Re: stochastic fair queueing in the elevator [Re: [BENCHMARK] 2.4.20-ck3 / aa / rmap with contest]

Hans Reiser
2003-02-10T10:30:15Z

Andrew Morton wrote:

>Hans Reiser <reiser@namesys.com> wrote:
>
>
>>reiser4 does directory readahead. It gets a lot of gain from it.
>>
>>
>
>What is "a lot"?
>
>
>
>
Vladimir Saveliev had the numbers ready at hand after all, and said:

The most noticeable gain is found in the folowing test (not sure that it
can be considered as effective readahead though): ls -l over directory
containing 30000 files (named numerically) created in random order :
4.87 with no readahead
2.99 with readahead (which is limited by 25% of ram or by directory and
all its stat data)

--
Hans