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

Marco Stornelli
2009-06-28T16:49:24Z

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).
> Pavel

If you knew that the results were machine-dependent I don't understand
why you were so upset by my previous benchmark.

Marco