Messages in this thread | | | Date | Wed, 20 Nov 2002 23:28:29 +0000 | From | Jamie Lokier <> | Subject | Re: [rfc] epoll interface change and glibc bits ... |
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Davide Libenzi wrote: > > > And the lower size of the structure will help to reduce the amount of > > > memory transfered to userspace. I just saw that adding the extra "obj" > > > member lowered performance of about 15% with crazy tests like Ben's > > > pipetest. This because it creates, on my machine, more than 400000 events > > > per second, and saving memory bandwidth on such conditions is a must. With > > > the "more human" http test performance are about the same. > > > > I'd be quite surprised if 400,000 word/sec of memory bandwidth can > > explain a 15% time difference, especially considering all the other > > things that are done to communicate over a pipe (wakeups etc). > > Jamie, they were 16 bytes * 400000, and the token passed through the pipe > was 12 bytes.
However, it's 4 bytes (1 word) * 400000 _difference_ between the two tests, yes?
-- Jamie
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