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From: Dave Chinner <david@fromorbit.com>
To: xfs@oss.sgi.com
Subject: [PATCH 01/14] libxfs: Optimize the loop for xfs_bitmap_empty
Date: Mon, 15 Feb 2016 17:18:12 +1100	[thread overview]
Message-ID: <1455517105-20033-2-git-send-email-david@fromorbit.com> (raw)
In-Reply-To: <1455517105-20033-1-git-send-email-david@fromorbit.com>

From: Jia He <hejianet@gmail.com>

Source kernel commit 1d4292bfdc77f4f7c520064be15d0c46bd025fd2

If there is any non zero bit in a long bitmap, it can jump out of the
loop and finish the function as soon as possible.

Signed-off-by: Jia He <hejianet@gmail.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
---
 libxfs/xfs_bit.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/libxfs/xfs_bit.c b/libxfs/xfs_bit.c
index 8b5b81c..041557a 100644
--- a/libxfs/xfs_bit.c
+++ b/libxfs/xfs_bit.c
@@ -32,13 +32,13 @@ int
 xfs_bitmap_empty(uint *map, uint size)
 {
 	uint i;
-	uint ret = 0;
 
 	for (i = 0; i < size; i++) {
-		ret |= map[i];
+		if (map[i] != 0)
+			return 0;
 	}
 
-	return (ret == 0);
+	return 1;
 }
 
 /*
-- 
2.5.0

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  reply	other threads:[~2016-02-15  6:18 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-02-15  6:18 [PATCH 0/14] xfsprogs: kernel libxfs sync up to 4.5-rc2 Dave Chinner
2016-02-15  6:18 ` Dave Chinner [this message]
2016-02-15  6:18 ` [PATCH 02/14] xfs: add missing bmap cancel calls in error paths Dave Chinner
2016-02-15  6:18 ` [PATCH 03/14] xfs: log local to remote symlink conversions correctly on v5 supers Dave Chinner
2016-02-15  6:18 ` [PATCH 04/14] xfs: per-filesystem stats counter implementation Dave Chinner
2016-02-15  6:18 ` [PATCH 05/14] xfs: introduce BMAPI_ZERO for allocating zeroed extents Dave Chinner
2016-02-16 19:20   ` Brian Foster
2016-02-15  6:18 ` [PATCH 06/14] xfs: get mp from bma->ip in xfs_bmap code Dave Chinner
2016-02-15  6:18 ` [PATCH 07/14] xfs: bmapbt checking on debug kernels too expensive Dave Chinner
2016-02-15  6:18 ` [PATCH 08/14] xfs: eliminate committed arg from xfs_bmap_finish Dave Chinner
2016-02-15  6:18 ` [PATCH 09/14] xfs: inode recovery readahead can race with inode buffer creation Dave Chinner
2016-02-15  6:18 ` [PATCH 10/14] xfs: handle dquot buffer readahead in log recovery correctly Dave Chinner
2016-02-16 19:20   ` Brian Foster
2016-02-15  6:18 ` [PATCH 11/14] xfs: swap leaf buffer into path struct atomically during path shift Dave Chinner
2016-02-15  6:18 ` [PATCH 12/14] libxfs: fix two comment typos Dave Chinner
2016-02-15  6:18 ` [PATCH 13/14] xfs: stop holding ILOCK over filldir callbacks Dave Chinner
2016-02-15  6:18 ` [PATCH 14/14] xfs: Validate the length of on-disk ACLs Dave Chinner
2016-02-16 19:19 ` [PATCH 0/14] xfsprogs: kernel libxfs sync up to 4.5-rc2 Brian Foster

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