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 C77B5C27C77 for ; Wed, 12 Jun 2024 16:00:46 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 0F3056B00A2; Wed, 12 Jun 2024 12:00:46 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 0A3E76B00A3; Wed, 12 Jun 2024 12:00:46 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E85026B00A7; Wed, 12 Jun 2024 12:00:45 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id C8AF56B00A2 for ; Wed, 12 Jun 2024 12:00:45 -0400 (EDT) Received: from smtpin08.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id 3EF7181800 for ; Wed, 12 Jun 2024 16:00:45 +0000 (UTC) X-FDA: 82222699650.08.8F10B85 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by imf24.hostedemail.com (Postfix) with ESMTP id 4E5CC180016 for ; Wed, 12 Jun 2024 16:00:42 +0000 (UTC) Authentication-Results: imf24.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b="C/wojmib"; spf=pass (imf24.hostedemail.com: domain of akpm@linux-foundation.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1718208043; 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=AdccrOhf88uz5pRDwrrb1HohSX2xWhLpPPv/9A9+SwY=; b=zyXb+/YDay8YyFydz1/KOFwq52jmQFEkIKVNYrIpMlw5pis+4+6esN82JHuxqyVn0IQWMW StaPUv5BTSS0io0IirUayWaQfYIMEaWBVqn8AHMt4B+INhNYABI2pitOcRmahghQhUT6Ll BvpZyJyKShAPqMGr4L/N5ZbLToSgPVU= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1718208043; a=rsa-sha256; cv=none; b=UbAx43+PaLkTCUpmKUpoPDaRWGk+xDGP79pIzBFkge6LdAvPY7hTi8AuCwt5fiQ7WXT0Ts pvTJ2eHdB5urR65w/fcvKVB3C7DQdNy9gxxn97aAdrl9ip6GdK3cZsXUxDwG7MOtrFAyBQ tu+WVvQr67Ng9J5qhNHybDlBr9Oh4DA= ARC-Authentication-Results: i=1; imf24.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b="C/wojmib"; spf=pass (imf24.hostedemail.com: domain of akpm@linux-foundation.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org; dmarc=none Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id A4F90614DD; Wed, 12 Jun 2024 16:00:41 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 40796C116B1; Wed, 12 Jun 2024 16:00:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1718208041; bh=6Dj6THRj+i4dDXGDhbJq/b5ZEprPGb16YF9d3o2hP8U=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=C/wojmibINCCfGxwyxeUp3zJk5SwfhlMG5IVAwKr2sxAjndRyFJ0ovSt9K0X9her0 iRnUdvQ2Z0IG6DKVJb97ZCWStxgzKOwSkW4blo2IOW150aAyUwWp54TTxjPzDcQRX2 irTHkYc9JpXxJ+C+dF4itzt/MYtrD1CpOBvLDFCs= Date: Wed, 12 Jun 2024 09:00:40 -0700 From: Andrew Morton To: Hugh Dickins Cc: "Huang, Ying" , Zi Yan , Baolin Wang , David Hildenbrand , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH hotfix] mm/migrate: fix kernel BUG at mm/compaction.c:2761! Message-Id: <20240612090040.090c20a398f3e9eb550e1a9d@linux-foundation.org> In-Reply-To: References: <46c948b4-4dd8-6e03-4c7b-ce4e81cfa536@google.com> <87msnq7key.fsf@yhuang6-desk2.ccr.corp.intel.com> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 4E5CC180016 X-Rspam-User: X-Rspamd-Server: rspam08 X-Stat-Signature: gh86j35mfo5pkxcizm5g8rfotjh571cp X-HE-Tag: 1718208042-244781 X-HE-Meta: U2FsdGVkX18K/8UoMCdSKfkm4i68A/DtAQbxxzbWQnHRKXyCyVuS0zNlW339+V1YhilJieZ3ww+DrpRFL3z+8giYAxgVwQvI4Fd8S4gbodZwMsfV7/WPIed2YuPLgFZ9OSI0jl466hW96qWiqAyeiHcsqRr6OsQM5oFYyy9goEBwKnOyIts+LDrIniC3O6/Af5N1yid8rNixZkaCVz05h5lCQ5vk/pD0i9xwXIgs97detLsedEx3QIWmdUW1IB2Mn1yWpNmivTwEjS0GjZV/34eJxWxhwsOmum/kvHmjGfaPRT96pUIzfLj97W1di9+gaozTe7n5HY/xcbjgWJAOSVKv+7j2nw9ndo1HksSAooX/vLEhR9Wk1+cmli075Q8W79L1T6KH3YLKFNiQ9v5viarwSBoIqHL8tTfwN5KJGeXcpgxKFNHOXbbjemUdV3VK2rv9AdL7Ps9nrZfTD9TT8RjFlfWiZ1fcIfrdSA94G/hE3T3Jm93kt9X+HdJP6sQiyOgS8Ez2vyn05O3JsMre4jpLUW1MHruS8eK16BScixQwOYKxgp9/SoFm0Mc4Mu5n4XXGsTjHeBR96m7UOJWQz+KqBwCigqPUAni7dRUNL4MGcFm+X1Xlw0OE3EEy5Ujl202u7VCSRNDGXwCSwKTrTMswCSVBVEancOM9AZQtdnmQWGocSS5N+d3MsB6f8ievkEY+3ETh7AgLbeZZvizoGgtL9yDq5hT2Lfs3dmBEVY7kl/MAWnvdSsJ8oGNjEmAy5kgMpiE5vdC7sFR6W4bWsw/1jGl5vW8P4wTwp1IIAopQdHwhHIUx0c5xcEBlxlXCzrcEw48gDWUc9hKtpp9RKzHzmaZPN+q+Y+Yuq5TuchcZx+htO4GWfcZk9W6MAU1CVuCs4uJJSowqjXlEnBCuVVkuvIPqhatRQ+Be+onuWz0bK9nuEqnC0qafBzbr6uh105BigZ5MjdPp4dDATqn w3jPph0P 9A6YQo1SsNcbCJDi3r5Vm2ESw48xh+8kUKNf6ePzDRHfcHqh7QPqZf5gNNEwjxndoGvEHzsPQOi4c+vSqUuCC0hS7ADlp+XObBVffHagmyzcR0YYXHjeQXe4LfsaI4E4cL0BGt/gFaSWyNG5YWwsoHbDzHkEYJOV77rTrBk3HEe0eqHVIg+mwpFo+Yiw6JShVFqTPUY8c0NkfDAApKDcJdgspUn7218ZXiYnbccYOY7s1Nv5pRmo2k8WVbaStPtOOzAmJbGIoPcrGCXq8abCRj0tk8UEiS/Qk+QUFyyT330jagVst+Cm3W+czSban6kQqlddusIcoP+GotrBVuPUeoiKGM7u5i3FOIvev 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 Wed, 12 Jun 2024 00:11:44 -0700 (PDT) Hugh Dickins wrote: > > It appears better to add > > > > stats->nr_thp_failed++; > > > > too. Otherwise, if migrate_pages_batch() is called via migrate_pages(, > > MIGRATE_ASYNC, ), nr_thp_failed will not increase. But if > > migrate_pages_batch() is called via migrate_pages(, MIGRATE_SYNC*, ), > > nr_thp_failed will increase in migrate_pages_sync() via > > > > stats->nr_thp_failed += astats.nr_thp_split; > > > > That is, they are not consistent. The issue exists since commit > > 7262f208ca68 ("mm/migrate: split source folio if it is on deferred split > > list"). > > Sorry, I'll have to let you take over and send your own patch instead > of mine - thanks. Those stats, and any attempt at consistency there, > is way beyond me! I thought consistency was impossible, unless all > the numbers were changed to order-0 counts. I'll add this patch as-is for now.