| Message ID | cover.1517423725.git.joseph.salisbury@canonical.com |
|---|---|
| Headers | show |
| Series | Fixes for LP:1744988 | expand |
On 01/02/18 18:59, Joseph Salisbury wrote: > BugLink: http://bugs.launchpad.net/bugs/1744988 > > == SRU Justification == > The bug reporter observeed NTP time drift on two servers running hwe kernels > in Xenial. After rebooting the servers to the 4.10 or 4.13 kernels we were > seeing a big time offset within minutes after booting. Despite running > ntpd, it would not keep up and the offset stayed and kept growing over time. > > This is a regression that did not exist in the 4.4 Xenial kernel. This regression > is fixed by three mainline commits, da4ae6c4a, b511203093 and 4b5b2127238. All > three commits were added to mainline in v4.15-rc9. > > Bionic already recieved these patches via upstream stable updates. > > == Fixes == > da4ae6c4a0b8 ("x86/tsc: Future-proof native_calibrate_tsc()") > b51120309348 ("x86/tsc: Fix erroneous TSC rate on Skylake Xeon") > 4b5b2127238e ("x86/tsc: Print tsc_khz, when it differs from cpu_khz") > > == Regression Potential == > Low. These three commits fix an existing regression. They were also cc'd to > stable so have had addition upstream review. > > == Test Case == > A test kernel was built with these patches and tested by the original bug reporter. > The bug reporter states the test kernel resolved the bug. > > > Len Brown (3): > x86/tsc: Future-proof native_calibrate_tsc() > x86/tsc: Fix erroneous TSC rate on Skylake Xeon > x86/tsc: Print tsc_khz, when it differs from cpu_khz > > arch/x86/kernel/tsc.c | 9 ++++++++- > 1 file changed, 8 insertions(+), 1 deletion(-) > Clean cherry picks, positive test results. Looks fine to me. Acked-by: Colin Ian King <colin.king@canonical.com>
On Thu, Feb 01, 2018 at 01:59:26PM -0500, Joseph Salisbury wrote: > BugLink: http://bugs.launchpad.net/bugs/1744988 > > == SRU Justification == > The bug reporter observeed NTP time drift on two servers running hwe kernels > in Xenial. After rebooting the servers to the 4.10 or 4.13 kernels we were > seeing a big time offset within minutes after booting. Despite running > ntpd, it would not keep up and the offset stayed and kept growing over time. > > This is a regression that did not exist in the 4.4 Xenial kernel. This regression > is fixed by three mainline commits, da4ae6c4a, b511203093 and 4b5b2127238. All > three commits were added to mainline in v4.15-rc9. > > Bionic already recieved these patches via upstream stable updates. Bionic is actually lacking "x86/tsc: Print tsc_khz, when it differs from cpu_khz", however since it only seems to print some information into dmesg I don't think it's critical that we pick it up.
On 2018-02-01 13:59:26 , Joseph Salisbury wrote: > BugLink: http://bugs.launchpad.net/bugs/1744988 > > == SRU Justification == > The bug reporter observeed NTP time drift on two servers running hwe kernels > in Xenial. After rebooting the servers to the 4.10 or 4.13 kernels we were > seeing a big time offset within minutes after booting. Despite running > ntpd, it would not keep up and the offset stayed and kept growing over time. > > This is a regression that did not exist in the 4.4 Xenial kernel. This regression > is fixed by three mainline commits, da4ae6c4a, b511203093 and 4b5b2127238. All > three commits were added to mainline in v4.15-rc9. > > Bionic already recieved these patches via upstream stable updates. > > == Fixes == > da4ae6c4a0b8 ("x86/tsc: Future-proof native_calibrate_tsc()") > b51120309348 ("x86/tsc: Fix erroneous TSC rate on Skylake Xeon") > 4b5b2127238e ("x86/tsc: Print tsc_khz, when it differs from cpu_khz") > > == Regression Potential == > Low. These three commits fix an existing regression. They were also cc'd to > stable so have had addition upstream review. > > == Test Case == > A test kernel was built with these patches and tested by the original bug reporter. > The bug reporter states the test kernel resolved the bug. > > > Len Brown (3): > x86/tsc: Future-proof native_calibrate_tsc() > x86/tsc: Fix erroneous TSC rate on Skylake Xeon > x86/tsc: Print tsc_khz, when it differs from cpu_khz > > arch/x86/kernel/tsc.c | 9 ++++++++- > 1 file changed, 8 insertions(+), 1 deletion(-) > Acked-by: Khalid Elmously <khalid.elmously@canonical.com>
Applied to artful On 2018-02-01 13:59:26 , Joseph Salisbury wrote: > BugLink: http://bugs.launchpad.net/bugs/1744988 > > == SRU Justification == > The bug reporter observeed NTP time drift on two servers running hwe kernels > in Xenial. After rebooting the servers to the 4.10 or 4.13 kernels we were > seeing a big time offset within minutes after booting. Despite running > ntpd, it would not keep up and the offset stayed and kept growing over time. > > This is a regression that did not exist in the 4.4 Xenial kernel. This regression > is fixed by three mainline commits, da4ae6c4a, b511203093 and 4b5b2127238. All > three commits were added to mainline in v4.15-rc9. > > Bionic already recieved these patches via upstream stable updates. > > == Fixes == > da4ae6c4a0b8 ("x86/tsc: Future-proof native_calibrate_tsc()") > b51120309348 ("x86/tsc: Fix erroneous TSC rate on Skylake Xeon") > 4b5b2127238e ("x86/tsc: Print tsc_khz, when it differs from cpu_khz") > > == Regression Potential == > Low. These three commits fix an existing regression. They were also cc'd to > stable so have had addition upstream review. > > == Test Case == > A test kernel was built with these patches and tested by the original bug reporter. > The bug reporter states the test kernel resolved the bug. > > > Len Brown (3): > x86/tsc: Future-proof native_calibrate_tsc() > x86/tsc: Fix erroneous TSC rate on Skylake Xeon > x86/tsc: Print tsc_khz, when it differs from cpu_khz > > arch/x86/kernel/tsc.c | 9 ++++++++- > 1 file changed, 8 insertions(+), 1 deletion(-) > > -- > 2.7.4 > > > -- > kernel-team mailing list > kernel-team@lists.ubuntu.com > https://lists.ubuntu.com/mailman/listinfo/kernel-team
BugLink: http://bugs.launchpad.net/bugs/1744988 == SRU Justification == The bug reporter observeed NTP time drift on two servers running hwe kernels in Xenial. After rebooting the servers to the 4.10 or 4.13 kernels we were seeing a big time offset within minutes after booting. Despite running ntpd, it would not keep up and the offset stayed and kept growing over time. This is a regression that did not exist in the 4.4 Xenial kernel. This regression is fixed by three mainline commits, da4ae6c4a, b511203093 and 4b5b2127238. All three commits were added to mainline in v4.15-rc9. Bionic already recieved these patches via upstream stable updates. == Fixes == da4ae6c4a0b8 ("x86/tsc: Future-proof native_calibrate_tsc()") b51120309348 ("x86/tsc: Fix erroneous TSC rate on Skylake Xeon") 4b5b2127238e ("x86/tsc: Print tsc_khz, when it differs from cpu_khz") == Regression Potential == Low. These three commits fix an existing regression. They were also cc'd to stable so have had addition upstream review. == Test Case == A test kernel was built with these patches and tested by the original bug reporter. The bug reporter states the test kernel resolved the bug. Len Brown (3): x86/tsc: Future-proof native_calibrate_tsc() x86/tsc: Fix erroneous TSC rate on Skylake Xeon x86/tsc: Print tsc_khz, when it differs from cpu_khz arch/x86/kernel/tsc.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-)