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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 10420FA3740 for ; Mon, 24 Oct 2022 11:11:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229587AbiJXLLO (ORCPT ); Mon, 24 Oct 2022 07:11:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59466 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230199AbiJXLLD (ORCPT ); Mon, 24 Oct 2022 07:11:03 -0400 Received: from smtp-out1.suse.de (smtp-out1.suse.de [IPv6:2001:67c:2178:6::1c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E570F3AB3C for ; Mon, 24 Oct 2022 04:10:59 -0700 (PDT) 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-out1.suse.de (Postfix) with ESMTPS id 936BF21E6C; Mon, 24 Oct 2022 11:10:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1666609858; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=c9LyPhw0fn06VJLpIWBBedHqVCQTOByd+fZNTw6i+9w=; b=P7qhGZV/D7QYWARtAPR+FrgfXcrTC5U0U0uwHWNnGBGLmtf7c4Q62C/dBRUu+zp3S6pzSo 2S0X1nzT5dDsti3bk5WZuMZBPJGWaOZmw0LWOOtvCELQNjg57atjdUiIN8PIHXHLajP9ZK KO84Y1BhxdEFbBoHPiBtih8zgdm6gu0= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1666609858; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=c9LyPhw0fn06VJLpIWBBedHqVCQTOByd+fZNTw6i+9w=; b=DbpVXtLXVrQcCfak4I6tx3O3sJjO2NeyGKACOfwHdp5t0U4ftk2WPocXxe+Xe4KV1VQZhT bQ3A2yveLjESqXBg== 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 6733D13357; Mon, 24 Oct 2022 11:10:58 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id jkuAGMJyVmN+LAAAMHmgww (envelope-from ); Mon, 24 Oct 2022 11:10:58 +0000 Message-ID: Date: Mon, 24 Oct 2022 13:10:57 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.3.3 Subject: Re: [PATCH] mm/slub: remove dead code for debug caches on deactivate_slab() Content-Language: en-US To: Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton , Roman Gushchin , linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20221014114322.97512-1-42.hyeyoo@gmail.com> <82e8147e-f031-6bc2-9395-56d2052e62cb@suse.cz> From: Vlastimil Babka In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/22/22 06:14, Hyeonggon Yoo wrote: > On Fri, Oct 21, 2022 at 12:43:42PM +0200, Vlastimil Babka wrote: >> On 10/14/22 13:43, Hyeonggon Yoo wrote: >> > After commit c7323a5ad0786 ("mm/slub: restrict sysfs validation to debug >> > caches and make it safe"), SLUB does not take a slab from partial list for >> >> I'm confused by "SLUB does not take a slab from partial list" here. Did you >> mean something like "SLUB never installs (even temporarily) a percpu slab >> for debug caches"? > > Yes. > >> So that means we never deactivate percpu slabs for debug >> caches. > > Yes. > >> And since debug caches are also the only ones that use the full >> list, we no longer need to care about the full list in deactivate_slab(), right? > > Yes, You got it right, exactly! > > Let me rephrase: > > "After commit c7323a5ad0786 ("mm/slub: restrict sysfs validation to debug > caches and make it safe"), SLUB never installs percpu slab for debug caches > and thus never deactivates percpu slab for them. > > Since only some of debug caches care about the full list, SLUB no longer > deactivates to full list. Remove dead code in deactivate_slab()." > > > Feel free to change this ;-) Great, thanks! Pushed to slab/for-6.2/cleanups