From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Mon, 23 Sep 2002 15:26:32 +0530 From: Dipankar Sarma Subject: Re: 2.5.38-mm2 [PATCH] (dcache) Message-ID: <20020923152632.C29900@in.ibm.com> Reply-To: dipankar@in.ibm.com References: <3D8E96AA.C2FA7D8@digeo.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3D8E96AA.C2FA7D8@digeo.com>; from akpm@digeo.com on Mon, Sep 23, 2002 at 04:22:28AM +0000 Sender: owner-linux-mm@kvack.org Return-Path: To: Andrew Morton Cc: lkml , "linux-mm@kvack.org" List-ID: On Mon, Sep 23, 2002 at 04:22:28AM +0000, Andrew Morton wrote: > url: http://www.zip.com.au/~akpm/linux/patches/2.5/2.5.38/2.5.38-mm2/ > > read_barrier_depends.patch > extended barrier primitives > > rcu_ltimer.patch > RCU core > > dcache_rcu.patch > Use RCU for dcache > Hi Andrew, dcache_rcu orders writes using wmb() (list_del_rcu) while deleting from the hash list and the d_lookup() hash list traversal requires an rmb() for alpha. So, we need to use the read_barrier_depends() interface there. This isn't a problem with any other archs AFAIK. Thanks -- Dipankar Sarma http://lse.sourceforge.net Linux Technology Center, IBM Software Lab, Bangalore, India. --- fs/dcache.c Mon Sep 23 11:47:26 2002 +++ /tmp/dcache.c Mon Sep 23 12:54:33 2002 @@ -870,7 +870,9 @@ rcu_read_lock(); tmp = head->next; for (;;) { - struct dentry * dentry = list_entry(tmp, struct dentry, d_hash); + struct dentry * dentry; + read_barrier_depends(); + dentry = list_entry(tmp, struct dentry, d_hash); if (tmp == head) break; tmp = tmp->next; -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/