From mboxrd@z Thu Jan 1 00:00:00 1970 From: NeilBrown Subject: Re: [PATCH v2 0/6] a caching layer for raid5/6 Date: Wed, 20 May 2015 15:23:53 +1000 Message-ID: <20150520152353.175365f4@notabene.brown> References: Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; boundary="Sig_//pL0=sHf_XTDKBMS9NDpAKS"; protocol="application/pgp-signature" Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: Shaohua Li Cc: linux-raid@vger.kernel.org, Kernel-team@fb.com, songliubraving@fb.com, hch@infradead.org, dan.j.williams@intel.com List-Id: linux-raid.ids --Sig_//pL0=sHf_XTDKBMS9NDpAKS Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable 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 batc= hes. Date: Wed, 13 May 2015 10:56:04 +1000 > What exactly do you expect to happen after the stripes in a batch after t= hey > 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 wrote: > Hi, >=20 > This is the second version of the raid5/6 caching layer patches. The patc= hes 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 pur= pose > is to improve raid performance (reduce read-modify-write) and fix write h= ole > issue. The main patch is patch 3 and the description has all details abou= t the > implementation. >=20 > Main changes of V2 are to improve performance. Meta data write doesn't us= e FUA > any more. Discard request is only dispatched when discard range is big en= ough. > Also have some bug fixing and code cleanup. Please review! >=20 > Thanks, > Shaohua >=20 >=20 > 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 >=20 > Song Liu (1): > MD: add a new disk role to present cache device >=20 > 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 >=20 --Sig_//pL0=sHf_XTDKBMS9NDpAKS Content-Type: application/pgp-signature Content-Description: OpenPGP digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIVAwUBVVwaaTnsnt1WYoG5AQL/bQ/6A6UWoCArqTBLyvQptgYvUdh/xg9y+RcE 9+8F+HWwpXYRkwG+9ccadJEm924Em6BgtNnKZ6Ot+FzHCkcS6VXewUuCAgBgiSQh 0Y5W37Cq7uA5bhBorweYCyoENU8UDvoxK+BUwNlGKrGOsZjQzGGlDYNExrfhZpQz rdCXkkpSRzSY+OR6tMPtM2HvssCAJNMI79QaFnOwHp0Vjr8X4Fifjb1WfuvCAER2 hN06LUq8rM7jBcAXnNk7YKCjeCw3rTHqIkPc1mDVzsi/nS46jVn9U+hpqDSW76rX dztBnl0BTNhVkE06tgnSiXrxBVqgQRky7C6TzepdoOUpAqcVYW90RkoFQZM8rf5P mKcRCMKPsVgrAeaACmLtxS4MDZ5u8KCX7RoHZwjEVyJxCrGtk7WQEEgQXHOPufM3 mU11xzSPrfbpknX5sw/QQaIoTb4SnW2dP5tXms3VFH4A27ODtErV2aud7Tw6GEX3 0+87ryOdSefW6FViR8Hzsu7Uc0oJ/BS3iYHIDMnNUZ1sfNptN5p4t7dtStNZi9zE hJu2H5/uy+fFGs8wBDoGWJFLsh1QQXcTYCzT4wWWYi+3flXKh8bvlrrFCRWzjRVZ aVeZTsZVE4sfVhspZKzOBpDHGDjit8JaZMrBz8lxd6bXrXj7tMJ9CbCCNuxccSfZ 2bmXZQuUu2k= =i4gO -----END PGP SIGNATURE----- --Sig_//pL0=sHf_XTDKBMS9NDpAKS--