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 98CFFC433F5 for ; Thu, 24 Feb 2022 18:10:39 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 24B268D0002; Thu, 24 Feb 2022 13:10:39 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 1FA688D0001; Thu, 24 Feb 2022 13:10:39 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0C38F8D0002; Thu, 24 Feb 2022 13:10:39 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.a.hostedemail.com [64.99.140.24]) by kanga.kvack.org (Postfix) with ESMTP id F27E38D0001 for ; Thu, 24 Feb 2022 13:10:38 -0500 (EST) Received: from smtpin15.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id 9C4D323B17 for ; Thu, 24 Feb 2022 18:10:38 +0000 (UTC) X-FDA: 79178463756.15.808CB3A Received: from mail-yw1-f177.google.com (mail-yw1-f177.google.com [209.85.128.177]) by imf01.hostedemail.com (Postfix) with ESMTP id ECF034000B for ; Thu, 24 Feb 2022 18:10:37 +0000 (UTC) Received: by mail-yw1-f177.google.com with SMTP id 00721157ae682-2d07c4a0d06so6766847b3.13 for ; Thu, 24 Feb 2022 10:10:37 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=5eZDgcxBiEahgQGqIVo4NOwq5Qo0wc2zSQHHLGRnIQM=; b=hOAnqSTI/Gh9yfCHqk+7dOsYcudQiruj8mpt7dmfjM5mWHLmv0u3d04DW8ALfBIXMG jo1aQNu8b37er4WOYMPhB0UKNBWuYIbVmK1S5rZBnKtE3j6emTQsT3qFtpIheorsTivo 5oFwymdPrzK0TL7yVgoFRt/N/qYgq59XcFETBcR/mN/BchTGsA3oSWbl70lTpcsstt5O nRtu1Pud8PUcNNfPv5BadE0iVwqkk4S+ioB/E0TkrKnbVoRVJH4C91+Hcq3PdR/ymM2E gaQI4Q/rQrPyeTqMR7KeZVadtXbPVvCVGUzET6Lt8AJ66Q92342VKnjcz1C6+ONF0BvN RdLw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=5eZDgcxBiEahgQGqIVo4NOwq5Qo0wc2zSQHHLGRnIQM=; b=JSd2FobsHYued9QJwYo0Ym91AFW0FaF01BAQzIhs6guKxGsCIgg/yYj8PBGZz/SQNt WCSr+ZgNvCtBZx4ByHnbUV0V4rXz8L+AupRE4+bGtsGPvyfop/3+Fbme5W9FEE0DrpYo BHYW+LLtYjlsZNB+3vjwT+4RaG4lEHl2p80Pu954jUjBlVZIqwrSrSmC+DtlAFGDGb1X O6MCup/on7mbC/t/P4pt2CiaWpc3OO/3v81VTGtR1mZDDrJiFdBcrsVx1VXHdqd5MKJm vN/MWPz1w7DB1fWsHcdGXFpyeuldreWczOYRuzTJYc0OKc/v0pVbypmzUSftxfwO9e2G hRuw== X-Gm-Message-State: AOAM533O4slEnatBC9f1VEAhMrUogEaObrPCn2ImQpgylKGwJNi+p3u/ v+C7pSbe9BS4+k+hXsRSYqhmbDkFa8ZAzb8lHLU= X-Google-Smtp-Source: ABdhPJzAIqYPKdGLE2EeqFKSCMroLeeiWgQwRfA5B8K+sGjJ+1Pn3nTjD/EQPHmJEn7zy85dqMfSQ0Bfo7hIsT3Znj8= X-Received: by 2002:a81:83d7:0:b0:2d6:b550:21b8 with SMTP id t206-20020a8183d7000000b002d6b55021b8mr3756069ywf.188.1645726237054; Thu, 24 Feb 2022 10:10:37 -0800 (PST) MIME-Version: 1.0 References: <164447124918.23354.17858831070003318849.stgit@noble.brown> <164447147262.23354.13106570458589592051.stgit@noble.brown> In-Reply-To: <164447147262.23354.13106570458589592051.stgit@noble.brown> From: Ryusuke Konishi Date: Fri, 25 Feb 2022 03:10:24 +0900 Message-ID: Subject: Re: [PATCH 08/11] Remove bdi_congested() and wb_congested() and related functions To: NeilBrown Cc: Andrew Morton , Jan Kara , Wu Fengguang , Jaegeuk Kim , Chao Yu , Jeff Layton , Ilya Dryomov , Miklos Szeredi , Trond Myklebust , Anna Schumaker , "Darrick J. Wong" , Philipp Reisner , Lars Ellenberg , Paolo Valente , Jens Axboe , linux-doc@vger.kernel.org, Linux MM , linux-nilfs , linux-nfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-ext4@vger.kernel.org, ceph-devel@vger.kernel.org, drbd-dev@lists.linbit.com, LKML , linux-block@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Authentication-Results: imf01.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=hOAnqSTI; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (imf01.hostedemail.com: domain of konishi.ryusuke@gmail.com designates 209.85.128.177 as permitted sender) smtp.mailfrom=konishi.ryusuke@gmail.com X-Rspam-User: X-Rspamd-Server: rspam07 X-Rspamd-Queue-Id: ECF034000B X-Stat-Signature: 581jzpmsysnopb1qbx9yaszq75rkhcq7 X-HE-Tag: 1645726237-834554 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: On Thu, Feb 10, 2022 at 2:41 PM NeilBrown wrote: > > These functions are no longer useful as no BDIs report congestions any > more. > > Removing the test on bdi_write_contested() in current_may_throttle() > could cause a small change in behaviour, but only when PF_LOCAL_THROTTLE > is set. > > So replace the calls by 'false' and simplify the code - and remove the > functions. > > Acked-by: Ryusuke Konishi (for nilfs bits) > Signed-off-by: NeilBrown > --- > drivers/block/drbd/drbd_int.h | 3 --- > drivers/block/drbd/drbd_req.c | 3 +-- > fs/ext2/ialloc.c | 5 ----- > fs/nilfs2/segbuf.c | 15 --------------- > fs/xfs/xfs_buf.c | 3 --- > include/linux/backing-dev.h | 26 -------------------------- > mm/vmscan.c | 4 +--- > 7 files changed, 2 insertions(+), 57 deletions(-) > > diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h > index f27d5b0f9a0b..f804b1bfb3e6 100644 > --- a/drivers/block/drbd/drbd_int.h > +++ b/drivers/block/drbd/drbd_int.h > @@ -638,9 +638,6 @@ enum { > STATE_SENT, /* Do not change state/UUIDs while this is set */ > CALLBACK_PENDING, /* Whether we have a call_usermodehelper(, UMH_WAIT_PROC) > * pending, from drbd worker context. > - * If set, bdi_write_congested() returns true, > - * so shrink_page_list() would not recurse into, > - * and potentially deadlock on, this drbd worker. > */ > DISCONNECT_SENT, > > diff --git a/drivers/block/drbd/drbd_req.c b/drivers/block/drbd/drbd_req.c > index 3235532ae077..2e5fb7e442e3 100644 > --- a/drivers/block/drbd/drbd_req.c > +++ b/drivers/block/drbd/drbd_req.c > @@ -909,8 +909,7 @@ static bool remote_due_to_read_balancing(struct drbd_device *device, sector_t se > > switch (rbm) { > case RB_CONGESTED_REMOTE: > - return bdi_read_congested( > - device->ldev->backing_bdev->bd_disk->bdi); > + return 0; > case RB_LEAST_PENDING: > return atomic_read(&device->local_cnt) > > atomic_read(&device->ap_pending_cnt) + atomic_read(&device->rs_pending_cnt); > diff --git a/fs/ext2/ialloc.c b/fs/ext2/ialloc.c > index df14e750e9fe..998dd2ac8008 100644 > --- a/fs/ext2/ialloc.c > +++ b/fs/ext2/ialloc.c > @@ -170,11 +170,6 @@ static void ext2_preread_inode(struct inode *inode) > unsigned long offset; > unsigned long block; > struct ext2_group_desc * gdp; > - struct backing_dev_info *bdi; > - > - bdi = inode_to_bdi(inode); > - if (bdi_rw_congested(bdi)) > - return; > > block_group = (inode->i_ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb); > gdp = ext2_get_group_desc(inode->i_sb, block_group, NULL); > diff --git a/fs/nilfs2/segbuf.c b/fs/nilfs2/segbuf.c > index 43287b0d3e9b..c4510f79037f 100644 > --- a/fs/nilfs2/segbuf.c > +++ b/fs/nilfs2/segbuf.c > @@ -343,17 +343,6 @@ static int nilfs_segbuf_submit_bio(struct nilfs_segment_buffer *segbuf, > struct bio *bio = wi->bio; > int err; > > - if (segbuf->sb_nbio > 0 && > - bdi_write_congested(segbuf->sb_super->s_bdi)) { > - wait_for_completion(&segbuf->sb_bio_event); > - segbuf->sb_nbio--; > - if (unlikely(atomic_read(&segbuf->sb_err))) { > - bio_put(bio); > - err = -EIO; > - goto failed; > - } > - } > - > bio->bi_end_io = nilfs_end_bio_write; > bio->bi_private = segbuf; > bio_set_op_attrs(bio, mode, mode_flags); > @@ -365,10 +354,6 @@ static int nilfs_segbuf_submit_bio(struct nilfs_segment_buffer *segbuf, > wi->nr_vecs = min(wi->max_pages, wi->rest_blocks); > wi->start = wi->end; > return 0; > - > - failed: > - wi->bio = NULL; > - return err; > } In this revised version, "int err" is no longer used, so could you delete it as well ? Regards, Ryusuke Konishi > > /** > diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c > index b45e0d50a405..b7ebcfe6b8d3 100644 > --- a/fs/xfs/xfs_buf.c > +++ b/fs/xfs/xfs_buf.c > @@ -843,9 +843,6 @@ xfs_buf_readahead_map( > { > struct xfs_buf *bp; > > - if (bdi_read_congested(target->bt_bdev->bd_disk->bdi)) > - return; > - > xfs_buf_read_map(target, map, nmaps, > XBF_TRYLOCK | XBF_ASYNC | XBF_READ_AHEAD, &bp, ops, > __this_address); > diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h > index 860b675c2929..2d764566280c 100644 > --- a/include/linux/backing-dev.h > +++ b/include/linux/backing-dev.h > @@ -135,11 +135,6 @@ static inline bool writeback_in_progress(struct bdi_writeback *wb) > > struct backing_dev_info *inode_to_bdi(struct inode *inode); > > -static inline int wb_congested(struct bdi_writeback *wb, int cong_bits) > -{ > - return wb->congested & cong_bits; > -} > - > long congestion_wait(int sync, long timeout); > > static inline bool mapping_can_writeback(struct address_space *mapping) > @@ -391,27 +386,6 @@ static inline void wb_blkcg_offline(struct blkcg *blkcg) > > #endif /* CONFIG_CGROUP_WRITEBACK */ > > -static inline int bdi_congested(struct backing_dev_info *bdi, int cong_bits) > -{ > - return wb_congested(&bdi->wb, cong_bits); > -} > - > -static inline int bdi_read_congested(struct backing_dev_info *bdi) > -{ > - return bdi_congested(bdi, 1 << WB_sync_congested); > -} > - > -static inline int bdi_write_congested(struct backing_dev_info *bdi) > -{ > - return bdi_congested(bdi, 1 << WB_async_congested); > -} > - > -static inline int bdi_rw_congested(struct backing_dev_info *bdi) > -{ > - return bdi_congested(bdi, (1 << WB_sync_congested) | > - (1 << WB_async_congested)); > -} > - > const char *bdi_dev_name(struct backing_dev_info *bdi); > > #endif /* _LINUX_BACKING_DEV_H */ > diff --git a/mm/vmscan.c b/mm/vmscan.c > index ce8492939bd3..0b930556c4f2 100644 > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -2362,9 +2362,7 @@ static unsigned int move_pages_to_lru(struct lruvec *lruvec, > */ > static int current_may_throttle(void) > { > - return !(current->flags & PF_LOCAL_THROTTLE) || > - current->backing_dev_info == NULL || > - bdi_write_congested(current->backing_dev_info); > + return !(current->flags & PF_LOCAL_THROTTLE); > } > > /* > >