From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from outgoing.mit.edu (outgoing-auth-1.mit.edu [18.9.28.11]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BEA6919AD58 for ; Thu, 27 Jun 2024 20:20:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=18.9.28.11 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719519644; cv=none; b=ns07pxd2yYy1QhiwaSgbPEvb//Ncqc7+/ElQjeGv4akPOxZ5Y4IbQaZT88zg3eNdOUymyVLIMfX5phIb3c/Nh71adXUrJ7dycNfQ/FUDgIz7B/dNHry1uS9KKisTgGkKszu8IAhw4oBH1bMpb0IE1vQ0YjdKV37CXw/acTMsbo0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719519644; c=relaxed/simple; bh=OXJiBBaFNNTePTOekfrLrNoxaM+AW+3/asjN77aGn8Y=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=FwGi5KW6KMYGsIAl8RkiZ4+6AE+XLAT2eckSC+Zhu/0mUiMiB8Bi91LhqKZqP8/qDdV/pdaHet+Ilhu1euXcsiIlPIOv3JGlb1ht1beRrvmzeebc1zdYkmGpuQjYVwMjAKv4YZUlOz+BKb4LBeSaebrggLnQ9KDgVm0zESQ4/tg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=mit.edu; spf=pass smtp.mailfrom=mit.edu; dkim=pass (2048-bit key) header.d=mit.edu header.i=@mit.edu header.b=fl17DrTA; arc=none smtp.client-ip=18.9.28.11 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=mit.edu Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=mit.edu Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=mit.edu header.i=@mit.edu header.b="fl17DrTA" Received: from cwcc.thunk.org (pool-173-48-120-63.bstnma.fios.verizon.net [173.48.120.63]) (authenticated bits=0) (User authenticated as tytso@ATHENA.MIT.EDU) by outgoing.mit.edu (8.14.7/8.12.4) with ESMTP id 45RKKN8J031179 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 27 Jun 2024 16:20:24 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mit.edu; s=outgoing; t=1719519625; bh=s+rFpXLKQ2ZhL/W/oYJbr5AUZbSOpyEQSq/ARRRaQ2M=; h=Date:From:Subject:Message-ID:MIME-Version:Content-Type; b=fl17DrTA9niz3J7NcW9+dmQ6WH86zi8MsyrKlnzYwm1+AMpX58HZs7q/kvUpIOmnJ VNh/95H/+NWAqO2mXk50tImiWBAqklNTMG8UMAQp2BoYYZvtfDvRA2YSFLNApquLcf kgHcYNU5s0n4USTcYV9NTybl1YAl8cT2OUKLYHXwLBVurBDBqyWiCyL7Gw0gAH/hcz TNlEzGo0iH8Fni3nRquYNQVw/YnHtJBbrPVVn8McpSAV2qszDU+m+M2lDaVccpazCa 81SVG8fkniKHWQiOn7VTRrFX4sTazvRV/dgMOyJzUJcCiksfKyY5Zv2z8djRUILJnT qyd64FSbPp58Q== Received: by cwcc.thunk.org (Postfix, from userid 15806) id D36C715C626C; Thu, 27 Jun 2024 16:20:22 -0400 (EDT) Date: Thu, 27 Jun 2024 16:20:22 -0400 From: "Theodore Ts'o" To: "Matthew Wilcox (Oracle)" Cc: Andreas Dilger , linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org, Hannes Reinecke Subject: Re: [PATCH 2/2] ext4: Remove array of buffer_heads from mext_page_mkuptodate() Message-ID: <20240627202022.GC419129@mit.edu> References: <20240516181651.2879778-1-willy@infradead.org> <20240516181651.2879778-2-willy@infradead.org> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240516181651.2879778-2-willy@infradead.org> On Thu, May 16, 2024 at 07:16:51PM +0100, Matthew Wilcox (Oracle) wrote: > The current code iterates over the list of buffer_heads, finds the > !uptodate ones and reads them, waiting for each one before submitting > the next one. Instead, submit all the read requests before waiting > for each of the needed ones. > > Signed-off-by: Matthew Wilcox (Oracle) Hey Willy, This patch is causing ext4/020 (which tests the EXT4_IOC_MOVE_EXT ioctl used by e4defrag). This can be easily reproduced via: "kvm-xfstests -c ext4/4k ext4/020". From /results/ext4/results-4k/ext4/020.out.bad: QA output created by 020 wrote 1048576/1048576 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) wrote 1023/1023 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) md5sum: WARNING: 1 computed checksum did NOT match SCRATCH_MNT/020.orig: FAILED I'm going to drop both this patch and the preceeding patch in this series ("ext4: reduce stack usage in ext4_mpage_readpages()") pending further investigation. - Ted