From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wi0-f169.google.com (mail-wi0-f169.google.com [209.85.212.169]) by kanga.kvack.org (Postfix) with ESMTP id 8A8FA6B0038 for ; Tue, 30 Dec 2014 15:48:56 -0500 (EST) Received: by mail-wi0-f169.google.com with SMTP id r20so26155394wiv.4 for ; Tue, 30 Dec 2014 12:48:55 -0800 (PST) Received: from mail-wg0-x232.google.com (mail-wg0-x232.google.com. [2a00:1450:400c:c00::232]) by mx.google.com with ESMTPS id cu3si80943696wjb.20.2014.12.30.12.48.55 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Tue, 30 Dec 2014 12:48:55 -0800 (PST) Received: by mail-wg0-f50.google.com with SMTP id a1so21126858wgh.23 for ; Tue, 30 Dec 2014 12:48:55 -0800 (PST) Message-ID: <54A30FB4.8020606@gmail.com> Date: Tue, 30 Dec 2014 21:48:52 +0100 From: "Michael Kerrisk (man-pages)" MIME-Version: 1.0 Subject: Re: [PATCH 2/2] posix_fadvise.2: Document the behaviour of partial page discard requests References: <1417567367-9298-1-git-send-email-mgorman@suse.de> <1417567367-9298-3-git-send-email-mgorman@suse.de> In-Reply-To: <1417567367-9298-3-git-send-email-mgorman@suse.de> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Mel Gorman , Andrew Morton Cc: mtk.manpages@gmail.com, Linux-MM , LKML On 12/03/2014 01:42 AM, Mel Gorman wrote: > It is not obvious from the interface that partial page discard requests > are ignored. It should be spelled out. Thanks, Mel. Applied. Cheers, Michael > Signed-off-by: Mel Gorman > --- > man2/posix_fadvise.2 | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/man2/posix_fadvise.2 b/man2/posix_fadvise.2 > index 25d0c50..07313a9 100644 > --- a/man2/posix_fadvise.2 > +++ b/man2/posix_fadvise.2 > @@ -144,6 +144,11 @@ A program may periodically request the kernel to free cached data > that has already been used, so that more useful cached pages are not > discarded instead. > > +Requests to discard partial pages are ignored. It is preferable to preserve > +needed data than discard unneeded data. If the application requires that > +data be considered for discarding then \fIoffset\fP and \fIlen\fP must be > +page-aligned. > + > Pages that have not yet been written out will be unaffected, so if the > application wishes to guarantee that pages will be released, it should > call > -- Michael Kerrisk Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ Linux/UNIX System Programming Training: http://man7.org/training/ -- 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: email@kvack.org