From: Christoph Hellwig <hch@lst.de>
To: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Christoph Hellwig <hch@lst.de>,
Dan Williams <dan.j.williams@intel.com>,
"linux-nvdimm@lists.01.org" <linux-nvdimm@ml01.01.org>,
Brian Boylston <brian.boylston@hpe.com>,
Tony Luck <tony.luck@intel.com>, Jan Kara <jack@suse.cz>,
Toshi Kani <toshi.kani@hpe.com>,
Mike Snitzer <snitzer@redhat.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"x86@kernel.org" <x86@kernel.org>, Jeff Moyer <jmoyer@redhat.com>,
Jens Axboe <axboe@fb.com>,
"dm-devel@redhat.com" <dm-devel@redhat.com>,
Ingo Molnar <mingo@redhat.com>, Al Viro <viro@zeniv.linux.org.uk>,
"H. Peter Anvin" <hpa@zytor.com>,
"linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Linus Torvalds <torvalds@linux-foundation.org>,
Ross Zwisler <ross.zwisler@linux.intel.com>
Subject: Re: [PATCH 00/13] dax, pmem: move cpu cache maintenance to libnvdimm
Date: Sun, 22 Jan 2017 17:29:10 +0100 [thread overview]
Message-ID: <20170122162910.GA5267@lst.de> (raw)
In-Reply-To: <BY2PR21MB00367799FE7B7E8302A99260CB730@BY2PR21MB0036.namprd21.prod.outlook.com>
On Sun, Jan 22, 2017 at 03:43:09PM +0000, Matthew Wilcox wrote:
> In the case of a network filesystem being used to communicate with
> a different VM on the same physical machine, there is no backing
> device, just a network protocol.
Again, do you mean block device? For a filesystem that does not do any
pagecache writeback we already don't need a backing device, so I don't
really see an issue there to start with.
> I'm not terribly enthusiastic about creating a fake block device to
> sit on top of a network filesystem, but I suppose we could go that
> way if we had to.
I see no need to a new network filesystem to have a fake block device.
We do need a fake block device for an unchanged or partial DAX aware
file system. And those are the only ones we have at the moment, although
XFS could be converted to do direct calls bypassing the block layer
fairly trivially if needed. For ext2 and ext4 that would be much harder
due to the buffer cache dependency.
next prev parent reply other threads:[~2017-01-22 16:38 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-01-20 3:50 [PATCH 00/13] dax, pmem: move cpu cache maintenance to libnvdimm Dan Williams
2017-01-20 3:50 ` [PATCH 01/13] x86, dax, pmem: remove indirection around memcpy_from_pmem() Dan Williams
2017-01-20 3:50 ` [PATCH 02/13] block, dax: introduce dax_operations Dan Williams
2017-01-20 17:28 ` Dan Williams
2017-01-20 3:50 ` [PATCH 03/13] x86, dax, pmem: introduce 'copy_from_iter' dax operation Dan Williams
2017-02-03 1:52 ` [lkp-robot] [x86, dax, pmem] 2e12109d1c: fio.write_bw_MBps -75% regression kernel test robot
2017-02-17 3:52 ` [PATCH 03/13] x86, dax, pmem: introduce 'copy_from_iter' dax operation Ross Zwisler
2017-02-17 3:56 ` Dan Williams
2017-01-20 3:50 ` [PATCH 04/13] dax, pmem: introduce an optional 'flush' " Dan Williams
2017-01-20 3:50 ` [PATCH 05/13] x86, dax: replace clear_pmem() with open coded memset + dax_ops->flush Dan Williams
2017-01-20 10:27 ` Jan Kara
2017-01-20 15:33 ` Dan Williams
2017-01-20 3:50 ` [PATCH 06/13] x86, dax, libnvdimm: move wb_cache_pmem() to libnvdimm Dan Williams
2017-01-20 3:50 ` [PATCH 07/13] x86, libnvdimm, pmem: move arch_invalidate_pmem() " Dan Williams
2017-01-20 3:50 ` [PATCH 08/13] x86, libnvdimm, dax: stop abusing __copy_user_nocache Dan Williams
2017-03-28 16:21 ` Ross Zwisler
2017-03-28 16:26 ` Dan Williams
2017-01-20 3:51 ` [PATCH 09/13] libnvdimm, pmem: implement cache bypass for all copy_from_iter() operations Dan Williams
2017-01-20 3:51 ` [PATCH 10/13] libnvdimm, pmem: fix persistence warning Dan Williams
2017-01-20 3:51 ` [PATCH 11/13] libnvdimm, nfit: enable support for volatile ranges Dan Williams
2017-01-20 3:51 ` [PATCH 12/13] libnvdimm, pmem: disable dax flushing when pmem is fronting a volatile region Dan Williams
2017-01-20 3:51 ` [PATCH 13/13] libnvdimm, pmem: disable dax flushing for 'cache flush on fail' platforms Dan Williams
2017-01-21 16:28 ` [PATCH 00/13] dax, pmem: move cpu cache maintenance to libnvdimm Matthew Wilcox
2017-01-21 17:52 ` Christoph Hellwig
2017-01-22 15:43 ` Matthew Wilcox
2017-01-22 16:29 ` Christoph Hellwig [this message]
2017-01-22 18:19 ` Matthew Wilcox
2017-01-22 18:30 ` Christoph Hellwig
2017-01-22 18:39 ` Matthew Wilcox
2017-01-22 18:44 ` Christoph Hellwig
2017-01-23 6:37 ` Matthew Wilcox
2017-01-23 7:10 ` Dan Williams
2017-01-23 16:00 ` Christoph Hellwig
2017-01-23 17:14 ` Dan Williams
2017-01-23 18:03 ` Christoph Hellwig
2017-01-23 18:31 ` Dan Williams
2017-01-23 15:58 ` Christoph Hellwig
2017-01-22 17:30 ` Dan Williams
2017-01-23 16:01 ` Christoph Hellwig
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