On Tue 27-10-15 19:55:06, Tejun Heo wrote: > On Tue, Oct 27, 2015 at 10:22:31AM +0100, Michal Hocko wrote: > ... > > stable kernels without causing any other regressions. 2) is the way > > to move forward for next kernels and we should really think whether > > WQ_MEM_RECLAIM should imply also WQ_HIGHPRI by default. If there is a > > general consensus that there are legitimate WQ_MEM_RECLAIM users which > > can do without the other flag then I am perfectly OK to use it for > > vmstat and oom sysrq dedicated workqueues. > > I don't think flagging these things is a good approach. These are too > easy to miss. If this is a problem which needs to be solved, which > I'm not convined it is at this point, the right thing to do would be > doing stall detection and kicking the next work item automatically. To be honest, I do not really care whether this gets "fixed" in the stall detection code or by making WQ_MEM_RECLAIM to flag a special behavior implicitly. All I would like to see is to have a guarantee that such workqueues are not staying behind just because all current workers are in the allocator. Adding artificial schedule_timeouts in the allocator is a fragile way to work around the issue. -- Michal Hocko SUSE Labs -- 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>