BC for ; Mon, 27 Jun 2011 16:42:57 +0900 (JST) Received: from smail (m1 [127.0.0.1]) by outgoing.m1.gw.fujitsu.co.jp (Postfix) with ESMTP id 40FDC45DF48 for ; Mon, 27 Jun 2011 16:42:57 +0900 (JST) Received: from s1.gw.fujitsu.co.jp (s1.gw.fujitsu.co.jp [10.0.50.91]) by m1.gw.fujitsu.co.jp (Postfix) with ESMTP id 286F845DF41 for ; Mon, 27 Jun 2011 16:42:57 +0900 (JST) Received: from s1.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s1.gw.fujitsu.co.jp (Postfix) with ESMTP id 1A59A1DB804D for ; Mon, 27 Jun 2011 16:42:57 +0900 (JST) Received: from ml13.s.css.fujitsu.com (ml13.s.css.fujitsu.com [10.240.81.133]) by s1.gw.fujitsu.co.jp (Postfix) with ESMTP id DB6D81DB803C for ; Mon, 27 Jun 2011 16:42:56 +0900 (JST) Message-ID: <4E08346F.3070203@jp.fujitsu.com> Date: Mon, 27 Jun 2011 16:42:39 +0900 From: KOSAKI Motohiro MIME-Version: 1.0 Subject: Re: [PATCH v3 0/2] fadvise: support POSIX_FADV_NOREUSE References: <1308923350-7932-1-git-send-email-andrea@betterlinux.com> <4E07F349.2040900@jp.fujitsu.com> <20110627071139.GC1247@thinkpad> In-Reply-To: <20110627071139.GC1247@thinkpad> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: 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 >>> 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: email@kvack.org