From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.223.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E7116392C33 for ; Tue, 13 Jan 2026 14:13:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=195.135.223.131 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768313625; cv=none; b=p3tP6PxrlQ8ZlH/QbDofScO3gxgg7s9OmxPeF48C1tt0MFpRIfj6s2sbqs7bh9dxXHpXcqWBYHkbH0gFQzPtzeseOghfx5MMMv/wWTpFg6oX6qDZLkN+3CcNFf2rxnEFYz6yoOY5zEYMPe+fjvGvfeGtXK6n2tiysiBjOP8PlvM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768313625; c=relaxed/simple; bh=d3ej2TsteXeZKg8yUqSYs5JeHy10lEv1wGS+YEfi3mE=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=R+s0K+9lps6Wt0pUWsilX5c4h9Ph9s1kEkQp/SXmhCfn5eEVpMFpSmXpmmb01r8bCdzOp3R7lHwHMQ0EVKEE72AUMRp14qM/R2uJFUqT7kEdi8gIBsD9izii5KhknhuRjE+4ojTLzLxUkN5lhuWrue4y2/vTR0w7GcHjuGKVaNI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=suse.cz; spf=pass smtp.mailfrom=suse.cz; dkim=pass (1024-bit key) header.d=suse.cz header.i=@suse.cz header.b=yHRxIc+g; dkim=permerror (0-bit key) header.d=suse.cz header.i=@suse.cz header.b=aH0TFDY2; dkim=pass (1024-bit key) header.d=suse.cz header.i=@suse.cz header.b=yHRxIc+g; dkim=permerror (0-bit key) header.d=suse.cz header.i=@suse.cz header.b=aH0TFDY2; arc=none smtp.client-ip=195.135.223.131 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=suse.cz Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=suse.cz Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=suse.cz header.i=@suse.cz header.b="yHRxIc+g"; dkim=permerror (0-bit key) header.d=suse.cz header.i=@suse.cz header.b="aH0TFDY2"; dkim=pass (1024-bit key) header.d=suse.cz header.i=@suse.cz header.b="yHRxIc+g"; dkim=permerror (0-bit key) header.d=suse.cz header.i=@suse.cz header.b="aH0TFDY2" Received: from imap1.dmz-prg2.suse.org (unknown [10.150.64.97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 44A975BCCA; Tue, 13 Jan 2026 14:13:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1768313622; 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=ewxiBRrNZaYohALbXtEzfnX/Vk+Fw/hKhgUAJ9escIc=; b=yHRxIc+gpCkX+kfXAPT/3p6zxCILpG5kw/9eLTT/KEp292/gn8MUwH2N/xzuNAohC4ArJM pylQ7/VpyV/Gv6U1OUO95fB2TQBmkoHZ2ha+O2p6hRfDwfnhXy1MX79tENIHdqiS3pYg+4 +zcyMrBm+T/PQd3RNYhI4spv2Bnp5+E= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1768313622; 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=ewxiBRrNZaYohALbXtEzfnX/Vk+Fw/hKhgUAJ9escIc=; b=aH0TFDY2S9oiLF/n9wDe+TChe6XDp2NllgSzFUlmgPcoXdO2XLCZP2UmckScBeKJwzM3Dr bqAxUPCr5JdMt9AA== Authentication-Results: smtp-out2.suse.de; none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1768313622; 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=ewxiBRrNZaYohALbXtEzfnX/Vk+Fw/hKhgUAJ9escIc=; b=yHRxIc+gpCkX+kfXAPT/3p6zxCILpG5kw/9eLTT/KEp292/gn8MUwH2N/xzuNAohC4ArJM pylQ7/VpyV/Gv6U1OUO95fB2TQBmkoHZ2ha+O2p6hRfDwfnhXy1MX79tENIHdqiS3pYg+4 +zcyMrBm+T/PQd3RNYhI4spv2Bnp5+E= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1768313622; 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=ewxiBRrNZaYohALbXtEzfnX/Vk+Fw/hKhgUAJ9escIc=; b=aH0TFDY2S9oiLF/n9wDe+TChe6XDp2NllgSzFUlmgPcoXdO2XLCZP2UmckScBeKJwzM3Dr bqAxUPCr5JdMt9AA== Received: from imap1.dmz-prg2.suse.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by imap1.dmz-prg2.suse.org (Postfix) with ESMTPS id 29E0E3EA63; Tue, 13 Jan 2026 14:13:42 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id wn37CRZTZmkqPwAAD6G6ig (envelope-from ); Tue, 13 Jan 2026 14:13:42 +0000 Message-ID: <11e83aa3-0ebb-44ad-b814-a76fd244cbf1@suse.cz> Date: Tue, 13 Jan 2026 15:13:41 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH V6 0/9] mm/slab: reduce slab accounting memory overhead by allocating slabobj_ext metadata within unsed slab space To: Harry Yoo , akpm@linux-foundation.org Cc: andreyknvl@gmail.com, cl@gentwo.org, dvyukov@google.com, glider@google.com, hannes@cmpxchg.org, linux-mm@kvack.org, mhocko@kernel.org, muchun.song@linux.dev, rientjes@google.com, roman.gushchin@linux.dev, ryabinin.a.a@gmail.com, shakeel.butt@linux.dev, surenb@google.com, vincenzo.frascino@arm.com, yeoreum.yun@arm.com, tytso@mit.edu, adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, hao.li@linux.dev References: <20260113061845.159790-1-harry.yoo@oracle.com> From: Vlastimil Babka Content-Language: en-US In-Reply-To: <20260113061845.159790-1-harry.yoo@oracle.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Spam-Score: -2.80 X-Spamd-Result: default: False [-2.80 / 50.00]; BAYES_HAM(-3.00)[99.99%]; SUSPICIOUS_RECIPS(1.50)[]; NEURAL_HAM_LONG(-1.00)[-1.000]; NEURAL_HAM_SHORT(-0.20)[-1.000]; MIME_GOOD(-0.10)[text/plain]; TAGGED_RCPT(0.00)[]; FUZZY_RATELIMITED(0.00)[rspamd.com]; MIME_TRACE(0.00)[0:+]; RCPT_COUNT_TWELVE(0.00)[23]; ARC_NA(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; RCVD_TLS_ALL(0.00)[]; FREEMAIL_ENVRCPT(0.00)[gmail.com]; TO_DN_SOME(0.00)[]; FROM_HAS_DN(0.00)[]; FREEMAIL_CC(0.00)[gmail.com,gentwo.org,google.com,cmpxchg.org,kvack.org,kernel.org,linux.dev,arm.com,mit.edu,dilger.ca,vger.kernel.org]; MID_RHS_MATCH_FROM(0.00)[]; FROM_EQ_ENVFROM(0.00)[]; RCVD_COUNT_TWO(0.00)[2]; TO_MATCH_ENVRCPT_ALL(0.00)[]; DKIM_SIGNED(0.00)[suse.cz:s=susede2_rsa,suse.cz:s=susede2_ed25519]; DBL_BLOCKED_OPENRESOLVER(0.00)[suse.cz:mid,imap1.dmz-prg2.suse.org:helo] X-Spam-Level: X-Spam-Flag: NO On 1/13/26 7:18 AM, Harry Yoo wrote: > V5: https://lore.kernel.org/linux-mm/20260105080230.13171-1-harry.yoo@oracle.com > V5 -> V6: > > - Patch 1: Added Closes: tag for related discussion (Vlastimil) > https://lore.kernel.org/linux-mm/1372138e-5837-4634-81de-447a1ef0a5ad@suse.cz > > - Patch 3: Addressed Vlastimil's comments > https://lore.kernel.org/linux-mm/e28c08e4-5048-429b-97a0-8d51e494efcd@suse.cz > > - Patch 4: Fixed incorrect function prototype of slab_obj_ext() on > !CONFIG_SLAB_OBJ_EXT builds and kept pointer type in > free_slab_obj_exts() (Hao, Vlastimil) > https://lore.kernel.org/linux-mm/n6kyluk3nahdxytwek4ijzy4en6mc6ps7fjjgftww4ith7llom@cijm4who24w2 > https://lore.kernel.org/linux-mm/473d479c-4eae-4589-b8c2-e2a29e8e6bc1@suse.cz > > - Patch 7, 9: Rewrote obj_exts_in_slab() to check if the pointer is within the > slab's range, and distinguish by stride (Vlastimil) > https://lore.kernel.org/linux-mm/644e163d-edd9-4128-9516-0f70a25526df@suse.cz > > - Patch 9: Fixed potentioal memory leak due to incorrect impl. of > obj_exts_in_object() (Vlastimil) > https://lore.kernel.org/linux-mm/8c67dcbe-f393-4da6-8d24-f9da79c246c4@suse.cz/ > > - Patch 9: Fixed incorrect ksize() implementation (Hao) > https://lore.kernel.org/linux-mm/fgx3lapibabra4x7tewx55nuvxz235ruvm3agpprjbdcmt3rc6@h54ln5tfdssz Merged to slab/for-7.0/obj_metadata and slab/for-next, thanks!