2015-08-19 15:51 GMT+02:00 Thor Lancelot Simon <t...@panix.com>:
> We should be shipping with DIRHASH turned on.
That´s it - top speed!
/root/test/files> time seq 1 30000|xargs touch
1.05s real 0.03s user 0.84s system
Is DIRHASH still considered experimental? It fixes one of NetBSD´s
most annoying shortcomings.
FreeBSD received dynamic memory allocation for DIRHASH which might be
even better.
(re-sending this as my editor intermittently distributes HTML mails)
>
> On Tue, Aug 18, 2015 at 04:19:57PM +0000, Michael van Elst wrote:
>> stephan...@googlemail.com (Stephan) writes:
>>
>> >This is from an amd64 server box with an aac raid controller.
>>
>> >/root/test/files> time seq 1 10000|xargs touch
>> > 3.10s real 0.01s user 3.07s system
>> >/root/test/files> rm *
>> >/root/test/files> time seq 1 20000|xargs touch
>> > 9.88s real 0.01s user 8.51s system
>> >/root/test/files> rm *
>> >/root/test/files> time seq 1 30000|xargs touch
>> > 23.45s real 0.04s user 20.41s system
>> >/root/test/files> time seq 1 40000|xargs touch
>> > 43.35s real 0.05s user 38.32s system
>>
>> >That is clearly not linear.
>>
>> Each lookup is linear (unless you use DIRHASH), so the total
>> time goes with n^2.
>>
>> --
>> --
>> Michael van Elst
>> Internet: mlel...@serpens.de
>> "A potential Snark may lurk in every tree."
>
> --
> Thor Lancelot Simon t...@panix.com
>
> "We cannot usually in social life pursue a single value or a single moral
> aim, untroubled by the need to compromise with others." - H.L.A. Hart
