Re: [PATCH] reiserfs: on-demand bitmap loading (testing only)

[Alexander Zarochentsev <zam@namesys.com>]

On Thursday 07 July 2005 02:45, Hans Reiser wrote:
> Jeff, are you sure that you need this code to exist?  Here are the
> problems I see:
>
>     for the average case, it is suboptimal.  The seeks to the bitmaps
> are far more expensive than the averaged cost of keeping them in ram.

It would be good to see the benchmark results which your opinion is based on.

I know that on-demand bitmap loading in reiser4 was under suspicion 
several times but I don't remember any benchmark results which showed a
slowdown regarding that.  

>
>     for 16TB filesystems, they will have plenty of budget for ram
>
>     it complicates code if it has to worry about such things as not
> enough clean memory for holding bitmaps, etc.
>
>     It is more appropriate to write this kind of code for the
> development branch which is V4.  This kind of code is likely to have
> hard to test and hit bugs.
>

Lena, may you check how the bitmap on-demand loading patch affects, say,
mongo results for reiserfs?

Thanks, 
Alex.