Re: [PATCH v2 0/6] a caching layer for raid5/6

[NeilBrown <neilb@suse.de>]

[-- Attachment #1: Type: text/plain, Size: 2033 bytes --]


hi,
 I cannot possible give any consideration to this caching layer until I'm
 happy with the code I got from you for stripe batching, and I'm not.

I asked:

Subject: Re: [PATCH 7/7] md/raid5: fix handling of degraded stripes in batches.
Date: Wed, 13 May 2015 10:56:04 +1000

> What exactly do you expect to happen after the stripes in a batch after they
> have been split up?

and haven't received a reply yet.
Did you not get that email?

Thanks,
NeilBrown



On Mon, 18 May 2015 19:57:28 -0700 Shaohua Li <shli@fb.com> wrote:

> Hi,
> 
> This is the second version of the raid5/6 caching layer patches. The patches add a
> caching layer for raid5/6. The caching layer uses a SSD as a cache for a raid
> 5/6. It works like the similar way of a hardware raid controller. The purpose
> is to improve raid performance (reduce read-modify-write) and fix write hole
> issue. The main patch is patch 3 and the description has all details about the
> implementation.
> 
> Main changes of V2 are to improve performance. Meta data write doesn't use FUA
> any more. Discard request is only dispatched when discard range is big enough.
> Also have some bug fixing and code cleanup. Please review!
> 
> Thanks,
> Shaohua
> 
> 
> Shaohua Li (5):
>   raid5: directly use mddev->queue
>   raid5: A caching layer for RAID5/6
>   raid5: add some sysfs entries
>   md: don't allow resize/reshape with cache support
>   raid5: skip resync if caching is enabled
> 
> Song Liu (1):
>   MD: add a new disk role to present cache device
> 
>  drivers/md/Makefile            |    2 +-
>  drivers/md/md.c                |   14 +-
>  drivers/md/md.h                |    4 +
>  drivers/md/raid5-cache.c       | 3519 ++++++++++++++++++++++++++++++++++++++++
>  drivers/md/raid5.c             |   97 +-
>  drivers/md/raid5.h             |   16 +-
>  include/uapi/linux/raid/md_p.h |   73 +
>  7 files changed, 3705 insertions(+), 20 deletions(-)
>  create mode 100644 drivers/md/raid5-cache.c
> 


[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 811 bytes --]