From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751349AbeC0Kuv (ORCPT ); Tue, 27 Mar 2018 06:50:51 -0400 Received: from mx2.suse.de ([195.135.220.15]:54661 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750993AbeC0Kuu (ORCPT ); Tue, 27 Mar 2018 06:50:50 -0400 Date: Tue, 27 Mar 2018 12:50:48 +0200 From: Michal Hocko To: Tetsuo Handa Cc: peterz@infradead.org, mingo@redhat.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, bp@suse.de, rientjes@google.com, tglx@linutronix.de Subject: Re: [PATCH v2] lockdep: Show address of "struct lockdep_map" at print_lock(). Message-ID: <20180327105048.GE5652@dhcp22.suse.cz> References: <1522059513-5461-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp> <20180326160549.GL4043@hirez.programming.kicks-ass.net> <201803270558.HCA41032.tVFJOFOMOFLHSQ@I-love.SAKURA.ne.jp> <201803271941.GBE57310.tVSOJLQOFFOHFM@I-love.SAKURA.ne.jp> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <201803271941.GBE57310.tVSOJLQOFFOHFM@I-love.SAKURA.ne.jp> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue 27-03-18 19:41:41, Tetsuo Handa wrote: > >From 91c081c4c5f6a99402542951e7de661c38f928ab Mon Sep 17 00:00:00 2001 > From: Tetsuo Handa > Date: Tue, 27 Mar 2018 19:38:33 +0900 > Subject: [PATCH v2] lockdep: Show address of "struct lockdep_map" at print_lock(). > > Since "struct lockdep_map" is embedded into lock objects, we can know > which instance of a lock object is acquired using hlock->instance field. > This will help finding which threads are causing a lock contention. > > Currently, print_lock() is printing hlock->acquire_ip field in both > "[<%px>]" and "%pS" format. But "[<%px>]" is little useful nowadays, for > we use scripts/faddr2line which receives "%pS" for finding the location > in the source code. And I want to reduce amount of output, for > debug_show_all_locks() might print a lot. > > Therefore, this patch replaces "[<%px>]" for printing hlock->acquire_ip > field with "%p" for printing hlock->instance field. > > [ 251.305475] 3 locks held by a.out/31106: > [ 251.308949] #0: 00000000b0f753ba (&mm->mmap_sem){++++}, at: copy_process.part.41+0x10d5/0x1fe0 > [ 251.314283] #1: 00000000ef64d539 (&mm->mmap_sem/1){+.+.}, at: copy_process.part.41+0x10fe/0x1fe0 > [ 251.319618] #2: 00000000b41a282e (&mapping->i_mmap_rwsem){++++}, at: copy_process.part.41+0x12f2/0x1fe0 > > Signed-off-by: Tetsuo Handa > Cc: Peter Zijlstra > Cc: Ingo Molnar > Cc: Borislav Petkov > Cc: Thomas Gleixner > Cc: David Rientjes > Cc: Michal Hocko Looks good to me. Feel free to add Acked-by: Michal Hocko -- Michal Hocko SUSE Labs