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]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 633A6CDB462 for ; Thu, 13 Nov 2025 23:08:17 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id A91758E0003; Thu, 13 Nov 2025 18:08:16 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id A691D8E0002; Thu, 13 Nov 2025 18:08:16 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 97EAE8E0003; Thu, 13 Nov 2025 18:08:16 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 873198E0002 for ; Thu, 13 Nov 2025 18:08:16 -0500 (EST) Received: from smtpin30.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id EB68856B5B for ; Thu, 13 Nov 2025 23:08:15 +0000 (UTC) X-FDA: 84107124150.30.996DB53 Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by imf17.hostedemail.com (Postfix) with ESMTP id 2CA4E40012 for ; Thu, 13 Nov 2025 23:08:14 +0000 (UTC) Authentication-Results: imf17.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=2V0F07x9; spf=pass (imf17.hostedemail.com: domain of akpm@linux-foundation.org designates 172.234.252.31 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=1763075294; 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=Kz6/SZauUBbNlBd3RH1toKaC8fR1t1d6HANf/8zakIQ=; b=Kd5TEit2OcWnzA9+A0hJZKKqTAl0fxfEvkZs7CdPLq0YCNshys4wTS56z/AGi0xsieCL7Z QaMJSwU8bv5MgattKDTNhxXDXvpEThIGevMiYOhgQMJdEtY522zzwCJP1FRHWmIqfwD0+l hcmurXGzwr7KqzewdzdX9WFRrp9bdk8= ARC-Authentication-Results: i=1; imf17.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=2V0F07x9; spf=pass (imf17.hostedemail.com: domain of akpm@linux-foundation.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org; dmarc=none ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1763075294; a=rsa-sha256; cv=none; b=F6ValPWffC8+bFrTaaFl65ujwMCTx1bROxSyfHPw2zuKuBj396H0lxQqSpqK9QH7zq2qb1 RVeaBV9FkEKxHWbUYpYHU79eVOT3elBAwAxqDDzPcF8MW4IbVb5ssWk+y7Vnvv6CwfDxCX Pe40J0ZzvH4KuJh02cFgqkBiCfwF2g0= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id BEF2E44138; Thu, 13 Nov 2025 23:08:12 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B8BBCC4CEF7; Thu, 13 Nov 2025 23:08:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1763075292; bh=2wvqa/HMit8pu0w6FTlokZJLz41y4povJ4/y0QBe68k=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=2V0F07x99YAiF85Sx7V1XWStJGYjslzh/mevzVy07rE/VuwVdP2ufpoJPqaCRs6Bk EN1xQs77scGH//E4rc4vilieGQQUwW44aylFuMIPg20ze2nBtAe21fLQKQpDoPL5Sh JXD/31O+MxpDt1neiBxsZiTtccuDP2TnCwhvKE60= Date: Thu, 13 Nov 2025 15:08:11 -0800 From: Andrew Morton To: Balbir Singh Cc: "David Hildenbrand (Red Hat)" , Lorenzo Stoakes , linux-kernel@vger.kernel.org, linux-mm@kvack.org, dri-devel@lists.freedesktop.org, Zi Yan , Joshua Hahn , Rakie Kim , Byungchul Park , Gregory Price , Ying Huang , Alistair Popple , Oscar Salvador , Baolin Wang , "Liam R. Howlett" , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lyude Paul , Danilo Krummrich , David Airlie , Simona Vetter , Ralph Campbell , Mika =?ISO-8859-1?Q?Penttil=E4?= , Matthew Brost , Francois Dugast Subject: Re: [PATCH] mm/huge_memory: fix override of entry in remove_migration_pmd Message-Id: <20251113150811.081a6dbdcca8b5c474d6e399@linux-foundation.org> In-Reply-To: <5092cfb0-ad25-40ff-9a07-3de86d37665f@nvidia.com> References: <20251113051352.1753714-1-balbirs@nvidia.com> <5092cfb0-ad25-40ff-9a07-3de86d37665f@nvidia.com> X-Mailer: Sylpheed 3.7.0 (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-Server: rspam05 X-Rspamd-Queue-Id: 2CA4E40012 X-Stat-Signature: oshdaowte1qtpa3ydjpci7zzcm98nxei X-Rspam-User: X-HE-Tag: 1763075294-975554 X-HE-Meta: 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 KYckiCrz p4HHlaTjyooWwdt4iylWjaBnggrylYRNNVS/5r5jy2r+NanSwVJmJGlF4CxX1LD1UwrXdNQnhtWeU5paKlAcACMsRdHbXjp9oikke4g3soiLd0q9aESe86tHRQrp5IDVP5pjkLsporSlDswFUO8PTugN2GDTWZ28g2iqjZ4hqsjgeTt8dQm77H3fb2G0cAEz70LPAK01yQDOjYP7YXZ8F+G9YeOUY2it5UUKipdtKsnClq3HGRMY+sK7CdtfI4tkKREJZ56L4BMnJKgjxwKqjOXpbtgODp743xh55xy67ml1IxRYkpNHhxvmlash4AR0rHffOQ7W9f9BLlUNQK4ax5NMwXsOVxEug7VdgXf5qEi3jKFxC8S70xmbIiRu+jvU440iCleUUVF0C34U= 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 Fri, 14 Nov 2025 07:55:29 +1100 Balbir Singh wrote: > >> THe logic LGTM but we don't want to have a bisect hazard here by having the bug > >> introduced earlier then resolved here. > > > > Exactly. > > > > The hazard is a VM_WARN_ON() that checks for is_migration_entry() in the > call to softleaf_is_migration_young(). I am happy to go down that path, > let me send out the fixups, it felt weird to break the rebase, but I > am sure Andrew has a better way of dealing with this stuff. Yes, please tell us which patch introduced the issue then send a fix for that patch. We can figure out the softleaf changes later. (Which this patch provides anyway). Also, confusing that the changelog says "The softleaf changes exposed a BUG in remove_rmap_pmd()" but it's remove_migration_pmd() that gets altered. Please expand and clarify?