On 05/11/2018 13:01, Ming Lei wrote: > If you mean the real huge page, this patch shouldn't have made a difference > because bio_vec->bv_offset is in [0, PAGE_SIZE), and iSer sets virt > boundary as 4K - 1. > > However, things will change after multipage bvec is introduced. Hi Ming, I've received a blktrace from our customer showing the issue [1]. In this example trace they've submitted (contiguous) 64K I/Os and without this patch, they're seeing a lot of splits as indicated by the trace. With the patch applied the I/O is directly issued to the LLDD without the splits. [1] http://beta.suse.com/private/jthumshirn/blktrace.txt Byte, Johannes -- Johannes Thumshirn SUSE Labs jthumshirn@xxxxxxx +49 911 74053 689 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: Felix Imendörffer, Jane Smithard, Graham Norton HRB 21284 (AG Nürnberg) Key fingerprint = EC38 9CAB C2C4 F25D 8600 D0D0 0393 969D 2D76 0850
