From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pl0-f71.google.com (mail-pl0-f71.google.com [209.85.160.71]) by kanga.kvack.org (Postfix) with ESMTP id B52CF6B000D for ; Tue, 27 Mar 2018 16:24:00 -0400 (EDT) Received: by mail-pl0-f71.google.com with SMTP id m6-v6so95230pln.8 for ; Tue, 27 Mar 2018 13:24:00 -0700 (PDT) Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id e39-v6sor873786plg.124.2018.03.27.13.23.59 for (Google Transport Security); Tue, 27 Mar 2018 13:23:59 -0700 (PDT) Date: Tue, 27 Mar 2018 13:23:57 -0700 (PDT) From: David Rientjes Subject: Re: [PATCH v2] lockdep: Show address of "struct lockdep_map" at print_lock(). In-Reply-To: <201803271941.GBE57310.tVSOJLQOFFOHFM@I-love.SAKURA.ne.jp> Message-ID: 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 Sender: owner-linux-mm@kvack.org List-ID: To: Tetsuo Handa Cc: peterz@infradead.org, mhocko@suse.com, mingo@redhat.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, bp@suse.de, tglx@linutronix.de On Tue, 27 Mar 2018, Tetsuo Handa wrote: > 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 Acked-by: David Rientjes