Re: Buffer Memory

Heinz Mauelshagen (mauelsha@ez-darmstadt.telekom.de)
Thu, 11 Jun 1998 13:48:25 METDST


On Thu, 11 Jun 1998, Rik van Riel wrote

<SNIP>

>
> o Patch is reverse :)
> o This can give some nasty deadlocks, better would be to
> allocate one 'last' page to the buffer memory, call
> bdflush, schedule and return. This might give us enough
> delay to clear things up.
> o Something like this, written by me, got rejected by
> Linus once for the very same reason I just outlined :)
>

Astonished by this, because i've had the effect of VERY bad performance
and even locking up WITHOUT my patch.

But with it i never recognized a lockup and allways had sufficient
performance, while doing REALLY i/o intesive tests???
For example fsck'ing large filesystem (20GB++) while doing i/o on
other filesystems.

I'm not sure, why this patch can cause a deadlock, because a "return 0;"
is the "normal" case, if "__get_free_page" in "grow_buffers()" fails.

Heinz

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