* Re: [Xenomai] ToD drift on i7-3740QM [not found] <CABxGBLRcHB_V1H-Da-yv5GMaN=_9-tD_K0werwc-SPSGgTRy5g@mail.gmail.com> @ 2015-01-29 13:04 ` Gilles Chanteperdrix 2015-01-30 11:15 ` Roland Pastorino 0 siblings, 1 reply; 10+ messages in thread From: Gilles Chanteperdrix @ 2015-01-29 13:04 UTC (permalink / raw) To: Roland Pastorino; +Cc: xenomai On Thu, Jan 29, 2015 at 01:59:36PM +0100, Roland Pastorino wrote: > 2015-01-29 13:25 GMT+01:00 Gilles Chanteperdrix > <gilles.chanteperdrix@xenomai.org>: > > On Sun, Jan 25, 2015 at 12:15:39PM +0100, Roland Pastorino wrote: > >> Good morning everyone, > >> > >> I would like to know if some of you could give me a hint on how to > >> solve my ToD drift problem. > >> This question is similar to this one -> > >> http://comments.gmane.org/gmane.linux.real-time.xenomai.users/19719 > >> > >> Problem: > >> After installing Xenomai and after the first reboot, my ToD drift was > >> around 500000 us/s. > >> After the second reboot, my ToD drift is around 500 us/s which I > >> presume is still too high. > >> I checked the troubleshooting information on Xenomai website but it didn't help. > >> > >> Machine and configuration: > >> - PC = Thinkpad w530 > >> - cpu = i7-3740QM > >> - kernel configuration file is attached. I followed the Xenomai > >> website for the configuration. > >> - cobalt kernel of Xenomai 3 > >> - Linux kernel 3.16 > >> - ipipe-core-3.16-x86-1.patch > >> - Ubuntu 14.10 > > > > Actually, the kernel configuration is not attached. But probably the > > only interesting item is whether CONFIG_CPU_FREQ is missing. > > > > > > -- > > Gilles. > > I've attached the kernel configuration this time... > > CONFIG_CPU_FREQ is like this: > # CPU Frequency scaling > # > # CONFIG_CPU_FREQ is not set > > This is the result of configuring the kernel via 'makemenuconfig'. > Also I noticed that the 'clocktest' can give different results > (without rebooting my machine). > For example now my ToD drift is around 67 us/s which is better but > different from the previously mentioned results. > The best I got was 0.6 us/s. Linux and Xenomai do not necessarily use the same clock source, and when they use the same, do not necessarily use the same frequency, especially when Linux has NTP running. So, unless you launch clocktest to watch CLOCK_HOST_REALTIME, a difference is expected. But 500us/s is abnormal, something is off. You need to look at the frequencies used by Linux and Xenomai, and see which one is off. -- Gilles. ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [Xenomai] ToD drift on i7-3740QM 2015-01-29 13:04 ` [Xenomai] ToD drift on i7-3740QM Gilles Chanteperdrix @ 2015-01-30 11:15 ` Roland Pastorino 2015-02-03 8:09 ` Roland Pastorino 0 siblings, 1 reply; 10+ messages in thread From: Roland Pastorino @ 2015-01-30 11:15 UTC (permalink / raw) To: Gilles Chanteperdrix; +Cc: xenomai 2015-01-29 14:04 GMT+01:00 Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>: > On Thu, Jan 29, 2015 at 01:59:36PM +0100, Roland Pastorino wrote: >> 2015-01-29 13:25 GMT+01:00 Gilles Chanteperdrix >> <gilles.chanteperdrix@xenomai.org>: >> > On Sun, Jan 25, 2015 at 12:15:39PM +0100, Roland Pastorino wrote: >> >> Good morning everyone, >> >> >> >> I would like to know if some of you could give me a hint on how to >> >> solve my ToD drift problem. >> >> This question is similar to this one -> >> >> http://comments.gmane.org/gmane.linux.real-time.xenomai.users/19719 >> >> >> >> Problem: >> >> After installing Xenomai and after the first reboot, my ToD drift was >> >> around 500000 us/s. >> >> After the second reboot, my ToD drift is around 500 us/s which I >> >> presume is still too high. >> >> I checked the troubleshooting information on Xenomai website but it didn't help. >> >> >> >> Machine and configuration: >> >> - PC = Thinkpad w530 >> >> - cpu = i7-3740QM >> >> - kernel configuration file is attached. I followed the Xenomai >> >> website for the configuration. >> >> - cobalt kernel of Xenomai 3 >> >> - Linux kernel 3.16 >> >> - ipipe-core-3.16-x86-1.patch >> >> - Ubuntu 14.10 >> > >> > Actually, the kernel configuration is not attached. But probably the >> > only interesting item is whether CONFIG_CPU_FREQ is missing. >> > >> > >> > -- >> > Gilles. >> >> I've attached the kernel configuration this time... >> >> CONFIG_CPU_FREQ is like this: >> # CPU Frequency scaling >> # >> # CONFIG_CPU_FREQ is not set >> >> This is the result of configuring the kernel via 'makemenuconfig'. >> Also I noticed that the 'clocktest' can give different results >> (without rebooting my machine). >> For example now my ToD drift is around 67 us/s which is better but >> different from the previously mentioned results. >> The best I got was 0.6 us/s. > > Linux and Xenomai do not necessarily use the same clock source, and > when they use the same, do not necessarily use the same frequency, > especially when Linux has NTP running. So, unless you launch > clocktest to watch CLOCK_HOST_REALTIME, a difference is expected. > But 500us/s is abnormal, something is off. You need to look at the > frequencies used by Linux and Xenomai, and see which one is off. > > > -- > Gilles. I see the point. If I run the 'clocktest' with CLOCK_HOST_REALTIME, I get this: == Tested clock: 8 (CLOCK_HOST_REALTIME) CPU ToD offset [us] ToD drift [us/s] warps max delta [us] --- -------------------- ---------------- ---------- -------------- 0 -339532135.1 122526.008 0 0.0 1 -339532070.5 121839.520 0 0.0 2 -339532420.1 122929.781 0 0.0 3 -339531750.8 123088.126 0 0.0 The drift is still way off. CLOCK_REALTIME gives: == Tested clock: 0 (CLOCK_REALTIME) CPU ToD offset [us] ToD drift [us/s] warps max delta [us] --- -------------------- ---------------- ---------- -------------- 0 -302580987.5 330900.325 0 0.0 1 -302580653.8 330346.234 0 0.0 2 -302580710.2 329623.634 0 0.0 3 -302580359.1 329730.306 0 0.0 I verified that NTP is running. $ sudo service ntp service * NTP server is running As you mentioned the Linux and/or Xenomai frequencies is/are probably off. I have to mention that my Linux clock (=date) can run faster or slower than the wall-clock time. Could you please tell me where I should start searching for a solution? Linux kernel sources, ipipe patch? Many Thanks. Roland Pastorino ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [Xenomai] ToD drift on i7-3740QM 2015-01-30 11:15 ` Roland Pastorino @ 2015-02-03 8:09 ` Roland Pastorino 2015-02-03 11:23 ` Gilles Chanteperdrix 0 siblings, 1 reply; 10+ messages in thread From: Roland Pastorino @ 2015-02-03 8:09 UTC (permalink / raw) To: Gilles Chanteperdrix; +Cc: xenomai 2015-01-30 12:15 GMT+01:00 Roland Pastorino <roland@rolandpastorino.com>: > 2015-01-29 14:04 GMT+01:00 Gilles Chanteperdrix > <gilles.chanteperdrix@xenomai.org>: >> On Thu, Jan 29, 2015 at 01:59:36PM +0100, Roland Pastorino wrote: >>> 2015-01-29 13:25 GMT+01:00 Gilles Chanteperdrix >>> <gilles.chanteperdrix@xenomai.org>: >>> > On Sun, Jan 25, 2015 at 12:15:39PM +0100, Roland Pastorino wrote: >>> >> Good morning everyone, >>> >> >>> >> I would like to know if some of you could give me a hint on how to >>> >> solve my ToD drift problem. >>> >> This question is similar to this one -> >>> >> http://comments.gmane.org/gmane.linux.real-time.xenomai.users/19719 >>> >> >>> >> Problem: >>> >> After installing Xenomai and after the first reboot, my ToD drift was >>> >> around 500000 us/s. >>> >> After the second reboot, my ToD drift is around 500 us/s which I >>> >> presume is still too high. >>> >> I checked the troubleshooting information on Xenomai website but it didn't help. >>> >> >>> >> Machine and configuration: >>> >> - PC = Thinkpad w530 >>> >> - cpu = i7-3740QM >>> >> - kernel configuration file is attached. I followed the Xenomai >>> >> website for the configuration. >>> >> - cobalt kernel of Xenomai 3 >>> >> - Linux kernel 3.16 >>> >> - ipipe-core-3.16-x86-1.patch >>> >> - Ubuntu 14.10 >>> > >>> > Actually, the kernel configuration is not attached. But probably the >>> > only interesting item is whether CONFIG_CPU_FREQ is missing. >>> > >>> > >>> > -- >>> > Gilles. >>> >>> I've attached the kernel configuration this time... >>> >>> CONFIG_CPU_FREQ is like this: >>> # CPU Frequency scaling >>> # >>> # CONFIG_CPU_FREQ is not set >>> >>> This is the result of configuring the kernel via 'makemenuconfig'. >>> Also I noticed that the 'clocktest' can give different results >>> (without rebooting my machine). >>> For example now my ToD drift is around 67 us/s which is better but >>> different from the previously mentioned results. >>> The best I got was 0.6 us/s. >> >> Linux and Xenomai do not necessarily use the same clock source, and >> when they use the same, do not necessarily use the same frequency, >> especially when Linux has NTP running. So, unless you launch >> clocktest to watch CLOCK_HOST_REALTIME, a difference is expected. >> But 500us/s is abnormal, something is off. You need to look at the >> frequencies used by Linux and Xenomai, and see which one is off. >> >> >> -- >> Gilles. > > I see the point. > If I run the 'clocktest' with CLOCK_HOST_REALTIME, I get this: > > == Tested clock: 8 (CLOCK_HOST_REALTIME) > CPU ToD offset [us] ToD drift [us/s] warps max delta [us] > --- -------------------- ---------------- ---------- -------------- > 0 -339532135.1 122526.008 0 0.0 > 1 -339532070.5 121839.520 0 0.0 > 2 -339532420.1 122929.781 0 0.0 > 3 -339531750.8 123088.126 0 0.0 > > The drift is still way off. > CLOCK_REALTIME gives: > > == Tested clock: 0 (CLOCK_REALTIME) > CPU ToD offset [us] ToD drift [us/s] warps max delta [us] > --- -------------------- ---------------- ---------- -------------- > 0 -302580987.5 330900.325 0 0.0 > 1 -302580653.8 330346.234 0 0.0 > 2 -302580710.2 329623.634 0 0.0 > 3 -302580359.1 329730.306 0 0.0 > > I verified that NTP is running. > $ sudo service ntp service > * NTP server is running > > As you mentioned the Linux and/or Xenomai frequencies is/are probably off. > I have to mention that my Linux clock (=date) can run faster or slower > than the wall-clock time. > Could you please tell me where I should start searching for a > solution? Linux kernel sources, ipipe patch? > > Many Thanks. > > Roland Pastorino I give you more insight into the problem. I prepared a Linux kernel 3.14.17 with Xenomai 3 (instead of the 3.16 I was using until now) in order to see if the problem disappeared. The kernel configuration is based on the one provided with Ubuntu 14.04 for kernel 3.13. With kernel 3.14.17 the problem remains. The only different is that the wifi on my PC now works. Then I prepared a Linux kernel 3.16 without Xenomai in order to see if something was wrong with my compilation process. The kernel configuration is based on the one provided with Ubuntu 14.10 for kernel 3.16. This kernel works perfectly. I welcome any comment/idea on how to proceed with the issue searching. Best Regards Roland Pastorino ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [Xenomai] ToD drift on i7-3740QM 2015-02-03 8:09 ` Roland Pastorino @ 2015-02-03 11:23 ` Gilles Chanteperdrix 2015-02-03 21:55 ` Roland Pastorino 0 siblings, 1 reply; 10+ messages in thread From: Gilles Chanteperdrix @ 2015-02-03 11:23 UTC (permalink / raw) To: Roland Pastorino; +Cc: xenomai On Tue, Feb 03, 2015 at 09:09:48AM +0100, Roland Pastorino wrote: > 2015-01-30 12:15 GMT+01:00 Roland Pastorino <roland@rolandpastorino.com>: > > 2015-01-29 14:04 GMT+01:00 Gilles Chanteperdrix > > <gilles.chanteperdrix@xenomai.org>: > >> On Thu, Jan 29, 2015 at 01:59:36PM +0100, Roland Pastorino wrote: > >>> 2015-01-29 13:25 GMT+01:00 Gilles Chanteperdrix > >>> <gilles.chanteperdrix@xenomai.org>: > >>> > On Sun, Jan 25, 2015 at 12:15:39PM +0100, Roland Pastorino wrote: > >>> >> Good morning everyone, > >>> >> > >>> >> I would like to know if some of you could give me a hint on how to > >>> >> solve my ToD drift problem. > >>> >> This question is similar to this one -> > >>> >> http://comments.gmane.org/gmane.linux.real-time.xenomai.users/19719 > >>> >> > >>> >> Problem: > >>> >> After installing Xenomai and after the first reboot, my ToD drift was > >>> >> around 500000 us/s. > >>> >> After the second reboot, my ToD drift is around 500 us/s which I > >>> >> presume is still too high. > >>> >> I checked the troubleshooting information on Xenomai website but it didn't help. > >>> >> > >>> >> Machine and configuration: > >>> >> - PC = Thinkpad w530 > >>> >> - cpu = i7-3740QM > >>> >> - kernel configuration file is attached. I followed the Xenomai > >>> >> website for the configuration. > >>> >> - cobalt kernel of Xenomai 3 > >>> >> - Linux kernel 3.16 > >>> >> - ipipe-core-3.16-x86-1.patch > >>> >> - Ubuntu 14.10 > >>> > > >>> > Actually, the kernel configuration is not attached. But probably the > >>> > only interesting item is whether CONFIG_CPU_FREQ is missing. > >>> > > >>> > > >>> > -- > >>> > Gilles. > >>> > >>> I've attached the kernel configuration this time... > >>> > >>> CONFIG_CPU_FREQ is like this: > >>> # CPU Frequency scaling > >>> # > >>> # CONFIG_CPU_FREQ is not set > >>> > >>> This is the result of configuring the kernel via 'makemenuconfig'. > >>> Also I noticed that the 'clocktest' can give different results > >>> (without rebooting my machine). > >>> For example now my ToD drift is around 67 us/s which is better but > >>> different from the previously mentioned results. > >>> The best I got was 0.6 us/s. > >> > >> Linux and Xenomai do not necessarily use the same clock source, and > >> when they use the same, do not necessarily use the same frequency, > >> especially when Linux has NTP running. So, unless you launch > >> clocktest to watch CLOCK_HOST_REALTIME, a difference is expected. > >> But 500us/s is abnormal, something is off. You need to look at the > >> frequencies used by Linux and Xenomai, and see which one is off. > >> > >> > >> -- > >> Gilles. > > > > I see the point. > > If I run the 'clocktest' with CLOCK_HOST_REALTIME, I get this: > > > > == Tested clock: 8 (CLOCK_HOST_REALTIME) > > CPU ToD offset [us] ToD drift [us/s] warps max delta [us] > > --- -------------------- ---------------- ---------- -------------- > > 0 -339532135.1 122526.008 0 0.0 > > 1 -339532070.5 121839.520 0 0.0 > > 2 -339532420.1 122929.781 0 0.0 > > 3 -339531750.8 123088.126 0 0.0 > > > > The drift is still way off. > > CLOCK_REALTIME gives: > > > > == Tested clock: 0 (CLOCK_REALTIME) > > CPU ToD offset [us] ToD drift [us/s] warps max delta [us] > > --- -------------------- ---------------- ---------- -------------- > > 0 -302580987.5 330900.325 0 0.0 > > 1 -302580653.8 330346.234 0 0.0 > > 2 -302580710.2 329623.634 0 0.0 > > 3 -302580359.1 329730.306 0 0.0 > > > > I verified that NTP is running. > > $ sudo service ntp service > > * NTP server is running > > > > As you mentioned the Linux and/or Xenomai frequencies is/are probably off. > > I have to mention that my Linux clock (=date) can run faster or slower > > than the wall-clock time. > > Could you please tell me where I should start searching for a > > solution? Linux kernel sources, ipipe patch? > > > > Many Thanks. > > > > Roland Pastorino > > I give you more insight into the problem. > I prepared a Linux kernel 3.14.17 with Xenomai 3 (instead of the 3.16 > I was using until now) in order to see if the problem disappeared. > The kernel configuration is based on the one provided with Ubuntu > 14.04 for kernel 3.13. > With kernel 3.14.17 the problem remains. The only different is that > the wifi on my PC now works. > > Then I prepared a Linux kernel 3.16 without Xenomai in order to see if > something was wrong with my compilation process. > The kernel configuration is based on the one provided with Ubuntu > 14.10 for kernel 3.16. > This kernel works perfectly. > > I welcome any comment/idea on how to proceed with the issue searching. As I said, you need to look at the frequencies used by Linux and Xenomai, and see which one is off. -- Gilles. ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [Xenomai] ToD drift on i7-3740QM 2015-02-03 11:23 ` Gilles Chanteperdrix @ 2015-02-03 21:55 ` Roland Pastorino 2015-02-04 9:20 ` Gilles Chanteperdrix 0 siblings, 1 reply; 10+ messages in thread From: Roland Pastorino @ 2015-02-03 21:55 UTC (permalink / raw) To: Gilles Chanteperdrix; +Cc: xenomai 2015-02-03 12:23 GMT+01:00 Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>: > On Tue, Feb 03, 2015 at 09:09:48AM +0100, Roland Pastorino wrote: >> 2015-01-30 12:15 GMT+01:00 Roland Pastorino <roland@rolandpastorino.com>: >> > 2015-01-29 14:04 GMT+01:00 Gilles Chanteperdrix >> > <gilles.chanteperdrix@xenomai.org>: >> >> On Thu, Jan 29, 2015 at 01:59:36PM +0100, Roland Pastorino wrote: >> >>> 2015-01-29 13:25 GMT+01:00 Gilles Chanteperdrix >> >>> <gilles.chanteperdrix@xenomai.org>: >> >>> > On Sun, Jan 25, 2015 at 12:15:39PM +0100, Roland Pastorino wrote: >> >>> >> Good morning everyone, >> >>> >> >> >>> >> I would like to know if some of you could give me a hint on how to >> >>> >> solve my ToD drift problem. >> >>> >> This question is similar to this one -> >> >>> >> http://comments.gmane.org/gmane.linux.real-time.xenomai.users/19719 >> >>> >> >> >>> >> Problem: >> >>> >> After installing Xenomai and after the first reboot, my ToD drift was >> >>> >> around 500000 us/s. >> >>> >> After the second reboot, my ToD drift is around 500 us/s which I >> >>> >> presume is still too high. >> >>> >> I checked the troubleshooting information on Xenomai website but it didn't help. >> >>> >> >> >>> >> Machine and configuration: >> >>> >> - PC = Thinkpad w530 >> >>> >> - cpu = i7-3740QM >> >>> >> - kernel configuration file is attached. I followed the Xenomai >> >>> >> website for the configuration. >> >>> >> - cobalt kernel of Xenomai 3 >> >>> >> - Linux kernel 3.16 >> >>> >> - ipipe-core-3.16-x86-1.patch >> >>> >> - Ubuntu 14.10 >> >>> > >> >>> > Actually, the kernel configuration is not attached. But probably the >> >>> > only interesting item is whether CONFIG_CPU_FREQ is missing. >> >>> > >> >>> > >> >>> > -- >> >>> > Gilles. >> >>> >> >>> I've attached the kernel configuration this time... >> >>> >> >>> CONFIG_CPU_FREQ is like this: >> >>> # CPU Frequency scaling >> >>> # >> >>> # CONFIG_CPU_FREQ is not set >> >>> >> >>> This is the result of configuring the kernel via 'makemenuconfig'. >> >>> Also I noticed that the 'clocktest' can give different results >> >>> (without rebooting my machine). >> >>> For example now my ToD drift is around 67 us/s which is better but >> >>> different from the previously mentioned results. >> >>> The best I got was 0.6 us/s. >> >> >> >> Linux and Xenomai do not necessarily use the same clock source, and >> >> when they use the same, do not necessarily use the same frequency, >> >> especially when Linux has NTP running. So, unless you launch >> >> clocktest to watch CLOCK_HOST_REALTIME, a difference is expected. >> >> But 500us/s is abnormal, something is off. You need to look at the >> >> frequencies used by Linux and Xenomai, and see which one is off. >> >> >> >> >> >> -- >> >> Gilles. >> > >> > I see the point. >> > If I run the 'clocktest' with CLOCK_HOST_REALTIME, I get this: >> > >> > == Tested clock: 8 (CLOCK_HOST_REALTIME) >> > CPU ToD offset [us] ToD drift [us/s] warps max delta [us] >> > --- -------------------- ---------------- ---------- -------------- >> > 0 -339532135.1 122526.008 0 0.0 >> > 1 -339532070.5 121839.520 0 0.0 >> > 2 -339532420.1 122929.781 0 0.0 >> > 3 -339531750.8 123088.126 0 0.0 >> > >> > The drift is still way off. >> > CLOCK_REALTIME gives: >> > >> > == Tested clock: 0 (CLOCK_REALTIME) >> > CPU ToD offset [us] ToD drift [us/s] warps max delta [us] >> > --- -------------------- ---------------- ---------- -------------- >> > 0 -302580987.5 330900.325 0 0.0 >> > 1 -302580653.8 330346.234 0 0.0 >> > 2 -302580710.2 329623.634 0 0.0 >> > 3 -302580359.1 329730.306 0 0.0 >> > >> > I verified that NTP is running. >> > $ sudo service ntp service >> > * NTP server is running >> > >> > As you mentioned the Linux and/or Xenomai frequencies is/are probably off. >> > I have to mention that my Linux clock (=date) can run faster or slower >> > than the wall-clock time. >> > Could you please tell me where I should start searching for a >> > solution? Linux kernel sources, ipipe patch? >> > >> > Many Thanks. >> > >> > Roland Pastorino >> >> I give you more insight into the problem. >> I prepared a Linux kernel 3.14.17 with Xenomai 3 (instead of the 3.16 >> I was using until now) in order to see if the problem disappeared. >> The kernel configuration is based on the one provided with Ubuntu >> 14.04 for kernel 3.13. >> With kernel 3.14.17 the problem remains. The only different is that >> the wifi on my PC now works. >> >> Then I prepared a Linux kernel 3.16 without Xenomai in order to see if >> something was wrong with my compilation process. >> The kernel configuration is based on the one provided with Ubuntu >> 14.10 for kernel 3.16. >> This kernel works perfectly. >> >> I welcome any comment/idea on how to proceed with the issue searching. > > As I said, you need to look at the frequencies used by Linux and > Xenomai, and see which one is off. > > -- > Gilles. Here goes the 'look into the frequencies'. The two commands that I used: $ cat /sys/devices/system/clocksource/clocksource0/available_clocksource $ cat /sys/devices/system/clocksource/clocksource0/current_clocksource Vanilla Ubuntu 14.10 kernel 3.16 |_ available clock sources -> tsc, hpet, acpi_pm |_ current clock source -> tsc Ubuntu 14.10 kernel 3.14.17 + Xenomai 3 (cobalt) |_ available clock sources -> refined-jiffies, jiffies, tsc |_ current clock source -> refined-jiffies Then I figured out with 'dmesg' that the kernel gives the following errors/warnings during boot-up: [ 0.577663] [Xenomai] SMI-enabled chipset found, but SMI workaround disabled (see xenomai.smi parameter). You might encounter high latencies! [ 3.841168] Clocksource tsc unstable (delta = 139968530 ns) [ 3.868256] Switched to clocksource refined-jiffies It is therefore clear that my clock drift problem comes from the fact that the Linux kernel is not able to use the TSC clock source. I will try to figure out why the clock source switches to refined-jiffies. Would you have any advice on this matter? I am now looking into this post on the Xenomai website https://xenomai.org//2014/06/dealing-with-x86-smi-troubles/ Best Regards Roland Pastorino ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [Xenomai] ToD drift on i7-3740QM 2015-02-03 21:55 ` Roland Pastorino @ 2015-02-04 9:20 ` Gilles Chanteperdrix 2015-02-05 21:28 ` Roland Pastorino 0 siblings, 1 reply; 10+ messages in thread From: Gilles Chanteperdrix @ 2015-02-04 9:20 UTC (permalink / raw) To: Roland Pastorino; +Cc: xenomai On Tue, Feb 03, 2015 at 10:55:40PM +0100, Roland Pastorino wrote: > 2015-02-03 12:23 GMT+01:00 Gilles Chanteperdrix > <gilles.chanteperdrix@xenomai.org>: > > On Tue, Feb 03, 2015 at 09:09:48AM +0100, Roland Pastorino wrote: > >> 2015-01-30 12:15 GMT+01:00 Roland Pastorino <roland@rolandpastorino.com>: > >> > 2015-01-29 14:04 GMT+01:00 Gilles Chanteperdrix > >> > <gilles.chanteperdrix@xenomai.org>: > >> >> On Thu, Jan 29, 2015 at 01:59:36PM +0100, Roland Pastorino wrote: > >> >>> 2015-01-29 13:25 GMT+01:00 Gilles Chanteperdrix > >> >>> <gilles.chanteperdrix@xenomai.org>: > >> >>> > On Sun, Jan 25, 2015 at 12:15:39PM +0100, Roland Pastorino wrote: > >> >>> >> Good morning everyone, > >> >>> >> > >> >>> >> I would like to know if some of you could give me a hint on how to > >> >>> >> solve my ToD drift problem. > >> >>> >> This question is similar to this one -> > >> >>> >> http://comments.gmane.org/gmane.linux.real-time.xenomai.users/19719 > >> >>> >> > >> >>> >> Problem: > >> >>> >> After installing Xenomai and after the first reboot, my ToD drift was > >> >>> >> around 500000 us/s. > >> >>> >> After the second reboot, my ToD drift is around 500 us/s which I > >> >>> >> presume is still too high. > >> >>> >> I checked the troubleshooting information on Xenomai website but it didn't help. > >> >>> >> > >> >>> >> Machine and configuration: > >> >>> >> - PC = Thinkpad w530 > >> >>> >> - cpu = i7-3740QM > >> >>> >> - kernel configuration file is attached. I followed the Xenomai > >> >>> >> website for the configuration. > >> >>> >> - cobalt kernel of Xenomai 3 > >> >>> >> - Linux kernel 3.16 > >> >>> >> - ipipe-core-3.16-x86-1.patch > >> >>> >> - Ubuntu 14.10 > >> >>> > > >> >>> > Actually, the kernel configuration is not attached. But probably the > >> >>> > only interesting item is whether CONFIG_CPU_FREQ is missing. > >> >>> > > >> >>> > > >> >>> > -- > >> >>> > Gilles. > >> >>> > >> >>> I've attached the kernel configuration this time... > >> >>> > >> >>> CONFIG_CPU_FREQ is like this: > >> >>> # CPU Frequency scaling > >> >>> # > >> >>> # CONFIG_CPU_FREQ is not set > >> >>> > >> >>> This is the result of configuring the kernel via 'makemenuconfig'. > >> >>> Also I noticed that the 'clocktest' can give different results > >> >>> (without rebooting my machine). > >> >>> For example now my ToD drift is around 67 us/s which is better but > >> >>> different from the previously mentioned results. > >> >>> The best I got was 0.6 us/s. > >> >> > >> >> Linux and Xenomai do not necessarily use the same clock source, and > >> >> when they use the same, do not necessarily use the same frequency, > >> >> especially when Linux has NTP running. So, unless you launch > >> >> clocktest to watch CLOCK_HOST_REALTIME, a difference is expected. > >> >> But 500us/s is abnormal, something is off. You need to look at the > >> >> frequencies used by Linux and Xenomai, and see which one is off. > >> >> > >> >> > >> >> -- > >> >> Gilles. > >> > > >> > I see the point. > >> > If I run the 'clocktest' with CLOCK_HOST_REALTIME, I get this: > >> > > >> > == Tested clock: 8 (CLOCK_HOST_REALTIME) > >> > CPU ToD offset [us] ToD drift [us/s] warps max delta [us] > >> > --- -------------------- ---------------- ---------- -------------- > >> > 0 -339532135.1 122526.008 0 0.0 > >> > 1 -339532070.5 121839.520 0 0.0 > >> > 2 -339532420.1 122929.781 0 0.0 > >> > 3 -339531750.8 123088.126 0 0.0 > >> > > >> > The drift is still way off. > >> > CLOCK_REALTIME gives: > >> > > >> > == Tested clock: 0 (CLOCK_REALTIME) > >> > CPU ToD offset [us] ToD drift [us/s] warps max delta [us] > >> > --- -------------------- ---------------- ---------- -------------- > >> > 0 -302580987.5 330900.325 0 0.0 > >> > 1 -302580653.8 330346.234 0 0.0 > >> > 2 -302580710.2 329623.634 0 0.0 > >> > 3 -302580359.1 329730.306 0 0.0 > >> > > >> > I verified that NTP is running. > >> > $ sudo service ntp service > >> > * NTP server is running > >> > > >> > As you mentioned the Linux and/or Xenomai frequencies is/are probably off. > >> > I have to mention that my Linux clock (=date) can run faster or slower > >> > than the wall-clock time. > >> > Could you please tell me where I should start searching for a > >> > solution? Linux kernel sources, ipipe patch? > >> > > >> > Many Thanks. > >> > > >> > Roland Pastorino > >> > >> I give you more insight into the problem. > >> I prepared a Linux kernel 3.14.17 with Xenomai 3 (instead of the 3.16 > >> I was using until now) in order to see if the problem disappeared. > >> The kernel configuration is based on the one provided with Ubuntu > >> 14.04 for kernel 3.13. > >> With kernel 3.14.17 the problem remains. The only different is that > >> the wifi on my PC now works. > >> > >> Then I prepared a Linux kernel 3.16 without Xenomai in order to see if > >> something was wrong with my compilation process. > >> The kernel configuration is based on the one provided with Ubuntu > >> 14.10 for kernel 3.16. > >> This kernel works perfectly. > >> > >> I welcome any comment/idea on how to proceed with the issue searching. > > > > As I said, you need to look at the frequencies used by Linux and > > Xenomai, and see which one is off. > > > > -- > > Gilles. > > Here goes the 'look into the frequencies'. > > The two commands that I used: > $ cat /sys/devices/system/clocksource/clocksource0/available_clocksource > $ cat /sys/devices/system/clocksource/clocksource0/current_clocksource > > Vanilla Ubuntu 14.10 kernel 3.16 > |_ available clock sources -> tsc, hpet, acpi_pm > |_ current clock source -> tsc > > Ubuntu 14.10 kernel 3.14.17 + Xenomai 3 (cobalt) > |_ available clock sources -> refined-jiffies, jiffies, tsc > |_ current clock source -> refined-jiffies > > Then I figured out with 'dmesg' that the kernel gives the following > errors/warnings during boot-up: > [ 0.577663] [Xenomai] SMI-enabled chipset found, but SMI workaround disabled > (see xenomai.smi parameter). You might encounter high latencies! > [ 3.841168] Clocksource tsc unstable (delta = 139968530 ns) > [ 3.868256] Switched to clocksource refined-jiffies > > It is therefore clear that my clock drift problem comes from the fact > that the Linux kernel is not able to use > the TSC clock source. No. Any clocksource should work. > I will try to figure out why the clock source switches to refined-jiffies. > Would you have any advice on this matter? Normally, there is some code in the I-pipe to prevent this from happening, I do not remember the details. -- Gilles. ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [Xenomai] ToD drift on i7-3740QM 2015-02-04 9:20 ` Gilles Chanteperdrix @ 2015-02-05 21:28 ` Roland Pastorino 0 siblings, 0 replies; 10+ messages in thread From: Roland Pastorino @ 2015-02-05 21:28 UTC (permalink / raw) To: Gilles Chanteperdrix; +Cc: xenomai 2015-02-04 10:20 GMT+01:00 Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>: > On Tue, Feb 03, 2015 at 10:55:40PM +0100, Roland Pastorino wrote: >> 2015-02-03 12:23 GMT+01:00 Gilles Chanteperdrix >> <gilles.chanteperdrix@xenomai.org>: >> > On Tue, Feb 03, 2015 at 09:09:48AM +0100, Roland Pastorino wrote: >> >> 2015-01-30 12:15 GMT+01:00 Roland Pastorino <roland@rolandpastorino.com>: >> >> > 2015-01-29 14:04 GMT+01:00 Gilles Chanteperdrix >> >> > <gilles.chanteperdrix@xenomai.org>: >> >> >> On Thu, Jan 29, 2015 at 01:59:36PM +0100, Roland Pastorino wrote: >> >> >>> 2015-01-29 13:25 GMT+01:00 Gilles Chanteperdrix >> >> >>> <gilles.chanteperdrix@xenomai.org>: >> >> >>> > On Sun, Jan 25, 2015 at 12:15:39PM +0100, Roland Pastorino wrote: >> >> >>> >> Good morning everyone, >> >> >>> >> >> >> >>> >> I would like to know if some of you could give me a hint on how to >> >> >>> >> solve my ToD drift problem. >> >> >>> >> This question is similar to this one -> >> >> >>> >> http://comments.gmane.org/gmane.linux.real-time.xenomai.users/19719 >> >> >>> >> >> >> >>> >> Problem: >> >> >>> >> After installing Xenomai and after the first reboot, my ToD drift was >> >> >>> >> around 500000 us/s. >> >> >>> >> After the second reboot, my ToD drift is around 500 us/s which I >> >> >>> >> presume is still too high. >> >> >>> >> I checked the troubleshooting information on Xenomai website but it didn't help. >> >> >>> >> >> >> >>> >> Machine and configuration: >> >> >>> >> - PC = Thinkpad w530 >> >> >>> >> - cpu = i7-3740QM >> >> >>> >> - kernel configuration file is attached. I followed the Xenomai >> >> >>> >> website for the configuration. >> >> >>> >> - cobalt kernel of Xenomai 3 >> >> >>> >> - Linux kernel 3.16 >> >> >>> >> - ipipe-core-3.16-x86-1.patch >> >> >>> >> - Ubuntu 14.10 >> >> >>> > >> >> >>> > Actually, the kernel configuration is not attached. But probably the >> >> >>> > only interesting item is whether CONFIG_CPU_FREQ is missing. >> >> >>> > >> >> >>> > >> >> >>> > -- >> >> >>> > Gilles. >> >> >>> >> >> >>> I've attached the kernel configuration this time... >> >> >>> >> >> >>> CONFIG_CPU_FREQ is like this: >> >> >>> # CPU Frequency scaling >> >> >>> # >> >> >>> # CONFIG_CPU_FREQ is not set >> >> >>> >> >> >>> This is the result of configuring the kernel via 'makemenuconfig'. >> >> >>> Also I noticed that the 'clocktest' can give different results >> >> >>> (without rebooting my machine). >> >> >>> For example now my ToD drift is around 67 us/s which is better but >> >> >>> different from the previously mentioned results. >> >> >>> The best I got was 0.6 us/s. >> >> >> >> >> >> Linux and Xenomai do not necessarily use the same clock source, and >> >> >> when they use the same, do not necessarily use the same frequency, >> >> >> especially when Linux has NTP running. So, unless you launch >> >> >> clocktest to watch CLOCK_HOST_REALTIME, a difference is expected. >> >> >> But 500us/s is abnormal, something is off. You need to look at the >> >> >> frequencies used by Linux and Xenomai, and see which one is off. >> >> >> >> >> >> >> >> >> -- >> >> >> Gilles. >> >> > >> >> > I see the point. >> >> > If I run the 'clocktest' with CLOCK_HOST_REALTIME, I get this: >> >> > >> >> > == Tested clock: 8 (CLOCK_HOST_REALTIME) >> >> > CPU ToD offset [us] ToD drift [us/s] warps max delta [us] >> >> > --- -------------------- ---------------- ---------- -------------- >> >> > 0 -339532135.1 122526.008 0 0.0 >> >> > 1 -339532070.5 121839.520 0 0.0 >> >> > 2 -339532420.1 122929.781 0 0.0 >> >> > 3 -339531750.8 123088.126 0 0.0 >> >> > >> >> > The drift is still way off. >> >> > CLOCK_REALTIME gives: >> >> > >> >> > == Tested clock: 0 (CLOCK_REALTIME) >> >> > CPU ToD offset [us] ToD drift [us/s] warps max delta [us] >> >> > --- -------------------- ---------------- ---------- -------------- >> >> > 0 -302580987.5 330900.325 0 0.0 >> >> > 1 -302580653.8 330346.234 0 0.0 >> >> > 2 -302580710.2 329623.634 0 0.0 >> >> > 3 -302580359.1 329730.306 0 0.0 >> >> > >> >> > I verified that NTP is running. >> >> > $ sudo service ntp service >> >> > * NTP server is running >> >> > >> >> > As you mentioned the Linux and/or Xenomai frequencies is/are probably off. >> >> > I have to mention that my Linux clock (=date) can run faster or slower >> >> > than the wall-clock time. >> >> > Could you please tell me where I should start searching for a >> >> > solution? Linux kernel sources, ipipe patch? >> >> > >> >> > Many Thanks. >> >> > >> >> > Roland Pastorino >> >> >> >> I give you more insight into the problem. >> >> I prepared a Linux kernel 3.14.17 with Xenomai 3 (instead of the 3.16 >> >> I was using until now) in order to see if the problem disappeared. >> >> The kernel configuration is based on the one provided with Ubuntu >> >> 14.04 for kernel 3.13. >> >> With kernel 3.14.17 the problem remains. The only different is that >> >> the wifi on my PC now works. >> >> >> >> Then I prepared a Linux kernel 3.16 without Xenomai in order to see if >> >> something was wrong with my compilation process. >> >> The kernel configuration is based on the one provided with Ubuntu >> >> 14.10 for kernel 3.16. >> >> This kernel works perfectly. >> >> >> >> I welcome any comment/idea on how to proceed with the issue searching. >> > >> > As I said, you need to look at the frequencies used by Linux and >> > Xenomai, and see which one is off. >> > >> > -- >> > Gilles. >> >> Here goes the 'look into the frequencies'. >> >> The two commands that I used: >> $ cat /sys/devices/system/clocksource/clocksource0/available_clocksource >> $ cat /sys/devices/system/clocksource/clocksource0/current_clocksource >> >> Vanilla Ubuntu 14.10 kernel 3.16 >> |_ available clock sources -> tsc, hpet, acpi_pm >> |_ current clock source -> tsc >> >> Ubuntu 14.10 kernel 3.14.17 + Xenomai 3 (cobalt) >> |_ available clock sources -> refined-jiffies, jiffies, tsc >> |_ current clock source -> refined-jiffies >> >> Then I figured out with 'dmesg' that the kernel gives the following >> errors/warnings during boot-up: >> [ 0.577663] [Xenomai] SMI-enabled chipset found, but SMI workaround disabled >> (see xenomai.smi parameter). You might encounter high latencies! >> [ 3.841168] Clocksource tsc unstable (delta = 139968530 ns) >> [ 3.868256] Switched to clocksource refined-jiffies >> >> It is therefore clear that my clock drift problem comes from the fact >> that the Linux kernel is not able to use >> the TSC clock source. > > No. Any clocksource should work. > >> I will try to figure out why the clock source switches to refined-jiffies. >> Would you have any advice on this matter? > > Normally, there is some code in the I-pipe to prevent this from > happening, I do not remember the details. > > -- > Gilles. I've had a look at the I-pipe code but it will take me some time to understand it and then modify it (if necessary). In the meantime I found that I can pass the clocksource as a kernel option in the GRUB configuration file. GRUB_CMDLINE_LINUX="clocksource=tsc" I still get the "Clocksource tsc unstable" message at boot-up but the clocksource does not switch to "refined-jiffies". As a consequence, the "clocktest" program gives ToD drift of maximum 500 us/s and minimum 0.2 us/s. I have seen also some rare pathological latencies (= several hundreds of us). -- Roland Pastorino ^ permalink raw reply [flat|nested] 10+ messages in thread
* [Xenomai] ToD drift on i7-3740QM @ 2015-01-25 11:15 Roland Pastorino 2015-01-29 12:25 ` Gilles Chanteperdrix 0 siblings, 1 reply; 10+ messages in thread From: Roland Pastorino @ 2015-01-25 11:15 UTC (permalink / raw) To: xenomai Good morning everyone, I would like to know if some of you could give me a hint on how to solve my ToD drift problem. This question is similar to this one -> http://comments.gmane.org/gmane.linux.real-time.xenomai.users/19719 Problem: After installing Xenomai and after the first reboot, my ToD drift was around 500000 us/s. After the second reboot, my ToD drift is around 500 us/s which I presume is still too high. I checked the troubleshooting information on Xenomai website but it didn't help. Machine and configuration: - PC = Thinkpad w530 - cpu = i7-3740QM - kernel configuration file is attached. I followed the Xenomai website for the configuration. - cobalt kernel of Xenomai 3 - Linux kernel 3.16 - ipipe-core-3.16-x86-1.patch - Ubuntu 14.10 clocktest: CPU ToD offset [us] ToD drift [us/s] warps max delta [us] --- -------------------- ---------------- ---------- -------------- 0 -772589.4 499.629 0 0.0 1 -772589.3 499.598 0 0.0 2 -772590.0 499.579 0 0.0 3 -772589.4 499.583 0 0.0 latency: RTT| 00:00:01 (periodic user-mode task, 100 us period, priority 99) RTH|----lat min|----lat avg|----lat max|-overrun|---msw|---lat best|--lat worst RTD| -2.256| -1.682| 1.962| 0| 0| -2.256| 1.962 RTD| -2.264| -1.685| 1.821| 0| 0| -2.264| 1.962 RTD| -2.256| -1.670| 2.489| 0| 0| -2.264| 2.489 RTD| -2.250| -1.654| 2.396| 0| 0| -2.264| 2.489 RTD| -2.254| -1.506| 2.867| 0| 0| -2.264| 2.867 RTD| -2.258| -1.647| 2.933| 0| 0| -2.264| 2.933 RTD| -2.252| -1.696| 1.800| 0| 0| -2.264| 2.933 RTD| -2.265| -1.733| 2.639| 0| 0| -2.265| 2.933 RTD| -2.260| -1.684| 2.659| 0| 0| -2.265| 2.933 RTD| -2.261| -1.737| 1.496| 0| 0| -2.265| 2.933 RTD| -2.262| -1.709| 4.076| 0| 0| -2.265| 4.076 RTD| -2.259| -1.691| 1.822| 0| 0| -2.265| 4.076 RTD| -2.258| -1.658| 2.680| 0| 0| -2.265| 4.076 RTD| -2.259| -1.724| 1.842| 0| 0| -2.265| 4.076 RTD| -2.254| -1.552| 2.312| 0| 0| -2.265| 4.076 ^C---|-----------|-----------|-----------|--------|------|------------------------- RTS| -2.265| -1.668| 4.076| 0| 0| 00:00:16/00:00:16 Thank you. Best Regards -- Roland Pastorino ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [Xenomai] ToD drift on i7-3740QM 2015-01-25 11:15 Roland Pastorino @ 2015-01-29 12:25 ` Gilles Chanteperdrix 2015-01-29 13:01 ` Roland Pastorino 0 siblings, 1 reply; 10+ messages in thread From: Gilles Chanteperdrix @ 2015-01-29 12:25 UTC (permalink / raw) To: Roland Pastorino; +Cc: xenomai On Sun, Jan 25, 2015 at 12:15:39PM +0100, Roland Pastorino wrote: > Good morning everyone, > > I would like to know if some of you could give me a hint on how to > solve my ToD drift problem. > This question is similar to this one -> > http://comments.gmane.org/gmane.linux.real-time.xenomai.users/19719 > > Problem: > After installing Xenomai and after the first reboot, my ToD drift was > around 500000 us/s. > After the second reboot, my ToD drift is around 500 us/s which I > presume is still too high. > I checked the troubleshooting information on Xenomai website but it didn't help. > > Machine and configuration: > - PC = Thinkpad w530 > - cpu = i7-3740QM > - kernel configuration file is attached. I followed the Xenomai > website for the configuration. > - cobalt kernel of Xenomai 3 > - Linux kernel 3.16 > - ipipe-core-3.16-x86-1.patch > - Ubuntu 14.10 Actually, the kernel configuration is not attached. But probably the only interesting item is whether CONFIG_CPU_FREQ is missing. -- Gilles. ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [Xenomai] ToD drift on i7-3740QM 2015-01-29 12:25 ` Gilles Chanteperdrix @ 2015-01-29 13:01 ` Roland Pastorino 0 siblings, 0 replies; 10+ messages in thread From: Roland Pastorino @ 2015-01-29 13:01 UTC (permalink / raw) To: Gilles Chanteperdrix; +Cc: xenomai 2015-01-29 13:25 GMT+01:00 Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>: > On Sun, Jan 25, 2015 at 12:15:39PM +0100, Roland Pastorino wrote: >> Good morning everyone, >> >> I would like to know if some of you could give me a hint on how to >> solve my ToD drift problem. >> This question is similar to this one -> >> http://comments.gmane.org/gmane.linux.real-time.xenomai.users/19719 >> >> Problem: >> After installing Xenomai and after the first reboot, my ToD drift was >> around 500000 us/s. >> After the second reboot, my ToD drift is around 500 us/s which I >> presume is still too high. >> I checked the troubleshooting information on Xenomai website but it didn't help. >> >> Machine and configuration: >> - PC = Thinkpad w530 >> - cpu = i7-3740QM >> - kernel configuration file is attached. I followed the Xenomai >> website for the configuration. >> - cobalt kernel of Xenomai 3 >> - Linux kernel 3.16 >> - ipipe-core-3.16-x86-1.patch >> - Ubuntu 14.10 > > Actually, the kernel configuration is not attached. But probably the > only interesting item is whether CONFIG_CPU_FREQ is missing. > > > -- > Gilles. I've attached the kernel configuration this time... CONFIG_CPU_FREQ is like this: # CPU Frequency scaling # # CONFIG_CPU_FREQ is not set This is the result of configuring the kernel via 'makemenuconfig'. Also I noticed that the 'clocktest' can give different results (without rebooting my machine). For example now my ToD drift is around 67 us/s which is better but different from the previously mentioned results. The best I got was 0.6 us/s. Many Thanks -- Roland Pastorino -------------- next part -------------- A non-text attachment was scrubbed... Name: config_w530_3.16.0_xenomai3.0 Type: application/octet-stream Size: 165196 bytes Desc: not available URL: <http://www.xenomai.org/pipermail/xenomai/attachments/20150129/7c4f0680/attachment.obj> ^ permalink raw reply [flat|nested] 10+ messages in thread
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2015-01-29 13:04 ` [Xenomai] ToD drift on i7-3740QM Gilles Chanteperdrix
2015-01-30 11:15 ` Roland Pastorino
2015-02-03 8:09 ` Roland Pastorino
2015-02-03 11:23 ` Gilles Chanteperdrix
2015-02-03 21:55 ` Roland Pastorino
2015-02-04 9:20 ` Gilles Chanteperdrix
2015-02-05 21:28 ` Roland Pastorino
2015-01-25 11:15 Roland Pastorino
2015-01-29 12:25 ` Gilles Chanteperdrix
2015-01-29 13:01 ` Roland Pastorino
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