From: Anton Ivanov <anton.ivanov@kot-begemot.co.uk>
To: user-mode-linux-devel@lists.sourceforge.net
Subject: Re: [uml-devel] [UM] Long loop in __getnsdayoftime() after resume from ram
Date: Mon, 27 Apr 2015 06:47:59 +0100 [thread overview]
Message-ID: <553DCD8F.7030007@kot-begemot.co.uk> (raw)
In-Reply-To: <553D51F1.9010900@nod.at>
On 26/04/15 22:00, Richard Weinberger wrote:
>
>>> Can you give the attached patch a try?
>>> Let's see if it proves my theory.
>>> Looks like UML's clocksource needs fixing.
>> Hi Richard,
>>
>> I did run this for an hour and did 4 suspend/resume cycles and it seems
>> not to hang any more!
> Yay!
> BTW: Changing the host's time should also work for testing...
>
>> I'll test your other patch the next week, but AFAIU using clock_gettime
>> should solve this hangs in a sane way.
> Yep. I have no idea why UML is currently using gettimeofday() as clocksource,
> this is completely bogus. ;-\
It is even more bogus than you think - read time.c, it is using itimer
on the virtual clock for all timers for extra spice so the timers are
dependent on how much cpu it uses at any given time.
It does not need to be - I wrote a patchset for it to use posix timers
and CLOCK_MONOTONIC. It went into Richard's queue ~ a year ago along
with an epoll based IRQ controller and some vNIC drivers.
Have not heard of it since.
A.
>
> Thanks,
> //richard
>
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next prev parent reply other threads:[~2015-04-27 6:10 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-10-20 9:51 [uml-devel] [UM] Long loop in __getnsdayoftime() after resume from ram Thomas Meyer
2014-10-20 9:56 ` Richard Weinberger
2014-10-20 19:19 ` Thomas Meyer
2015-04-24 19:58 ` Thomas Meyer
2015-04-26 18:32 ` Richard Weinberger
2015-04-26 20:20 ` Richard Weinberger
2015-04-26 20:57 ` Thomas Meyer
2015-04-26 21:00 ` Richard Weinberger
2015-04-27 5:47 ` Anton Ivanov [this message]
2015-04-27 7:23 ` Richard Weinberger
2015-04-27 8:20 ` Anton Ivanov
2015-04-30 16:40 ` Thomas Meyer
-- strict thread matches above, loose matches on Subject: below --
2014-10-19 12:39 Thomas Meyer
2014-10-20 8:27 ` Richard Weinberger
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