Re: [PATCH v5 00/15] md/md-bitmap: introduce CONFIG_MD_BITMAP

[Yu Kuai <yukuai@kernel.org>]

在 2025/7/7 9:26, Yu Kuai 写道:
> From: Yu Kuai <yukuai3@huawei.com>
>
> Changes in v5:
>   - rebase on the top of md-6.17;
>   - fix compile problem if md-mod is build as module;
>   - fix two problems for lvm2 dm-raid tests, patch 5,13
>   - other cleanups;
> Changes in v4:
>   - rebase on the top of other patchset;
> Changes in v3:
>   - update commit message.
> Changes in v2:
>   - don't export apis, and don't support build md-bitmap as module
>
> Due to known performance issues with md-bitmap and the unreasonable
> implementations like following:
>
>   - self-managed pages, bitmap_storage->filemap;
>   - self-managed IO submitting like filemap_write_page();
>   - global spin_lock
>   ...
>
> I have decided not to continue optimizing based on the current bitmap
> implementation, and plan to invent a new lock-less bitmap. And a new
> kconfig option is a good way for isolation.
>
> However, we still encourage anyone who wants to continue optimizing the
> current implementation
>
> Yu Kuai (15):
>    md/raid1: change r1conf->r1bio_pool to a pointer type
>    md/raid1: remove struct pool_info and related code
>    md/md-bitmap: remove the parameter 'init' for bitmap_ops->resize()
>    md/md-bitmap: merge md_bitmap_group into bitmap_operations
>    md/md-bitmap: add a new parameter 'flush' to bitmap_ops->enabled
>    md/md-bitmap: add md_bitmap_registered/enabled() helper
>    md/md-bitmap: handle the case bitmap is not enabled before
>      start_sync()
>    md/md-bitmap: handle the case bitmap is not enabled before end_sync()
>    md/raid1: check bitmap before behind write
>    md/raid1: check before referencing mddev->bitmap_ops
>    md/raid10: check before referencing mddev->bitmap_ops
>    md/raid5: check before referencing mddev->bitmap_ops
>    md/dm-raid: check before referencing mddev->bitmap_ops
>    md: check before referencing mddev->bitmap_ops
>    md/md-bitmap: introduce CONFIG_MD_BITMAP
>
>   drivers/md/Kconfig      |  18 +++++
>   drivers/md/Makefile     |   3 +-
>   drivers/md/dm-raid.c    |  18 +++--
>   drivers/md/md-bitmap.c  |  74 +++++++++---------
>   drivers/md/md-bitmap.h  |  62 ++++++++++++++-
>   drivers/md/md-cluster.c |   2 +-
>   drivers/md/md.c         | 112 +++++++++++++++++++--------
>   drivers/md/md.h         |   4 +-
>   drivers/md/raid1-10.c   |   2 +-
>   drivers/md/raid1.c      | 163 +++++++++++++++++++---------------------
>   drivers/md/raid1.h      |  22 +-----
>   drivers/md/raid10.c     |  49 ++++++------
>   drivers/md/raid5.c      |  30 ++++----
>   13 files changed, 330 insertions(+), 229 deletions(-)
>
Applied to md-6.17
Thanks