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 57063C77B75 for ; Mon, 22 May 2023 07:35:13 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id C38496B0074; Mon, 22 May 2023 03:35:12 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id BBFF66B0075; Mon, 22 May 2023 03:35:12 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A6135900002; Mon, 22 May 2023 03:35:12 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id 9437D6B0074 for ; Mon, 22 May 2023 03:35:12 -0400 (EDT) Received: from smtpin23.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 5A3F0ADD9C for ; Mon, 22 May 2023 07:35:12 +0000 (UTC) X-FDA: 80817080064.23.88315C7 Received: from szxga08-in.huawei.com (szxga08-in.huawei.com [45.249.212.255]) by imf19.hostedemail.com (Postfix) with ESMTP id C2B121A0014 for ; Mon, 22 May 2023 07:35:09 +0000 (UTC) Authentication-Results: imf19.hostedemail.com; dkim=none; dmarc=pass (policy=quarantine) header.from=huawei.com; spf=pass (imf19.hostedemail.com: domain of gongruiqi1@huawei.com designates 45.249.212.255 as permitted sender) smtp.mailfrom=gongruiqi1@huawei.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1684740910; 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:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=+zyMHySpPh8XlgELXOlw+871ujfaZvOUK/GYK0H4SM4=; b=ZrPSes2WApKjGncQg9be3niVd4vDSXeaLcFvuTMBmgI+YRQoAYYs5nX5JsDtNEwc/eQj27 ZMdl/LeKF76Mmgi6mJ6pqZNwmOTPanvj7DmMkQ2pI874FHuJd+8W9y3WwKWTO65XbJs9JF 6kTw5RsuOrAN1GDbUwkEeP93IT9shXI= ARC-Authentication-Results: i=1; imf19.hostedemail.com; dkim=none; dmarc=pass (policy=quarantine) header.from=huawei.com; spf=pass (imf19.hostedemail.com: domain of gongruiqi1@huawei.com designates 45.249.212.255 as permitted sender) smtp.mailfrom=gongruiqi1@huawei.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1684740910; a=rsa-sha256; cv=none; b=1jyppdtqbl46+TwqJ6r8bffrO4eptCtIi/lbivvJAWHqZNh5lhnNdQ/GCHCA2pTan1tt5L mQ+bSFELSr441O93W2ArzQJobkrIzWcEIv2HE8BmV42pfaYwFzbD5knUGconGDAQuY+6g6 /Ptyk4wuFwmUcyoxPx0nM/0jZ5Ru+A8= Received: from dggpemm500016.china.huawei.com (unknown [172.30.72.56]) by szxga08-in.huawei.com (SkyGuard) with ESMTP id 4QPpyN5MqDz18LZm; Mon, 22 May 2023 15:30:36 +0800 (CST) Received: from [10.67.110.48] (10.67.110.48) by dggpemm500016.china.huawei.com (7.185.36.25) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.23; Mon, 22 May 2023 15:35:03 +0800 Message-ID: <19707cc6-fa5e-9835-f709-bc8568e4c9cd@huawei.com> Date: Mon, 22 May 2023 15:35:02 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.10.0 Subject: Re: [PATCH RFC v2] Randomized slab caches for kmalloc() Content-Language: en-US To: Hyeonggon Yoo <42.hyeyoo@gmail.com> CC: , , , Alexander Lobakin , , Wang Weiyang , Xiu Jianfeng , Vlastimil Babka , Christoph Lameter , David Rientjes , Roman Gushchin , Joonsoo Kim , Andrew Morton , Pekka Enberg , Kees Cook , Paul Moore , James Morris , "Serge E. Hallyn" , "Gustavo A. R. Silva" , "GONG, Ruiqi" References: <20230508075507.1720950-1-gongruiqi1@huawei.com> <5f5a858a-7017-5424-0fa0-db3b79e5d95e@huawei.com> From: Gong Ruiqi In-Reply-To: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit X-Originating-IP: [10.67.110.48] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To dggpemm500016.china.huawei.com (7.185.36.25) X-CFilter-Loop: Reflected X-Rspamd-Queue-Id: C2B121A0014 X-Rspam-User: X-Rspamd-Server: rspam05 X-Stat-Signature: q5i1ctyd58413fkqg46iauwjfde7ewzs X-HE-Tag: 1684740909-765069 X-HE-Meta: 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 sg0+5dMg /pyfDk30T3N5f4oqy7fCmn/RPfPL/KbXsCsbCD0XzQXINr/naF1CiRhIw8FCSfGlmXC2IZx++pdREbChz4cDB4qCCIZWRDGRURf1T6q73lUheNwuwvir1KIti7VqH/7s77gLb4yT0wWb18jHokgE5Dl2GQvbWZsRW7V21NFTAEfYOA9H6gQwy3vBiMOFzLcwI4D72ZueCxqJOHGVibPAofftd51H1LTPjn3RP 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 2023/05/17 6:35, Hyeonggon Yoo wrote: > [Resending this email after noticing I did not reply-to-all] > > On Fri, May 12, 2023 at 7:11 PM Gong Ruiqi wrote: >> [...] > >>>> +#ifdef CONFIG_RANDOM_KMALLOC_CACHES >>>> +# define SLAB_RANDOMSLAB ((slab_flags_t __force)0x01000000U) >>>> +#else >>>> +# define SLAB_RANDOMSLAB 0 >>>> +#endif > > There is already the SLAB_KMALLOC flag that indicates if a cache is a > kmalloc cache. I think that would be enough for preventing merging > kmalloc caches? After digging into the code of slab merging (e.g. slab_unmergeable(), find_mergeable(), SLAB_NEVER_MERGE, SLAB_MERGE_SAME etc), I haven't found an existing mechanism that prevents normal kmalloc caches with SLAB_KMALLOC from being merged with other slab caches. Maybe I missed something? While SLAB_RANDOMSLAB, unlike SLAB_KMALLOC, is added into SLAB_NEVER_MERGE, which explicitly indicates the no-merge policy.