All of lore.kernel.org
 help / color / mirror / Atom feed
From: Brian Foster <bfoster@redhat.com>
To: linux-fsdevel@vger.kernel.org
Cc: linux-xfs@vger.kernel.org
Subject: [PATCH 1/2] iomap: resched ioend completion when in non-atomic context
Date: Fri,  2 Oct 2020 11:33:56 -0400	[thread overview]
Message-ID: <20201002153357.56409-2-bfoster@redhat.com> (raw)
In-Reply-To: <20201002153357.56409-1-bfoster@redhat.com>

The iomap ioend mechanism has the ability to construct very large,
contiguous bios and/or bio chains. This has been reported to lead to
soft lockup warnings in bio completion due to the amount of page
processing that occurs. Update the ioend completion path with a
parameter to indicate atomic context and insert a cond_resched()
call to avoid soft lockups in either scenario.

Signed-off-by: Brian Foster <bfoster@redhat.com>
---
 fs/iomap/buffered-io.c | 15 +++++++++------
 fs/xfs/xfs_aops.c      |  2 +-
 include/linux/iomap.h  |  2 +-
 3 files changed, 11 insertions(+), 8 deletions(-)

diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index bcfc288dba3f..5dfdb77a05b2 100644
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -1092,7 +1092,7 @@ iomap_finish_page_writeback(struct inode *inode, struct page *page,
  * ioend after this.
  */
 static void
-iomap_finish_ioend(struct iomap_ioend *ioend, int error)
+iomap_finish_ioend(struct iomap_ioend *ioend, int error, bool atomic)
 {
 	struct inode *inode = ioend->io_inode;
 	struct bio *bio = &ioend->io_inline_bio;
@@ -1115,8 +1115,11 @@ iomap_finish_ioend(struct iomap_ioend *ioend, int error)
 			next = bio->bi_private;
 
 		/* walk each page on bio, ending page IO on them */
-		bio_for_each_segment_all(bv, bio, iter_all)
+		bio_for_each_segment_all(bv, bio, iter_all) {
 			iomap_finish_page_writeback(inode, bv->bv_page, error);
+			if (!atomic)
+				cond_resched();
+		}
 		bio_put(bio);
 	}
 	/* The ioend has been freed by bio_put() */
@@ -1129,17 +1132,17 @@ iomap_finish_ioend(struct iomap_ioend *ioend, int error)
 }
 
 void
-iomap_finish_ioends(struct iomap_ioend *ioend, int error)
+iomap_finish_ioends(struct iomap_ioend *ioend, int error, bool atomic)
 {
 	struct list_head tmp;
 
 	list_replace_init(&ioend->io_list, &tmp);
-	iomap_finish_ioend(ioend, error);
+	iomap_finish_ioend(ioend, error, atomic);
 
 	while (!list_empty(&tmp)) {
 		ioend = list_first_entry(&tmp, struct iomap_ioend, io_list);
 		list_del_init(&ioend->io_list);
-		iomap_finish_ioend(ioend, error);
+		iomap_finish_ioend(ioend, error, atomic);
 	}
 }
 EXPORT_SYMBOL_GPL(iomap_finish_ioends);
@@ -1208,7 +1211,7 @@ static void iomap_writepage_end_bio(struct bio *bio)
 {
 	struct iomap_ioend *ioend = bio->bi_private;
 
-	iomap_finish_ioend(ioend, blk_status_to_errno(bio->bi_status));
+	iomap_finish_ioend(ioend, blk_status_to_errno(bio->bi_status), true);
 }
 
 /*
diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
index b35611882ff9..3e061ea99922 100644
--- a/fs/xfs/xfs_aops.c
+++ b/fs/xfs/xfs_aops.c
@@ -188,7 +188,7 @@ xfs_end_ioend(
 done:
 	if (ioend->io_private)
 		error = xfs_setfilesize_ioend(ioend, error);
-	iomap_finish_ioends(ioend, error);
+	iomap_finish_ioends(ioend, error, false);
 	memalloc_nofs_restore(nofs_flag);
 }
 
diff --git a/include/linux/iomap.h b/include/linux/iomap.h
index 4d1d3c3469e9..4d3778dc4318 100644
--- a/include/linux/iomap.h
+++ b/include/linux/iomap.h
@@ -229,7 +229,7 @@ struct iomap_writepage_ctx {
 	const struct iomap_writeback_ops *ops;
 };
 
-void iomap_finish_ioends(struct iomap_ioend *ioend, int error);
+void iomap_finish_ioends(struct iomap_ioend *ioend, int error, bool atomic);
 void iomap_ioend_try_merge(struct iomap_ioend *ioend,
 		struct list_head *more_ioends,
 		void (*merge_private)(struct iomap_ioend *ioend,
-- 
2.25.4


  reply	other threads:[~2020-10-02 15:34 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-02 15:33 [PATCH 0/2] iomap: avoid soft lockup warnings on large ioends Brian Foster
2020-10-02 15:33 ` Brian Foster [this message]
2020-10-02 15:33 ` [PATCH 2/2] xfs: kick extra large ioends to completion workqueue Brian Foster
2020-10-02 16:19   ` Darrick J. Wong
2020-10-02 16:38     ` Brian Foster
2020-10-03  0:26   ` kernel test robot
2020-10-03  0:26     ` kernel test robot
2020-10-05 15:21   ` [PATCH v2 " Brian Foster
2020-10-06  3:55     ` Darrick J. Wong
2020-10-06 12:44       ` Brian Foster
2021-05-06 19:31         ` Darrick J. Wong
2021-05-07 14:06           ` Brian Foster
2021-05-07 14:40             ` Matthew Wilcox
2021-05-10  2:45               ` Dave Chinner
2020-10-06 14:07       ` Matthew Wilcox
2021-05-06 19:34         ` Darrick J. Wong
2021-05-06 19:45           ` Matthew Wilcox

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20201002153357.56409-2-bfoster@redhat.com \
    --to=bfoster@redhat.com \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-xfs@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.