Re: Ideas for memory management hackers (2)

Harald Koenig (koenig@tat.physik.uni-tuebingen.de)
Mon, 17 Nov 1997 08:48:30 +0100


On Nov 16, Alan Cox wrote:

> > > - VM areas are limited to 128MB. This leads to many swap-files. (I am
> > > not quite shure about further limitation. Does it mean that bigger
> > > mmaps are not possible? The swapfile limitation is definitely in the
> > > kernel.)
> >
> > no more than 128MB shared memory AFAIK?! this is bad for some (big) databases...
>
> The kernel is happy with > 128Mbytes, the only limit is on physical memory
> (1Gig) and virtual (3Gig). The limit he refers to is swap file/partition size
> per partition and is becoming an irritiation in itself for osme

On Mon, 6 Oct 1997, greg@netset.com wrote in linux-kernel :

> > In the kernel include file include/asm/shmparam.h SHMMAX is set to
> > 16MB (0x1000000) and I was wondering if it would be a bad thing to
> > set it to 64MB (0x4000000) or 128MB (0x8000000) provided the machine
> > in question had 64MB+ or 128MB+ memory.
>
> In theory, increasing SHMMAX to 128MB should be possible... Beyond that,
> not without difficulty - the mm subsystem uses 128MB swap areas, of which
> shared memory is one.

so it's not true that SHMMAX is limited to 128MB right now ?
I don't have that much DRAM so I can't test it, sorry;) ?

Harald

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