From: Stefan Priebe <s.priebe@profihost.ag>
To: qemu-devel <qemu-devel@nongnu.org>
Subject: [Qemu-devel] guest: NO_HZ FULL will not work with unstable sched clock
Date: Sat, 15 Aug 2015 20:44:07 +0200 [thread overview]
Message-ID: <55CF8877.30802@profihost.ag> (raw)
Hi,
while switching to a FULL tickless kernel i detected that all our VMs
produce the following stack trace while running under qemu 2.3.0.
[ 0.195160] HPET: 3 timers in total, 0 timers will be used for
per-cpu timer
[ 0.195181] hpet0: at MMIO 0xfed00000, IRQs 2, 8, 0
[ 0.195188] hpet0: 3 comparators, 64-bit 100.000000 MHz counter
[ 0.200119] Switched to clocksource hpet
[ 0.201164] ------------[ cut here ]------------
[ 0.201193] WARNING: CPU: 1 PID: 1 at kernel/time/tick-sched.c:192
can_stop_full_tick+0x1c1/0x200()
[ 0.201199] NO_HZ FULL will not work with unstable sched clock
[ 0.201203] Modules linked in:
[ 0.201214] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 3.18.20+55-ph #1
[ 0.201219] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
BIOS rel-1.8.1-0-g4adadbd-20150316_085822-nilsson.home.kraxel.org 04/01/2014
[ 0.201226] 0000000000000009 ffff88023fc43e88 ffffffff815f5889
00000000000008df
[ 0.201230] ffff88023fc43ed8 ffff88023fc43ec8 ffffffff8107433c
ffff88023fc43ea8
[ 0.201233] 0000000000000000 0000000000000001 ffff880236c41300
00000000cbbde78b
[ 0.201237] Call Trace:
[ 0.201240] <IRQ> [<ffffffff815f5889>] dump_stack+0x46/0x58
[ 0.201260] [<ffffffff8107433c>] warn_slowpath_common+0x8c/0xc0
[ 0.201264] [<ffffffff81074426>] warn_slowpath_fmt+0x46/0x50
[ 0.201270] [<ffffffff810ddc31>] can_stop_full_tick+0x1c1/0x200
[ 0.201274] [<ffffffff810ddfc7>] tick_nohz_irq_exit+0x97/0xd0
[ 0.201277] [<ffffffff81077f0d>] irq_exit+0xcd/0x130
[ 0.201286] [<ffffffff8103419a>] smp_apic_timer_interrupt+0x4a/0x60
[ 0.201293] [<ffffffff815fc4ea>] apic_timer_interrupt+0x6a/0x70
[ 0.201296] <EOI> [<ffffffff811bc1d5>] ? __d_lookup+0x55/0x160
[ 0.201309] [<ffffffff811bc315>] d_lookup+0x35/0x60
[ 0.201312] [<ffffffff811adc1b>] lookup_dcache+0x3b/0xd0
[ 0.201315] [<ffffffff811adcd3>] __lookup_hash+0x23/0x50
[ 0.201319] [<ffffffff811aeaae>] lookup_one_len+0xce/0x120
[ 0.201328] [<ffffffff812d062f>] __create_file+0x8f/0x260
[ 0.201332] [<ffffffff812d089b>] debugfs_create_dir+0x1b/0x20
[ 0.201338] [<ffffffff8111d9a8>] event_create_dir+0x68/0x520
[ 0.201342] [<ffffffff81d5bdb0>] event_trace_init+0x188/0x210
[ 0.201348] [<ffffffff81113e1b>] ? trace_create_file+0x1b/0x50
[ 0.201352] [<ffffffff81d5bc28>] ? event_trace_enable+0x1a2/0x1a2
[ 0.201359] [<ffffffff81000328>] do_one_initcall+0xd8/0x200
[ 0.201368] [<ffffffff81090200>] ? parse_args+0x1f0/0x470
[ 0.201373] [<ffffffff810b1c33>] ? __wake_up+0x53/0x70
[ 0.201378] [<ffffffff81d3e1ce>] kernel_init_freeable+0x168/0x1ff
[ 0.201381] [<ffffffff81d3d917>] ? do_early_param+0x8c/0x8c
[ 0.201389] [<ffffffff812f0680>] ? cryptomgr_probe+0x60/0xe0
[ 0.201398] [<ffffffff815e6f30>] ? rest_init+0x80/0x80
[ 0.201401] [<ffffffff815e6f3e>] kernel_init+0xe/0xf0
[ 0.201405] [<ffffffff815fb708>] ret_from_fork+0x58/0x90
[ 0.201408] [<ffffffff815e6f30>] ? rest_init+0x80/0x80
[ 0.201415] ---[ end trace a15ba3bc1d247b4c ]---
Stefan
next reply other threads:[~2015-08-15 18:44 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-08-15 18:44 Stefan Priebe [this message]
2015-08-15 22:20 ` [Qemu-devel] guest: NO_HZ FULL will not work with unstable sched clock Stefan Priebe
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