Re: CPU hog in vnlru and arc_prune on 13-STABLE

From: Juraj Lutter <juraj_at_lutter.sk>
Date: Fri, 01 Mar 2024 19:47:47 UTC 

> On 1 Mar 2024, at 20:43, Lexi Winter <lexi@le-fay.org> wrote:
> 
> Juraj Lutter:
>> I have a fresh (git b9880e247b26) 13.3-STABLE running in bhyve with 2 vCPU and 10G of RAM.
>> 
>> I’ve put some load on it (building lang/rust from ports outside poudriere, using make -j2) and the system
>> started to respond very slowly.
>> 
>> I did break the make process and I was able to look into top where there was:
>> 
>>  PID USERNAME    PRI NICE   SIZE    RES STATE    C   TIME    WCPU COMMAND
>>    0 root         -8    -     0B  1808K CPU1     1  35:53  99.79% kernel{arc_prune}
>>   15 root         20    -     0B    16K RUN      0  34:19  99.35% vnlru
> 
> this could be [0]: "High CPU usage by arc_prune; analysis and fix".
> 
> [0] https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=275594

Indeed, the symptoms are very similar. Thanks for the pointer.

—
Juraj Lutter
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