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 59E5FC07E85 for ; Fri, 7 Dec 2018 09:23:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1DB1420868 for ; Fri, 7 Dec 2018 09:23:01 +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="eRV6L/jg" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1DB1420868 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 S1726038AbeLGJW7 (ORCPT ); Fri, 7 Dec 2018 04:22:59 -0500 Received: from bombadil.infradead.org ([198.137.202.133]:53802 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725976AbeLGJW7 (ORCPT ); Fri, 7 Dec 2018 04:22:59 -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=9jv/tzLBJ2Sd5N2aLTwi6/bZCZcUyV9P0jELjak4TQU=; b=eRV6L/jgX3OGLr7LMcSsc2iBM dL0nwXBcNCGIt6UaDARWPHMI34DTu0AOn0msoxgSssfNkZZGHtx5Need9JDfWmL81fT/WdtGm3uJt B9zD75YRWbscL95bSx7EYW78uDwPkgnWQWcw9ROOjMGK2SbRBQ+P1TOX+N3FwrUPMfjF6R95yIq2I /q2BDiIqaKI97Dbs0l4DkSTcn5Rwv40FM74pGAmaqwsfMY/tvpu2frC3cUD+004FMBSrvaZZNdF9L mJGmjYCNvV2G4CIdDjtqbmGh3ozqmgRmtgOsiDbDRnl7f7Jf9sF01cb+queQDaRAnMOv69m8yemgK c6BUSbs+A==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by bombadil.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1gVCLW-0007Kx-E8; Fri, 07 Dec 2018 09:22:54 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id EF8C42072617E; Fri, 7 Dec 2018 10:22:52 +0100 (CET) Date: Fri, 7 Dec 2018 10:22:52 +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, iommu@lists.linux-foundation.org, Petr Mladek , Sergey Senozhatsky , Andrey Ryabinin , Tejun Heo , Andrew Morton Subject: Re: [PATCH v2 08/17] locking/lockdep: Add support for nestable terminal locks Message-ID: <20181207092252.GF2237@hirez.programming.kicks-ass.net> References: <1542653726-5655-1-git-send-email-longman@redhat.com> <1542653726-5655-9-git-send-email-longman@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1542653726-5655-9-git-send-email-longman@redhat.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 19, 2018 at 01:55:17PM -0500, Waiman Long wrote: > There are use cases where we want to allow nesting of one terminal lock > underneath another terminal-like lock. That new lock type is called > nestable terminal lock which can optionally allow the acquisition of > no more than one regular (non-nestable) terminal lock underneath it. I think I asked for a more coherent changelog on this. The above is still self contradictory and doesn't explain why you'd ever want such a 'misfeature' :-)