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Subject Re: cvs commit: apache-2.0/src/main http_core.c http_protocol.c
Date Tue, 03 Oct 2000 21:55:21 GMT
On Tue, 3 Oct 2000, Greg Ames wrote:
> wrote:
> > The way to solve this is to stop allocating buckets everytime they are
> > needed.  We need to keep a free list of buckets, so that we are just doing
> > pointer manipulation, but nobody has had the time to implement this yet.
> >
> Yes, the cost of allocating/destroying buckets could be greatly reduced.  But it still
> costs something, and you can't avoid setting some fields in each bucket.  Those
> operations are likely to cause cache misses when the buckets are first stored into,
> then again each time a filter references them many nanoseconds later.

Why would we have a cache miss when referenceing the bucket?  I expect a
cache miss the first time we store into a bucket, but not when referencing
the data that we stored.

> > Touching multiple buckets is just a bit more pointer manipulation.  It is
> > not a performance issue, once we have a free list.
> >
> Do you realize how much cache misses degrade performance on modern CPUs?

Yes, I do realize how much they degrade performance.  Why are we going to
suffer all those cache misses.  I expect far fewer than you do I think.

Ryan Bloom               
406 29th St.
San Francisco, CA 94131

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