On Wed, May 17, 2017 at 04:22:44PM -0600, Liu Bo wrote: > v1: - Drop the RFC tag. > - Update to use bio_segments accordingly as __bio_segments is removed. > - Remove if (!bio) since bio_clone_fast with bioset and GFP_NOFS will > never fail. > > This attempts to use bio_clone_fast() in the places where we clone bio, > such as when bio got cloned for multiple disks and when bio got split > during dio submit. > > One benefit is to simplify dio submit to avoid calling bio_add_page one by > one. > > Another benefit is that comparing to bio_clone_bioset, bio_clone_fast is > faster because of copying the vector pointer directly, and bio_clone_fast > doesn't modify bi_vcnt, so the extra work is to fix up bi_vcnt usage we > currently have to use bi_iter to iterate bvec. > > Here are some numbers collected with the script [1], note that most of > performance tests usually issue bs=4k dio write/read so our directIO split > code > is not tested as it requires bs > stripe_len(64K), thus I made this simple > script which writes 2G with bs=128K. > > - vanilla: > real 0m10.265s > user 0m0.005s > sys 0m9.164s > > - patched: > real 0m8.973s > user 0m0.006s > sys 0m7.804s > > [1]: > #!/bin/bash > > M=/mnt/btrfs > D1=/dev/pmem0p1 > D2=/dev/pmem0p2 > > umount $M > mkfs.btrfs -f $D1 $D2 >/dev/null || exit > > mount $D1 $M -onodatasum || exit > > xfs_io -f -c "falloc 0 2G" $M/foo > > time xfs_io -d -c "pwrite -b 128K 0 2G" $M/foo > > Liu Bo (8): > Btrfs: use bio_clone_fast to clone our bio > Btrfs: new helper btrfs_bio_clone_partial > Btrfs: use bio_clone_bioset_partial to simplify DIO submit > Btrfs: change how we iterate bios in endio > Btrfs: record error if one block has failed to retry > Btrfs: make check-integrity use bvec_iter > Btrfs: unify naming of btrfs_io_bio > Btrfs: hardcode GFP_NOFS for btrfs_bio_clone_partial
Added to 4.13 queue, thankgs. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
