Re: LTP rwtest01 blocks on DAX mountpoint

[Ross Zwisler]

On Tue, Jan 03, 2017 at 02:49:22PM +0800, Xiong Zhou wrote:
> On Mon, Jan 02, 2017 at 02:49:41PM -0700, Ross Zwisler wrote:
> > On Mon, Jan 02, 2017 at 06:16:17PM +0100, Jan Kara wrote:
> > > On Fri 30-12-16 17:33:53, Xiong Zhou wrote:
> > > > On Sat, Dec 24, 2016 at 07:07:14PM +0800, Xiong Zhou wrote:
> > > > > Hi lists,
> snip
> > > I was trying to reproduce this but for me rwtest01 completes just fine on
> > > dax mountpoint (I've used your reproducer). So can you sample several
> > > kernel stack traces to get a rough idea where the kernel is running?
> > > Thanks!
> > > 
> > > 								Honza
> > 
> > I'm also unable to reproduce this issue.  I've tried with both the blamed
> > commit:
> > 4b4bb46 (HEAD) dax: clear dirty entry tags on cache flush
> > and with v4.9-rc2.  Both pass the test in my setup.
> > Perhaps the variable is the size of your PMEM partitions?
> > # fdisk -l /dev/pmem0
> > Disk /dev/pmem0: 16 GiB, 17179869184 bytes, 33554432 sectors
> > Units: sectors of 1 * 512 = 512 bytes
> > Sector size (logical/physical): 512 bytes / 4096 bytes
> > I/O size (minimum/optimal): 4096 bytes / 4096 bytes
> > Disklabel type: dos
> > Disk identifier: 0xfe50c900
> > Device       Boot    Start      End  Sectors Size Id Type
> > /dev/pmem0p1          4096 25165823 25161728  12G 83 Linux
> > /dev/pmem0p2      25165824 33550335  8384512   4G 83 Linux
> > 
> > What does your setup look like?
> > I'm using the current tip of the LTP tree:
> > 8cc4165  waitid02: define _XOPEN_SOURCE 500
> > Thanks,
> > - Ross
> 
> Thanks all for looking into it.
> 
> Turns out the rc2 relative updates fix this issue, so does
> an old issue i reported a while ago:
> multi-threads libvmmalloc fork test hang
> https://lists.01.org/pipermail/linux-nvdimm/2016-October/007602.html
> 
> I'm able to reproduce these issues before rc2, now it
> passes on current Linus tree:
> c8b4ec8 Merge tag 'fscrypt-for-stable'

Hmm...I'm able to reproduce the other libvmmalloc issue with both v4.10-rc2
and with "c8b4ec8 Merge tag 'fscrypt-for-stable'".  I'm debugging that issue
today.

It's interesting that both tests started passing for you.  Did you change
something in your test setup?