2020-08-24 15:10:50

by Matthew Wilcox

Subject: [PATCH 4/9] iomap: Use bitmap ops to set uptodate bits

Now that the bitmap is protected by a spinlock, we can use the
more efficient bitmap ops instead of individual test/set bit ops.

Signed-off-by: Matthew Wilcox (Oracle) <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
---
fs/iomap/buffered-io.c | 12 ++----------
1 file changed, 2 insertions(+), 10 deletions(-)

diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index 639d54a4177e..dbf9572dabe9 100644
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -134,19 +134,11 @@ iomap_iop_set_range_uptodate(struct page *page, unsigned off, unsigned len)
struct inode *inode = page->mapping->host;
unsigned first = off >> inode->i_blkbits;
unsigned last = (off + len - 1) >> inode->i_blkbits;
- bool uptodate = true;
unsigned long flags;
- unsigned int i;

spin_lock_irqsave(&iop->uptodate_lock, flags);
- for (i = 0; i < i_blocks_per_page(inode, page); i++) {
- if (i >= first && i <= last)
- set_bit(i, iop->uptodate);
- else if (!test_bit(i, iop->uptodate))
- uptodate = false;
- }
-
- if (uptodate)
+ bitmap_set(iop->uptodate, first, last - first + 1);
+ if (bitmap_full(iop->uptodate, i_blocks_per_page(inode, page)))
SetPageUptodate(page);
spin_unlock_irqrestore(&iop->uptodate_lock, flags);
}
--
2.28.0

2020-08-24 23:59:59

by Dave Chinner

Subject: Re: [PATCH 4/9] iomap: Use bitmap ops to set uptodate bits

On Mon, Aug 24, 2020 at 03:55:05PM +0100, Matthew Wilcox (Oracle) wrote:
> Now that the bitmap is protected by a spinlock, we can use the
> more efficient bitmap ops instead of individual test/set bit ops.
>
> Signed-off-by: Matthew Wilcox (Oracle) <[email protected]>
> Reviewed-by: Christoph Hellwig <[email protected]>
> ---
> fs/iomap/buffered-io.c | 12 ++----------
> 1 file changed, 2 insertions(+), 10 deletions(-)

Looks good.

Reviewed-by: Dave Chinner <[email protected]>
--
Dave Chinner
[email protected]

2020-08-25 20:56:02

by Darrick J. Wong

Subject: Re: [PATCH 4/9] iomap: Use bitmap ops to set uptodate bits

On Mon, Aug 24, 2020 at 03:55:05PM +0100, Matthew Wilcox (Oracle) wrote:
> Now that the bitmap is protected by a spinlock, we can use the
> more efficient bitmap ops instead of individual test/set bit ops.
>
> Signed-off-by: Matthew Wilcox (Oracle) <[email protected]>
> Reviewed-by: Christoph Hellwig <[email protected]>

Yay!
Reviewed-by: Darrick J. Wong <[email protected]>

--D

> ---
> fs/iomap/buffered-io.c | 12 ++----------
> 1 file changed, 2 insertions(+), 10 deletions(-)
>
> diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
> index 639d54a4177e..dbf9572dabe9 100644
> --- a/fs/iomap/buffered-io.c
> +++ b/fs/iomap/buffered-io.c
> @@ -134,19 +134,11 @@ iomap_iop_set_range_uptodate(struct page *page, unsigned off, unsigned len)
> struct inode *inode = page->mapping->host;
> unsigned first = off >> inode->i_blkbits;
> unsigned last = (off + len - 1) >> inode->i_blkbits;
> - bool uptodate = true;
> unsigned long flags;
> - unsigned int i;
>
> spin_lock_irqsave(&iop->uptodate_lock, flags);
> - for (i = 0; i < i_blocks_per_page(inode, page); i++) {
> - if (i >= first && i <= last)
> - set_bit(i, iop->uptodate);
> - else if (!test_bit(i, iop->uptodate))
> - uptodate = false;
> - }
> -
> - if (uptodate)
> + bitmap_set(iop->uptodate, first, last - first + 1);
> + if (bitmap_full(iop->uptodate, i_blocks_per_page(inode, page)))
> SetPageUptodate(page);
> spin_unlock_irqrestore(&iop->uptodate_lock, flags);
> }
> --
> 2.28.0
>