My problem is probably the same that Doug Smythies described in bug 1626564 . I used the "echo workqueue:workqueue_queue_work > /sys/kernel/debug/tracing/set_event" method and had about 1000 work items enqueued by "memcg_kmem_cache_create_func" all at pretty much the same time, which correlates nicely with the 1000 kworker processes I see after boot.
If Martin has the same issue with lots of kworkers (I'm still not quite sure?), this might be the same issue. So I suspect the bad commit might be: 81ae6d03952c1bfb96e1a716809bd65e7cd14360 "mm/slub.c: replace kick_all_cpus_sync() with synchronize_sched() in kmem_cache_shrink()" according to https://bugzilla.kernel.org/show_bug.cgi?id=172991 This commit was released in Linux 4.7. This patch might fix the issue, but I haven't tested it: https://patchwork.kernel.org/patch/9359271/ ** Bug watch added: Linux Kernel Bug Tracker #172991 http://bugzilla.kernel.org/show_bug.cgi?id=172991 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1626436 Title: [4.8 regression] boot has become very slow To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1626436/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
