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SubjectRe: Scheduling latencies news: less RAM = less latency

On Sat, 31 Jul 1999, Ingo Molnar wrote:
> no, it really happens. With 512M RAM and a 4-way Xeon i easily got
> 20ms+ latencies. These latencies are rare because it's caused by
> prune_dcache(), but they do happen.

prune_dcache() I can believe. But the report was about d_lookup(). So
somebody is using bad profiling information, and that's dangerous.

Also, the si_meminfo() etc stuff is just ridiculous. It's not a question
of latency: it's a question of CPU usage. We need to just get rid of those
functions instead of hacking around them - regardless of whether you add
"reschedule" calls in them, they just eat too much CPU, plain and simple.
Again, please don't treat the symptoms - I will not accept patches that
just say "oh, this is crap, so let's reschedule a bit here". They need to
be fixed properly or not at all.


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