Re: [uml-devel] [PATCH v3] um: Switch clocksource to hrtimers

[Anton Ivanov <anton.ivanov@kot-begemot.co.uk>]

On 02/11/15 08:37, Richard Weinberger wrote:
> Hi!
>
> Am 02.11.2015 um 09:14 schrieb Anton Ivanov:
>> I was testing under similar conditions (CPU pinning using taskset -c 0 on a multicore).
>>
>> I have removed it and run some retests - I cannot reproduce the hang at this point with my config
>>
>> I am going to run a defconfig and compare the results to see if this will give me any insights on the root cause.
> I can reproduce on both my build machine (8 core) and my laptop (4 core).
> If it helps I can share the rootfs.
>
> On my laptop I was able to reproduce within 5 minutes.
> 1. make defconfig ARCH=um
> 2. make -j 4 linux ARCH=um
> 3. ./linux ubda=../Downloads/Debian-Squeeze-AMD64-root_fs mem=1G
> 4. login to tty0
> 5. wait a few minutes
> 6. try to run top, it will hang in nanosleep

Pretty much the same. Does not hang, multiple test runs. Userspace is a 
relatively full install of a debian jessie.

I ran deconfig and did a diff. The prime suspect differences between my 
config and defconfig are stack order 3 (not 1) and io sched of cfq, not 
deadline.

I am going to retest just with these first to see if one of them is the 
culprit, if that does not make a difference, run it with defconfig and 
try to reproduce the hang.

A.

>
> Thanks,
> //richard
>


------------------------------------------------------------------------------
_______________________________________________
User-mode-linux-devel mailing list
User-mode-linux-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel