From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 33AACC43441 for ; Sun, 11 Nov 2018 01:30:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EF62F208A3 for ; Sun, 11 Nov 2018 01:30:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="JznFdFVx" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EF62F208A3 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727382AbeKKLRU (ORCPT ); Sun, 11 Nov 2018 06:17:20 -0500 Received: from bombadil.infradead.org ([198.137.202.133]:38980 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726946AbeKKLRU (ORCPT ); Sun, 11 Nov 2018 06:17:20 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=llNjy+cfCYVvm8F8o8jFCmXqWk9GrLmU9yludmjnSxg=; b=JznFdFVx23u4+Is87BDbfixh2 32KvvcRWFQNmFjK7djAoGeaX45HCGcPE5HUYMVtIAbtwSDzM0Wt31quttpwg4hjtjcL4rouY6Ps3W ECv7lC44GRfL1GC2/ts1OrIac4afhlUVrCuL6mrr6qc+/qMjy+4MgvNKjMoiuDQksKk8N5mr0xTTE p10H108V2v3/fOkFnkHq4Acc7GkZ6421/6MVtEp38AsRxAKLBifBF731Hz0iZX0Y99H917vZ/Pwho 7qyentQPb6rivHqSkKfH92/S3LclR6FWAkEwAPkvXiq6hJkXL9IfG37l0a+CSgtm3qq9SBi9BYeTh AUvkwNLcA==; Received: from [64.114.255.114] (helo=worktop) by bombadil.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1gLeZu-0000h8-21; Sun, 11 Nov 2018 01:30:18 +0000 Received: by worktop (Postfix, from userid 1000) id 71AC76E07D5; Sun, 11 Nov 2018 02:30:17 +0100 (CET) Date: Sun, 11 Nov 2018 02:30:17 +0100 From: Peter Zijlstra To: Waiman Long Cc: Ingo Molnar , Will Deacon , Thomas Gleixner , linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com, linux-mm@kvack.org, Petr Mladek , Sergey Senozhatsky , Andrey Ryabinin , Tejun Heo , Andrew Morton Subject: Re: [RFC PATCH 07/12] locking/lockdep: Add support for nested terminal locks Message-ID: <20181111013017.GC12766@worktop.psav.com> References: <1541709268-3766-1-git-send-email-longman@redhat.com> <1541709268-3766-8-git-send-email-longman@redhat.com> <20181110142023.GG3339@worktop.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.22.1 (2013-10-16) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Nov 10, 2018 at 07:30:54PM -0500, Waiman Long wrote: > On 11/10/2018 09:20 AM, Peter Zijlstra wrote: > > On Thu, Nov 08, 2018 at 03:34:23PM -0500, Waiman Long wrote: > >> There are use cases where we want to allow 2-level nesting of one > >> terminal lock underneath another one. So the terminal lock type is now > >> extended to support a new nested terminal lock where it can allow the > >> acquisition of another regular terminal lock underneath it. > > You're stretching things here... If you're allowing things under it, it > > is no longer a terminal lock. > > > > Why would you want to do such a thing? > > A majority of the gain in debugobjects is to make the hash lock a kind > of terminal lock. Yes, I may be stretching it a bit here. I will take > back the nesting patch and consider doing that in a future patch. Maybe try and write a better changelog? I'm not following, but that could also be because I've been awake for almost 20 hours :/