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 8D7EDC4345F for ; Thu, 25 Apr 2024 20:10:29 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 2328F6B0089; Thu, 25 Apr 2024 16:10:29 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 1E2996B008A; Thu, 25 Apr 2024 16:10:29 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0D1C26B008C; Thu, 25 Apr 2024 16:10:29 -0400 (EDT) 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 E14526B0089 for ; Thu, 25 Apr 2024 16:10:28 -0400 (EDT) Received: from smtpin01.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 750CD1C13D1 for ; Thu, 25 Apr 2024 20:10:28 +0000 (UTC) X-FDA: 82049146536.01.E215B6A Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf13.hostedemail.com (Postfix) with ESMTP id EDE6D2000A for ; Thu, 25 Apr 2024 20:10:24 +0000 (UTC) Authentication-Results: imf13.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=cDuRE8Ic; spf=none (imf13.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1714075825; 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=ut2lFHkwpmb+K3EVBzWHNHhXkqQsbBQiLvTVM0eN3X0=; b=ElqjUG7WelPCx3OHdSQqYy05Klmpr4VntkDAm9qiM8FQ9eLzetw7FxvWHNgAaDjzxPBi5U q9bKSqB0rFIJgMbilLJYa5FG6hSsMnOsj2cW7c9tu+0IoieU1wUUUAoa3TvQxZIyou4eYG sYLlnubCyVPG/zaQE8ru54UjkM/ylwI= ARC-Authentication-Results: i=1; imf13.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=cDuRE8Ic; spf=none (imf13.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org; dmarc=none ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1714075825; a=rsa-sha256; cv=none; b=H2NlcLYI1/L6Ua+uY1vCq76hDKBSR/yxoOnpQOE0U0FhQg5EZN3CbrqPC/P1WNX3qZtt7j RTR0QKgCIosJQZVY2V5s3cR7yQVJwNb65zYHBV3S3gPLP47yjaheqZduey/OHWtIdczTLf TNei6Z01erNenfOsAQMFW5taC62YDcw= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=ut2lFHkwpmb+K3EVBzWHNHhXkqQsbBQiLvTVM0eN3X0=; b=cDuRE8IcWqDQDDIRZPUpK027nB xwfg9QuplaZFv+VpFFWIvtWT73JCqK/a1vhPkOIzHuMZ+X3hUT38iIn8NGjdTDbskzo3PQXcJo0nB EehnMcTq+mZrfAuV7jQybmKBkzGjPpO1wBFLZAjRJ+qgjdz+aV9W+2WYADSpf+APwM3HVzEDp17wx JmZf7Y2MLLlqPIbRMUw8RXfY/2KP/i4IwLFEibc9z9h4NIsxupSc5ZLNG1BpBMS7oZQxNNea8UUEo po85wU7raeUp1Dn5YinkeiZIYukVdn4vDpYDPR/vhwkBsDcgl3umYUQFhG/i4oA03nTt8G2FHEWy8 yUWvwvOg==; Received: from willy by casper.infradead.org with local (Exim 4.97.1 #2 (Red Hat Linux)) id 1s05Q9-00000003hkb-01z4; Thu, 25 Apr 2024 20:10:17 +0000 Date: Thu, 25 Apr 2024 21:10:16 +0100 From: Matthew Wilcox To: "Pankaj Raghav (Samsung)" Cc: djwong@kernel.org, brauner@kernel.org, david@fromorbit.com, chandan.babu@oracle.com, akpm@linux-foundation.org, linux-fsdevel@vger.kernel.org, hare@suse.de, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-xfs@vger.kernel.org, mcgrof@kernel.org, gost.dev@samsung.com, p.raghav@samsung.com Subject: Re: [PATCH v4 05/11] mm: do not split a folio if it has minimum folio order requirement Message-ID: References: <20240425113746.335530-1-kernel@pankajraghav.com> <20240425113746.335530-6-kernel@pankajraghav.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240425113746.335530-6-kernel@pankajraghav.com> X-Stat-Signature: ze8cionicn4iwcw8za8fm1tepayqxwzt X-Rspamd-Queue-Id: EDE6D2000A X-Rspamd-Server: rspam02 X-Rspam-User: X-HE-Tag: 1714075824-865237 X-HE-Meta: U2FsdGVkX19PBlj+z86uMu6f1x7te36sHfLQ4fmB8Ca10RZ3a986WEtNvXTaU/V00uszjZeW3jagBqMMFuuh0EiXam+elauBhM6oWh32tt7a8NRQwyZLuUGSrOCnmDuYX1u0wq5R1fCNp15A8Mbr6qcuw56MtBxYvnMTRM6v71AnJsGgxHKVMHb8R7JvHg/WiZhX/KHcmQYROO+2yme6uWUCxImrZtE8mKao+QgzROyZTasbxyBP+TacTH+eaC///QD9STPCWZpLnGDxw6oFzJdr+e4+8CruaTYt59LWMLPn4c408jte10WoitGY95PVdRvp7erISiybanHm6X0fpLchqG0sLGikcWULM7hgxY5xPs4pAXqlRBAEsyyFHqMenEf07ImpAd8aIpT/3ZdHjZl9O1vNm9ALAEtAXtmz/guyVbwaD1M+ioiJYx0Qist9+5yNGidf6zoH9bkwm4S1/iBBVWp/PvPlPx60Z+6xh+/5H64aa8e7j29jPZ2561qzrSTD8DrEWnxROxlA2a6Y3G8IdBP/s6KtJCvdQB6oo2LZ+wuKxXcNvQ3Ln0dCKh6lFvoLKNGYM6WCyrEFHeS5IQBQB+JVcknL8MgTHF8vJ0gnNbZ5Ev8AvLPgeIy0O5fIfMMv94CKOoBbP8Ty26dBmGVyCo35UeGM5ebWqsEkjWUXfyN2j1Lz8K0E+qNQhSJYiLJeeJQsn5jm9PCu75N99xRyM6EePga11VfyKk4kU/li7R3P+X2ap+wolXRcRMB+KwUrG95OjhOJM905VHmi0OEjqiX7c1PxlT7EfgZhmN8V5AR/kUmRaU1h5EQAsOUZZ/eT3ymwsPUMZCXTBjqlYg== 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 Thu, Apr 25, 2024 at 01:37:40PM +0200, Pankaj Raghav (Samsung) wrote: > From: Pankaj Raghav > > Splitting a larger folio with a base order is supported using > split_huge_page_to_list_to_order() API. However, using that API for LBS > is resulting in an NULL ptr dereference error in the writeback path [1]. > > Refuse to split a folio if it has minimum folio order requirement until > we can start using split_huge_page_to_list_to_order() API. Splitting the > folio can be added as a later optimization. > > [1] https://gist.github.com/mcgrof/d12f586ec6ebe32b2472b5d634c397df Obviously this has to be tracked down and fixed before this patchset can be merged ... I think I have some ideas. Let me look a bit. How would I go about reproducing this?