Re: Poor performance during disk writes

Jens Axboe (axboe@kernel.org)
Fri, 21 Dec 2001 17:50:07 +0100


On Thu, Dec 20 2001, Andrew Morton wrote:
> --- linux-2.4.17-pre6/drivers/block/ll_rw_blk.c Mon Nov 5 21:01:11 2001
> +++ linux-akpm/drivers/block/ll_rw_blk.c Sat Dec 8 11:10:36 2001
> @@ -690,7 +690,8 @@ again:
> } else if (q->head_active && !q->plugged)
> head = head->next;
>
> - el_ret = elevator->elevator_merge_fn(q, &req, head, bh, rw,max_sectors);
> + el_ret = elevator->elevator_merge_fn(q, &req, head, bh,
> + rw, max_sectors, elevator->max_bomb_segments);

merge function can just grab max_bomb_segments ala

int mbs = q->elevator.max_bomb_segments

so no need to modify the merge functions.

-- 
Jens Axboe

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