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=-2.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no 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 0C5F2C2D0B1 for ; Tue, 4 Feb 2020 08:51:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D5BC22084E for ; Tue, 4 Feb 2020 08:50:59 +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="Zq5jWAfc" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726578AbgBDIu7 (ORCPT ); Tue, 4 Feb 2020 03:50:59 -0500 Received: from bombadil.infradead.org ([198.137.202.133]:59694 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726230AbgBDIu6 (ORCPT ); Tue, 4 Feb 2020 03:50:58 -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; bh=G7VctEgtjynjEUnuDLfpYDGr0Hv8ZLxsIqD15TpfUCo=; b=Zq5jWAfcP8iBdhRld+v/tyUOK5 U7WBl522Eps+E5fGRH+nmrfr1QPOAFcvCZuAPXDrxKromnCjIBAfQPyK/Np+VeNTli4nNnz+daXpn XZaPim5dM22gZkUwDQ1UUut9/lD4vvMv71hLnDZhu50osU+urNKvSl7ZlB9awR6Vqcvr9LzbBehmZ jXOeqogfDKDlcAxqNFdIPdgUsL3yFrQvKioCqYLwi3AseOnTJ4mZ7c+qptkgrE7tWJ4vMtBvbtg61 QJ1asyRpWiFynrCq44kDEJsSh7G0iPIK9Y9DkbJQpGEh6qrjQJyXywFfN76b2wE5iqJvM2+ooTaXM er8OD8LA==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by bombadil.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1iytv1-0003oE-TA; Tue, 04 Feb 2020 08:50:52 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id D39A830257C; Tue, 4 Feb 2020 09:49:03 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 4FF222024714B; Tue, 4 Feb 2020 09:50:49 +0100 (CET) Date: Tue, 4 Feb 2020 09:50:49 +0100 From: Peter Zijlstra To: Christoph Hellwig Cc: mingo@kernel.org, will@kernel.org, oleg@redhat.com, tglx@linutronix.de, linux-kernel@vger.kernel.org, bigeasy@linutronix.de, juri.lelli@redhat.com, williams@redhat.com, bristot@redhat.com, longman@redhat.com, dave@stgolabs.net, jack@suse.com Subject: Re: [PATCH -v2 5/7] locking/percpu-rwsem: Remove the embedded rwsem Message-ID: <20200204085049.GN14914@hirez.programming.kicks-ass.net> References: <20200131150703.194229898@infradead.org> <20200131151540.155211856@infradead.org> <20200203142050.GA28595@infradead.org> <20200203150933.GJ14914@hirez.programming.kicks-ass.net> <20200203174831.GA9834@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200203174831.GA9834@infradead.org> 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, Feb 03, 2020 at 09:48:31AM -0800, Christoph Hellwig wrote: > On Mon, Feb 03, 2020 at 04:09:33PM +0100, Peter Zijlstra wrote: > > > Can you split the removal of the non-owned resem support into a separate > > > patch? I still think keeping this one and moving aio to that scheme is > > > a better idea than the current ad-hoc locking scheme that has all kinds > > > of issues. > > > > That's basically 2 lines of code and a comment, surely we can ressurect > > that if/when it's needed again? > > Sure, I could. But then you'd still need to update your commit log for > this patch explaining why it includes unrelated changes to a different > subsystem. By splitting it you also document your changes much better. I really don't see the argument; the diffstat is: include/linux/percpu-rwsem.h | 19 +---- include/linux/rwsem.h | 6 - include/linux/wait.h | 1 kernel/locking/percpu-rwsem.c | 153 ++++++++++++++++++++++++++++++------------ kernel/locking/rwsem.c | 11 +-- kernel/locking/rwsem.h | 12 --- There is no unrelated subsystem, it's all locking (well, strictly speaking wait.h is sched, bit that one flag is actually mentioned in the Changelog). Also, cleaning up unused bits is quite common without mention. Anyway, I'll go split, since you seem to care so deeply.