Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264293AbUDNQyu (ORCPT ); Wed, 14 Apr 2004 12:54:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264292AbUDNQyu (ORCPT ); Wed, 14 Apr 2004 12:54:50 -0400 Received: from e3.ny.us.ibm.com ([32.97.182.103]:49055 "EHLO e3.ny.us.ibm.com") by vger.kernel.org with ESMTP id S264293AbUDNQxV convert rfc822-to-8bit (ORCPT ); Wed, 14 Apr 2004 12:53:21 -0400 Content-Type: text/plain; charset=US-ASCII From: Badari Pulavarty To: Andrew Morton , Mingming Cao Subject: Re: [PATCH 0/4] ext3 block reservation patch set Date: Wed, 14 Apr 2004 09:42:29 -0700 User-Agent: KMail/1.4.1 Cc: tytso@mit.edu, linux-kernel@vger.kernel.org, ext2-devel@lists.sourceforge.net References: <200403190846.56955.pbadari@us.ibm.com> <1081903949.3548.6837.camel@localhost.localdomain> <20040413194734.3a08c80f.akpm@osdl.org> In-Reply-To: <20040413194734.3a08c80f.akpm@osdl.org> MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Message-Id: <200404140942.29648.pbadari@us.ibm.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1402 Lines: 32 On Tuesday 13 April 2004 07:47 pm, Andrew Morton wrote: > - You're performing ext3_discard_reservation() in ext3_release_file(). > Note that the file may still have pending allocations at this stage: say, > open a file, map it MAP_SHARED, dirty some pages which lie over file > holes then close the file again. > > Later, the VM will come along and write those dirty pages into the > file, at which point allocations need to be performed. But we have no > reservation data and, later, we may have no inode->write_state at all. > > What will happen? Block allocations happen after ext3_release_file() ? In that case, we would have dropped all our reservations at the time of last file close. But if allocations happen later, the current code will start new reservation window and start allocations from there. > - Have you tested and profiled this with a huge number of open files? At > what stage do we get into search complexity problems? Come to think of it, the current code has pretty bad search algorithm. We need to fix that. We hold the spinlock for entire search, thats why our CPU utilization is pretty high. Thanks, Badari - 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/