On Thu, May 31, 2018 at 09:02:52PM -0700, Dan Williams wrote: > On Thu, May 31, 2018 at 7:24 PM, Dave Chinner <david@xxxxxxxxxxxxx> wrote: > > On Thu, May 31, 2018 at 06:57:33PM -0700, Dan Williams wrote: > >> > FWIW, XFS+DAX used to just work on this setup (I hadn't even > >> > installed ndctl until this morning!) but after changing the kernel > >> > it no longer works. That would make it a regression, yes? [....] > >> I suspect your kernel does not have CONFIG_ZONE_DEVICE enabled which > >> has the following dependencies: > >> > >> depends on MEMORY_HOTPLUG > >> depends on MEMORY_HOTREMOVE > >> depends on SPARSEMEM_VMEMMAP > > > > Filesystem DAX now has a dependency on memory hotplug? [....] > > OK, works now I've found the magic config incantantions to turn > > everything I now need on. By enabling these options, my test VM now has a ~30s pause in the boot very soon after the nvdimm subsystem is initialised. [ 1.523718] Serial: 8250/16550 driver, 4 ports, IRQ sharing enabled [ 1.550353] 00:05: ttyS0 at I/O 0x3f8 (irq = 4, base_baud = 115200) is a 16550A [ 1.552175] Non-volatile memory driver v1.3 [ 2.332045] tsc: Refined TSC clocksource calibration: 2199.909 MHz [ 2.333280] clocksource: tsc: mask: 0xffffffffffffffff max_cycles: 0x1fb5dcd4620, max_idle_ns: 440795264143 ns [ 37.217453] brd: module loaded [ 37.225423] loop: module loaded [ 37.228441] virtio_blk virtio2: [vda] 10485760 512-byte logical blocks (5.37 GB/5.00 GiB) [ 37.245418] virtio_blk virtio3: [vdb] 146800640 512-byte logical blocks (75.2 GB/70.0 GiB) [ 37.255794] virtio_blk virtio4: [vdc] 1073741824000 512-byte logical blocks (550 TB/500 TiB) [ 37.265403] nd_pmem namespace1.0: unable to guarantee persistence of writes [ 37.265618] nd_pmem namespace0.0: unable to guarantee persistence of writes The system does not appear to be consuming CPU, but it is blocking NMIs so I can't get a CPU trace. For a VM that I rely on booting in a few seconds because I reboot it tens of times a day, this is a problem.... Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx
