Christoph Lameter wrote: > On Wed, 28 Oct 2015, Tejun Heo wrote: > > > The only thing necessary here is WQ_MEM_RECLAIM. I don't see how > > WQ_SYSFS and WQ_FREEZABLE make sense here. > I can still trigger silent livelock with this patchset applied. ---------- [ 272.283217] MemAlloc-Info: 9 stalling task, 0 dying task, 0 victim task. [ 272.285089] MemAlloc: a.out(11325) gfp=0x24280ca order=0 delay=19164 [ 272.286817] MemAlloc: a.out(11326) gfp=0x242014a order=0 delay=19104 [ 272.288512] MemAlloc: vmtoolsd(1897) gfp=0x242014a order=0 delay=19072 [ 272.290280] MemAlloc: kworker/1:3(11286) gfp=0x2400000 order=0 delay=19056 [ 272.292114] MemAlloc: sshd(11202) gfp=0x242014a order=0 delay=18927 [ 272.293908] MemAlloc: tuned(2073) gfp=0x242014a order=0 delay=18799 [ 272.297360] MemAlloc: nmbd(4752) gfp=0x242014a order=0 delay=16532 [ 272.299115] MemAlloc: auditd(529) gfp=0x242014a order=0 delay=13073 [ 272.302248] MemAlloc: irqbalance(1696) gfp=0x242014a order=0 delay=10529 (...snipped...) [ 272.851035] Showing busy workqueues and worker pools: [ 272.852583] workqueue events: flags=0x0 [ 272.853942] pwq 6: cpus=3 node=0 flags=0x0 nice=0 active=1/256 [ 272.855781] pending: vmw_fb_dirty_flush [vmwgfx] [ 272.857500] pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=1/256 [ 272.859359] pending: vmpressure_work_fn [ 272.860840] workqueue events_freezable_power_: flags=0x84 [ 272.862461] pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=2/256 [ 272.864479] in-flight: 11286:disk_events_workfn [ 272.866065] pending: disk_events_workfn [ 272.867587] workqueue vmstat: flags=0x8 [ 272.868942] pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=1/256 [ 272.870785] pending: vmstat_update [ 272.872248] pool 2: cpus=1 node=0 flags=0x0 nice=0 workers=4 idle: 14 218 43 ---------- > 2. Create a separate workqueue so that the vmstat updater > is not blocked by other work requeusts. This creates a > new kernel thread <sigh> and avoids the issue of > differentials not folded in a timely fashion. Did you really mean "the vmstat updater is not blocked by other work requeusts"? -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>