On 2021-06-25 21:39, Thomas Bogendoerfer wrote:
On Thu, Jun 24, 2021 at 11:22:12AM +0800, zhanglianjie wrote:The cause of the problem is as follows: 1. when cat /sys/devices/system/memory/memory0/valid_zones, test_pages_in_a_zone() will be called. 2. test_pages_in_a_zone() finds the zone according to stat_pfn = 0. The smallest pfn of the numa node in the mips architecture is 128, and the page corresponding to the previous 0~127 pfn is not initialized (page->flags is 0xFFFFFFFF) 3. The nid and zonenum obtained using page_zone(pfn_to_page(0)) are out of bounds in the corresponding array, &NODE_DATA(page_to_nid(page))->node_zones[page_zonenum(page)], access to the out-of-bounds zone member variables appear abnormal, resulting in Oops. Therefore, it is necessary to keep the page between 0 and the minimum pfn to prevent Oops from appearing. Signed-off-by: zhanglianjie <zhanglianjie@xxxxxxxxxxxxx> --- arch/mips/kernel/setup.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c index 23a140327a0b..f1da2b2ba5e9 100644 --- a/arch/mips/kernel/setup.c +++ b/arch/mips/kernel/setup.c @@ -653,6 +653,8 @@ static void __init arch_mem_init(char **cmdline_p) */ memblock_set_current_limit(PFN_PHYS(max_low_pfn)); + memblock_reserve(0, PAGE_SIZE * NODE_DATA(0)->node_start_pfn); +which platform needs this ? This look it should be better fixed in the platform memory registration code. Thomas.
I have a problem on the loogson platform. -- Regards, Zhang Lianjie
