Re: [patch] 2.2.9_andrea-VM1.gz

Peter Steiner (p.steiner@t-online.de)
Tue, 8 Jun 1999 22:45:39 +0200 (CEST)

> >> I forgot that ext2/truncate is still buggy in 2.2.9.
> >
> >It didn't happen with plain 2.2.9... At least I didn't notice it.
>
> Yes of course, my patch triggers the bug but it's a bug in ext2fs (it's
> present also in ufs and minix btw) and it's just been fixed in 2.3.x
> infact.

It works now, thanks.

> >>--8<--
> >
> >Maybe an average bucketsize of 8 is too high? This is sufficient with 64MB
> >since the buffer cache doesn't grow so much anyway. Try reducing it to 4
> >(The original hashfn has an average bucketsize of 1).
>
> Good idea, I'll set the distribution to 1, I don't want to lose because I
> am more conservative in memory.

Could someone please tell me the typical size of the buffer cache in big
real world servers?

An average bucketsize of 1 is too much for the average desktop but it may
indeed help for servers. It seems there should be a config option:

"[*] Optimize for big buffer caches" --> avg bucket zize = 1
else avg bucket size = 4

And for 386/486 there should be a shift/add hashfn. On a 486 it takes 40
cycles for one multiplication and it would be nice to still support these
old PCs.

Peter

-- 
   _   x    ___
  / \_/_\_ /,--'  p.steiner@t-online.de (Peter Steiner)
  \/>'~~~~//
    \_____/   signature V0.2 alpha


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