Re: [PATCH v3 7/7] bio: don't copy bvec for direct IO

2021-01-10 Thread Ming Lei
On Sat, Jan 09, 2021 at 04:03:03PM +, Pavel Begunkov wrote: > The block layer spends quite a while in blkdev_direct_IO() to copy and > initialise bio's bvec. However, if we've already got a bvec in the input > iterator it might be reused in some cases, i.e. when new > ITER_BVEC_FLAG_FIXED flag

[PATCH v3 7/7] bio: don't copy bvec for direct IO

2021-01-09 Thread Pavel Begunkov
The block layer spends quite a while in blkdev_direct_IO() to copy and initialise bio's bvec. However, if we've already got a bvec in the input iterator it might be reused in some cases, i.e. when new ITER_BVEC_FLAG_FIXED flag is set. Simple tests show considerable performance boost, and it also