linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Dominique Martinet <asmadeus@codewreck.org>
To: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: 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: Tue, 8 Jan 2019 00:48:39 +0100	[thread overview]
Message-ID: <20190107234839.GA15269@nautica> (raw)
In-Reply-To: <CA+CK2bDj1f=VpT+k-e8kSSaoLJ3W9-JPPq9udFdDwd6ijXi28g@mail.gmail.com>

Pavel Tatashin wrote on Mon, Jan 07, 2019:
> I could not reproduce the problem. Did you suspend to memory between
> wake ups? Does this time jump happen every time, even if your laptop
> sleeps for a minute?

I'm not sure I understand "suspend to memory between the wake ups".
The full sequence is:
 - start a VM (just in case, I let it boot till the end)
 - suspend to memory (aka systemctl suspend) the host
 - after resuming the host, soft reboot the VM (login through
serial/ssh/whatever and reboot or in the qemu console 'system_reset')

I've just slept exactly one minute and reproduced again with the fedora
stock kernel now (4.19.13-300.fc29.x86_64) in the VM.

Interestingly I'm not getting the same offset between multiple reboots
now despite not suspending again; but if I don't suspend I cannot seem
to get it to give an offset at all (only tried for a few minutes; this
might not be true) ; OTOH I pushed my luck further and even with a five
seconds sleep I'm getting a noticeable offset on first VM reboot after
resume:

[    0.000000] Hypervisor detected: KVM
[    0.000000] kvm-clock: Using msrs 4b564d01 and 4b564d00
[  179.362163] kvm-clock: cpu 0, msr 13c01001, primary cpu clock
[  179.362163] clocksource: kvm-clock: mask: 0xffffffffffffffff max_cycles: 0x1cd42e4dffb, max_idle_ns: 881590591483 ns

Honestly not sure what more information I could give, I'll try on some
other hardware than my laptop (if I can get a server to resume after
suspend through ipmi or wake on lan); but I don't have anything I could
install ubuntu on to try their qemu's version... although I really don't
want to believe that's the difference...

Thanks,
-- 
Dominique

  reply	other threads:[~2019-01-07 23:48 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 [this message]
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
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>

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20190107234839.GA15269@nautica \
    --to=asmadeus@codewreck.org \
    --cc=boris.ostrovsky@oracle.com \
    --cc=carnil@debian.org \
    --cc=daniel.m.jordan@oracle.com \
    --cc=douly.fnst@cn.fujitsu.com \
    --cc=feng.tang@intel.com \
    --cc=gnomes@lxorguk.ukuu.org.uk \
    --cc=heiko.carstens@de.ibm.com \
    --cc=hpa@zytor.com \
    --cc=jgross@suse.com \
    --cc=john.stultz@linaro.org \
    --cc=kvm@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-s390@vger.kernel.org \
    --cc=linux@armlinux.org.uk \
    --cc=mingo@redhat.com \
    --cc=pasha.tatashin@soleen.com \
    --cc=pavel.tatashin@microsoft.com \
    --cc=pbonzini@redhat.com \
    --cc=peterz@infradead.org \
    --cc=pmladek@suse.com \
    --cc=prarit@redhat.com \
    --cc=qemu-devel@nongnu.org \
    --cc=sboyd@codeaurora.org \
    --cc=schwidefsky@de.ibm.com \
    --cc=steven.sistare@oracle.com \
    --cc=tglx@linutronix.de \
    --cc=virtualization@lists.linux-foundation.org \
    --cc=x86@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).