From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Wilcox Subject: Re: [PATCH 18/18] fs: Reduce inode I_FREEING and factor inode disposal Date: Sat, 9 Oct 2010 11:22:44 -0600 Message-ID: <20101009172244.GG10421@parisc-linux.org> References: <1286515292-15882-1-git-send-email-david@fromorbit.com> <1286515292-15882-19-git-send-email-david@fromorbit.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org To: Dave Chinner Return-path: Content-Disposition: inline In-Reply-To: <1286515292-15882-19-git-send-email-david@fromorbit.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On Fri, Oct 08, 2010 at 04:21:32PM +1100, Dave Chinner wrote: > /* > - * dispose_list - dispose of the contents of a local list > - * @head: the head of the list to free > + * Free the inode passed in, removing it from the lists it is still connected > + * to but avoiding unnecessary lock round-trips for the lists it is no longer > + * on. > * > - * Dispose-list gets a local list with local inodes in it, so it doesn't > - * need to worry about list corruption and SMP locks. > + * An inode must already be marked I_FREEING so that we avoid the inode being > + * moved back onto lists if we race with other code that manipulates the lists > + * (e.g. writeback_single_inode). > */ > -static void dispose_list(struct list_head *head) > +static void dispose_one_inode(struct inode *inode) > { > - while (!list_empty(head)) { > - struct inode *inode; > + BUG_ON(!(inode->i_state & I_FREEING)); I think this may be my favourite comment in this whole patch set. It's a real pain to hit BUG_ONs and not know why it's there. Thank you. -- Matthew Wilcox Intel Open Source Technology Centre "Bill, look, we understand that you're interested in selling us this operating system, but compare it to ours. We can't possibly take such a retrograde step."