From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 22230 invoked by alias); 26 May 2013 16:31:30 -0000 Mailing-List: contact glibc-bugs-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Post: List-Help: , Sender: glibc-bugs-owner@sourceware.org Received: (qmail 22172 invoked by uid 48); 26 May 2013 16:31:25 -0000 From: "green at linuxhacker dot ru" To: glibc-bugs@sourceware.org Subject: [Bug stdio/4099] Overly agressive caching by stream i/o functions. Date: Sun, 26 May 2013 16:31:00 -0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: glibc X-Bugzilla-Component: stdio X-Bugzilla-Version: unspecified X-Bugzilla-Keywords: X-Bugzilla-Severity: enhancement X-Bugzilla-Who: green at linuxhacker dot ru X-Bugzilla-Status: NEW X-Bugzilla-Priority: P2 X-Bugzilla-Assigned-To: unassigned at sourceware dot org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-Bugzilla-URL: http://sourceware.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-SW-Source: 2013-05/txt/msg00234.txt.bz2 http://sourceware.org/bugzilla/show_bug.cgi?id=4099 --- Comment #6 from Oleg Drokin --- I would mostly agree with Rich that it does not make much sense to do a lot of caching for reading. Bulk of the benefit is realized once 4K or so is read. Then, seeks don't need to "pre-buffer" as much data as well which is a plus too (and a lot of people consider seek to be a free operation). This should not even be used when doing O_SYNC (that's where I disagree). On the other hand, using full st_blksize for write caching makes total sense and I see little to be gained from removing this, filesystems that advertize bigger st_blksize would definitely get a big benefit out of it, allowing more optimal write placing or whatever other benefits there might be from it's perspective. -- You are receiving this mail because: You are on the CC list for the bug.