Re: Disabling CPUs

N.B. Typo alert. I entered 1.1W for idle on  4 P threads. That should be
10.1. Very sorry for the error.

1.1W was really unbelievable, and I should have realized it. I collected
the 4 threads numbers and recorded them much earlier then I switched to 8 E
threads and created my reply.

On Sat, Oct 8, 2022 at 6:28 PM Kevin Oberman <rkoberman@gmail.com> wrote:

> On Sat, Oct 8, 2022 at 5:54 PM Kevin Oberman <rkoberman@gmail.com> wrote:
>
>> On Fri, Oct 7, 2022 at 9:56 AM Ian Smith <smithi@nimnet.asn.au> wrote:
>>
>>> On 7 October 2022 2:05:32 pm AEDT, Kevin Oberman <rkoberman@gmail.com>
>>> wrote:
>>>
>>> [...]
>>>
>>>  > I've been silent while waiting for the additional memory since I
>>>  > could not
>>>  > do any real work with only 8G. It finally arrived and I installed it
>>>  > yesterday. I'm very happy to say that my VirtualBox VMs seem to now
>>>  > be
>>>  > working correctly. I've done limited testing, but seen no problems to
>>>  > this
>>>  > point. Much better than an instant system panic when a VM finished
>>>  > loading.
>>>  >
>>>  > On the plus side, with "cpuset -s 1 -l 0-3", things seem reasonably
>>>  > stable.
>>>  > That means no crashes with many hours of use and a lot of
>>>  > compilations.
>>>  > With only 4 cores, it's not a fast as I had hoped, but I will be
>>>  > benchmarking soon.
>>>
>>> Hi Kevin, three questions if I may:
>>>
>>> I may have missed it, but did you wind up testing sched_ULE vs 4BSD?
>>>
>>
>> cpuset(8) only works with ULE, so that is what I am running. So far I
>> have not seen the interactivity issues that caused me to move to 4BSD over
>> a decade ago.
>>
>>
>>> Is that 4 cores including HT, or not?
>>>
>>
>> Yes, 2 cores and 4 threads. Sorry to have failed to make that clear. My
>> CPU has 2 P cores and 8 E cores. It has never crashed  when running the 2 P
>> cores, but I had one crash running the 8 E cores. Now that I have a
>> stable system, I may try switching back to just the E cores as they  seem
>> to provide almost double the performance of the 2 P cores. Oddly, while
>> using rsync to move a big batch of files from my backup disk to the new
>> system after cpuset, I saw 0-3 busy, as I would expect, but one E core was
>> running at about 30% the entire time, as well. I have no idea why.
>>
>>>
>>> And how much power does your new Thinkpad T16 use on battery, say, at
>>> idle and 'fairly busy' (acpiconf -i0) ?
>>>
>>
>> With  the 2 P cores I see about 1.1W idle. Wow! While compiling Firefox
>> (all  threads running at over 95%), I see about 25.3W. With a 52500 mWh
>> battery, it will last a long time.
>> With the 9 E cores I see about 10.4W idle. Wow, the other way. While
>> compiling Firefox, I saw a momentary spike of 35W, but it varied between
>> 20.5 and 27.8 W with occasional hits up to 31 W. The E core power
>> consumption seems far more inconsistent thaa the P cores. compile time with
>> P cores was 1:29 while it was only :50 with the 8 E cores.
>>
>> In both cases I had my Mate desktop running.
>>
>> The L15 was a piece of junk where I learned my lesson about budget
>> systems.  The ABS case started cracking at both hinges after about a year
>> of use. That was after about 9 months of trying to get it working properly
>> after Lenovo had replaced the motherboard and the disk. and, finally, the
>> keyboard. I think the MB was fine, but was the obvious suspect for system
>> lock-ups in POST. Took my a while to track it down to the keyboard and the
>> tech who swapped it out didn't believe that the keyboard was the problem
>> but agreed to humor me. As a result, by the time the case started cracking,
>> the warranty had expired. If I had been willing to give up the TrackPoint,
>> I would have bought a non-Lenovo/IBM for the first time ever.
>>
>> The T16 is built like a T series with a metal frame and feels solid. My
>> T16 is all SSD. Yes, it's heavier. The L15 flexed noticeably with no frame,
>> just the MB, battery, and disk attached to the ABS case.
>>
>> cheers, Ian
>>>
>> Sigh. Less than 5 minutes after I sent my reply, the "all E core" system
> panicked. The usual vfs/ufs crash in ufs_lookup_ino. I'm back to all P
> core" as that has never cashed. So far I have seen no activity on my ticket.
> --
> Kevin Oberman, Part time kid herder and retired Network Engineer
> E-mail: rkoberman@gmail.com
> PGP Fingerprint: D03FB98AFA78E3B78C1694B318AB39EF1B055683
>


-- 
Kevin Oberman, Part time kid herder and retired Network Engineer
E-mail: rkoberman@gmail.com
PGP Fingerprint: D03FB98AFA78E3B78C1694B318AB39EF1B055683