Messages in this thread | | | Subject | Re: [PATCH] block: respect virtual boundary mask in bvecs | From | Sagi Grimberg <> | Date | Tue, 6 Nov 2018 19:11:36 -0800 |
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>> 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 >
This patch makes sense to me. However I agree that we need to clarify that this addresses cases where PAGE_SIZE-1 > queue_virt_boundary(q).
And also, lets replace "like iser" with "drivers that sets a virtual boundary constraint" as nvme-rdma does the same thing.
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