Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751607AbaEAC7p (ORCPT ); Wed, 30 Apr 2014 22:59:45 -0400 Received: from mail-ve0-f171.google.com ([209.85.128.171]:63158 "EHLO mail-ve0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750842AbaEAC7o (ORCPT ); Wed, 30 Apr 2014 22:59:44 -0400 MIME-Version: 1.0 In-Reply-To: <20140501025105.GY18016@ZenIV.linux.org.uk> References: <20140430195918.GS18016@ZenIV.linux.org.uk> <20140430203823.GT18016@ZenIV.linux.org.uk> <20140430211206.GU18016@ZenIV.linux.org.uk> <20140430221238.GV18016@ZenIV.linux.org.uk> <20140430234341.GX18016@ZenIV.linux.org.uk> <20140501025105.GY18016@ZenIV.linux.org.uk> Date: Wed, 30 Apr 2014 19:59:43 -0700 X-Google-Sender-Auth: _mCp4G6Uli0Qlsa8SfGz2LQPhAk Message-ID: Subject: Re: dcache shrink list corruption? From: Linus Torvalds To: Al Viro Cc: Miklos Szeredi , Dave Chinner , Linux Kernel Mailing List , linux-fsdevel Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Apr 30, 2014 at 7:51 PM, Al Viro wrote: > > Help with profiling is needed; the loads to watch are > the ones where dentry_kill() + dentry_free() are sufficiently high in profiles > for the differences to matter. Any takers? I really hope there are no such loads, my "lock/unlock pairing" suggestion was mostly so that the pairing is clearer, not necessarily for performance. That said, I'd assume that it migth be worth testing at least the "lots of concurrent lookups of 'simple_dentry_operations' dentries". So most of /proc, most uses of simple_lookup(). That at least triggers the dentry_kill() path in dput(), so it should be fairly easy to get profiles. But real loads with real filesystems? That sounds harder. Linus -- 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/