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=-10.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 C2C40C4338F for ; Thu, 29 Jul 2021 15:43:07 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 569EC60F21 for ; Thu, 29 Jul 2021 15:43:07 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 569EC60F21 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=techsingularity.net Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id CF6DD6B005D; Thu, 29 Jul 2021 11:43:06 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id CA66B6B006C; Thu, 29 Jul 2021 11:43:06 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id BBCD06B0070; Thu, 29 Jul 2021 11:43:06 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0250.hostedemail.com [216.40.44.250]) by kanga.kvack.org (Postfix) with ESMTP id A21CA6B005D for ; Thu, 29 Jul 2021 11:43:06 -0400 (EDT) Received: from smtpin31.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 4A7F21846A703 for ; Thu, 29 Jul 2021 15:43:06 +0000 (UTC) X-FDA: 78416043972.31.101FB82 Received: from outbound-smtp25.blacknight.com (outbound-smtp25.blacknight.com [81.17.249.193]) by imf11.hostedemail.com (Postfix) with ESMTP id 8CD68F000221 for ; Thu, 29 Jul 2021 15:43:05 +0000 (UTC) Received: from mail.blacknight.com (pemlinmail01.blacknight.ie [81.17.254.10]) by outbound-smtp25.blacknight.com (Postfix) with ESMTPS id F260FCAF69 for ; Thu, 29 Jul 2021 16:43:03 +0100 (IST) Received: (qmail 15224 invoked from network); 29 Jul 2021 15:43:03 -0000 Received: from unknown (HELO techsingularity.net) (mgorman@techsingularity.net@[84.203.17.255]) by 81.17.254.9 with ESMTPSA (AES256-SHA encrypted, authenticated); 29 Jul 2021 15:43:03 -0000 Date: Thu, 29 Jul 2021 16:43:02 +0100 From: Mel Gorman To: Vlastimil Babka Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Christoph Lameter , David Rientjes , Pekka Enberg , Joonsoo Kim , Mike Galbraith , Sebastian Andrzej Siewior , Thomas Gleixner , Jesper Dangaard Brouer , Jann Horn Subject: Re: [PATCH v3 31/35] mm, slub: optionally save/restore irqs in slab_[un]lock()/ Message-ID: <20210729154302.GF3809@techsingularity.net> References: <20210729132132.19691-1-vbabka@suse.cz> <20210729132132.19691-32-vbabka@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <20210729132132.19691-32-vbabka@suse.cz> User-Agent: Mutt/1.10.1 (2018-07-13) X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 8CD68F000221 Authentication-Results: imf11.hostedemail.com; dkim=none; dmarc=none; spf=pass (imf11.hostedemail.com: domain of mgorman@techsingularity.net designates 81.17.249.193 as permitted sender) smtp.mailfrom=mgorman@techsingularity.net X-Stat-Signature: h4agdaoimdfbnpxmm3au9kftaff3jprj X-HE-Tag: 1627573385-259566 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Thu, Jul 29, 2021 at 03:21:28PM +0200, Vlastimil Babka wrote: > For PREEMPT_RT we will need to disable irqs for this bit spinlock. As a > preparation, add a flags parameter, and an internal version that takes > additional bool parameter to control irq saving/restoring (the flags > parameter is compile-time unused if the bool is a constant false). > > Convert ___cmpxchg_double_slab(), which also comes with the same bool > parameter, to use the internal version. > > Signed-off-by: Vlastimil Babka On arm64 allmodconfig, the following build warning was new In file included from ./include/linux/spinlock.h:54, from ./include/linux/mmzone.h:8, from ./include/linux/gfp.h:6, from ./include/linux/mm.h:10, from mm/slub.c:13: mm/slub.c: In function '___cmpxchg_double_slab.isra.0': ./include/linux/irqflags.h:177:3: warning: 'flags' may be used uninitialized in this function [-Wmaybe-uninitialized] 177 | arch_local_irq_restore(flags); \ | ^~~~~~~~~~~~~~~~~~~~~~ mm/slub.c:408:17: note: 'flags' was declared here 408 | unsigned long flags; | ^~~~~ In file included from ./include/linux/string.h:262, from ./include/linux/bitmap.h:10, from ./include/linux/cpumask.h:12, No idea what's special about arm allmodconfig that confuses the compiler. -- Mel Gorman SUSE Labs