Re: [PATCH] (1/2) reverse mapping VM for 2.5.23 (rmap-13b)

Date: Tue Jun 25 2002 - 05:58:37 EST

> Maybe Randy Hron (added to Cc) can find some spare time
> to benchmark these sometime before the summit too[1].

dbench isn't scaling as well with the -rmap13b patch.
With 128 processes, dbench throughput is less than 1/3
of mainline.

dbench ext2 32 processes Average High Low
2.5.24 28.24 28.84 27.30 mb/sec
2.5.24-rmap13b 21.64 23.50 19.71

dbench ext2 128 processes Average High Low
2.5.24 19.32 21.05 18.05
2.5.24-rmap13b 5.34 5.38 5.30

Sequential reads, rmap had about 10% more throughput
and lower max latency.
For random reads, throughput was lower and max latency
was higher with rmap.

Most metrics look better with rmap. Exceptions
are fork/exec latency and mmap latency. mmap
latency was 18% higher with rmap.

Autoconf build (fork test) was about 5% faster
without rmap.

Details at:

Randy Hron

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