From: Christoph Hellwig <hch@lst.de>
To: "Darrick J. Wong" <djwong@kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>, nvdimm@lists.linux.dev
Subject: DAX setup pains, was Re: RFC: switch iomap to an iterator model
Date: Tue, 27 Jul 2021 10:07:19 +0200 [thread overview]
Message-ID: <20210727080719.GA17464@lst.de> (raw)
In-Reply-To: <20210719175756.GM22357@magnolia>
On Mon, Jul 19, 2021 at 10:57:56AM -0700, Darrick J. Wong wrote:
> Which seems to translate to:
>
> -machine pc-q35-4.2,accel=kvm,usb=off,vmport=off,dump-guest-core=off,nvdimm=on
> -object memory-backend-file,id=memnvdimm0,prealloc=no,mem-path=/run/g.mem,share=yes,size=10739515392,align=128M
> -device nvdimm,memdev=memnvdimm0,id=nvdimm0,slot=0,label-size=2M
>
> Evidently something was added to the pmem code(?) that makes it fussy if
> the memory region doesn't align to a 128M boundary or the label isn't
> big enough for ... whatever gets written into them.
>
> The file /run/g.mem is intended to provide 10GB of pmem to the VM, with
> an additional 2M allocated for the label.
I managed to get something like this to work, and had two pmem devices
shown up. But of course they don't actually support DAX without a
reconfiguration in the VM, and the #$%$@^$^$ DAX code won't even
tell you about why as the printk for that is a pr_debug (patch to fix
this coming). After a fair amount of goodling I tried to copy this
command line to reconfigure them:
$NDCTL create-namespace --force --reconfig=namespace0.0 --mode=fsdax --map=mem
$NDCTL create-namespace --force --reconfig=namespace1.0 --mode=fsdax --map=mem
Of course that fails with EINVAL. And after the first run the second
namespace is gone entirely. The DAX user story is just a trainwreck.
next prev parent reply other threads:[~2021-07-27 8:07 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-19 10:34 RFC: switch iomap to an iterator model Christoph Hellwig
2021-07-19 10:34 ` [PATCH 01/27] iomap: fix a trivial comment typo in trace.h Christoph Hellwig
2021-07-19 16:00 ` Darrick J. Wong
2021-07-19 10:34 ` [PATCH 02/27] iomap: remove the iomap arguments to ->page_{prepare,done} Christoph Hellwig
2021-07-19 16:04 ` Darrick J. Wong
2021-07-19 10:34 ` [PATCH 03/27] iomap: mark the iomap argument to iomap_sector const Christoph Hellwig
2021-07-19 16:08 ` Darrick J. Wong
2021-07-20 9:52 ` Nikolay Borisov
2021-07-26 8:12 ` Christoph Hellwig
2021-07-19 10:34 ` [PATCH 04/27] fs: mark the iomap argument to __block_write_begin_int const Christoph Hellwig
2021-07-19 17:35 ` Darrick J. Wong
2021-07-19 10:34 ` [PATCH 05/27] fsdax: mark the iomap argument to dax_iomap_sector as const Christoph Hellwig
2021-07-19 17:35 ` Darrick J. Wong
2021-07-19 10:34 ` [PATCH 06/27] iomap: mark the iomap argument to iomap_read_inline_data const Christoph Hellwig
2021-07-19 17:35 ` Darrick J. Wong
2021-07-19 10:35 ` [PATCH 07/27] iomap: mark the iomap argument to iomap_read_page_sync const Christoph Hellwig
2021-07-19 17:35 ` Darrick J. Wong
2021-07-19 10:35 ` [PATCH 08/27] iomap: add the new iomap_iter model Christoph Hellwig
2021-07-19 16:56 ` Darrick J. Wong
2021-07-26 8:15 ` Christoph Hellwig
2021-07-19 21:48 ` Dave Chinner
2021-07-26 8:17 ` Christoph Hellwig
2021-07-19 10:35 ` [PATCH 09/27] iomap: switch readahead and readpage to use iomap_iter Christoph Hellwig
2021-07-19 10:35 ` [PATCH 10/27] iomap: switch iomap_file_buffered_write " Christoph Hellwig
2021-07-19 10:35 ` [PATCH 11/27] iomap: switch iomap_file_unshare " Christoph Hellwig
2021-07-19 10:35 ` [PATCH 12/27] iomap: switch iomap_zero_range " Christoph Hellwig
2021-07-19 10:35 ` [PATCH 13/27] iomap: switch iomap_page_mkwrite " Christoph Hellwig
2021-07-19 10:35 ` [PATCH 14/27] iomap: switch __iomap_dio_rw " Christoph Hellwig
2021-07-19 10:35 ` [PATCH 15/27] iomap: switch iomap_fiemap " Christoph Hellwig
2021-07-19 10:35 ` [PATCH 16/27] iomap: switch iomap_bmap " Christoph Hellwig
2021-07-19 17:05 ` Darrick J. Wong
2021-07-26 8:19 ` Christoph Hellwig
2021-07-26 16:39 ` Darrick J. Wong
2021-07-27 6:31 ` Christoph Hellwig
2021-07-27 14:32 ` Darrick J. Wong
2021-07-19 10:35 ` [PATCH 17/27] iomap: switch iomap_seek_hole " Christoph Hellwig
2021-07-19 17:22 ` Darrick J. Wong
2021-07-26 8:22 ` Christoph Hellwig
2021-07-26 16:41 ` Darrick J. Wong
2021-07-19 10:35 ` [PATCH 18/27] iomap: switch iomap_seek_data " Christoph Hellwig
2021-07-19 10:35 ` [PATCH 19/27] iomap: switch iomap_swapfile_activate " Christoph Hellwig
2021-07-19 10:35 ` [PATCH 20/27] fsdax: switch dax_iomap_rw " Christoph Hellwig
2021-07-19 22:10 ` Dave Chinner
2021-07-26 8:25 ` Christoph Hellwig
2021-07-19 10:35 ` [PATCH 21/27] iomap: remove iomap_apply Christoph Hellwig
2021-07-19 17:48 ` Darrick J. Wong
2021-07-19 10:35 ` [PATCH 22/27] iomap: pass an iomap_iter to various buffered I/O helpers Christoph Hellwig
2021-07-19 17:48 ` Darrick J. Wong
2021-07-19 10:35 ` [PATCH 23/27] iomap: rework unshare flag Christoph Hellwig
2021-07-19 17:44 ` Darrick J. Wong
2021-07-19 10:35 ` [PATCH 24/27] fsdax: factor out helpers to simplify the dax fault code Christoph Hellwig
2021-07-19 10:35 ` [PATCH 25/27] fsdax: factor out a dax_fault_actor() helper Christoph Hellwig
2021-07-19 10:35 ` [PATCH 26/27] fsdax: switch the fault handlers to use iomap_iter Christoph Hellwig
2021-07-19 17:35 ` Darrick J. Wong
2021-07-19 10:35 ` [PATCH 27/27] iomap: constify iomap_iter_srcmap Christoph Hellwig
2021-07-19 17:44 ` Darrick J. Wong
2021-07-19 17:57 ` RFC: switch iomap to an iterator model Darrick J. Wong
2021-07-27 8:07 ` Christoph Hellwig [this message]
2021-07-29 20:33 ` Darrick J. Wong
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