From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f200.google.com (mail-pf0-f200.google.com [209.85.192.200]) by kanga.kvack.org (Postfix) with ESMTP id A1E4B6B0033 for ; Thu, 12 Jan 2017 21:45:27 -0500 (EST) Received: by mail-pf0-f200.google.com with SMTP id 204so94575804pfx.1 for ; Thu, 12 Jan 2017 18:45:27 -0800 (PST) Received: from lgeamrelo11.lge.com (LGEAMRELO11.lge.com. [156.147.23.51]) by mx.google.com with ESMTP id e3si3695033pld.47.2017.01.12.18.45.26 for ; Thu, 12 Jan 2017 18:45:26 -0800 (PST) Date: Fri, 13 Jan 2017 11:45:18 +0900 From: Byungchul Park Subject: Re: [PATCH v4 05/15] lockdep: Make check_prev_add can use a separate stack_trace Message-ID: <20170113024518.GB3326@X58A-UD3R> References: <1481260331-360-1-git-send-email-byungchul.park@lge.com> <1481260331-360-6-git-send-email-byungchul.park@lge.com> <20170112161643.GB3144@twins.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170112161643.GB3144@twins.programming.kicks-ass.net> Sender: owner-linux-mm@kvack.org List-ID: To: Peter Zijlstra Cc: mingo@kernel.org, tglx@linutronix.de, walken@google.com, boqun.feng@gmail.com, kirill@shutemov.name, linux-kernel@vger.kernel.org, linux-mm@kvack.org, iamjoonsoo.kim@lge.com, akpm@linux-foundation.org, npiggin@gmail.com On Thu, Jan 12, 2017 at 05:16:43PM +0100, Peter Zijlstra wrote: > On Fri, Dec 09, 2016 at 02:12:01PM +0900, Byungchul Park wrote: > > check_prev_add() saves a stack trace of the current. But crossrelease > > feature needs to use a separate stack trace of another context in > > check_prev_add(). So make it use a separate stack trace instead of one > > of the current. > > > > So I was thinking, can't we make check_prevs_add() create the stack > trace unconditionally but record if we used it or not, and then return > the entries when unused. All that is serialized by graph_lock anyway and > that way we already pass a stack into check_prev_add() so we can easily > pass in a different one. > > I think that removes a bunch of tricky and avoids all the new tricky. Looks very good. -- 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/ . Don't email: email@kvack.org