Re: [PATCH v2] libxfs: Optimize the loop for xfs_bitmap_empty

From: hejianet <hejianet@gmail.com>
To: xfs@oss.sgi.com, david@fromorbit.com
Cc: Brian Foster <bfoster@redhat.com>
Subject: Re: [PATCH v2] libxfs: Optimize the loop for xfs_bitmap_empty
Date: Wed, 16 Dec 2015 11:04:56 +0800	[thread overview]
Message-ID: <5670D4D8.9090500@gmail.com> (raw)
In-Reply-To: <20151111124833.GB52153@bfoster.bfoster>

Hi David

Do you have any comments from your point of view? Thanks ;)

B.R.
Justin

在 11/11/15 8:48 PM, Brian Foster 写道:
> On Wed, Nov 11, 2015 at 03:49:01PM +0800, Jia He wrote:
>> 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>
>> ---
> Looks good to me:
>
> Reviewed-by: 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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