lkml.org 
[lkml]   [2015]   [May]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    From
    Subject[PATCH v4 00/11] simplify block layer based on immutable biovecs
    Date
    v4:
    - rebase on top of 4.1-rc4
    - use BIO_POOL_SIZE instead of number 4 for bioset_create()
    - call blk_queue_split() in blk_mq_make_request()
    - call blk_queue_split() in zram_make_request()
    - add patch "block: remove bio_get_nr_vecs()"
    - remove split code in blkdev_issue_discard()
    - drop patch "md/raid10: make sync_request_write() call bio_copy_data()".
    NeilBrown queued it.
    - drop patch "block: allow __blk_queue_bounce() to handle bios larger than BIO_MAX_PAGES".
    Will send it seperately

    v3:
    - rebase on top of 4.1-rc2
    - support for QUEUE_FLAG_SG_GAPS
    - update commit logs of patch 2&4
    - split bio for chunk_aligned_read

    v2: https://lkml.org/lkml/2015/4/28/28
    v1: https://lkml.org/lkml/2014/12/22/128

    This is the 4th attempt of simplifying block layer based on immutable
    biovecs. Immutable biovecs, implemented by Kent Overstreet, have been
    available in mainline since v3.14. Its original goal was actually making
    generic_make_request() accept arbitrarily sized bios, and pushing the
    splitting down to the drivers or wherever it's required. See also
    discussions in the past, [1] [2] [3].

    This will bring not only performance improvements, but also a great amount
    of reduction in code complexity all over the block layer. Performance gain
    is possible due to the fact that bio_add_page() does not have to check
    unnecesary conditions such as queue limits or if biovecs are mergeable.
    Those will be delegated to the driver level. Kent already said that he
    actually benchmarked the impact of this with fio on a micron p320h, which
    showed definitely a positive impact.

    Moreover, this patchset also allows a lot of code to be deleted, mainly
    because of removal of merge_bvec_fn() callbacks. We have been aware that
    it has been always a delicate issue for stacking block drivers (e.g. md
    and bcache) to handle merging bio consistently. This simplication will
    help every individual block driver avoid having such an issue.

    Patches are against 4.1-rc4. These are also available in my git repo at:

    https://git.kernel.org/cgit/linux/kernel/git/mlin/linux.git/log/?h=block-generic-req
    git://git.kernel.org/pub/scm/linux/kernel/git/mlin/linux.git block-generic-req

    This patchset is a prerequisite of other consecutive patchsets, e.g.
    multipage biovecs, rewriting plugging, or rewriting direct-IO, which are
    excluded this time. That means, this patchset should not bring any
    regression to end-users.

    Comments are welcome.
    Ming

    [1] https://lkml.org/lkml/2014/11/23/263
    [2] https://lkml.org/lkml/2013/11/25/732
    [3] https://lkml.org/lkml/2014/2/26/618

    Dongsu Park (1):
    Documentation: update notes in biovecs about arbitrarily sized bios

    Kent Overstreet (8):
    block: make generic_make_request handle arbitrarily sized bios
    block: simplify bio_add_page()
    bcache: remove driver private bio splitting code
    btrfs: remove bio splitting and merge_bvec_fn() calls
    md/raid5: get rid of bio_fits_rdev()
    block: kill merge_bvec_fn() completely
    fs: use helper bio_add_page() instead of open coding on bi_io_vec
    block: remove bio_get_nr_vecs()

    Ming Lin (2):
    block: remove split code in blkdev_issue_discard
    md/raid5: split bio for chunk_aligned_read

    Documentation/block/biovecs.txt | 10 +-
    block/bio.c | 152 ++++++++++------------------
    block/blk-core.c | 19 ++--
    block/blk-lib.c | 73 +++----------
    block/blk-merge.c | 148 +++++++++++++++++++++++++--
    block/blk-mq.c | 4 +
    block/blk-settings.c | 22 ----
    drivers/block/drbd/drbd_int.h | 1 -
    drivers/block/drbd/drbd_main.c | 1 -
    drivers/block/drbd/drbd_req.c | 37 +------
    drivers/block/pktcdvd.c | 27 +----
    drivers/block/ps3vram.c | 2 +
    drivers/block/rbd.c | 47 ---------
    drivers/block/rsxx/dev.c | 2 +
    drivers/block/umem.c | 2 +
    drivers/block/zram/zram_drv.c | 2 +
    drivers/md/bcache/bcache.h | 18 ----
    drivers/md/bcache/io.c | 100 +-----------------
    drivers/md/bcache/journal.c | 4 +-
    drivers/md/bcache/request.c | 16 +--
    drivers/md/bcache/super.c | 32 +-----
    drivers/md/bcache/util.h | 5 +-
    drivers/md/bcache/writeback.c | 4 +-
    drivers/md/dm-cache-target.c | 21 ----
    drivers/md/dm-crypt.c | 16 ---
    drivers/md/dm-era-target.c | 15 ---
    drivers/md/dm-flakey.c | 16 ---
    drivers/md/dm-io.c | 2 +-
    drivers/md/dm-linear.c | 16 ---
    drivers/md/dm-log-writes.c | 16 ---
    drivers/md/dm-snap.c | 15 ---
    drivers/md/dm-stripe.c | 21 ----
    drivers/md/dm-table.c | 8 --
    drivers/md/dm-thin.c | 31 ------
    drivers/md/dm-verity.c | 16 ---
    drivers/md/dm.c | 122 +---------------------
    drivers/md/dm.h | 2 -
    drivers/md/linear.c | 43 --------
    drivers/md/md.c | 28 +----
    drivers/md/md.h | 12 ---
    drivers/md/multipath.c | 21 ----
    drivers/md/raid0.c | 56 ----------
    drivers/md/raid0.h | 2 -
    drivers/md/raid1.c | 58 +----------
    drivers/md/raid10.c | 121 +---------------------
    drivers/md/raid5.c | 92 ++++++-----------
    drivers/s390/block/dcssblk.c | 2 +
    drivers/s390/block/xpram.c | 2 +
    drivers/staging/lustre/lustre/llite/lloop.c | 2 +
    fs/btrfs/compression.c | 5 +-
    fs/btrfs/extent_io.c | 9 +-
    fs/btrfs/inode.c | 3 +-
    fs/btrfs/scrub.c | 18 +---
    fs/btrfs/volumes.c | 72 -------------
    fs/buffer.c | 7 +-
    fs/direct-io.c | 2 +-
    fs/ext4/page-io.c | 3 +-
    fs/ext4/readpage.c | 2 +-
    fs/gfs2/lops.c | 9 +-
    fs/jfs/jfs_logmgr.c | 14 +--
    fs/logfs/dev_bdev.c | 4 +-
    fs/mpage.c | 4 +-
    fs/nilfs2/segbuf.c | 2 +-
    fs/xfs/xfs_aops.c | 3 +-
    include/linux/bio.h | 1 -
    include/linux/blkdev.h | 13 +--
    include/linux/device-mapper.h | 4 -
    mm/page_io.c | 8 +-
    68 files changed, 336 insertions(+), 1331 deletions(-)



    \
     
     \ /
      Last update: 2015-05-22 20:41    [W:4.051 / U:0.060 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site