[OpenAFS-devel] Patch to implement default tuning proposal discussed a while ago

[Martin MOKREJŠ]

chas williams - CONTRACTOR wrote:
> In message <20050816154428.C04501BAF3@citi.umich.edu>,Jim Rees writes:
> 
>>I'm inclined to commit the new code and let Niklas or others work on making
>>it better for large caches later.  Comments?
> 
> 
> how about choosing the sqrt(cachesize/1024) as the "average file size"?
> 
> 	cachesize	avg file size(k)	#files
> 
> 	150M		~12			12500
> 	350M		~18			19444
> 	1G		~32			32768
> 	10G		~98			102040
> 	20G		~143			146653
> 
> i choose sqrt() for no particular reason other than the numbers seems to
> more closly match the original sizes for smaller caches and for larger
> caches it matches the newly suggested average of 32k.  for huge caches
> it "safely" limits the amount of kernel space required.

Hi,
  will it be possible to set an arbitrary value on startup?
I am right now making caches of 40GB in size and I don't expect
more than a hundred files in it. I don't care if a bad luck
happens and a file has to be fetched from the server just because of
too restrictive value. But I don't want the kernel to waste space.
If a file is fetched "unnecessarily" maybe once per 1000 iterations,
I'm fine with that. I just won't use even 12500 files.
Martin