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