[PATCH] blk-throttle: Fix calculation of max number of WRITES to be dispatched

[PATCH] blk-throttle: Fix calculation of max number of WRITES to be dispatched

[Vivek Goyal]

o Currently we try to dispatch more READS and less WRITES (75%, 25%) in one
  dispatch round. ummy pointed out that there is a bug in max_nr_writes
  calculation. This patch fixes it.

Reported-by: ummy y <yummylln@yahoo.com.cn>
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
---
 block/blk-throttle.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Index: linux-2.6/block/blk-throttle.c
===================================================================
--- linux-2.6.orig/block/blk-throttle.c	2010-10-27 10:57:25.000000000 -0400
+++ linux-2.6/block/blk-throttle.c	2010-10-27 11:02:33.733048194 -0400
@@ -645,7 +645,7 @@ static int throtl_dispatch_tg(struct thr
 {
 	unsigned int nr_reads = 0, nr_writes = 0;
 	unsigned int max_nr_reads = throtl_grp_quantum*3/4;
-	unsigned int max_nr_writes = throtl_grp_quantum - nr_reads;
+	unsigned int max_nr_writes = throtl_grp_quantum - max_nr_reads;
 	struct bio *bio;
 
 	/* Try to dispatch 75% READS and 25% WRITES */

Re: [PATCH] blk-throttle: Fix calculation of max number of WRITES to be dispatched

[Vivek Goyal]

On Wed, Oct 27, 2010 at 01:29:41PM -0400, Vivek Goyal wrote:
> o Currently we try to dispatch more READS and less WRITES (75%, 25%) in one
>   dispatch round. ummy pointed out that there is a bug in max_nr_writes
>   calculation. This patch fixes it.
> 
> Reported-by: ummy y <yummylln@yahoo.com.cn>
> Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
> ---

Hi Jens,

Do you have any concerns about this patch? If not, can you please apply
it.

Thanks
Vivek

>  block/blk-throttle.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> Index: linux-2.6/block/blk-throttle.c
> ===================================================================
> --- linux-2.6.orig/block/blk-throttle.c	2010-10-27 10:57:25.000000000 -0400
> +++ linux-2.6/block/blk-throttle.c	2010-10-27 11:02:33.733048194 -0400
> @@ -645,7 +645,7 @@ static int throtl_dispatch_tg(struct thr
>  {
>  	unsigned int nr_reads = 0, nr_writes = 0;
>  	unsigned int max_nr_reads = throtl_grp_quantum*3/4;
> -	unsigned int max_nr_writes = throtl_grp_quantum - nr_reads;
> +	unsigned int max_nr_writes = throtl_grp_quantum - max_nr_reads;
>  	struct bio *bio;
>  
>  	/* Try to dispatch 75% READS and 25% WRITES */

Re: [PATCH] blk-throttle: Fix calculation of max number of WRITES to be dispatched

[Jens Axboe]

On 2010-11-15 16:28, Vivek Goyal wrote:
> On Wed, Oct 27, 2010 at 01:29:41PM -0400, Vivek Goyal wrote:
>> o Currently we try to dispatch more READS and less WRITES (75%, 25%) in one
>>   dispatch round. ummy pointed out that there is a bug in max_nr_writes
>>   calculation. This patch fixes it.
>>
>> Reported-by: ummy y <yummylln@yahoo.com.cn>
>> Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
>> ---
> 
> Hi Jens,
> 
> Do you have any concerns about this patch? If not, can you please apply
> it.

Applied, thanks.

-- 
Jens Axboe