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From: Jia He <hejianet@gmail.com>
To: xfs@oss.sgi.com
Cc: Jia He <hejianet@gmail.com>, Brian Foster <bfoster@redhat.com>
Subject: [PATCH v2] libxfs: Optimize the loop for xfs_bitmap_empty
Date: Wed, 11 Nov 2015 15:49:01 +0800	[thread overview]
Message-ID: <1447228141-17408-1-git-send-email-hejianet@gmail.com> (raw)
In-Reply-To: <20151110125403.GC21670@bfoster.bfoster>

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>
Cc: Dave Chinner <david@fromorbit.com> 
Cc: Brian Foster <bfoster@redhat.com> 
---
 fs/xfs/libxfs/xfs_bit.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/fs/xfs/libxfs/xfs_bit.c b/fs/xfs/libxfs/xfs_bit.c
index 0e8885a..0a94cce 100644
--- a/fs/xfs/libxfs/xfs_bit.c
+++ b/fs/xfs/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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  parent reply	other threads:[~2015-11-11  7:49 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-11-09 14:31 [PATCH] libxfs: Optimize the loop for xfs_bitmap_empty Jia He
2015-11-10 12:54 ` Brian Foster
2015-11-11  6:37   ` hejianet
2015-11-11  7:49   ` Jia He [this message]
2015-11-11 12:48     ` [PATCH v2] " Brian Foster
2015-12-16  3:04       ` hejianet

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