On Fri 23-02-18 11:51:41, Laura Abbott wrote: > Hi, > > The Fedora arm-32 build VMs have a somewhat long standing problem > of hanging when running mkfs.ext4 with a bunch of processes stuck > in D state. This has been seen as far back as 4.13 but is still > present on 4.14: > [...] > This looks like everything is blocked on the writeback completing but > the writeback has been throttled. According to the infra team, this problem > is _not_ seen without LPAE (i.e. only 4G of RAM). I did see > https://patchwork.kernel.org/patch/10201593/ but that doesn't seem to > quite match since this seems to be completely stuck. Any suggestions to > narrow the problem down? How much dirtyable memory does the system have? We do allow only lowmem to be dirtyable by default on 32b highmem systems. Maybe you have the lowmem mostly consumed by the kernel memory. Have you tried to enable highmem_is_dirtyable? -- Michal Hocko SUSE Labs
