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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8000CEB64D7 for ; Fri, 23 Jun 2023 09:21:08 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id D11698D0002; Fri, 23 Jun 2023 05:21:07 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id CC1578D0001; Fri, 23 Jun 2023 05:21:07 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id BAF8D8D0002; Fri, 23 Jun 2023 05:21:07 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id AA75D8D0001 for ; Fri, 23 Jun 2023 05:21:07 -0400 (EDT) Received: from smtpin05.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay04.hostedemail.com (Postfix) with ESMTP id 5F85D1A024B for ; Fri, 23 Jun 2023 09:21:07 +0000 (UTC) X-FDA: 80933468574.05.F025989 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) by imf21.hostedemail.com (Postfix) with ESMTP id 004E11C0011 for ; Fri, 23 Jun 2023 09:21:03 +0000 (UTC) Authentication-Results: imf21.hostedemail.com; dkim=pass header.d=suse.com header.s=susede1 header.b=a+gnj219; spf=pass (imf21.hostedemail.com: domain of mhocko@suse.com designates 195.135.220.29 as permitted sender) smtp.mailfrom=mhocko@suse.com; dmarc=pass (policy=quarantine) header.from=suse.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1687512064; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=hNTXjlyc5af6regivyfal3HBd9Aq9WpuIP4kkRd7TxM=; b=UuQTn772l+V7TkF+0q9oV3YNsxDIjIrADaBIBthVvZelM/hfnes38MoCZDSRSOU2Gdl0pm uomh20b66gqVX05tqoLVc9YuTEncfHaOrxFGwqv4/roTHG1Q6AUdmEGkaO8akVvPtNGp0z WTNbGZ05zaBJN70AliPN2k2OsS21598= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1687512064; a=rsa-sha256; cv=none; b=rALUCGK73R6RW+gYEzqHWHoMFOjOOnEgo+WWRuQkG5BMKqKRz95ZJ6fIUuLXbA3GG8EY/h FhmA3RWT3PXHcZTW52HSE4cBh4tuxQCW49Bb3lI+FWc+CkXfHdbqG/gjNaNuwfVm8gstWG hcgL7MjT1TjdIL+dppasoQ5uzQgg8Fk= ARC-Authentication-Results: i=1; imf21.hostedemail.com; dkim=pass header.d=suse.com header.s=susede1 header.b=a+gnj219; spf=pass (imf21.hostedemail.com: domain of mhocko@suse.com designates 195.135.220.29 as permitted sender) smtp.mailfrom=mhocko@suse.com; dmarc=pass (policy=quarantine) header.from=suse.com Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 512F71F38D; Fri, 23 Jun 2023 09:21:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1687512062; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=hNTXjlyc5af6regivyfal3HBd9Aq9WpuIP4kkRd7TxM=; b=a+gnj219/7uZ5464g5IAey8YCg0UZyFG5c8KnZdn2U74Jqj1ebe9hIyQMQYc3zzHyElT24 UY0CV5Cfvv0wUkTuN9A4Z9ZJmRUKP5keHEPqxoSUOIH19rP5qn08zhgrFPGQ5U99uuYnSe Kwt7mHPViDkSpIVLM8BEO2B5xfQAWlQ= Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 23334134FB; Fri, 23 Jun 2023 09:21:02 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id GXBEBv5jlWQZZQAAMHmgww (envelope-from ); Fri, 23 Jun 2023 09:21:02 +0000 Date: Fri, 23 Jun 2023 11:21:01 +0200 From: Michal Hocko To: Sebastian Andrzej Siewior Cc: Petr Mladek , Tetsuo Handa , linux-mm@kvack.org, "Luis Claudio R. Goncalves" , Andrew Morton , Mel Gorman , Thomas Gleixner , John Ogness Subject: Re: [PATCH] mm/page_alloc: Use write_seqlock_irqsave() instead write_seqlock() + local_irq_save(). Message-ID: References: <20230621104034.HT6QnNkQ@linutronix.de> <0e9fc992-8e05-2e63-b3b1-d8d3ce89fc16@I-love.SAKURA.ne.jp> <20230621130641.-5iueY1I@linutronix.de> <20230621143421.BgHjJklo@linutronix.de> <20230623081250.h20rlLik@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230623081250.h20rlLik@linutronix.de> X-Rspamd-Queue-Id: 004E11C0011 X-Rspam-User: X-Stat-Signature: 673ykc8q1exiweg1qknherw5zg5qbh3e X-Rspamd-Server: rspam03 X-HE-Tag: 1687512063-649925 X-HE-Meta: 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 +QtrZ49R M5T/as51IefiMPYE/lwZKAWJjBEDxQwTR68MdMZV/kRwZDDAnt2lNHqVPjGfabWPOPcxXcQOG/PouJXMsYVVN8Qx11EbvA3x1ZN6bKHYCutyPOnJG5I9gC8kfa8KnM45mCyJTiFkFfVC+KqoVfrft9Fwc1e7AiLQHGK80B7Vu8W852LJjbBfUHkrsHS7aRRpaeeOR 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 Fri 23-06-23 10:12:50, Sebastian Andrzej Siewior wrote: [...] > It would do _but_ is it really needed? All users but one (the one in > __build_all_zonelists()) have interrupts already disabled. This isn't a > hot path and is not used very common. Does it justify the ifdef? This is not my call of course but let me just stress out that if all that is just because of __build_all_zonelists then it is likely not really worth it. We are talking about memory hoptlug here. I seriously doubt that this is something anybody would be using with RT expectations. -- Michal Hocko SUSE Labs