From: Bibo Mao <maobibo@xxxxxxxxxxx>
commit c8477bb0a8e7f6b2e47952b403c5cb67a6929e55 upstream.
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@xxxxxxxxxxxxxxx # 6.8+
Fixes: ff6c3d81f2e8 ("NUMA: optimize detection of memory with no node id assigned by firmware")
Signed-off-by: Bibo Mao <maobibo@xxxxxxxxxxx>
Signed-off-by: Huacai Chen <chenhuacai@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/loongarch/kernel/setup.c | 3 +++
1 file changed, 3 insertions(+)
--- a/arch/loongarch/kernel/setup.c
+++ b/arch/loongarch/kernel/setup.c
@@ -400,6 +400,9 @@ static void __init check_kernel_sections
*/
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");
Patches currently in stable-queue which might be from maobibo@xxxxxxxxxxx are
queue-6.6/loongarch-set-max_pfn-with-the-pfn-of-the-last-page.patch
