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. -- Crap can work. Given enough thrust pigs will fly, but it's not necessarily a good idea. [ RFC1925, 2.3 ]
