From: Pavel Tatashin <pasha.tatashin@soleen.com>
To: Dominique Martinet <asmadeus@codewreck.org>,
Salvatore Bonaccorso <carnil@debian.org>,
Steven Sistare <steven.sistare@oracle.com>,
Pavel Tatashin <pavel.tatashin@microsoft.com>,
Daniel Jordan <daniel.m.jordan@oracle.com>,
linux@armlinux.org.uk, schwidefsky@de.ibm.com,
heiko.carstens@de.ibm.com, John Stultz <john.stultz@linaro.org>,
sboyd@codeaurora.org, x86@kernel.org,
LKML <linux-kernel@vger.kernel.org>,
mingo@redhat.com, Thomas Gleixner <tglx@linutronix.de>,
hpa@zytor.com, douly.fnst@cn.fujitsu.com,
Peter Zijlstra <peterz@infradead.org>,
prarit@redhat.com, feng.tang@intel.com,
Petr Mladek <pmladek@suse.com>,
gnomes@lxorguk.ukuu.org.uk, linux-s390@vger.kernel.org,
boris.ostrovsky@oracle.com, jgross@suse.com, pbonzini@redhat.com,
virtualization@lists.linux-foundation.org, kvm@vger.kernel.org,
qemu-devel@nongnu.org
Subject: Re: [PATCH v15 23/26] sched: early boot clock
Date: Sat, 26 Jan 2019 16:11:37 +0000 [thread overview]
Message-ID: <20190126161137.gme4vsrz3xmncbkx@soleen.tm1wkky2jk1uhgkn0ivaxijq1c.bx.internal.cloudapp.net> (raw)
In-Reply-To: <20190126020410.GB3796@feynman.vault24.org>
On 19-01-25 21:04:10, Jon DeVree wrote:
>
> * KVM_FEATURE_CLOCKSOURCE_STABLE_BIT is always set by the hypervisor
> starting with Linux v2.6.35 - 371bcf646d17 ("KVM: x86: Tell the guest
> we'll warn it about tsc stability")
> * PVCLOCK_TSC_STABLE_BIT is set starting in Linux v3.8 but only if the
> clocksource is the TSC - d828199e8444 ("KVM: x86: implement
> PVCLOCK_TSC_STABLE_BIT pvclock flag")
>
> I changed the clocksource of a hypervisor that wasn't having issues from
> TSC to HPET and when I started up a guest VM the bug suddenly appeared.
> I shut down the guest, set the hypervisor's clocksource back to TSC,
> started up the guest and the bug went away again.
>
> You don't actually have to reboot the guest before the bug is visible
> either, just letting the guest sit at the GRUB menu for a minute or two
> before loading Linux is enough to make the bug plainly visible in the
> printk timestamps.
>
> I don't know enough to actually fix the bug, but hopefully this is
> enough to allow everyone else to reproduce it and come up with a fix.
Thank you very much for your analysis, I am now able to reproduce the
problem by setting clocksource on my machine to hpet. I will soon submit a
patch with a fix.
Pasha
>
> --
> Jon
> X(7): A program for managing terminal windows. See also screen(1) and tmux(1).
next prev parent reply other threads:[~2019-01-26 16:11 UTC|newest]
Thread overview: 76+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-19 20:55 [PATCH v15 00/26] Early boot time stamps Pavel Tatashin
2018-07-19 20:55 ` [PATCH v15 01/26] x86/kvmclock: Remove memblock dependency Pavel Tatashin
2018-07-19 22:21 ` [tip:x86/timers] " tip-bot for Pavel Tatashin
2018-07-19 20:55 ` [PATCH v15 02/26] x86/kvmclock: Remove page size requirement from wall_clock Pavel Tatashin
2018-07-19 22:22 ` [tip:x86/timers] " tip-bot for Thomas Gleixner
2018-07-19 20:55 ` [PATCH v15 03/26] x86/kvmclock: Decrapify kvm_register_clock() Pavel Tatashin
2018-07-19 22:23 ` [tip:x86/timers] " tip-bot for Thomas Gleixner
2018-07-19 20:55 ` [PATCH v15 04/26] x86/kvmclock: Cleanup the code Pavel Tatashin
2018-07-19 22:23 ` [tip:x86/timers] " tip-bot for Thomas Gleixner
2018-07-19 20:55 ` [PATCH v15 05/26] x86/kvmclock: Mark variables __initdata and __ro_after_init Pavel Tatashin
2018-07-19 22:24 ` [tip:x86/timers] " tip-bot for Thomas Gleixner
2018-07-19 20:55 ` [PATCH v15 06/26] x86/kvmclock: Move kvmclock vsyscall param and init to kvmclock Pavel Tatashin
2018-07-19 22:24 ` [tip:x86/timers] " tip-bot for Thomas Gleixner
2018-07-19 20:55 ` [PATCH v15 07/26] x86/kvmclock: Switch kvmclock data to a PER_CPU variable Pavel Tatashin
2018-07-19 22:25 ` [tip:x86/timers] " tip-bot for Thomas Gleixner
2018-07-19 20:55 ` [PATCH v15 08/26] x86: text_poke() may access uninitialized struct pages Pavel Tatashin
2018-07-19 22:25 ` [tip:x86/timers] x86/alternatives, jumplabel: Use text_poke_early() before mm_init() tip-bot for Pavel Tatashin
2018-07-19 20:55 ` [PATCH v15 09/26] x86: initialize static branching early Pavel Tatashin
2018-07-19 22:26 ` [tip:x86/timers] x86/jump_label: Initialize " tip-bot for Pavel Tatashin
2018-07-19 20:55 ` [PATCH v15 10/26] x86/CPU: Call detect_nopl() only on the BSP Pavel Tatashin
2018-07-19 22:26 ` [tip:x86/timers] " tip-bot for Borislav Petkov
2018-07-19 20:55 ` [PATCH v15 11/26] x86/tsc: redefine notsc to behave as tsc=unstable Pavel Tatashin
2018-07-19 22:27 ` [tip:x86/timers] x86/tsc: Redefine " tip-bot for Pavel Tatashin
2018-07-19 20:55 ` [PATCH v15 12/26] x86/xen/time: initialize pv xen time in init_hypervisor_platform Pavel Tatashin
2018-07-19 22:27 ` [tip:x86/timers] x86/xen/time: Initialize pv xen time in init_hypervisor_platform() tip-bot for Pavel Tatashin
2018-07-19 20:55 ` [PATCH v15 13/26] x86/xen/time: output xen sched_clock time from 0 Pavel Tatashin
2018-07-19 22:28 ` [tip:x86/timers] x86/xen/time: Output " tip-bot for Pavel Tatashin
2018-07-19 20:55 ` [PATCH v15 14/26] s390/time: add read_persistent_wall_and_boot_offset() Pavel Tatashin
2018-07-19 22:28 ` [tip:x86/timers] s390/time: Add read_persistent_wall_and_boot_offset() tip-bot for Pavel Tatashin
2018-07-19 20:55 ` [PATCH v15 15/26] time: replace read_boot_clock64() with read_persistent_wall_and_boot_offset() Pavel Tatashin
2018-07-19 22:29 ` [tip:x86/timers] timekeeping: Replace " tip-bot for Pavel Tatashin
2018-07-19 20:55 ` [PATCH v15 16/26] time: default boot time offset to local_clock() Pavel Tatashin
2018-07-19 22:29 ` [tip:x86/timers] timekeeping: Default " tip-bot for Pavel Tatashin
2018-07-19 20:55 ` [PATCH v15 17/26] s390/time: remove read_boot_clock64() Pavel Tatashin
2018-07-19 22:30 ` [tip:x86/timers] s390/time: Remove read_boot_clock64() tip-bot for Pavel Tatashin
2018-07-19 20:55 ` [PATCH v15 18/26] ARM/time: remove read_boot_clock64() Pavel Tatashin
2018-07-19 22:30 ` [tip:x86/timers] ARM/time: Remove read_boot_clock64() tip-bot for Pavel Tatashin
2018-07-19 20:55 ` [PATCH v15 19/26] x86/tsc: calibrate tsc only once Pavel Tatashin
2018-07-19 22:31 ` [tip:x86/timers] x86/tsc: Calibrate " tip-bot for Pavel Tatashin
2018-07-19 20:55 ` [PATCH v15 20/26] x86/tsc: initialize cyc2ns when tsc freq. is determined Pavel Tatashin
2018-07-19 22:31 ` [tip:x86/timers] x86/tsc: Initialize cyc2ns when tsc frequency " tip-bot for Pavel Tatashin
2018-07-19 20:55 ` [PATCH v15 21/26] x86/tsc: use tsc early Pavel Tatashin
2018-07-19 22:32 ` [tip:x86/timers] x86/tsc: Use TSC as sched clock early tip-bot for Pavel Tatashin
2018-07-19 20:55 ` [PATCH v15 22/26] sched: move sched clock initialization and merge with generic clock Pavel Tatashin
2018-07-19 22:32 ` [tip:x86/timers] sched/clock: Move " tip-bot for Pavel Tatashin
2018-07-19 20:55 ` [PATCH v15 23/26] sched: early boot clock Pavel Tatashin
2018-07-19 22:33 ` [tip:x86/timers] sched/clock: Enable sched clock early tip-bot for Pavel Tatashin
2018-07-24 19:52 ` Guenter Roeck
2018-07-24 20:22 ` Pavel Tatashin
2018-07-25 0:36 ` Pavel Tatashin
2018-07-25 1:24 ` Guenter Roeck
2018-07-25 2:05 ` Pavel Tatashin
2018-07-25 2:41 ` Pavel Tatashin
2018-07-30 12:36 ` Peter Zijlstra
2018-07-30 13:44 ` Pavel Tatashin
2018-07-20 8:09 ` [PATCH v15 23/26] sched: early boot clock Peter Zijlstra
2018-07-20 10:00 ` [tip:x86/timers] sched/clock: Close a hole in sched_clock_init() tip-bot for Peter Zijlstra
2018-11-06 5:42 ` [PATCH v15 23/26] sched: early boot clock Dominique Martinet
2018-11-06 11:35 ` Steven Sistare
2019-01-02 20:20 ` Salvatore Bonaccorso
2019-01-03 21:28 ` Pavel Tatashin
2019-01-03 23:43 ` Dominique Martinet
2019-01-07 18:17 ` Pavel Tatashin
2019-01-07 23:48 ` Dominique Martinet
2019-01-08 1:04 ` Pavel Tatashin
2019-01-08 1:09 ` Dominique Martinet
2019-01-26 2:04 ` Jon DeVree
2019-01-26 16:11 ` Pavel Tatashin [this message]
2019-01-04 7:30 ` [PATCH v15 23/26] sched: early boot clock (was Re: Bug#918036: linux: uptime after reboot wrong (kvm-clock related?)) Thorsten Glaser
2018-07-19 20:55 ` [PATCH v15 24/26] sched: use static key for sched_clock_running Pavel Tatashin
2018-07-19 22:33 ` [tip:x86/timers] sched/clock: Use " tip-bot for Pavel Tatashin
2018-07-19 20:55 ` [PATCH v15 25/26] x86/tsc: split native_calibrate_cpu() into early and late parts Pavel Tatashin
2018-07-19 22:34 ` [tip:x86/timers] x86/tsc: Split " tip-bot for Pavel Tatashin
2018-07-19 20:55 ` [PATCH v15 26/26] x86/tsc: use tsc_calibrate_cpu_early and pit_hpet_ptimer_calibrate_cpu Pavel Tatashin
2018-07-19 22:35 ` [tip:x86/timers] x86/tsc: Make use of tsc_calibrate_cpu_early() tip-bot for Pavel Tatashin
2018-07-19 22:34 ` [PATCH v15 00/26] Early boot time stamps Thomas Gleixner
[not found] <154644530361.2390.18185252504260044930.reportbug@ci-busyapps.lan.tarent.de>
[not found] ` <20190102163939.GB13145@eldamar.local>
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