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 48A56CD3420 for ; Mon, 2 Sep 2024 19:08:49 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id D60A08D0104; Mon, 2 Sep 2024 15:08:48 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id D10218D00E7; Mon, 2 Sep 2024 15:08:48 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id BFF398D0104; Mon, 2 Sep 2024 15:08:48 -0400 (EDT) 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 9F8968D00E7 for ; Mon, 2 Sep 2024 15:08:48 -0400 (EDT) Received: from smtpin19.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay04.hostedemail.com (Postfix) with ESMTP id 58B351A18E0 for ; Mon, 2 Sep 2024 19:08:48 +0000 (UTC) X-FDA: 82520735136.19.7E9133C Received: from nyc.source.kernel.org (nyc.source.kernel.org [147.75.193.91]) by imf09.hostedemail.com (Postfix) with ESMTP id 966C714001A for ; Mon, 2 Sep 2024 19:08:46 +0000 (UTC) Authentication-Results: imf09.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=GaQ1xhjD; spf=pass (imf09.hostedemail.com: domain of brauner@kernel.org designates 147.75.193.91 as permitted sender) smtp.mailfrom=brauner@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1725304052; 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: in-reply-to:in-reply-to:references:references:dkim-signature; bh=CHrZDwtO4t0H3B/XN+U3+nif+odrel9o7eYuqYQAbWU=; b=B+DuoMdmmoasAHshL/i7VVL2cQSPB5+5/c3VLapSvatmBCsFMnV+bim2T3qEazHqPYGxlS P3LT6hWuybSISBDPeJ1xC0jXhPH2w8z4HdJKiUjLhAPhJhMz5TnNdmw6YUf5RcDQ4n64wA DA7mY+sODTVXQlvY6cvvPU7xNB11hLs= ARC-Authentication-Results: i=1; imf09.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=GaQ1xhjD; spf=pass (imf09.hostedemail.com: domain of brauner@kernel.org designates 147.75.193.91 as permitted sender) smtp.mailfrom=brauner@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1725304052; a=rsa-sha256; cv=none; b=jZ0W/YrxIYtUdSBQ0bSUfCix0xMLBSCNH+QomNQN/3W98MXw0n4GAxZAkq6xkj7/Fj61T4 faBoasOi5VJci0BFJqjvtuPUUeVWL2rlY5K+0+Glgt3jspVa6q/6ctwnbtS5YP7qRVWeuh Q3r+sILKgl6fETMSd/0Plm9SwGM3sNQ= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by nyc.source.kernel.org (Postfix) with ESMTP id DEC81A428C3; Mon, 2 Sep 2024 19:08:38 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D487AC4CEC7; Mon, 2 Sep 2024 19:08:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1725304125; bh=apI5HiY67Z6hG4LwlOvdVoI6AOvyzBAzhK3n1UGdu9A=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=GaQ1xhjD2FPmkjAlwi/ht1PYDXQrbuM5jyqYs1DUdmLk+4PwKguPDVR/IddiDq2+q BWBYE2/OmFDfPcW4zb0YxAWYCD7QrquIS96zFI1l4Be9WVxLSuI+pIJ7IuWK29lGxw ASs4cT5FUdn4zogy2UP8srbIbHtb+90k5iKMQQZ13hR6/n7d7QcCZpH8mDn+95PMvC Whz7WHwcs5j9HWVChNGvHbWtsS+OpekfaOmw+Wez2z2J84ykkQEhcT7P3uUDtdqHwi PQZ/F05v8TX09Zoi+VTnJ/rOY/0en1bh/ZuJLNtKJ2zplJUHBbx1k9NoRu5CsAvJbJ CuVBAv1iGBH9g== Date: Mon, 2 Sep 2024 21:08:39 +0200 From: Christian Brauner To: "Pankaj Raghav (Samsung)" Cc: Matthew Wilcox , sfr@canb.auug.org.au, akpm@linux-foundation.org, linux-next@vger.kernel.org, mcgrof@kernel.org, ziy@nvidia.com, da.gomez@samsung.com, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, Pankaj Raghav , Sven Schnelle Subject: Re: [PATCH] mm: don't convert the page to folio before splitting in split_huge_page() Message-ID: <20240902-leiblich-aufsehen-841e42a5a09d@brauner> References: <20240902124931.506061-2-kernel@pankajraghav.com> <20240902-wovor-knurren-01ba56e0460e@brauner> <20240902144841.gfk4bakvtz6bxdqx@quentin> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20240902144841.gfk4bakvtz6bxdqx@quentin> X-Stat-Signature: pww8y5asf1dhyk1whdrqowdddfpaqjgu X-Rspam-User: X-Rspamd-Queue-Id: 966C714001A X-Rspamd-Server: rspam02 X-HE-Tag: 1725304126-994957 X-HE-Meta: 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 ZKqbv4Jt yH4GbIE9a9qMJHqjWfkCaKaB/f5G/w7bRIBVF3FPOPKg0LnvivGneqb38n4YbseweJM/AG+6Foy6wfMPw/VZYbGT+b/GnDbe7j4pmnCwf/Fj+pInB1Ah1+eY6R3hrpzm6teNiDntIs4HSLAnt+areiAM9H6ROV4fXnIXr2fYzqb29YSyZ538W+rZ/ZovKzRmNgLOfwV5lyLfw7cHdp6FidL4PyMATfcwnfOi/6wb/Rhd4iDBmI3vXp05zWHcHqW4trUUXicktYqHK8A1MapXn/hMPm3xBwOMw5TAKyvatfduByHkfuDefH9kpZhhGwpumpvwhkEUdSwpdr6MR4V1jEZEYw522YL2zi2oqZprYsC5lm1KGmo4oRN+G56B9hL1Nh4EbnJBXPSjkim4= 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 Mon, Sep 02, 2024 at 02:48:41PM GMT, Pankaj Raghav (Samsung) wrote: > On Mon, Sep 02, 2024 at 04:21:09PM +0200, Christian Brauner wrote: > > On Mon, Sep 02, 2024 at 03:00:37PM GMT, Matthew Wilcox wrote: > > > On Mon, Sep 02, 2024 at 02:49:32PM +0200, Pankaj Raghav (Samsung) wrote: > > > > From: Pankaj Raghav > > > > > > > > Sven reported that a commit from bs > ps series was breaking the ksm ltp > > > > test[1]. > > > > > > > > split_huge_page() takes precisely a page that is locked, and it also > > > > expects the folio that contains that page to be locked after that > > > > huge page has been split. The changes introduced converted the page to > > > > folio, and passed the head page to be split, which might not be locked, > > > > resulting in a kernel panic. > > > > > > > > This commit fixes it by always passing the correct page to be split from > > > > split_huge_page() with the appropriate minimum order for splitting. > > > > > > This should be folded into the patch that is broken, not be a separate > > > fix commit, otherwise it introduces a bisection hazard which are to be > > > avoided when possible. > > > > Patch folded into "mm: split a folio in minimum folio order chunks" > > with the Link to this patch. Please double-check. > Thanks a lot! > > I still don't see it upstream[1]. Maybe it is yet to be pushed? > > [1] https://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs.git/commit/?h=vfs.blocksize&id=fd031210c9ceb399db1dea001c6a5e98f3b4e2e7 Pushed now.