Re: BUG: isofs broken (2.2 and 2.4)

From: Harald Koenig (koenig@tat.physik.uni-tuebingen.de)
Date: Fri Nov 17 2000 - 17:26:52 EST


On Nov 17, Andries.Brouwer@cwi.nl wrote:

>
> > > + if (cpnt)
> > > + kfree(cpnt);
>
> > this seems to make things much worse
>
> Yes, I meant
>
> if (cpnt) {
> kfree(cpnt);
> cpnt = NULL;
> }
>
> at that place, otherwise things will be freed multiple times.

_MUCH_ better now!!! no lockups anymore, no memory leak(s).

BUT: there is still this small performace and memory usage issue:

each of these CDs contains >80k files in ~110 directories each
(the full db consists of 18 CDs!) and running "find" or "du"
on one CDROM (or 4MB isofs loop mount from hard disk) takes
a huge amount of time (real and system cpu) with cold cache:

        time find /cdrom
        0.610u 97.250s 1:40.58 97.2% 0+0k 0+0io 98pf+0w

flush cache...

        time du /cdrom
        0.470u 97.220s 1:40.29 97.4% 0+0k 0+0io 112pf+0w

whereas with hot cache (takes ~45MB memory off the value
for "free + buffer/cache" for a 4MB isofs image!) gives (PPro200, 128MB):

        time find /cdrom
        0.460u 1.280s 0:01.79 97.2% 0+0k 0+0io 102pf+0w

        time du /cdrom
        0.270u 1.260s 0:01.54 99.3% 0+0k 0+0io 108pf+0w

so it seems to work (data still not checked, can do this only next week)
but performace really sucks :(

anyway, thanks a lot for your help and quick patch !
now at least we can copy all the data to some hard disk
and use it that way.

a patch for 2.2.x (the real production machine can't run 2.4.x yet)
and/or fixes for the bad performace would be appreciated anyway ;^)

thanks!

Harald

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