6.12-stable review patch. If anyone has any objections, please let me know.
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From: Bibo Mao maobibo@loongson.cn
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@vger.kernel.org # 6.8+ Fixes: ff6c3d81f2e8 ("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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/loongarch/kernel/setup.c | 3 +++ 1 file changed, 3 insertions(+)
--- a/arch/loongarch/kernel/setup.c +++ b/arch/loongarch/kernel/setup.c @@ -387,6 +387,9 @@ 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");