On Fri, 2002-10-04 at 11:55, Andi Kleen wrote:
> On Fri, Oct 04, 2002 at 11:44:57AM -0500, Steve Lord wrote:
> > On Fri, 2002-10-04 at 11:21, Andi Kleen wrote:
> > > > OK, I went and had a look, and we are actually as efficient as we can
> > > > be in use of the memory itself. Only problem is that we allocate 4 times
> > > > what we use. I fixed this in cvs.
> > >
> > > Unless you memset it (=actually using, not allocating) and it still
> > > fits into the 32big address space that could be worked around by
> > > echo 1 > /proc/sys/vm/overcommit_memory
> >
> > It uses all the memory, 4 bits per filesystem block, we record what
> > type of information is in that part of the fs - including free blocks.
>
> When it allocates more than it actually faults in then this tweak may help.
Well, a 1 Tbyte filesystem with 4K blocks went from needing 256Mbytes
to hold block information to 64Mbytes, so in some setups it is the
difference between running out of memory and not.
Steve
--
Steve Lord voice: +1-651-683-3511
Principal Engineer, Filesystem Software email: lord@xxxxxxx
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