search for: timekeeping

From: David Vrabel <david.vrabel@citrix.com> Instead of passing multiple bools to timekeeping_updated(), define flags and use a single ''action'' parameter. It is then more obvious what each timekeeping_update() call does. Signed-off-by: David Vrabel <david.vrabel@citrix.com> --- kernel/time/timekeeping.c | 21 ++++++++++++--------- 1 files changed, 12 insertions(...

...utek Wilk <konrad.wilk@oracle.com> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Richard Cochran <richardcochran@gmail.com> Cc: <xen-devel@lists.xen.org> Cc: stable <stable@vger.kernel.org> #3.11+ Signed-off-by: John Stultz <john.stultz@linaro.org> --- kernel/time/timekeeping.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index c615e9d..e429229 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -1297,7 +1297,7 @@ static inline unsigned int accumulate_nsecs_to_s...

...utek Wilk <konrad.wilk@oracle.com> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Richard Cochran <richardcochran@gmail.com> Cc: <xen-devel@lists.xen.org> Cc: stable <stable@vger.kernel.org> #3.11+ Signed-off-by: John Stultz <john.stultz@linaro.org> --- kernel/time/timekeeping.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 6bad3d9..998ec751 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -1295,7 +1295,7 @@ static inline unsigned int accumulate_nsecs_to_...

...nges to the system time with clock_was_set() or clock_was_set_delayed() calls. If other parts of the kernel require similar notification there is no clear place to hook into. Add a clock_was_set atomic notifier chain (clock_was_set_notifier_list) and call this in place of clock_was_set(). If the timekeeping locks are held, the calls are deferred to a new tasklet. The hrtimer code adds a notifier block to this chain and uses it to call (the now internal) clock_was_set(). Since the timekeeping code does not call the chain from the timer irq clock_was_set_delayed() and associated code can be removed....

This is really stupid question. But referring to: http://lists.centos.org/pipermail/centos/2009-October/083791.html I don't see any line related to ntpd in my /var/log/messages . Do I need to turn-on ntpd for timekeeping on VMs? Some people say not to use ntpd on VMs for timekeeping or is it ntpdate cron job? Can someone please elaborate on this? Thanks, Jonathan. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.centos.org/pipermail/centos/attachments/20091130/218a80...

People at vmware have provided patches for RHEL 5 that aim to fix timekeeping issues in vmware guests. https://bugzilla.redhat.com/show_bug.cgi?id=463573 Description of problem (excerpt) : "In a virtual environment, timekeeping for RHEL 64 bit kernels can be problematic, since time is kept by counting timer interrupts for this kernel. The problem arises when the VM...

On 03/03/16 09:18, Patrick Masotta wrote: >>>> How so? > > it says they cannot emulate the timer interrupt very well; > that's what I understood... If it's the VMware document I'm thinking of (titled "Timekeeping in VMware Virtual Machines"), then the issue is that emulating the timer interrupt can cause a heavy load on the host if the guest timer is configured to run at a high rate. Michael

Hello, I was thinking of creating a wiki page about Xen clocksources and timekeeping.. including dom0, PV guests and HVM guests. Dan and Jeremy: You guys might have some ideas for this page.. please let me know your thoughts :) Subjects to cover: - Xen hypervisor clocksources (hpet, acpi_pm, pit) - Xen dom0 clocksource, ntpd, etc - Xen PV guest clocksources, independent_wall...

Before 6.X Syslinux used a "Tick-less" timekeeping approach implemented in /core/bios.inc 6.X now implements a "Tick-counting" strategy (timer interrupt) implemented in /core/timer.inc I think this change presents issues when Sysylinux runs on Virtual Machines emulating a BIOS environment as they cannot correctly emulate the time...

Howdy, I am having time-drift issues on my CentOS VM. I had referred to following documentation: http://wiki.centos.org/TipsAndTricks/VMWare_Server , however it didn't help. I used kickstart for creating this VM and I am listing important steps in ref to timekeeping issue. Any comments or suggestion would be appreciated. - CS. ------------------- # For EL5 virtual machines, Append the following in Grub to help keep the clock from drifting # and to reduce the interupt requests # 32bit: --append="rhgb quiet divider=10 clocksource=acpi_pm" # 64bit...

...gt; there is any reason preventing us from going back to the "Tick-less" >> approach. Thanks. >> > > There are quite a few; primarily we simply cannot make lwIP > (lpxelinux.0) work without it. However, pxelinux.0 should not depend on > this. > Now, tickful timekeeping is wasteful, but this is a bootloader, and functionality is the main concern. The "tickless" version still depended on the BIOS tick. -hpa

> > There are quite a few; primarily we simply cannot make lwIP > (lpxelinux.0) work without it. However, pxelinux.0 should not depend on > this. I'm finding most of the problems on lpxelinux.0 > >Now, tickful timekeeping is wasteful, but this is a bootloader, and >functionality is the main concern. The "tickless" version still >depended on the BIOS tick. > Not really, a virtual environment can easily emulate the BIOS_timer at 0x046C but it has problems emulating a "real" timer interru...

On 03/03/16 07:31, Patrick Masotta wrote: > > The timer interrupt works fine in at least KVM, Xen, VMware, and > > Hyper-V. (I've tested iPXE in all of those virtual environments, and > > iPXE relies on the timer interrupt actually triggering a call to an ISR > > within the VM.) > > Well, that contradicts what the VMware document says. How so? Michael

>>> If it's the VMware document I'm thinking of (titled "Timekeeping in VMware Virtual Machines"), then the issue is that emulating the timer interrupt can cause a heavy load on the host if the guest timer is configured to run at a high rate. Michael <<< It seems it's more that that even at the regular rate... Best, Patrick

On 03/03/16 09:34, Patrick Masotta wrote: > > If it's the VMware document I'm thinking of (titled "Timekeeping in > > VMware Virtual Machines"), then the issue is that emulating the timer > > interrupt can cause a heavy load on the host if the guest timer is > > configured to run at a high rate. > > It seems it's more that that even at the regular rate... At the BIOS standa...

Hi everyone, I have the problem with Xen domU's and timekeeping in dom0. Time in dom0 was incorrect by 5 hours due to wrong timezone assumed. Fixed it by ntpdate ntp.nist.gov. The time on a dom0 was changed. I didn't append xen.independent_wallclock=1 to sysctl.conf thus the time in all domU's was also changed. But THEY DIDN'T "KNOW" T...

https://bugs.freedesktop.org/show_bug.cgi?id=98709 Bug ID: 98709 Summary: [NV50] clocksource: timekeeping watchdog on CPU2: Marking clocksource 'tsc' as unstable because the skew is too large Product: Mesa Version: 12.0 Hardware: x86-64 (AMD64) OS: Linux (All) Status: NEW Severity: norm...

On Sun, Jul 22, 2012 at 03:34:42PM +0200, Ingo Molnar wrote: > Linus, > > Please pull the latest timers-core-for-linus git tree from: > > git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git timers-core-for-linus > > HEAD: eec19d1a0d04c80e66eef634f7b8f460f2ca5643 Merge branch ''linus'' into timers/core > > Continued cleanups of the core

On 03/01/16 07:21, Patrick Masotta via Syslinux wrote: > > At the moment I'm seeing timing issues on TFTP transfers (lwIP depends > on the new interrupt based timer). I have consistently detected > > multiple Requests, double ACKs, etc. All these problems seem to be > > sourced on the now unreliable timeouts. > I have used TFTP on the same (BIOS VM) scenarios with

On 02/03/16 22:47, Patrick Masotta via Syslinux wrote: > Not really, a virtual environment can easily emulate the BIOS_timer at 0x046C > but it has problems emulating a "real" timer interrupt to be hooked... > That's the real problem. The timer interrupt works fine in at least KVM, Xen, VMware, and Hyper-V. (I've tested iPXE in all of those virtual environments, and