> On Tue, 28 Apr 1998, George wrote:
> > On Tue, 28 Apr 1998, Rik van Riel wrote:
> >
> > >Following some observations from Michael Remski (sent
> > >to me by private e-mail), I've come to the conlusion
> > >that we really should do something about out-of-VM
> > >situations.
> >
> > At the moment, (2.1.98), I can lock my 64 MB machine up with a 'make
> > MAKE='make -j20' zImage'.
> >
> > At the time of memory death:
> > * It has 4 megabytes of free pages.
> > * It has 6 megabytes of buffer memory.
> > * But it dies because it has 0 swap left.
> >
> > Those hard limits on memory how much memory to not grab should definitely
> > go.
>
> You can tune the buffermem & pagecache amount of memory
> in /proc/sys/vm/{buffermem,pagecache}.
Every time before he starts compiling, and then return to old values
when he's finished?
IMNSHO, kernel should be autotuning.
> But why your system has 4 MB of free memory I really
> don't know...
mm/page_alloc.c (in free_memory_available()):
/*
* If we have more than about 6% of all memory free,
* consider it to be good enough for anything.
* It may not be, due to fragmentation, but we
* don't want to keep on forever trying to find
* free unfragmented memory.
*/
if (nr_free_pages > num_physpages >> 4)
return nr+1;
With 64MB of memory, last 4MB are almost never used!!!
MM in last kernels is not very good.
Except Stephens great improvements of the swapping system, where he
did a really good job, I believe we did a step backward with recent
changes.
Regards,
-- Posted by Zlatko Calusic E-mail: <Zlatko.Calusic@CARNet.hr> --------------------------------------------------------------------- (A)bort, (R)etry, (P)retend this never happened...- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.rutgers.edu