Messages in this thread | | | Date | Sat, 31 Jul 1999 13:16:01 -0700 (PDT) | From | Linus Torvalds <> | Subject | Re: Scheduling latencies news: less RAM = less latency |
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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.
Linus
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