On Nov 24, 2008, at 6:10 PM, Michael Ellerman wrote:
On Mon, 2008-11-24 at 14:07 -0600, Hollis Blanchard wrote:
On Fri, 2008-11-14 at 16:09 -0600, Hollis Blanchard wrote:
If this is all too much, then I'm close to giving up and burning a
64KB page, which requires only ALIGN_DOWN() in the kernel.
ppc: force memory size to be a multiple of PAGE_SIZE
Ensure that total memory size is page-aligned, because otherwise
bootmem.c gets upset.
This error case was triggered by using 64 KiB pages in the kernel
while
arch/powerpc/boot/4xx.c arbitrarily reduced the amount of memory by
4096 (to
work around the "CHIP11" errata which affects the last 256 bytes of
physical memory).
Signed-off-by: Hollis Blanchard <[EMAIL PROTECTED]>
---
This is on a common code path, and lmb_enforce_memory_limit() will now
always take action, so wider testing would be good.
This patch supercedes http://patchwork.ozlabs.org/patch/8211/ .
diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -1200,6 +1200,11 @@ void __init early_init_devtree(void *par
early_reserve_mem();
phyp_dump_reserve_mem();
+ /* Ensure that total memory size is page-aligned, because otherwise
+ * bootmem.c gets upset. */
+ lmb_analyze();
+ memory_limit = lmb_phys_mem_size() & PAGE_MASK;
All of the current code using memory_limit looks like it'll be safe
with
this change, although there are several cases of this we could remove:
if (memory_limit && <some other condition>)
Because memory_limit will now always be true.
memory_limit was the result of parsing mem= from the command line.
Does this break that?
Still, I think it would be better to only set memory_limit when the mem
size is not a multiple of the PAGE_SIZE - so that memory_limit retains
it's function as both the value of the limit and a boolean.
I would have expected this trimming to occur where we actually transfer
the memory from lmb to bootmem, since it is bootmem that has the
aligned size requirement.
milton
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