LoongArch: Set max_pfn with the PFN of the last page

The current max_pfn equals to zero. In this case, it causes user cannot
get some page information through /proc filesystem such as kpagecount.
The following message is displayed by stress-ng test suite with command
"stress-ng --verbose --physpage 1 -t 1".

 # stress-ng --verbose --physpage 1 -t 1
 stress-ng: error: [1691] physpage: cannot read page count for address 0x134ac000 in /proc/kpagecount, errno=22 (Invalid argument)
 stress-ng: error: [1691] physpage: cannot read page count for address 0x7ffff207c3a8 in /proc/kpagecount, errno=22 (Invalid argument)
 stress-ng: error: [1691] physpage: cannot read page count for address 0x134b0000 in /proc/kpagecount, errno=22 (Invalid argument)
 ...

After applying this patch, the kernel can pass the test.

 # stress-ng --verbose --physpage 1 -t 1
 stress-ng: debug: [1701] physpage: [1701] started (instance 0 on CPU 3)
 stress-ng: debug: [1701] physpage: [1701] exited (instance 0 on CPU 3)
 stress-ng: debug: [1700] physpage: [1701] terminated (success)

Cc: stable@vger.kernel.org  # 6.8+
Fixes: ff6c3d81f2 ("NUMA: optimize detection of memory with no node id assigned by firmware")
Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
This commit is contained in:
Bibo Mao
2025-03-08 13:51:32 +08:00
committed by Huacai Chen
parent c9117434c8
commit c8477bb0a8
+3
View File
@@ -387,6 +387,9 @@ static void __init check_kernel_sections_mem(void)
*/
static void __init arch_mem_init(char **cmdline_p)
{
/* Recalculate max_low_pfn for "mem=xxx" */
max_pfn = max_low_pfn = PHYS_PFN(memblock_end_of_DRAM());
if (usermem)
pr_info("User-defined physical RAM map overwrite\n");