Messages in this thread | | | Date | Wed, 8 Aug 2012 11:06:34 +0800 | Subject | Re: [RFC PATCH] block:Fix some problems about handling plug in blk_queue_bio(). | From | Shaohua Li <> |
| |
2012/8/8 Jianpeng Ma <majianpeng@gmail.com>: > I think there are three problems about handling plug in blk_queue_bio(): > 1:if request_count >= BLK_MAX_REQUEST_COUNT, avoid unnecessary plug->should_sort judge. this makes sense, though not a big deal, nice to fix it.
> 2:Only two device can trace plug. I didn't get the point, can you have more details?
> 3:When exec blk_flush_plug_list,it use list_sort which has > O(nlog(n)) complexity. When insert and sort, it only O(n) complexity. but now you do the list iterator for every request, so it's O(n*n)? The plug list is unlikely too long, so I didn't worry about the time spending on list sort.
| |