Re: [PATCH] ida: document IDA_BITMAP_LONGS calculation

[Tejun Heo <tj@kernel.org>]

On 09/23/2010 01:25 PM, Jiri Kosina wrote:
> On Fri, 3 Sep 2010, Namhyung Kim wrote:
> 
>> IDA_BITMAP_LONGS value is calculated take into account struct ida_bitmap
>> not to waste memory space. Comment it.
>>
>> Signed-off-by: Namhyung Kim <namhyung@gmail.com>
>> Acked-by: Tejun Heo <tj@kernel.org>
>> ---
>>  include/linux/idr.h |    5 ++++-
>>  1 files changed, 4 insertions(+), 1 deletions(-)
>>
>> diff --git a/include/linux/idr.h b/include/linux/idr.h
>> index e968db7..3f4b718 100644
>> --- a/include/linux/idr.h
>> +++ b/include/linux/idr.h
>> @@ -117,10 +117,13 @@ void idr_init(struct idr *idp);
>>  /*
>>   * IDA - IDR based id allocator, use when translation from id to
>>   * pointer isn't necessary.
>> + *
>> + * IDA_BITMAP_LONGS is calculated to be one less to accommodate
>> + * ida_bitmap->nr_busy so that the whole struct fits in 128 bytes.
>>   */
>>  #define IDA_CHUNK_SIZE		128	/* 128 bytes per chunk */
>>  #define IDA_BITMAP_LONGS	(128 / sizeof(long) - 1)
>> -#define IDA_BITMAP_BITS		(IDA_BITMAP_LONGS * sizeof(long) * 8)
>> +#define IDA_BITMAP_BITS 	(IDA_BITMAP_LONGS * sizeof(long) * 8)
>>  
>>  struct ida_bitmap {
>>  	long			nr_busy;
> 
> Tejun, any word on this patch? Doesn't seem to be present in linux-next.

Ooh, I was hoping this one could go through the trivial tree.  It
would be great if you can pick up the patch.

Thank you.

-- 
tejun