Re: [PATCH 00/14] Pramfs: Persistent and protected ram filesystem

[Pavel Machek <pavel@ucw.cz>]

On Sun 2009-06-28 19:33:02, Marco Stornelli wrote:
> Pavel Machek wrote:
> >>>>> Ah now the write protection is a "needed feature", in your previous
> >>>>> comment you talked about why not use ext2/3.......
> >>>>>
> >>>>> Marco
> >>>>>
> >>>> Just for your information I tried the same test with pc in a virtual machine with 32MB of RAM:
> >>>>
> >>>> Version 1.03e       ------Sequential Output------ --Sequential Input- --Random-
> >>>>                     -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
> >>>> Machine   Size:chnk K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP  /sec %CP
> >>>> hostname     15M:1k 14156  99 128779 100 92240 100 11669 100 166242  99 80058  82
> >>>>                     ------Sequential Create------ --------Random Create--------
> >>>>                     -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete--
> >>>>               files  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP
> >>>>                   4  2842  99 133506 104 45088 101  2787  99 79581 101 58212 102
> >>>>
> >>>> These data are the proof of the importance of the environment, workload and so on when we talk
> >>>> about benchmark. Your consideration are really superficial.
> >>> Unfortunately, your numbers are meaningless.
> >> I don't think so.
> >>
> >>> (PCs should have cca 3GB/sec RAM transfer rates; and you demosstrated
> >>> cca 166MB/sec read rate; disk is 80MB/sec, so that's too slow. If you
> >>> want to prove your filesystem the filesystem is reasonably fast,
> >>> compare it with ext2 on ramdisk.)
> >>>
> >> This is the point. I don't want compare it with ext2 from performance
> >> point of view. This comparison makes no sense for me. I've done this
> >> test to prove that if you change environment you can change in a
> >> purposeful way the results.
> > 
> > Yes, IOW you demonstrated that the numbers are machine-dependend and
> > really meaningless.
> > 
> > ext2 comparison would tell you how much pramfs sucks (or not).
> 
> Here the test with ext2 (same environment):
> 
> Version 1.03e       ------Sequential Output------ --Sequential Input- --Random-
>                     -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
> Machine   Size:chnk K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP  /sec %CP
> hostname     15M:1k 10262  83 40847  82 38574  82  9866  92 62252  98 25204  81
>                     ------Sequential Create------ --------Random Create--------
>                     -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete--
>               files  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP
>                   1 19859  98 44804  61 68830 100 13566  99 157129 100 30431  98
> 

Ok, so pramfs is  significantly faster than ext2. Interesting, and good
for pramfs.
								Pavel 

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