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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 88A5BC433FE for ; Thu, 30 Sep 2021 21:11:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 71E3761A0B for ; Thu, 30 Sep 2021 21:11:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1348775AbhI3VMq (ORCPT ); Thu, 30 Sep 2021 17:12:46 -0400 Received: from smtp-out1.suse.de ([195.135.220.28]:55648 "EHLO smtp-out1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1348668AbhI3VMn (ORCPT ); Thu, 30 Sep 2021 17:12:43 -0400 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 23B4B225F5; Thu, 30 Sep 2021 21:10:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1633036259; 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=hF1+AiAkOiwxS7GYNWFY7mrQc9otq7zFJhOd9XeK0UI=; b=sIdcON51m/C0XKXzQk94plviKDHXpAnnHT2MTXjurEoYOi3l+ppLUiESWHP63ASv+Drjhv GZDnNsiRgqttory5uKonjDBv2FEJTtxtvF0CeXxoJDeGq4cjgT7Kt2B3PIYKKwTixYWill 6OaecVNdNO/PCqC1rANe2oxeWcK3P7k= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1633036259; 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=hF1+AiAkOiwxS7GYNWFY7mrQc9otq7zFJhOd9XeK0UI=; b=txE+MXYPMA8AKS3I5AOUXdzpLNFIZVkV8Yl9tZVtKfYJYsNd5lPsGBiORDVTGxhL+GM/I1 PseKpwG+r+56bJCg== 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 E2F7713B63; Thu, 30 Sep 2021 21:10:58 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id 6nSdNuInVmFPQwAAMHmgww (envelope-from ); Thu, 30 Sep 2021 21:10:58 +0000 Subject: Re: [PATCH] xfs: use kmem_cache_free() for kmem_cache objects To: Rustam Kovhaev Cc: Dave Chinner , djwong@kernel.org, linux-xfs@vger.kernel.org, cl@linux.com, penberg@kernel.org, rientjes@google.com, iamjoonsoo.kim@lge.com, akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, gregkh@linuxfoundation.org, Al Viro References: <20210929212347.1139666-1-rkovhaev@gmail.com> <20210930044202.GP2361455@dread.disaster.area> <17f537b3-e2eb-5d0a-1465-20f3d3c960e2@suse.cz> From: Vlastimil Babka Message-ID: Date: Thu, 30 Sep 2021 23:10:10 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.12.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 9/30/21 8:48 PM, Rustam Kovhaev wrote: > On Thu, Sep 30, 2021 at 10:13:40AM +0200, Vlastimil Babka wrote: >> >> I think it's fair if something like XFS (not meant for tiny systems AFAIK?) >> excludes SLOB (meant for tiny systems). Clearly nobody tried to use these >> two together last 5 years anyway. > > +1 for adding Kconfig option, it seems like some things are not meant to > be together. But if we patch SLOB, we won't need it. >> Maybe we could also just add the 4 bytes to all SLOB objects, declare >> kfree() is always fine and be done with it. Yes, it will make SLOB footprint >> somewhat less tiny, but even whan we added kmalloc power of two alignment >> guarantees, the impact on SLOB was negligible. > > I'll send a patch to add a 4-byte header for kmem_cache_alloc() > allocations. Thanks. Please report in the changelog slab usage from /proc/meminfo before and after patch (at least a snapshot after a full boot). >>> Thoughts? >>> >>> Cheers, >>> >>> Dave. >>> >>