On 08/14/2017 02:50 AM, Minchan Kim wrote: > Hi Jens, > > On Fri, Aug 11, 2017 at 08:26:59AM -0600, Jens Axboe wrote: >> On 08/11/2017 04:46 AM, Christoph Hellwig wrote: >>> On Wed, Aug 09, 2017 at 08:06:24PM -0700, Dan Williams wrote: >>>> I like it, but do you think we should switch to sbvec[<constant>] to >>>> preclude pathological cases where nr_pages is large? >>> >>> Yes, please. >>> >>> Then I'd like to see that the on-stack bio even matters for >>> mpage_readpage / mpage_writepage. Compared to all the buffer head >>> overhead the bio allocation should not actually matter in practice. >> >> I'm skeptical for that path, too. I also wonder how far we could go >> with just doing a per-cpu bio recycling facility, to reduce the cost >> of having to allocate a bio. The on-stack bio parts are fine for >> simple use case, where simple means that the patch just special >> cases the allocation, and doesn't have to change much else. >> >> I had a patch for bio recycling and batched freeing a year or two >> ago, I'll see if I can find and resurrect it. > > So, you want to go with per-cpu bio recycling approach to > remove rw_page? > > So, do you want me to hold this patchset? I don't want to hold this series up, but I do think the recycling is a cleaner approach since we don't need to special case anything. I hope I'll get some time to dust it off, retest, and post soon. -- Jens Axboe -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
