[Kernel-packages] [Bug 1857922] Re: hpet lost interrupts on kdump
** Changed in: linux (Ubuntu Eoan) Status: Fix Committed => Fix Released -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1857922 Title: hpet lost interrupts on kdump Status in linux package in Ubuntu: Fix Released Status in linux source package in Bionic: Fix Released Status in linux source package in Eoan: Fix Released Status in linux source package in Focal: Fix Released Bug description: It was noticed that during the kdump kernel initialization, hpet is getting interrupts lost, like the following message inform: [2.816266] hpet1: lost 35 rtc interrupts Started a bisect, the behavior is present on kernel versions v4.5 and subsequent. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1857922/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
[Kernel-packages] [Bug 1857922] Re: hpet lost interrupts on kdump
Bionic just got kernel 4.15.0-96 released with the fix, hence marking as Fix Released. ** Changed in: linux (Ubuntu Bionic) Status: Fix Committed => Fix Released -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1857922 Title: hpet lost interrupts on kdump Status in linux package in Ubuntu: Fix Released Status in linux source package in Bionic: Fix Released Status in linux source package in Eoan: Fix Committed Status in linux source package in Focal: Fix Released Bug description: It was noticed that during the kdump kernel initialization, hpet is getting interrupts lost, like the following message inform: [2.816266] hpet1: lost 35 rtc interrupts Started a bisect, the behavior is present on kernel versions v4.5 and subsequent. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1857922/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
[Kernel-packages] [Bug 1857922] Re: hpet lost interrupts on kdump
The investigation was narrowed down to shared IRQs. Whenever an IRQ is
set to shared, if kernel is booted with irqpoll or irqfixup, at every
interrupt received all shared interrupt handlers are triggered. This is
specially performance harming for HPET-based RTC interrupt handler,
since HPET access is known to be slow.
We proposed a simple patch [0] to address the issue, but Andy Shevchenko
(the maintainer) noticed the issue originally addressed by 079062b28fb4
("rtc: cmos: prevent kernel warning on IRQ flags mismatch") was fixed by
commit a1e23a42f1bd ("rtc: cmos: Do not assume irq 8 for rtc when there
are no legacy irqs"), originally merged in kernel 4.12.
Hence, Andy came up with a better solution for the hereby reported issue
in the form of commit: b6da197a2e96 ("rtc: cmos: Stop using shared
IRQ"), present in Focal kernel since 5.4.0-21 and to be released in
Bionic (4.15.0-94) and Eoan (5.3.0-47+). Xenial doesn't suffer from this
issue since its base kernel is 4.4 (and the offender commit was
introduced later); Xenial/HWE will get the fix organically since Bionic
has the fix.
Thanks,
Guilherme
[0] lore.kernel.org/linux-rtc/20200103140240.6507-1-gpicc...@canonical.com/T
--
You received this bug notification because you are a member of Kernel
Packages, which is subscribed to linux in Ubuntu.
https://bugs.launchpad.net/bugs/1857922
Title:
hpet lost interrupts on kdump
Status in linux package in Ubuntu:
Fix Released
Status in linux source package in Bionic:
Fix Committed
Status in linux source package in Eoan:
Fix Committed
Status in linux source package in Focal:
Fix Released
Bug description:
It was noticed that during the kdump kernel initialization, hpet is
getting interrupts lost, like the following message inform:
[2.816266] hpet1: lost 35 rtc interrupts
Started a bisect, the behavior is present on kernel versions v4.5 and
subsequent.
To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1857922/+subscriptions
--
Mailing list: https://launchpad.net/~kernel-packages
Post to : kernel-packages@lists.launchpad.net
Unsubscribe : https://launchpad.net/~kernel-packages
More help : https://help.launchpad.net/ListHelp
[Kernel-packages] [Bug 1857922] Re: hpet lost interrupts on kdump
** Changed in: linux (Ubuntu) Status: Confirmed => In Progress ** Also affects: linux (Ubuntu Focal) Importance: Medium Assignee: Guilherme G. Piccoli (gpiccoli) Status: In Progress ** Also affects: linux (Ubuntu Eoan) Importance: Undecided Status: New ** Also affects: linux (Ubuntu Bionic) Importance: Undecided Status: New ** Changed in: linux (Ubuntu Eoan) Assignee: (unassigned) => Guilherme G. Piccoli (gpiccoli) ** Changed in: linux (Ubuntu Bionic) Assignee: (unassigned) => Guilherme G. Piccoli (gpiccoli) ** Changed in: linux (Ubuntu Eoan) Importance: Undecided => Medium ** Changed in: linux (Ubuntu Bionic) Importance: Undecided => Medium ** Changed in: linux (Ubuntu Eoan) Status: New => Fix Committed ** Changed in: linux (Ubuntu Bionic) Status: New => Fix Committed ** Changed in: linux (Ubuntu Focal) Status: In Progress => Fix Released -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1857922 Title: hpet lost interrupts on kdump Status in linux package in Ubuntu: Fix Released Status in linux source package in Bionic: Fix Committed Status in linux source package in Eoan: Fix Committed Status in linux source package in Focal: Fix Released Bug description: It was noticed that during the kdump kernel initialization, hpet is getting interrupts lost, like the following message inform: [2.816266] hpet1: lost 35 rtc interrupts Started a bisect, the behavior is present on kernel versions v4.5 and subsequent. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1857922/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
[Kernel-packages] [Bug 1857922] Re: hpet lost interrupts on kdump
Bisect concluded, the first bad commit is: 079062b28fb4 ("rtc: cmos:
prevent kernel warning on IRQ flags mismatch"). This commit basically
sets IRQ shared in the request_irq() call from rtc_cmos, so requires now
investigation on why this causes the issue with HPET.
--
You received this bug notification because you are a member of Kernel
Packages, which is subscribed to linux in Ubuntu.
https://bugs.launchpad.net/bugs/1857922
Title:
hpet lost interrupts on kdump
Status in linux package in Ubuntu:
Confirmed
Bug description:
It was noticed that during the kdump kernel initialization, hpet is
getting interrupts lost, like the following message inform:
[2.816266] hpet1: lost 35 rtc interrupts
Started a bisect, the behavior is present on kernel versions v4.5 and
subsequent.
To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1857922/+subscriptions
--
Mailing list: https://launchpad.net/~kernel-packages
Post to : kernel-packages@lists.launchpad.net
Unsubscribe : https://launchpad.net/~kernel-packages
More help : https://help.launchpad.net/ListHelp
