On Tue, Jun 2, 2020 at 4:47 AM Artur Paszkiewicz <artur.paszkiewicz@xxxxxxxxx> wrote: > > On 6/2/20 8:48 AM, Song Liu wrote: > >> + clone = bio_clone_fast(bio, GFP_NOIO, &mddev->md_io_bs); > > > > Handle clone == NULL? > > I think this should never fail - bio_alloc_bioset() guarantees that. It > is used in a similar manner in raid1 and raid10. How about > BUG_ON(clone == NULL)? I misread the code. Current version is fine. > > > Also, have you done benchmarks with this change? > > I tested 4k random reads on a raid0 (4x P4510 2TB) and it was 2550k vs > 2567k IOPS, that's slower only by about 0.66%: Thanks for the test. I will do some more tests and process the patch after the merge window. Song
