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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 08535C433F5 for ; Wed, 5 Jan 2022 19:10:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243362AbiAETKC (ORCPT ); Wed, 5 Jan 2022 14:10:02 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50120 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243363AbiAETJ7 (ORCPT ); Wed, 5 Jan 2022 14:09:59 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BE7A3C061245; Wed, 5 Jan 2022 11:09:58 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 60F50618E1; Wed, 5 Jan 2022 19:09:58 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B9F22C36AE0; Wed, 5 Jan 2022 19:09:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1641409797; bh=1m7JNzEs6h7AUbdTf9WL1gJ+URfwbVnYu243vT+/00E=; h=Date:From:To:Subject:References:In-Reply-To:From; b=fCiw785/QNNK/3p6u3BjCIuLHg8GUtllV7ZcMi51Eu2LQwiQlefLJ9iOCQna1I8qI UxN2PW6qdzTYX+gL1BCBKhITJw7VQA//3P3DwsXb59hOYUdVGhCKBErNygEXI8noPE lmoYiltSwOtAMB9wA2PvQTwI/SFz/PUagTaFXHPnF9tUrMSBbizibQ4VLdcbW7cPvJ xdc4b1fLNZYPUq3cTiAGkhzT1jwWLOrnuWz2fLiyQeHVv2XkOSP3Ptarm74YFa9Uzl SffWzU3u+P+ZBGHy4Xb4boBHVO57BLhga1sls2NCAcOTvnbpu/SbnmLxBMI1sUqg2s iV9lcVf1GpMbA== Date: Wed, 5 Jan 2022 11:09:57 -0800 From: "Darrick J. Wong" To: Eryu Guan , fstests@vger.kernel.org, xfs , zlang@redhat.com Subject: Re: [PATCH] xfs/014: try a few times to create speculative preallocations Message-ID: <20220105190957.GJ656707@magnolia> References: <20220104020417.GB31566@magnolia> <20220105161905.jaobft32wosjy3fv@zlang-mailbox> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220105161905.jaobft32wosjy3fv@zlang-mailbox> Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org On Thu, Jan 06, 2022 at 12:19:05AM +0800, Zorro Lang wrote: > On Mon, Jan 03, 2022 at 06:04:17PM -0800, Darrick J. Wong wrote: > > From: Darrick J. Wong > > > > This test checks that speculative file preallocations are transferred to > > threads writing other files when space is low. Since we have background > > threads to clear those preallocations, it's possible that the test > > program might not get a speculative preallocation on the first try. > > > > This problem has become more pronounced since the introduction of > > background inode inactivation since userspace no longer has direct > > control over the timing of file blocks being released from unlinked > > files. As a result, the author has seen an increase in sporadic > > warnings from this test about speculative preallocations not appearing. > > > > Therefore, modify the function to try up to five times to create the > > speculative preallocation before emitting warnings that then cause > > golden output failures. > > > > Signed-off-by: Darrick J. Wong > > --- > > tests/xfs/014 | 41 +++++++++++++++++++++++++---------------- > > 1 file changed, 25 insertions(+), 16 deletions(-) > > > > diff --git a/tests/xfs/014 b/tests/xfs/014 > > index a605b359..1f0ebac3 100755 > > --- a/tests/xfs/014 > > +++ b/tests/xfs/014 > > @@ -33,27 +33,36 @@ _cleanup() > > # failure. > > _spec_prealloc_file() > > { > > - file=$1 > > + local file=$1 > > + local prealloc_size=0 > > + local i=0 > > > > - rm -f $file > > + # Now that we have background garbage collection processes that can be > > + # triggered by low space/quota conditions, it's possible that we won't > > + # succeed in creating a speculative preallocation on the first try. > > + for ((tries = 0; tries < 5 && prealloc_size == 0; tries++)); do > > + rm -f $file > > > > - # a few file extending open-write-close cycles should be enough to > > - # trigger the fs to retain preallocation. write 256k in 32k intervals to > > - # be sure > > - for i in $(seq 0 32768 262144); do > > - $XFS_IO_PROG -f -c "pwrite $i 32k" $file >> $seqres.full > > + # a few file extending open-write-close cycles should be enough > > + # to trigger the fs to retain preallocation. write 256k in 32k > > + # intervals to be sure > > + for i in $(seq 0 32768 262144); do > > + $XFS_IO_PROG -f -c "pwrite $i 32k" $file >> $seqres.full > > + done > > + > > + # write a 4k aligned amount of data to keep the calculations > > + # simple > > + $XFS_IO_PROG -c "pwrite 0 128m" $file >> $seqres.full > > + > > + size=`_get_filesize $file` > > + blocks=`stat -c "%b" $file` > > + blocksize=`stat -c "%B" $file` > > + > > + prealloc_size=$((blocks * blocksize - size)) > > So we only try same pwrite operations 5 times, and only check the prealloc_size after 5 > times done? Should we break from this loop once prealloc_size > 0? The second clause of the for loop tests for that, does it not? --D > > Thanks, > Zorro > > > done > > > > - # write a 4k aligned amount of data to keep the calculations simple > > - $XFS_IO_PROG -c "pwrite 0 128m" $file >> $seqres.full > > - > > - size=`_get_filesize $file` > > - blocks=`stat -c "%b" $file` > > - blocksize=`stat -c "%B" $file` > > - > > - prealloc_size=$((blocks * blocksize - size)) > > if [ $prealloc_size -eq 0 ]; then > > - echo "Warning: No speculative preallocation for $file." \ > > + echo "Warning: No speculative preallocation for $file after $tries iterations." \ > > "Check use of the allocsize= mount option." > > fi > > > > >