Re: SMP/highmem problem

[Rik van Riel <riel@conectiva.com.br>]

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On Sat, 19 May 2001, [iso-8859-1] Thomas Langas wrote:
> Rik van Riel:
> > A few fixes for this situation have gone into 2.4.5-pre2 and
> > 2.4.5-pre3. If you have the time, could you test if this problem
> > has gotten less or has gone away in the latest kernels ?
> 
> Ok, now we've tested 2.4.5-pre3, and it's still like described before.
> However, it's a bit better. 

Whooops, now that I looked at the source code for -pre3
I realise the particular patch which could fix this
problem hasn't gone into -pre3.

I'll send a patch SOON (almost like the one I sent a
few days ago, but with a few new fixes which have been
accumulating in the last few days).

> So, any other ideas are very welcome :)

The basis for the patch will be the page_alloc.c VM
patch on http://www.surriel.com/patches/, but with 2
minor changes:

1) don't allow GFP_BUFFER pages to loop in __alloc_pages(),
   but have them fail after a while ... needed to avoid
   deadlocks
2) never allow nr_free_buffer_pages to return a number
   larger than how many dirty pages would reasonably fit
   in ZONE_DMA and ZONE_NORMAL ... should fix your problem

regards,

Rik
--
Virtual memory is like a game you can't win;
However, without VM there's truly nothing to lose...

http://www.surriel.com/		http://distro.conectiva.com/

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