Re: [User-mode-linux-user] lmbench numbers?

[lars b. <la...@no...>]

lars brinkhoff <la...@no...> writes:
> Processor, Processes - times in microseconds - smaller is better
> ----------------------------------------------------------------
> Host               OS  Mhz null null      open selct sig  sig  fork exec sh  
>                            call  I/O stat clos       inst hndl proc proc proc
> --------- ----------- ---- ---- ---- ---- ---- ----- ---- ---- ---- ---- ----
> i686-linu Linux 2.2.5  499  0.6  0.9    4    5 0.04K  1.9    3 0.3K   1K   6K
> um-linuxo Linux 2.3.51 499 95.1  159  126  230 0.14K 98.5   31 9.2K  19K  56K

User-mode Linux seems to be about 100 times slower than Linux on bare
hardware on fast operations.  Slower operations like fork() and exec()
does better.

> File & VM system latencies in microseconds - smaller is better
> --------------------------------------------------------------
> Host                 OS   0K File      10K File      Mmap    Prot    Page
>                         Create Delete Create Delete  Latency Fault   Fault
> --------- ------------- ------ ------ ------ ------  ------- -----   ----- 
> i686-linu Linux 2.2.5-2     14      1     26      2    22126     1    0.6K
> um-linuxo Linux 2.3.51-     48     15     60     18     6635          0.2K

Surprisingly, user-mode Linux seems to be do mmap() and page faults
faster than Linux on hardware.  I wonder why?