Messages in this thread | | | Subject | Re: [PATCH] block: blk-merge: fast-clone bio when splitting rw bios | From | Jens Axboe <> | Date | Thu, 17 Sep 2015 09:19:11 -0600 |
| |
On 09/17/2015 09:13 AM, Ming Lei wrote: > biovecs has become immutable since v3.13, so it isn't necessary > to allocate biovecs for the new cloned bios, then we can save > one extra biovecs allocation/copy, and the allocation is often > not fixed-length and a bit more expensive. > > For example, if the 'max_sectors_kb' of null blk's queue is set > as 16(32 sectors) via sysfs just for making more splits, this patch > can increase throught about ~70% in the sequential read test over > null_blk(direct io, bs: 1M).
I'd be curious how this compares to before we did the splitting, not exceeding the limits through bio_add_page() instead?
-- Jens Axboe
| |