On Tue, Jan 22, 2013 at 09:00:25PM +0300, Andrey Korolyov wrote: > Hi, > > problem described in the title happens on heavy I/O pressure on the > host, without idle=poll trace almost always is the same, involving > mwait, with poll and nohz=off RIP varies from time to time, at the > previous hang it was tg_throttle_down, rather than test_ti_thread_flag > in attached one. Both possible clocksource drivers, hpet and tsc, able > to reproduce that with equal probability. VMs are pinned over one of > two numa sets on two-head machine, mean emulator thread and each of > vcpu threads has its own cpuset cg with '0-5,12-17' or '6-11,18-23'. > I`ll appreciate any suggestions to try. Andrey, Can you reproduce with an upstream kernel? Commit 5cfc2aabcb282f fixes a livelock. d2 75 c3 eb 03 41 89 c6 48 83 c4 18 44 89 f0 5b 5d 41 5c 41 5d 41 5e 41 5f c3 <31> c0 c3 48 63 ff 48 c7 c2 80 37 01 00 48 8b 0c fd e0 d6 68 81 [12738.508644] Call Trace: [12738.508648] [<ffffffff81035a66>] ? walk_tg_tree_from+0x70/0x99 [12738.508652] [<ffffffff81014c03>] ? __switch_to_xtra+0x14c/0x160 [12738.508656] [<ffffffff8103bcce>] ? throttle_cfs_rq+0x4d/0x109 [12738.508660] [<ffffffff8103be70>] ? put_prev_task_fair+0x3f/0x65 [12738.508663] [<ffffffff8134c8ae>] ? __schedule+0x32e/0x5c3 [12738.508666] [<ffffffff8134ceee>] ? yield_to+0xfa/0x10c [12738.508669] [<ffffffff8105d5af>] ? atomic_inc+0x3/0x4 [12738.508678] [<ffffffffa03a8fc4>] ? kvm_vcpu_on_spin+0x8c/0xf7 [kvm] [12738.508684] [<ffffffffa030602f>] ? handle_pause+0x11/0x18 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html