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=-0.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 5D268C433E0 for ; Wed, 20 May 2020 02:05:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 309A5207C4 for ; Wed, 20 May 2020 02:05:27 +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="Ht9zTnd8" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728408AbgETCF0 (ORCPT ); Tue, 19 May 2020 22:05:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53104 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726379AbgETCF0 (ORCPT ); Tue, 19 May 2020 22:05:26 -0400 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 10EC3C061A0E; Tue, 19 May 2020 19:05:26 -0700 (PDT) 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=Lz/fgGTegv3Vw8bKhUOxZNBgmTWewtj8bcybw8IaH6Y=; b=Ht9zTnd8qZSO8pVr+tEfSmR7ng 87al1q64oL/b+1Fm1HtRX15bBmhD/rPl/xZI9GlNYJZbhIqTfZhujWsh7CgimT/ZhhctMxkV4LJte w3KzxbTjh8j2sgd6qy8hkvnndnc+S/jeSuutx5KESxbaiP1FgX0UUKE60TzG/jUdVTrAl3RQ9FKa1 3tN/iB+D+HGOpBuyTR369QYk4CLqGkQXSnQhOwhakuWf2+SxFK7Hl0gIdJ7RNbQZ2oigBUkOtzj5E ZcBJJh0BbNItr2Gd0BkRMQbUS9vCWFGPTAq62O6IW8+kW5zZFcKrm3o4QieUCg2C8rlCVO+V6Lkxq hkQPChaQ==; Received: from willy by bombadil.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1jbE6e-0004S2-5O; Wed, 20 May 2020 02:05:16 +0000 Date: Tue, 19 May 2020 19:05:16 -0700 From: Matthew Wilcox To: Steven Rostedt Cc: Sebastian Andrzej Siewior , linux-kernel@vger.kernel.org, Peter Zijlstra , Ingo Molnar , Will Deacon , Thomas Gleixner , "Paul E . McKenney" , Linus Torvalds , linux-fsdevel@vger.kernel.org Subject: Re: [PATCH 2/8] radix-tree: Use local_lock for protection Message-ID: <20200520020516.GB16070@bombadil.infradead.org> References: <20200519201912.1564477-1-bigeasy@linutronix.de> <20200519201912.1564477-3-bigeasy@linutronix.de> <20200519204545.GA16070@bombadil.infradead.org> <20200519165453.0a795ca1@gandalf.local.home> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200519165453.0a795ca1@gandalf.local.home> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 19, 2020 at 04:54:53PM -0400, Steven Rostedt wrote: > On Tue, 19 May 2020 13:45:45 -0700 > Matthew Wilcox wrote: > > > On Tue, May 19, 2020 at 10:19:06PM +0200, Sebastian Andrzej Siewior wrote: > > > The radix-tree and idr preload mechanisms use preempt_disable() to protect > > > the complete operation between xxx_preload() and xxx_preload_end(). > > > > > > As the code inside the preempt disabled section acquires regular spinlocks, > > > which are converted to 'sleeping' spinlocks on a PREEMPT_RT kernel and > > > eventually calls into a memory allocator, this conflicts with the RT > > > semantics. > > > > > > Convert it to a local_lock which allows RT kernels to substitute them with > > > a real per CPU lock. On non RT kernels this maps to preempt_disable() as > > > before, but provides also lockdep coverage of the critical region. > > > No functional change. > > > > I don't seem to have a locallock.h in my tree. Where can I find more > > information about it? > > PATCH 1 ;-) ... this is why we have the convention to cc everybody on all the patches. > https://lore.kernel.org/r/20200519201912.1564477-1-bigeasy@linutronix.de > > With lore and b4, it should now be easy to get full patch series. Thats asking too much of the random people cc'd on random patches. What is b4 anyway?