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 638F9C47DD9 for ; Wed, 28 Feb 2024 05:15:11 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id C86026B0270; Wed, 28 Feb 2024 00:15:10 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id C36E56B0271; Wed, 28 Feb 2024 00:15:10 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id AFE606B0272; Wed, 28 Feb 2024 00:15:10 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id 9D5456B0270 for ; Wed, 28 Feb 2024 00:15:10 -0500 (EST) Received: from smtpin28.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 72518A13C7 for ; Wed, 28 Feb 2024 05:15:10 +0000 (UTC) X-FDA: 81840048780.28.CA6E088 Received: from out-188.mta0.migadu.com (out-188.mta0.migadu.com [91.218.175.188]) by imf26.hostedemail.com (Postfix) with ESMTP id 2B452140010 for ; Wed, 28 Feb 2024 05:15:06 +0000 (UTC) Authentication-Results: imf26.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=GHsy7BXO; spf=pass (imf26.hostedemail.com: domain of chengming.zhou@linux.dev designates 91.218.175.188 as permitted sender) smtp.mailfrom=chengming.zhou@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1709097309; a=rsa-sha256; cv=none; b=GhcrEPf1sDHR2SQ3xiy3URf7Xv9WPbx0nNOlAs91cOGkVxvDrtH0autVB7Mee1fhfCQKX3 Bn5yYg2VDT9LVNCDAau+X7DB65XcL9g8KgkOZCM2u1uxeV6ppdLPkaTtw0MlwWv0dP8bpI zZMK/lu4KfCtDDEbhhTAKD/fM7oK61w= ARC-Authentication-Results: i=1; imf26.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=GHsy7BXO; spf=pass (imf26.hostedemail.com: domain of chengming.zhou@linux.dev designates 91.218.175.188 as permitted sender) smtp.mailfrom=chengming.zhou@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1709097309; 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:dkim-signature; bh=zgZMTdjfNWQh0YDiJwwEXmgUlMNBEeWeipdoEla6gn8=; b=fmdfWdd58D4dz44tlXsOhB4SUF7iRhBDpTJJmy8gT3dJMNcXpwnwZREV/BlG7engh+otOU i67X62xE6c3R3CjWVBpwYpr/aod+lKOwMbZeJ5MiyRY617iGChcHbZ7ddPF30lbJDfcJTJ Pe8RoXOFpF7DmDhOPN+u8D74olKq8LE= Message-ID: <5a556476-05b2-483e-8875-eeb3e2a51151@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1709097304; h=from:from: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=zgZMTdjfNWQh0YDiJwwEXmgUlMNBEeWeipdoEla6gn8=; b=GHsy7BXOca+egXV4CajBfaEUEScRqCFSkIt0tELiypa4eFBUjfK9sxpf6IjkETbBUG14mB JKS/dxFB+Q4w4mIbjNrGawSDzZgNUV+yEysExTYDOGK+jdxLy1fCEkEnU3DDQ4O1bGzBtx TusvMbLtZHyVNvKegnvNJkNsdg/F3I8= Date: Wed, 28 Feb 2024 13:14:48 +0800 MIME-Version: 1.0 Subject: Re: [PATCH 1/2] mm/zsmalloc: don't hold locks of all pages when free_zspage() Content-Language: en-US To: Sergey Senozhatsky , Chengming Zhou Cc: yosryahmed@google.com, hannes@cmpxchg.org, nphamcs@gmail.com, Andrew Morton , Minchan Kim , linux-kernel@vger.kernel.org, linux-mm@kvack.org References: <20240226-zsmalloc-zspage-rcu-v1-0-456b0ef1a89d@bytedance.com> <20240226-zsmalloc-zspage-rcu-v1-1-456b0ef1a89d@bytedance.com> <20240228043358.GF11972@google.com> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Chengming Zhou In-Reply-To: <20240228043358.GF11972@google.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: 2B452140010 X-Stat-Signature: bihzba5npzh83fiqrsagfz4indfnodwi X-Rspam-User: X-HE-Tag: 1709097306-423380 X-HE-Meta: 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 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: List-Subscribe: List-Unsubscribe: On 2024/2/28 12:33, Sergey Senozhatsky wrote: > On (24/02/27 03:02), Chengming Zhou wrote: > [..] >> @@ -978,10 +974,11 @@ static struct zspage *alloc_zspage(struct zs_pool *pool, >> pages[i] = page; >> } >> >> - create_page_chain(class, zspage, pages); >> init_zspage(class, zspage); >> zspage->pool = pool; >> zspage->class = class->index; >> + /* RCU set_zspage() after zspage initialized. */ >> + create_page_chain(class, zspage, pages); > > So this hasn't been tested, has it? I have tested it in my test vm, but it hasn't KASAN enabled. I tested the kernel build in tmpfs with zswap enabled using zsmalloc pool, not sure why the kernel didn't crash then... > > init_zspage() does not like to be invoked before create_page_chain(), > because we haven't setup required pointers yet. You're right, I can reproduce the problem with KASAN enabled this time, create_page_chain() should be put before init_zspage(), which will iterate over the pages to create free objects list. > > So when init_zspage() calls get_first_page() it gets NULL zspage->first_page > which we then use in is_first_page(first_page)->PagePrivate(page). As far as > I can tell. Thanks! I will fix it and test throughly before send an update.