All of lore.kernel.org
 help / color / mirror / Atom feed
From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
To: linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>,
	"Darrick J . Wong" <darrick.wong@oracle.com>,
	Christoph Hellwig <hch@infradead.org>,
	linux-nvdimm@lists.01.org, linux-kernel@vger.kernel.org,
	Dave Kleikamp <shaggy@kernel.org>,
	jfs-discussion@lists.sourceforge.net
Subject: [PATCH v2 6/9] iomap: Convert read_count to read_bytes_pending
Date: Fri, 11 Sep 2020 00:47:04 +0100	[thread overview]
Message-ID: <20200910234707.5504-7-willy@infradead.org> (raw)
In-Reply-To: <20200910234707.5504-1-willy@infradead.org>

Instead of counting bio segments, count the number of bytes submitted.
This insulates us from the block layer's definition of what a 'same page'
is, which is not necessarily clear once THPs are involved.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
 fs/iomap/buffered-io.c | 41 ++++++++++++-----------------------------
 1 file changed, 12 insertions(+), 29 deletions(-)

diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index 9670c096b83e..1cf976a8e55c 100644
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -26,7 +26,7 @@
  * to track sub-page uptodate status and I/O completions.
  */
 struct iomap_page {
-	atomic_t		read_count;
+	atomic_t		read_bytes_pending;
 	atomic_t		write_count;
 	spinlock_t		uptodate_lock;
 	unsigned long		uptodate[];
@@ -72,7 +72,7 @@ iomap_page_release(struct page *page)
 
 	if (!iop)
 		return;
-	WARN_ON_ONCE(atomic_read(&iop->read_count));
+	WARN_ON_ONCE(atomic_read(&iop->read_bytes_pending));
 	WARN_ON_ONCE(atomic_read(&iop->write_count));
 	WARN_ON_ONCE(bitmap_full(iop->uptodate, nr_blocks) !=
 			PageUptodate(page));
@@ -167,13 +167,6 @@ iomap_set_range_uptodate(struct page *page, unsigned off, unsigned len)
 		SetPageUptodate(page);
 }
 
-static void
-iomap_read_finish(struct iomap_page *iop, struct page *page)
-{
-	if (!iop || atomic_dec_and_test(&iop->read_count))
-		unlock_page(page);
-}
-
 static void
 iomap_read_page_end_io(struct bio_vec *bvec, int error)
 {
@@ -187,7 +180,8 @@ iomap_read_page_end_io(struct bio_vec *bvec, int error)
 		iomap_set_range_uptodate(page, bvec->bv_offset, bvec->bv_len);
 	}
 
-	iomap_read_finish(iop, page);
+	if (!iop || atomic_sub_and_test(bvec->bv_len, &iop->read_bytes_pending))
+		unlock_page(page);
 }
 
 static void
@@ -267,30 +261,19 @@ iomap_readpage_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
 	}
 
 	ctx->cur_page_in_bio = true;
+	if (iop)
+		atomic_add(plen, &iop->read_bytes_pending);
 
-	/*
-	 * Try to merge into a previous segment if we can.
-	 */
+	/* Try to merge into a previous segment if we can */
 	sector = iomap_sector(iomap, pos);
-	if (ctx->bio && bio_end_sector(ctx->bio) == sector)
+	if (ctx->bio && bio_end_sector(ctx->bio) == sector) {
+		if (__bio_try_merge_page(ctx->bio, page, plen, poff,
+				&same_page))
+			goto done;
 		is_contig = true;
-
-	if (is_contig &&
-	    __bio_try_merge_page(ctx->bio, page, plen, poff, &same_page)) {
-		if (!same_page && iop)
-			atomic_inc(&iop->read_count);
-		goto done;
 	}
 
-	/*
-	 * If we start a new segment we need to increase the read count, and we
-	 * need to do so before submitting any previous full bio to make sure
-	 * that we don't prematurely unlock the page.
-	 */
-	if (iop)
-		atomic_inc(&iop->read_count);
-
-	if (!ctx->bio || !is_contig || bio_full(ctx->bio, plen)) {
+	if (!is_contig || bio_full(ctx->bio, plen)) {
 		gfp_t gfp = mapping_gfp_constraint(page->mapping, GFP_KERNEL);
 		gfp_t orig_gfp = gfp;
 		int nr_vecs = (length + PAGE_SIZE - 1) >> PAGE_SHIFT;
-- 
2.28.0
_______________________________________________
Linux-nvdimm mailing list -- linux-nvdimm@lists.01.org
To unsubscribe send an email to linux-nvdimm-leave@lists.01.org

WARNING: multiple messages have this Message-ID (diff)
From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
To: linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>,
	"Darrick J . Wong" <darrick.wong@oracle.com>,
	Christoph Hellwig <hch@infradead.org>,
	linux-nvdimm@lists.01.org, linux-kernel@vger.kernel.org,
	Dave Kleikamp <shaggy@kernel.org>,
	jfs-discussion@lists.sourceforge.net
Subject: [PATCH v2 6/9] iomap: Convert read_count to read_bytes_pending
Date: Fri, 11 Sep 2020 00:47:04 +0100	[thread overview]
Message-ID: <20200910234707.5504-7-willy@infradead.org> (raw)
In-Reply-To: <20200910234707.5504-1-willy@infradead.org>

Instead of counting bio segments, count the number of bytes submitted.
This insulates us from the block layer's definition of what a 'same page'
is, which is not necessarily clear once THPs are involved.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
 fs/iomap/buffered-io.c | 41 ++++++++++++-----------------------------
 1 file changed, 12 insertions(+), 29 deletions(-)

diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index 9670c096b83e..1cf976a8e55c 100644
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -26,7 +26,7 @@
  * to track sub-page uptodate status and I/O completions.
  */
 struct iomap_page {
-	atomic_t		read_count;
+	atomic_t		read_bytes_pending;
 	atomic_t		write_count;
 	spinlock_t		uptodate_lock;
 	unsigned long		uptodate[];
@@ -72,7 +72,7 @@ iomap_page_release(struct page *page)
 
 	if (!iop)
 		return;
-	WARN_ON_ONCE(atomic_read(&iop->read_count));
+	WARN_ON_ONCE(atomic_read(&iop->read_bytes_pending));
 	WARN_ON_ONCE(atomic_read(&iop->write_count));
 	WARN_ON_ONCE(bitmap_full(iop->uptodate, nr_blocks) !=
 			PageUptodate(page));
@@ -167,13 +167,6 @@ iomap_set_range_uptodate(struct page *page, unsigned off, unsigned len)
 		SetPageUptodate(page);
 }
 
-static void
-iomap_read_finish(struct iomap_page *iop, struct page *page)
-{
-	if (!iop || atomic_dec_and_test(&iop->read_count))
-		unlock_page(page);
-}
-
 static void
 iomap_read_page_end_io(struct bio_vec *bvec, int error)
 {
@@ -187,7 +180,8 @@ iomap_read_page_end_io(struct bio_vec *bvec, int error)
 		iomap_set_range_uptodate(page, bvec->bv_offset, bvec->bv_len);
 	}
 
-	iomap_read_finish(iop, page);
+	if (!iop || atomic_sub_and_test(bvec->bv_len, &iop->read_bytes_pending))
+		unlock_page(page);
 }
 
 static void
@@ -267,30 +261,19 @@ iomap_readpage_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
 	}
 
 	ctx->cur_page_in_bio = true;
+	if (iop)
+		atomic_add(plen, &iop->read_bytes_pending);
 
-	/*
-	 * Try to merge into a previous segment if we can.
-	 */
+	/* Try to merge into a previous segment if we can */
 	sector = iomap_sector(iomap, pos);
-	if (ctx->bio && bio_end_sector(ctx->bio) == sector)
+	if (ctx->bio && bio_end_sector(ctx->bio) == sector) {
+		if (__bio_try_merge_page(ctx->bio, page, plen, poff,
+				&same_page))
+			goto done;
 		is_contig = true;
-
-	if (is_contig &&
-	    __bio_try_merge_page(ctx->bio, page, plen, poff, &same_page)) {
-		if (!same_page && iop)
-			atomic_inc(&iop->read_count);
-		goto done;
 	}
 
-	/*
-	 * If we start a new segment we need to increase the read count, and we
-	 * need to do so before submitting any previous full bio to make sure
-	 * that we don't prematurely unlock the page.
-	 */
-	if (iop)
-		atomic_inc(&iop->read_count);
-
-	if (!ctx->bio || !is_contig || bio_full(ctx->bio, plen)) {
+	if (!is_contig || bio_full(ctx->bio, plen)) {
 		gfp_t gfp = mapping_gfp_constraint(page->mapping, GFP_KERNEL);
 		gfp_t orig_gfp = gfp;
 		int nr_vecs = (length + PAGE_SIZE - 1) >> PAGE_SHIFT;
-- 
2.28.0


  parent reply	other threads:[~2020-09-10 23:47 UTC|newest]

Thread overview: 64+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-10 23:46 [PATCH v2 0/9] THP iomap patches for 5.10 Matthew Wilcox (Oracle)
2020-09-10 23:46 ` Matthew Wilcox (Oracle)
2020-09-10 23:46 ` [PATCH v2 1/9] iomap: Fix misplaced page flushing Matthew Wilcox (Oracle)
2020-09-10 23:46   ` Matthew Wilcox (Oracle)
2020-09-10 23:47 ` [PATCH v2 2/9] fs: Introduce i_blocks_per_page Matthew Wilcox (Oracle)
2020-09-10 23:47   ` Matthew Wilcox (Oracle)
2020-09-15 14:58   ` Dave Kleikamp
2020-09-15 14:58     ` Dave Kleikamp
2020-09-15 15:40   ` David Laight
2020-09-15 15:40     ` David Laight
2020-09-15 15:49     ` Matthew Wilcox
2020-09-15 15:49       ` Matthew Wilcox
2020-09-10 23:47 ` [PATCH v2 3/9] iomap: Use kzalloc to allocate iomap_page Matthew Wilcox (Oracle)
2020-09-10 23:47   ` Matthew Wilcox (Oracle)
2020-09-10 23:47 ` [PATCH v2 4/9] iomap: Use bitmap ops to set uptodate bits Matthew Wilcox (Oracle)
2020-09-10 23:47   ` Matthew Wilcox (Oracle)
2020-09-10 23:47 ` [PATCH v2 5/9] iomap: Support arbitrarily many blocks per page Matthew Wilcox (Oracle)
2020-09-10 23:47   ` Matthew Wilcox (Oracle)
2020-09-11  5:36   ` Christoph Hellwig
2020-09-11  5:36     ` Christoph Hellwig
2020-09-17 22:00   ` Darrick J. Wong
2020-09-17 22:00     ` Darrick J. Wong
2020-09-22 16:23   ` Qian Cai
2020-09-22 16:23     ` Qian Cai
2020-09-22 17:05     ` Matthew Wilcox
2020-09-22 17:05       ` Matthew Wilcox
2020-09-22 17:25       ` Qian Cai
2020-09-22 17:25         ` Qian Cai
2020-09-23  1:06       ` Qian Cai
2020-09-23  1:06         ` Qian Cai
2020-09-23  2:48         ` Matthew Wilcox
2020-09-23  2:48           ` Matthew Wilcox
2020-09-23  5:00           ` Darrick J. Wong
2020-09-23  5:00             ` Darrick J. Wong
2020-09-23 18:59             ` Matthew Wilcox
2020-09-23 18:59               ` Matthew Wilcox
2020-09-23 16:55           ` Qian Cai
2020-09-23 16:55             ` Qian Cai
2020-09-24  1:07       ` Matthew Wilcox
2020-09-24  1:07         ` Matthew Wilcox
2020-09-10 23:47 ` Matthew Wilcox (Oracle) [this message]
2020-09-10 23:47   ` [PATCH v2 6/9] iomap: Convert read_count to read_bytes_pending Matthew Wilcox (Oracle)
2020-09-11  5:36   ` Christoph Hellwig
2020-09-11  5:36     ` Christoph Hellwig
2020-09-17 22:02   ` Darrick J. Wong
2020-09-17 22:02     ` Darrick J. Wong
2020-09-10 23:47 ` [PATCH v2 7/9] iomap: Convert write_count to write_bytes_pending Matthew Wilcox (Oracle)
2020-09-10 23:47   ` Matthew Wilcox (Oracle)
2020-09-17 22:02   ` Darrick J. Wong
2020-09-17 22:02     ` Darrick J. Wong
2020-09-10 23:47 ` [PATCH v2 8/9] iomap: Convert iomap_write_end types Matthew Wilcox (Oracle)
2020-09-10 23:47   ` Matthew Wilcox (Oracle)
2020-09-17 22:03   ` Darrick J. Wong
2020-09-17 22:03     ` Darrick J. Wong
2020-09-10 23:47 ` [PATCH v2 9/9] iomap: Change calling convention for zeroing Matthew Wilcox (Oracle)
2020-09-10 23:47   ` Matthew Wilcox (Oracle)
2020-09-11  6:42   ` Christoph Hellwig
2020-09-11  6:42     ` Christoph Hellwig
2020-09-17 22:05   ` Darrick J. Wong
2020-09-17 22:05     ` Darrick J. Wong
2020-09-17 22:11     ` Matthew Wilcox
2020-09-17 22:11       ` Matthew Wilcox
2020-09-17 22:18       ` Darrick J. Wong
2020-09-17 22:18         ` Darrick J. Wong

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=20200910234707.5504-7-willy@infradead.org \
    --to=willy@infradead.org \
    --cc=darrick.wong@oracle.com \
    --cc=hch@infradead.org \
    --cc=jfs-discussion@lists.sourceforge.net \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-nvdimm@lists.01.org \
    --cc=linux-xfs@vger.kernel.org \
    --cc=shaggy@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.