From: Marc Herbert <Marc.Herbert@intel.com>
To: Prarit Bhargava <prarit@redhat.com>, Andi Kleen <ak@linux.intel.com>
Cc: kan.liang@intel.com, linux-kernel@vger.kernel.org,
dzickus@redhat.com, mingo@kernel.org, akpm@linux-foundation.org,
babu.moger@oracle.com, atomlin@redhat.com,
torvalds@linux-foundation.org, peterz@infradead.org,
tglx@linutronix.de, eranian@google.com, acme@redhat.com,
stable@vger.kernel.org
Subject: Re: [PATCH] kernel/watchdog: fix spurious hard lockups
Date: Wed, 21 Jun 2017 14:02:48 -0700 [thread overview]
Message-ID: <6920d83c-19b9-9243-c6aa-0f21288a4006@intel.com> (raw)
In-Reply-To: <9320cd00-88f4-49c5-aaa5-4bb4a80c8813@redhat.com>
On 20/06/17 17:12, Prarit Bhargava wrote:
>>> Hmm ... odd that I haven't seen this. We're running a pretty wide
>>> variety of systems here. Do you have a reproducer? I'd like to see
>>> this occur on production HW.
"Production" is where this patch was born and still lives right now:
https://chromium-review.googlesource.com/c/506327/
>> It only happens on a few specific CPU SKUs with a very wide Turbo range.
>
> Which ones?
>
The ones with turbo mode > 2.5 x TSC_MHz when you stress them hard and long
enough. Simple maths: just compare the soft and hard timers in the code.
The factor 3 moves the condition to: turbo > 7.5 x TSC_MHz.
next prev parent reply other threads:[~2017-06-21 21:02 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-06-20 21:33 kan.liang
2017-06-20 22:03 ` Andrew Morton
2017-06-21 12:40 ` Liang, Kan
2017-06-21 13:47 ` Don Zickus
2017-06-21 14:10 ` Liang, Kan
2017-06-20 22:34 ` Prarit Bhargava
2017-06-20 23:00 ` Andi Kleen
2017-06-21 0:12 ` Prarit Bhargava
2017-06-21 21:02 ` Marc Herbert [this message]
2017-06-21 13:40 ` Don Zickus
2017-06-21 14:02 ` Liang, Kan
2017-06-28 11:40 ` Michal Hocko
2017-06-28 13:24 ` Liang, Kan
2017-06-28 14:29 ` Michal Hocko
2017-06-28 14:32 ` Liang, Kan
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=6920d83c-19b9-9243-c6aa-0f21288a4006@intel.com \
--to=marc.herbert@intel.com \
--cc=acme@redhat.com \
--cc=ak@linux.intel.com \
--cc=akpm@linux-foundation.org \
--cc=atomlin@redhat.com \
--cc=babu.moger@oracle.com \
--cc=dzickus@redhat.com \
--cc=eranian@google.com \
--cc=kan.liang@intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@kernel.org \
--cc=peterz@infradead.org \
--cc=prarit@redhat.com \
--cc=stable@vger.kernel.org \
--cc=tglx@linutronix.de \
--cc=torvalds@linux-foundation.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®