From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755393AbYIPN6O (ORCPT ); Tue, 16 Sep 2008 09:58:14 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752361AbYIPN55 (ORCPT ); Tue, 16 Sep 2008 09:57:57 -0400 Received: from web26206.mail.ukl.yahoo.com ([217.12.10.243]:22970 "HELO web26206.mail.ukl.yahoo.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1753603AbYIPN54 convert rfc822-to-8bit (ORCPT ); Tue, 16 Sep 2008 09:57:56 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.it; h=X-YMail-OSG:Received:X-Mailer:Date:From:Subject:To:Cc:MIME-Version:Content-Type:Content-Transfer-Encoding:Message-ID; b=Rg2Irs8kF92sbpK7vW47+6sG189gHhoGKHXjkB5jJVzuXmkEk/IyGzaV0JBWW93ANa2oSrk56Fc1kLL5LdDX3BCq1bImozCaQswnFc9cgcTUY4kK9hJOzbnM35Voho3IhhNvwjHjCkfT8WDvsye8dTNF0pnGzSJ8ukwt4DYeEjQ=; X-YMail-OSG: OFEONQ4VM1lvkhA05UOlG5qFMtyArymWrZnYi67ktgjLWoZBfHaU6XTitb8iNDLCGtfoI8AQbgRX__5jeomi8uWxuhv_7PWdXEDGgyLrPwWRNLbffunKCfqP5jXszZYyvdXPcCv.eifNmI.b3cI- X-Mailer: YahooMailRC/1096.28 YahooMailWebService/0.7.218.2 Date: Tue, 16 Sep 2008 13:57:54 +0000 (GMT) From: Michael Trimarchi Subject: Re: [PATCH] VFS: make file->f_pos access atomic on 32bit arch To: Nick Piggin Cc: Hisashi Hifumi , akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8BIT Message-ID: <476002.75149.qm@web26206.mail.ukl.yahoo.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, ----- Messaggio originale ----- > Da: Nick Piggin > A: Michael Trimarchi > Cc: Hisashi Hifumi ; akpm@linux-foundation.org; linux-kernel@vger.kernel.org; linux-fsdevel@vger.kernel.org > Inviato: Marted́ 16 settembre 2008, 14:54:21 > Oggetto: Re: [PATCH] VFS: make file->f_pos access atomic on 32bit arch > > On Tuesday 16 September 2008 21:11, Michael Trimarchi wrote: > > Hi, > > > > > + if (offset != file_pos_read(file)) > > > + file_pos_write(file, offset); > > > retval = offset; > > > } > > > > Is not more efficient here a compare xchg operation? > > The compiler should do it if it was. > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ i was thinking about introducing a file_pos_update() not implemented using file_pos_read()/file_pos_write() and taking the seq_lock or disabling preemption only one time __________________________________________________ Do You Yahoo!? Poco spazio e tanto spam? Yahoo! Mail ti protegge dallo spam e ti da tanto spazio gratuito per i tuoi file e i messaggi http://mail.yahoo.it