On Thu, Sep 13, 2018 at 5:23 PM Oleg Nesterov <o...@redhat.com> wrote: > > On 09/13, Rafael J. Wysocki wrote: > > > > On Wed, Sep 12, 2018 at 6:11 PM Vitaly Kuznetsov <vkuzn...@redhat.com> > > wrote: > > > > > > It is possible to observe hung_task complaints when system goes to > > > suspend-to-idle state: > > > > > > PM: Syncing filesystems ... done. > > > Freezing user space processes ... (elapsed 0.001 seconds) done. > > > OOM killer disabled. > > > Freezing remaining freezable tasks ... (elapsed 0.002 seconds) done. > > > sd 0:0:0:0: [sda] Synchronizing SCSI cache > > > INFO: task bash:1569 blocked for more than 120 seconds. > > > Not tainted 4.19.0-rc3_+ #687 > > > "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. > > > bash D 0 1569 604 0x00000000 > > > Call Trace: > > > ? __schedule+0x1fe/0x7e0 > > > schedule+0x28/0x80 > > > suspend_devices_and_enter+0x4ac/0x750 > > > pm_suspend+0x2c0/0x310 > > > > This actually is a good catch, but the problem is related to what > > happens to the monotonic clock during suspend to idle. > > > > The clock issue needs to be addressed anyway IMO and then this problem > > will go away automatically. > > I don't understand your discussion with Vitaly, but shouldn't we make > khungtaskd thread freezable anyway?
Well, if the Vitaly's patch is applied, that shouldn't be necessary and I wouldn't like to add more freezable kernel threads if that's avoidable TBH. Cheers, Rafael
