From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Tue, 25 Sep 2001 17:00:54 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Tue, 25 Sep 2001 17:00:34 -0400 Received: from host154.207-175-42.redhat.com ([207.175.42.154]:32424 "EHLO lacrosse.corp.redhat.com") by vger.kernel.org with ESMTP id ; Tue, 25 Sep 2001 17:00:30 -0400 Date: Tue, 25 Sep 2001 17:00:55 -0400 From: Benjamin LaHaise To: "David S. Miller" Cc: marcelo@conectiva.com.br, andrea@suse.de, torvalds@transmeta.com, linux-kernel@vger.kernel.org Subject: Re: Locking comment on shrink_caches() Message-ID: <20010925170055.B19494@redhat.com> In-Reply-To: <20010925.131528.78383994.davem@redhat.com> <20010925.132905.32720330.davem@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: <20010925.132905.32720330.davem@redhat.com>; from davem@redhat.com on Tue, Sep 25, 2001 at 01:29:05PM -0700 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Sep 25, 2001 at 01:29:05PM -0700, David S. Miller wrote: > Well, there are two things happing in that patch. Per-hash chain > locks for the page cache itself, and the lock added to the address > space for that page list. Last time I looked, those patches made the already ugly vm locking even worse. I'd rather try to use some of the rcu techniques for page cache lookup, and per-page locking for page cache removal which will lead to *cleaner* code as well as a much more scalable kernel. Keep in mind that just because a lock is on someone's hitlist doesn't mean that it is for the right reasons. Look at the io_request_lock that is held around the bounce buffer copies in the scsi midlayer. *shudder* -ben