From: "孙世龙 sunshilong" <sunshilong369@gmail.com>
To: "Valdis Klētnieks" <valdis.kletnieks@vt.edu>
Cc: kernelnewbies <Kernelnewbies@kernelnewbies.org>
Subject: Re: How can I investigate the cause of "watchdog: BUG: soft lockup"?
Date: Sat, 4 Jul 2020 17:13:45 +0800 [thread overview]
Message-ID: <CAAvDm6aemz5qoYUNtyaGc0EhtfgheQGKYnDpWeRg1G6M2Sca_w@mail.gmail.com> (raw)
In-Reply-To: <CAAvDm6aOUTJ3vQZ7UiGgNF_ARQgKdhgQPxWLx4cEqVmuOF7pCA@mail.gmail.com>
Hi, Valdis Klētnieks
Thank you for taking the time to respond to me.
I have a better understanding of this matter.
>> Can I draw the conclusion that continually acquiring the spinlock causes the soft
>> lockup and the CPU has been stuck for 22s?
>> Can I think in this way?
>No. It's been stuck for 22s *TRYING* and *FAILING* to get the spinlock.
I see. So there is a thread that has held the corresponding spinlock
for more 22s, and a CPU is sticking(busy acquiring the spinlock) at the
same duration.
Can I think in this way?
Thank you for your attention to this matter.
Best Regards.
Valdis Klētnieks <valdis.kletnieks@vt.edu> 于2020年7月4日周六 下午4:09写道：
孙世龙 sunshilong <sunshilong369@gmail.com> 于2020年7月4日周六 下午5:04写道：
>
> Hi, Valdis Klētnieks
>
> Thank you for taking the time to respond to me.
> I have a better understanding of this matter.
>
> >> Can I draw the conclusion that continually acquiring the spinlock causes the soft
> >> lockup and the CPU has been stuck for 22s?
> >> Can I think in this way?
>
> >No. It's been stuck for 22s *TRYING* and *FAILING* to get the spinlock.
>
> I see. So there is a thread that has held the corresponding spinlock
> for more 22s.
> Can I think in this way?
>
> Thank you for your attention to this matter.
> Best Regards.
>
> Valdis Klētnieks <valdis.kletnieks@vt.edu> 于2020年7月4日周六 下午4:09写道：
> >
> >
> > > Can I draw the conclusion that continually acquiring the spinlock causes the soft
> > > lockup and the CPU has been stuck for 22s?
> > > Can I think in this way?
> >
> > No. It's been stuck for 22s *TRYING* and *FAILING* to get the spinlock.
> >
> > For comparison - spinlocks are usually used when you need a lock, but the
> > code protected by the lock is short (things like adding to a linked list, etc),
> > so it should again become available in milliseconds - things where it would take
> > longer to put this thread to sleep and wake another one up than we expect
> > to be waiting for this lock.
_______________________________________________
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
next prev parent reply other threads:[~2020-07-04 9:13 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-04 2:20 How can I investigate the cause of "watchdog: BUG: soft lockup"? 孙世龙 sunshilong
2020-07-04 4:39 ` Valdis Klētnieks
2020-07-04 7:51 ` 孙世龙 sunshilong
2020-07-04 8:09 ` Valdis Klētnieks
2020-07-04 9:04 ` 孙世龙 sunshilong
2020-07-04 9:13 ` 孙世龙 sunshilong [this message]
2020-07-08 5:19 ` 孙世龙 sunshilong
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=CAAvDm6aemz5qoYUNtyaGc0EhtfgheQGKYnDpWeRg1G6M2Sca_w@mail.gmail.com \
--to=sunshilong369@gmail.com \
--cc=Kernelnewbies@kernelnewbies.org \
--cc=valdis.kletnieks@vt.edu \
/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;
as well as URLs for NNTP newsgroup(s).