From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752088AbdBGBeU (ORCPT ); Mon, 6 Feb 2017 20:34:20 -0500 Received: from smtprelay0155.hostedemail.com ([216.40.44.155]:55561 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751456AbdBGBeT (ORCPT ); Mon, 6 Feb 2017 20:34:19 -0500 X-Session-Marker: 726F737465647440676F6F646D69732E6F7267 X-Spam-Summary: 20,1.5,0,,d41d8cd98f00b204,rostedt@goodmis.org,:::,RULES_HIT:41:355:379:541:599:800:960:968:973:988:989:1260:1277:1311:1313:1314:1345:1359:1437:1515:1516:1518:1534:1541:1593:1594:1711:1730:1747:1777:1792:2194:2199:2393:2553:2559:2562:2693:2901:3138:3139:3140:3141:3142:3352:3622:3673:3865:3866:3867:3868:3871:3872:3873:3874:5007:6261:7576:7774:7875:7903:9108:10009:10400:10848:10967:11026:11232:11473:11658:11914:12050:12438:12740:12760:12895:13069:13255:13311:13357:13439:14096:14097:14181:14659:14721:21080:21451:30054:30070:30090:30091,0,RBL:none,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fn,MSBL:0,DNSBL:none,Custom_rules:0:1:0,LFtime:2,LUA_SUMMARY:none X-HE-Tag: tent32_2565673c20f44 X-Filterd-Recvd-Size: 1937 Date: Mon, 6 Feb 2017 20:34:15 -0500 From: Steven Rostedt To: Al Viro Cc: LKML Subject: Re: [PATCH] namei: Remove unlikely annotation for revalidate check in lookup_fast() Message-ID: <20170206203415.1bd33992@grimm.local.home> In-Reply-To: <20170207000642.GH13195@ZenIV.linux.org.uk> References: <20170206171735.17d2a5c8@gandalf.local.home> <20170207000642.GH13195@ZenIV.linux.org.uk> X-Mailer: Claws Mail 3.14.1 (GTK+ 2.24.31; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 7 Feb 2017 00:06:42 +0000 Al Viro wrote: > On Mon, Feb 06, 2017 at 05:17:35PM -0500, Steven Rostedt wrote: > > From: "Steven Rostedt (VMware)" > > > > The likely/unlikely profiler showed that the unlikely around the > > dentry->d_flags & DCACHE_OP_REVALIDATE was wrong 95% of the time. Adding > > trace_printk()s, it revealed that the dentry ops had hooks to: > > > > kernfs_dop_revalidate > > pid_revalidate > > proc_sys_revalidate > > tid_fd_revalidate > > > > As tools today now access files that have these operations often, it's best > > just to remove the annotation, as it is more dependent on use cases and not > > normal mode of operation if it will be true or not. > > "Tools" being what, exactly? What kind of load had that been measured on? I first saw it on my system that I ran for 3 weeks. But I investigated it more on a test box that was mostly idle. On the test box the "tools" was mostly systemd and journald. I can look deeper into it if you like. -- Steve