From patchwork Tue Mar 22 21:39:10 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Morton X-Patchwork-Id: 12789054 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 2DCF6C433FE for ; Tue, 22 Mar 2022 21:39:15 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id B33166B0073; Tue, 22 Mar 2022 17:39:14 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id AE3966B0085; Tue, 22 Mar 2022 17:39:14 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9D28F6B0087; Tue, 22 Mar 2022 17:39:14 -0400 (EDT) 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 8CDB56B0073 for ; Tue, 22 Mar 2022 17:39:14 -0400 (EDT) Received: from smtpin11.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 5E98C61C52 for ; Tue, 22 Mar 2022 21:39:14 +0000 (UTC) X-FDA: 79273338228.11.F607CE7 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by imf30.hostedemail.com (Postfix) with ESMTP id C4F6A80018 for ; Tue, 22 Mar 2022 21:39:13 +0000 (UTC) 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 ams.source.kernel.org (Postfix) with ESMTPS id 8ED18B81DB1; Tue, 22 Mar 2022 21:39:12 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 300E0C340EE; Tue, 22 Mar 2022 21:39:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1647985151; bh=+H2hovwJcf5n3EEZVRMt5DqfX/fHf+o4DI+lqA0+9Jc=; h=Date:To:From:In-Reply-To:Subject:From; b=BOy0mx7kgtF9yPO+JKC1eebqPaHgzP86fUY0pCN51/69M+BpVigZKZVGJLWHLUhJS LlgRldCSx10DkdIMUmCaYoq2a6Cin86vHYoqXQs2ore4ocBOdtF5Dtv+0DQW4Q36nH kZu0kNiffRt1GP2LS1mi1+DSiOV2TyoPzOrmCXg0= Date: Tue, 22 Mar 2022 14:39:10 -0700 To: trond.myklebust@hammerspace.com,philipp.reisner@linbit.com,paolo.valente@linaro.org,miklos@szeredi.hu,lars.ellenberg@linbit.com,konishi.ryusuke@gmail.com,jlayton@kernel.org,jaegeuk@kernel.org,jack@suse.cz,idryomov@gmail.com,fengguang.wu@intel.com,djwong@kernel.org,chao@kernel.org,axboe@kernel.dk,Anna.Schumaker@Netapp.com,neilb@suse.de,akpm@linux-foundation.org,patches@lists.linux.dev,linux-mm@kvack.org,mm-commits@vger.kernel.org,torvalds@linux-foundation.org,akpm@linux-foundation.org From: Andrew Morton In-Reply-To: <20220322143803.04a5e59a07e48284f196a2f9@linux-foundation.org> Subject: [patch 013/227] remove bdi_congested() and wb_congested() and related functions Message-Id: <20220322213911.300E0C340EE@smtp.kernel.org> X-Rspamd-Server: rspam09 X-Rspam-User: X-Stat-Signature: doffmbz58igbwfsq5m8zd8ftmuy54m5u Authentication-Results: imf30.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=BOy0mx7k; dmarc=none; spf=pass (imf30.hostedemail.com: domain of akpm@linux-foundation.org designates 145.40.68.75 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org X-Rspamd-Queue-Id: C4F6A80018 X-HE-Tag: 1647985153-731515 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: From: NeilBrown Subject: remove bdi_congested() and wb_congested() and related functions 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. [akpm@linux-foundation.org: fix build] Link: https://lkml.kernel.org/r/164549983742.9187.2570198746005819592.stgit@noble.brown Signed-off-by: NeilBrown Acked-by: Ryusuke Konishi [nilfs] Cc: Anna Schumaker Cc: Chao Yu Cc: Darrick J. Wong Cc: Ilya Dryomov Cc: Jaegeuk Kim Cc: Jan Kara Cc: Jeff Layton Cc: Jens Axboe Cc: Lars Ellenberg Cc: Miklos Szeredi Cc: Paolo Valente Cc: Philipp Reisner Cc: Trond Myklebust Cc: Wu Fengguang Signed-off-by: Andrew Morton --- drivers/block/drbd/drbd_int.h | 3 --- drivers/block/drbd/drbd_req.c | 3 +-- fs/ext2/ialloc.c | 5 ----- fs/nilfs2/segbuf.c | 16 ---------------- fs/xfs/xfs_buf.c | 3 --- include/linux/backing-dev.h | 26 -------------------------- mm/vmscan.c | 4 +--- 7 files changed, 2 insertions(+), 58 deletions(-) --- a/drivers/block/drbd/drbd_int.h~remove-bdi_congested-and-wb_congested-and-related-functions +++ a/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, --- a/drivers/block/drbd/drbd_req.c~remove-bdi_congested-and-wb_congested-and-related-functions +++ a/drivers/block/drbd/drbd_req.c @@ -909,8 +909,7 @@ static bool remote_due_to_read_balancing 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); --- a/fs/ext2/ialloc.c~remove-bdi_congested-and-wb_congested-and-related-functions +++ a/fs/ext2/ialloc.c @@ -170,11 +170,6 @@ static void ext2_preread_inode(struct in 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); --- a/fs/nilfs2/segbuf.c~remove-bdi_congested-and-wb_congested-and-related-functions +++ a/fs/nilfs2/segbuf.c @@ -341,18 +341,6 @@ static int nilfs_segbuf_submit_bio(struc int mode_flags) { 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; @@ -365,10 +353,6 @@ static int nilfs_segbuf_submit_bio(struc wi->nr_vecs = min(wi->max_pages, wi->rest_blocks); wi->start = wi->end; return 0; - - failed: - wi->bio = NULL; - return err; } /** --- a/fs/xfs/xfs_buf.c~remove-bdi_congested-and-wb_congested-and-related-functions +++ a/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); --- a/include/linux/backing-dev.h~remove-bdi_congested-and-wb_congested-and-related-functions +++ a/include/linux/backing-dev.h @@ -135,11 +135,6 @@ static inline bool writeback_in_progress 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(stru #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 */ --- a/mm/vmscan.c~remove-bdi_congested-and-wb_congested-and-related-functions +++ a/mm/vmscan.c @@ -2364,9 +2364,7 @@ static unsigned int move_pages_to_lru(st */ 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); } /*