On Sun, Jan 10, 1999 at 05:22:59PM +0100, Thomas Bogendoerfer wrote:
> I now know the reason for this. Before giving out memory via brk() the
> kernel checks, whether there is enough memory. The kernel holds back
> (2 + page_cache.min_percent + buffer_mem.min_pecent) percent of the
> available memory (see function vm_enough_memory() in mm/mmap.c). Problem
> on the Indy is, that num_physpages is wrong by 128MB, because we account
> the memory by only looking at the highest page number and forget about
> holes in the memory map. And the Indy has a big hole between 0x80002000
> and 0x88002000 ...
>
> Right now I can't think of a good fix for this problem. Any ideas ?
Attached is a quickfix which just fixes the calculation of num_physpages.
The real thing is to us the PG_skip flag and implement the PageSkip macro.
See the Sparc / Sparc64 code for how to implement. Implementing this
will save us alot of memory as well. I'll post a real patch later.
Ralf
--- arch/mips/mm/init.c.orig Sun Jan 10 23:50:12 1999
+++ arch/mips/mm/init.c Sun Jan 10 23:50:53 1999
@@ -247,8 +247,9 @@
#endif
end_mem &= PAGE_MASK;
- max_mapnr = num_physpages = MAP_NR(end_mem);
+ max_mapnr = MAP_NR(end_mem);
high_memory = (void *)end_mem;
+ num_physpages = 0;
/* mark usable pages in the mem_map[] */
start_mem = PAGE_ALIGN(start_mem);
@@ -278,6 +279,7 @@
datapages++;
continue;
}
+ num_physpages++;
atomic_set(&mem_map[MAP_NR(tmp)].count, 1);
#ifdef CONFIG_BLK_DEV_INITRD
if (!initrd_start || (tmp < initrd_start || tmp >=
