Re: Memory hotplug softlock issue

[Baoquan He <bhe@redhat.com>]

On 11/15/18 at 02:19pm, Michal Hocko wrote:
> On Thu 15-11-18 21:12:11, Baoquan He wrote:
> > On 11/15/18 at 09:30am, Michal Hocko wrote:
> [...]
> > > It would be also good to find out whether this is fs specific. E.g. does
> > > it make any difference if you use a different one for your stress
> > > testing?
> > 
> > Created a ramdisk and put stress bin there, then run stress -m 200, now
> > seems it's stuck in libc-2.28.so migrating. And it's still xfs. So now xfs
> > is a big suspect. At bottom I paste numactl printing, you can see that it's
> > the last 4G.
> > 
> > Seems it's trying to migrate libc-2.28.so, but stress program keeps trying to
> > access and activate it.
> 
> Is this still with faultaround disabled? I have seen exactly same
> pattern in the bug I am working on. It was ext4 though.

No, forgot disabling faultround after reboot. Do we need to disable it and
retest?

> 
> > [ 5055.461652] migrating pfn 190f4fb3e failed 
> > [ 5055.461671] page:ffffea643d3ecf80 count:257 mapcount:251 mapping:ffff888e7a6ac528 index:0x85
> > [ 5055.474734] xfs_address_space_operations [xfs] 
> > [ 5055.474742] name:"libc-2.28.so" 
> > [ 5055.481070] flags: 0x1dfffffc0000026(referenced|uptodate|active)
> > [ 5055.490329] raw: 01dfffffc0000026 ffffc900000e3d80 ffffc900000e3d80 ffff888e7a6ac528
> > [ 5055.498080] raw: 0000000000000085 0000000000000000 000000fc000000f9 ffff88810a8f2000
> > [ 5055.505823] page->mem_cgroup:ffff88810a8f2000
> > [ 5056.335970] migrating pfn 190f4fb3e failed 
> > [ 5056.335990] page:ffffea643d3ecf80 count:255 mapcount:250 mapping:ffff888e7a6ac528 index:0x85
> > [ 5056.348994] xfs_address_space_operations [xfs] 
> > [ 5056.348998] name:"libc-2.28.so" 
> > [ 5056.353555] flags: 0x1dfffffc0000026(referenced|uptodate|active)
> > [ 5056.364680] raw: 01dfffffc0000026 ffffc900000e3d80 ffffc900000e3d80 ffff888e7a6ac528
> > [ 5056.372428] raw: 0000000000000085 0000000000000000 000000fc000000f9 ffff88810a8f2000
> > [ 5056.380172] page->mem_cgroup:ffff88810a8f2000
> > [ 5057.332806] migrating pfn 190f4fb3e failed 
> > [ 5057.332821] page:ffffea643d3ecf80 count:261 mapcount:250 mapping:ffff888e7a6ac528 index:0x85
> > [ 5057.345889] xfs_address_space_operations [xfs] 
> > [ 5057.345900] name:"libc-2.28.so" 
> > [ 5057.350451] flags: 0x1dfffffc0000026(referenced|uptodate|active)
> > [ 5057.359707] raw: 01dfffffc0000026 ffffc900000e3d80 ffffc900000e3d80 ffff888e7a6ac528
> > [ 5057.369285] raw: 0000000000000085 0000000000000000 000000fc000000f9 ffff88810a8f2000
> > [ 5057.377030] page->mem_cgroup:ffff88810a8f2000
> > [ 5058.285457] migrating pfn 190f4fb3e failed 
> > [ 5058.285489] page:ffffea643d3ecf80 count:257 mapcount:250 mapping:ffff888e7a6ac528 index:0x85
> > [ 5058.298544] xfs_address_space_operations [xfs] 
> > [ 5058.298556] name:"libc-2.28.so" 
> > [ 5058.303092] flags: 0x1dfffffc0000026(referenced|uptodate|active)
> > [ 5058.314358] raw: 01dfffffc0000026 ffffc900000e3d80 ffffc900000e3d80 ffff888e7a6ac528
> > [ 5058.322109] raw: 0000000000000085 0000000000000000 000000fc000000f9 ffff88810a8f2000
> > [ 5058.329848] page->mem_cgroup:ffff88810a8f2000
> -- 
> Michal Hocko
> SUSE Labs