On Wed, 19 Mar 2014 07:14:25 +0000
Atsushi Kumagai <kumagai-atsushi at mxc.nes.nec.co.jp> wrote:
> >Hello Atsushi,
> >
> >I debugged my problem a bit further and tried to implement
> >a function that gets the maximum page frame number from the
> >Linux kernel memory management structures.
> >
> >I am no memory management expert, so the following patch probably
> >is not complete, but at least for my setup it worked.
>
> The patch looks good for your case, but I don't think it's a proper
> approach for this problem.
Hello Atsushi,
If you don't like that solution, what about using the mem_map_data[]
array of makedumpfile to adjust "max_mapnr"?
The patch below also works fine for my dump.
Michael
---
makedumpfile.c | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)
--- a/makedumpfile.c
+++ b/makedumpfile.c
@@ -2829,7 +2829,8 @@ get_mem_map_without_mm(void)
int
get_mem_map(void)
{
- int ret;
+ unsigned long max_pfn = 0;
+ int ret, i;
switch (get_mem_type()) {
case SPARSEMEM:
@@ -2861,6 +2862,17 @@ get_mem_map(void)
ret = FALSE;
break;
}
+ /*
+ * Adjust "max_mapnr" for the case that Linux uses less memory
+ * than is dumped. For example when "mem=" has been used for the
+ * dumped system.
+ */
+ for (i = 0; i < info->num_mem_map; i++) {
+ if (info->mem_map_data[i].mem_map == NOT_MEMMAP_ADDR)
+ continue;
+ max_pfn = MAX(max_pfn, info->mem_map_data[i].pfn_end);
+ }
+ info->max_mapnr = max_pfn;
return ret;
}
