Re: [PATCH] watchdog: hpwdt: Remove spinlock acquire and BIOS calls from NMI context
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
- Subject: Re: [PATCH] watchdog: hpwdt: Remove spinlock acquire and BIOS calls from NMI context
- From: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
- Date: Wed, 14 Feb 2018 10:38:35 +0100
- Cc: Tim Chen <tim.c.chen@xxxxxxxxxxxxxxx>, Dave Hansen <dave@xxxxxxxx>, hpa@xxxxxxxxx, tglx@xxxxxxxxxxxxx, torvalds@xxxxxxxxxxxxxxxxxxxx, linux-kernel@xxxxxxxxxxxxxxx, dwmw@xxxxxxxxxxxx, linux-tip-commits@xxxxxxxxxxxxxxx, Borislav Petkov <bp@xxxxxxxxx>, Arjan van de Ven <arjan@xxxxxxxxxxxxx>
- In-reply-to: <20180214093159.mdzfupne547bi5qx@gmail.com>
- References: <1518362359-1005-1-git-send-email-dwmw@amazon.co.uk> <tip-670c3e8da87fa4046a55077b1409cf250865a203@git.kernel.org> <20180212102211.cdrrqqd4hdw7xu5y@gmail.com> <a85c28b8-1255-3264-bb4a-89e85e3c6009@sr71.net> <20180212165835.GO25181@hirez.programming.kicks-ass.net> <20180213075540.3lkikkpgjoe6ocjk@gmail.com> <5c3ba123-abbe-f153-7b75-a89d31d25c72@linux.intel.com> <20180214093159.mdzfupne547bi5qx@gmail.com>
- User-agent: Mutt/1.9.2 (2017-12-15)
On Wed, Feb 14, 2018 at 10:31:59AM +0100, Ingo Molnar wrote:
> Because in this particular case it does not appear to be so: the reason for the
> BIOS/firmware call appears to be to determine how we nmi_panic() after receiving
> an NMI that no other NMI handler handled: with a passive-aggressive "I don't know"
> panic message or with a slightly more informative panic message.
However much I like just ripping all that out, I think the ROM call
actually does that logging, or that is how I read things.
If you look at the original Changelog for that driver:
Hp is providing a Hardware WatchDog Timer driver that will only work with the
specific HW Timer located in the HP ProLiant iLO 2 ASIC. The iLO 2 HW Timer
will generate a Non-maskable Interrupt (NMI) 9 seconds before physically
resetting the server, by removing power, so that the event can be logged to
the HP Integrated Management Log (IML), a Non-Volatile Random Access Memory
(NVRAM). The logging of the event is performed using the HP ProLiant ROM via
an Industry Standard access known as a BIOS Service Directory Entry.
--
To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
[Index of Archives]
[Linux Stable Commits]
[Linux Stable Kernel]
[Linux Kernel]
[Linux USB Devel]
[Linux Video &Media]
[Linux Audio Users]
[Yosemite News]
[Linux SCSI]