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 X-Spam-Level: X-Spam-Status: No, score=-11.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6805CC433DF for ; Mon, 17 Aug 2020 06:30:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4DF1820716 for ; Mon, 17 Aug 2020 06:30:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726683AbgHQGay (ORCPT ); Mon, 17 Aug 2020 02:30:54 -0400 Received: from mx2.suse.de ([195.135.220.15]:48528 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726451AbgHQGay (ORCPT ); Mon, 17 Aug 2020 02:30:54 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 9B029B5D4; Mon, 17 Aug 2020 06:31:16 +0000 (UTC) Subject: Re: [PATCH 09/14] bcache: avoid data copy between cache_set->sb and cache->sb To: Hannes Reinecke Cc: linux-bcache@vger.kernel.org, linux-block@vger.kernel.org References: <20200815041043.45116-1-colyli@suse.de> <20200815041043.45116-10-colyli@suse.de> <041fed5e-f54f-d0eb-a5cc-2a52ded7b623@suse.de> From: Coly Li Autocrypt: addr=colyli@suse.de; keydata= mQINBFYX6S8BEAC9VSamb2aiMTQREFXK4K/W7nGnAinca7MRuFUD4JqWMJ9FakNRd/E0v30F qvZ2YWpidPjaIxHwu3u9tmLKqS+2vnP0k7PRHXBYbtZEMpy3kCzseNfdrNqwJ54A430BHf2S GMVRVENiScsnh4SnaYjFVvB8SrlhTsgVEXEBBma5Ktgq9YSoy5miatWmZvHLFTQgFMabCz/P j5/xzykrF6yHo0rHZtwzQzF8rriOplAFCECp/t05+OeHHxjSqSI0P/G79Ll+AJYLRRm9til/ K6yz/1hX5xMToIkYrshDJDrUc8DjEpISQQPhG19PzaUf3vFpmnSVYprcWfJWsa2wZyyjRFkf J51S82WfclafNC6N7eRXedpRpG6udUAYOA1YdtlyQRZa84EJvMzW96iSL1Gf+ZGtRuM3k49H 1wiWOjlANiJYSIWyzJjxAd/7Xtiy/s3PRKL9u9y25ftMLFa1IljiDG+mdY7LyAGfvdtIkanr iBpX4gWXd7lNQFLDJMfShfu+CTMCdRzCAQ9hIHPmBeZDJxKq721CyBiGAhRxDN+TYiaG/UWT 7IB7LL4zJrIe/xQ8HhRO+2NvT89o0LxEFKBGg39yjTMIrjbl2ZxY488+56UV4FclubrG+t16 r2KrandM7P5RjR+cuHhkKseim50Qsw0B+Eu33Hjry7YCihmGswARAQABtBhDb2x5IExpIDxj b2x5bGlAc3VzZS5kZT6JAlYEEwEIAEACGyMHCwkIBwMCAQYVCAIJCgsEFgIDAQIeAQIXgBYh BOo+RS/0+Uhgjej60Mc5B5Nrffj8BQJcR84dBQkY++fuAAoJEMc5B5Nrffj8ixcP/3KAKg1X EcoW4u/0z+Ton5rCyb/NpAww8MuRjNW82UBUac7yCi1y3OW7NtLjuBLw5SaVG5AArb7IF3U0 qTOobqfl5XHsT0o5wFHZaKUrnHb6y7V3SplsJWfkP3JmOooJsQB3z3K96ZTkFelsNb0ZaBRu gV+LA4MomhQ+D3BCDR1it1OX/tpvm2uaDF6s/8uFtcDEM9eQeqATN/QAJ49nvU/I8zDSY9rc 0x9mP0x+gH4RccbnoPu/rUG6Fm1ZpLrbb6NpaYBBJ/V1BC4lIOjnd24bsoQrQmnJn9dSr60X 1MY60XDszIyzRw7vbJcUn6ZzPNFDxFFT9diIb+wBp+DD8ZlD/hnVpl4f921ZbvfOSsXAJrKB 1hGY17FPwelp1sPcK2mDT+pfHEMV+OQdZzD2OCKtza/5IYismJJm3oVUYMogb5vDNAw9X2aP XgwUuG+FDEFPamFMUwIfzYHcePfqf0mMsaeSgtA/xTxzx/0MLjUJHl46Bc0uKDhv7QUyGz0j Ywgr2mHTvG+NWQ/mDeHNGkcnsnp3IY7koDHnN2xMFXzY4bn9m8ctqKo2roqjCzoxD/njoAhf KBzdybLHATqJG/yiZSbCxDA1n/J4FzPyZ0rNHUAJ/QndmmVspE9syFpFCKigvvyrzm016+k+ FJ59Q6RG4MSy/+J565Xj+DNY3/dCuQINBFYX6S8BEADZP+2cl4DRFaSaBms08W8/smc5T2CO YhAoygZn71rB7Djml2ZdvrLRjR8Qbn0Q/2L2gGUVc63pJnbrjlXSx2LfAFE0SlfYIJ11aFdF 9w7RvqWByQjDJor3Z0fWvPExplNgMvxpD0U0QrVT5dIGTx9hadejCl/ug09Lr6MPQn+a4+qs aRWwgCSHaIuDkH3zI1MJXiqXXFKUzJ/Fyx6R72rqiMPHH2nfwmMu6wOXAXb7+sXjZz5Po9GJ g2OcEc+rpUtKUJGyeQsnCDxUcqJXZDBi/GnhPCcraQuqiQ7EGWuJfjk51vaI/rW4bZkA9yEP B9rBYngbz7cQymUsfxuTT8OSlhxjP3l4ZIZFKIhDaQeZMj8pumBfEVUyiF6KVSfgfNQ/5PpM R4/pmGbRqrAAElhrRPbKQnCkGWDr8zG+AjN1KF6rHaFgAIO7TtZ+F28jq4reLkur0N5tQFww wFwxzROdeLHuZjL7eEtcnNnzSkXHczLkV4kQ3+vr/7Gm65mQfnVpg6JpwpVrbDYQeOFlxZ8+ GERY5Dag4KgKa/4cSZX2x/5+KkQx9wHwackw5gDCvAdZ+Q81nm6tRxEYBBiVDQZYqO73stgT ZyrkxykUbQIy8PI+g7XMDCMnPiDncQqgf96KR3cvw4wN8QrgA6xRo8xOc2C3X7jTMQUytCz9 0MyV1QARAQABiQI8BBgBCAAmAhsMFiEE6j5FL/T5SGCN6PrQxzkHk2t9+PwFAlxHziAFCRj7 5/EACgkQxzkHk2t9+PxgfA//cH5R1DvpJPwraTAl24SUcG9EWe+NXyqveApe05nk15zEuxxd e4zFEjo+xYZilSveLqYHrm/amvQhsQ6JLU+8N60DZHVcXbw1Eb8CEjM5oXdbcJpXh1/1BEwl 4phsQMkxOTns51bGDhTQkv4lsZKvNByB9NiiMkT43EOx14rjkhHw3rnqoI7ogu8OO7XWfKcL CbchjJ8t3c2XK1MUe056yPpNAT2XPNF2EEBPG2Y2F4vLgEbPv1EtpGUS1+JvmK3APxjXUl5z 6xrxCQDWM5AAtGfM/IswVjbZYSJYyH4BQKrShzMb0rWUjkpXvvjsjt8rEXpZEYJgX9jvCoxt oqjCKiVLpwje9WkEe9O9VxljmPvxAhVqJjX62S+TGp93iD+mvpCoHo3+CcvyRcilz+Ko8lfO hS9tYT0HDUiDLvpUyH1AR2xW9RGDevGfwGTpF0K6cLouqyZNdhlmNciX48tFUGjakRFsxRmX K0Jx4CEZubakJe+894sX6pvNFiI7qUUdB882i5GR3v9ijVPhaMr8oGuJ3kvwBIA8lvRBGVGn 9xvzkQ8Prpbqh30I4NMp8MjFdkwCN6znBKPHdjNTwE5PRZH0S9J0o67IEIvHfH0eAWAsgpTz +jwc7VKH7vkvgscUhq/v1/PEWCAqh9UHy7R/jiUxwzw/288OpgO+i+2l11Y= Message-ID: Date: Mon, 17 Aug 2020 14:30:47 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:68.0) Gecko/20100101 Thunderbird/68.11.0 MIME-Version: 1.0 In-Reply-To: <041fed5e-f54f-d0eb-a5cc-2a52ded7b623@suse.de> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-bcache-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-bcache@vger.kernel.org On 2020/8/17 14:22, Hannes Reinecke wrote: > On 8/15/20 6:10 AM, Coly Li wrote: >> struct cache_sb embedded in struct cache_set is only partial used and >> not a real copy from cache's in-memory super block. When removing the >> embedded cache_set->sb, it is unncessary to copy data between these two >> in-memory super blocks (cache_set->sb and cache->sb), it is sufficient >> to just use cache->sb. >> >> This patch removes the data copy between these two in-memory super >> blocks in bch_cache_set_alloc() and bcache_write_super(). In future >> except for set_uuid, cache's super block will be referenced by cache >> set, no copy any more. >> >> Signed-off-by: Coly Li >> --- >>   drivers/md/bcache/super.c | 22 +++------------------- >>   1 file changed, 3 insertions(+), 19 deletions(-) >> >> diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c >> index 748b08ab4f11..05c5a7e867bb 100644 >> --- a/drivers/md/bcache/super.c >> +++ b/drivers/md/bcache/super.c >> @@ -350,16 +350,10 @@ void bcache_write_super(struct cache_set *c) >>       down(&c->sb_write_mutex); >>       closure_init(cl, &c->cl); >>   -    c->sb.seq++; >> +    ca->sb.seq++; >>   -    if (c->sb.version > version) >> -        version = c->sb.version; >> - >> -    ca->sb.version        = version; >> -    ca->sb.seq        = c->sb.seq; >> -    ca->sb.last_mount    = c->sb.last_mount; >> - >> -    SET_CACHE_SYNC(&ca->sb, CACHE_SYNC(&c->sb)); >> +    if (ca->sb.version < version) >> +        ca->sb.version = version; >>         bio_init(bio, ca->sb_bv, 1); >>       bio_set_dev(bio, ca->bdev); >> @@ -1860,16 +1854,6 @@ struct cache_set *bch_cache_set_alloc(struct >> cache_sb *sb) >>       bch_cache_accounting_init(&c->accounting, &c->cl); >>         memcpy(c->set_uuid, sb->set_uuid, 16); >> -    c->sb.block_size    = sb->block_size; >> -    c->sb.bucket_size    = sb->bucket_size; >> -    c->sb.nr_in_set        = sb->nr_in_set; >> -    c->sb.last_mount    = sb->last_mount; >> -    c->sb.version        = sb->version; >> -    if (c->sb.version >= BCACHE_SB_VERSION_CDEV_WITH_FEATURES) { >> -        c->sb.feature_compat = sb->feature_compat; >> -        c->sb.feature_ro_compat = sb->feature_ro_compat; >> -        c->sb.feature_incompat = sb->feature_incompat; >> -    } >>         c->bucket_bits        = ilog2(sb->bucket_size); >>       c->block_bits        = ilog2(sb->block_size); >> > Please fold it into patch 13, as then it's obvious why we don't need > this copy actions anymore. Sure, I will do it in next version series. Thanks. Coly Li