From: ori@eigenstate.org
To: plan9fullfrontal@qs.co.nz, 9front@9front.org
Subject: Re: [9front] Bug in time cmd?
Date: Tue, 10 Mar 2020 19:33:30 -0700 [thread overview]
Message-ID: <218E628908F4F406572E19D8F6D873AA@eigenstate.org> (raw)
In-Reply-To: <e1a905b2-fc9a-7666-e380-fbe4f875d4b1@qs.co.nz>
> On 03/11/2020 01:11 PM, Alex Musolino wrote:
>
>> These figures come from the Waitmsg structure returned by wait(2). The
>> 'u' time is the total user time of the child process *and descendants*.
>> Given that you likely have a multiprocessor and mk will parallelise its
>> work according to the NPROC environemnt variable, that ought to explain
>> how you are able to achieve 14s of user time in only 6s real time.
> Ok, setting NROC=1 verifies the result I am seeing.
> While I understand the info, I have to think what this actually means as
> a measurement.
> I guess it is telling me that 16 threads only makes a 2x speed
> improvement. Which seems to correlate
> with the fact that the load on the CPU never gets very high. Utilization
> is poor.
>
out of curiosity, are you running on a machine with 16 physical cores?
next prev parent reply other threads:[~2020-03-11 2:33 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-11 0:11 Alex Musolino
2020-03-11 2:28 ` Trevor Higgins
2020-03-11 2:33 ` ori [this message]
2020-03-11 4:15 ` Trevor Higgins
2020-03-11 4:45 ` ori
-- strict thread matches above, loose matches on Subject: below --
2020-03-10 23:39 Trevor Higgins
2020-03-13 16:55 ` [9front] " Ethan Gardener
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