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,
Dave Chinner <dchinner@redhat.com>
Subject: [PATCH v2 5/9] iomap: Support arbitrarily many blocks per page
Date: Fri, 11 Sep 2020 00:47:03 +0100 [thread overview]
Message-ID: <20200910234707.5504-6-willy@infradead.org> (raw)
In-Reply-To: <20200910234707.5504-1-willy@infradead.org>
Size the uptodate array dynamically to support larger pages in the
page cache. With a 64kB page, we're only saving 8 bytes per page today,
but with a 2MB maximum page size, we'd have to allocate more than 4kB
per page. Add a few debugging assertions.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
---
fs/iomap/buffered-io.c | 22 +++++++++++++++++-----
1 file changed, 17 insertions(+), 5 deletions(-)
diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index 7fc0e02d27b0..9670c096b83e 100644
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -22,18 +22,25 @@
#include "../internal.h"
/*
- * Structure allocated for each page when block size < PAGE_SIZE to track
- * sub-page uptodate status and I/O completions.
+ * Structure allocated for each page or THP when block size < page size
+ * to track sub-page uptodate status and I/O completions.
*/
struct iomap_page {
atomic_t read_count;
atomic_t write_count;
spinlock_t uptodate_lock;
- DECLARE_BITMAP(uptodate, PAGE_SIZE / 512);
+ unsigned long uptodate[];
};
static inline struct iomap_page *to_iomap_page(struct page *page)
{
+ /*
+ * per-block data is stored in the head page. Callers should
+ * not be dealing with tail pages (and if they are, they can
+ * call thp_head() first.
+ */
+ VM_BUG_ON_PGFLAGS(PageTail(page), page);
+
if (page_has_private(page))
return (struct iomap_page *)page_private(page);
return NULL;
@@ -45,11 +52,13 @@ static struct iomap_page *
iomap_page_create(struct inode *inode, struct page *page)
{
struct iomap_page *iop = to_iomap_page(page);
+ unsigned int nr_blocks = i_blocks_per_page(inode, page);
- if (iop || i_blocks_per_page(inode, page) <= 1)
+ if (iop || nr_blocks <= 1)
return iop;
- iop = kzalloc(sizeof(*iop), GFP_NOFS | __GFP_NOFAIL);
+ iop = kzalloc(struct_size(iop, uptodate, BITS_TO_LONGS(nr_blocks)),
+ GFP_NOFS | __GFP_NOFAIL);
spin_lock_init(&iop->uptodate_lock);
attach_page_private(page, iop);
return iop;
@@ -59,11 +68,14 @@ static void
iomap_page_release(struct page *page)
{
struct iomap_page *iop = detach_page_private(page);
+ unsigned int nr_blocks = i_blocks_per_page(page->mapping->host, page);
if (!iop)
return;
WARN_ON_ONCE(atomic_read(&iop->read_count));
WARN_ON_ONCE(atomic_read(&iop->write_count));
+ WARN_ON_ONCE(bitmap_full(iop->uptodate, nr_blocks) !=
+ PageUptodate(page));
kfree(iop);
}
--
2.28.0
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next prev parent reply other threads:[~2020-09-10 23:47 UTC|newest]
Thread overview: 32+ 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 ` [PATCH v2 1/9] iomap: Fix misplaced page flushing Matthew Wilcox (Oracle)
2020-09-10 23:47 ` [PATCH v2 2/9] fs: Introduce i_blocks_per_page Matthew Wilcox (Oracle)
2020-09-15 14:58 ` Dave Kleikamp
2020-09-15 15:40 ` David Laight
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 ` [PATCH v2 4/9] iomap: Use bitmap ops to set uptodate bits Matthew Wilcox (Oracle)
2020-09-10 23:47 ` Matthew Wilcox (Oracle) [this message]
2020-09-11 5:36 ` [PATCH v2 5/9] iomap: Support arbitrarily many blocks per page Christoph Hellwig
2020-09-17 22:00 ` Darrick J. Wong
2020-09-22 16:23 ` Qian Cai
2020-09-22 17:05 ` Matthew Wilcox
2020-09-22 17:25 ` Qian Cai
2020-09-23 1:06 ` Qian Cai
2020-09-23 2:48 ` Matthew Wilcox
2020-09-23 5:00 ` Darrick J. Wong
2020-09-23 18:59 ` Matthew Wilcox
2020-09-23 16:55 ` Qian Cai
2020-09-24 1:07 ` Matthew Wilcox
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
2020-09-17 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)
2020-09-17 22:02 ` Darrick J. Wong
2020-09-10 23:47 ` [PATCH v2 8/9] iomap: Convert iomap_write_end types Matthew Wilcox (Oracle)
2020-09-17 22:03 ` Darrick J. Wong
2020-09-10 23:47 ` [PATCH v2 9/9] iomap: Change calling convention for zeroing Matthew Wilcox (Oracle)
2020-09-11 6:42 ` Christoph Hellwig
2020-09-17 22:05 ` Darrick J. Wong
2020-09-17 22:11 ` Matthew Wilcox
2020-09-17 22:18 ` Darrick J. Wong
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