From: Yang Yingliang <yangyingliang@huawei.com> hulk inclusion category: bugfix bugzilla: https://atomgit.com/openeuler/kernel/issues/8748 CVE: NA -------------------------------------------------- The memory stat is not done in real time, it have some gap with real value. In CPU-less NUMA node, the values of MemTotal and MemFree can be nearly equal, the gap make cause MemFree is bigger than MemTotal, it leads MemUsed is negative which print as a large positive number. cat /sys/devices/system/node/node17/meminfo Node 17 MemTotal: 4194304 kB Node 17 MemFree: 4195552 kB Node 17 MemUsed: 18446744073709550368 kB Node 17 Active: 52 kB Node 17 Inactive: 320 kB Node 17 Active(anon): 0 kB Node 17 Inactive(anon): 0 kB Node 17 Active(file): 52 kB Node 17 Inactive(file): 320 kB Node 17 Unevictable: 0 kB Node 17 Mlocked: 0 kB Node 17 Dirty: 0 kB Node 17 Writeback: 0 kB Node 17 FilePages: 372 kB Node 17 Mapped: 320 kB Node 17 AnonPages: 0 kB Node 17 Shmem: 0 kB Node 17 KernelStack: 0 kB Node 17 PageTables: 0 kB Node 17 NFS_Unstable: 0 kB Node 17 Bounce: 0 kB Node 17 WritebackTmp: 0 kB Node 17 KReclaimable: 0 kB Node 17 Slab: 0 kB Node 17 SReclaimable: 0 kB Node 17 SUnreclaim: 0 kB Node 17 AnonHugePages: 79872 kB Node 17 ShmemHugePages: 0 kB Node 17 ShmemPmdMapped: 0 kB Node 17 FileHugePages: 0 kB Node 17 FilePmdMapped: 0 kB Node 17 HugePages_Total: 0 Node 17 HugePages_Free: 0 Node 17 HugePages_Surp: 0 To avoid this exception, make MemFree equals MemTotal, when MemFree is bigger than MemTotal Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- mm/page_alloc.c | 1 + 1 file changed, 1 insertion(+) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 72d5303f8000..02db21de93aa 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -5837,6 +5837,7 @@ void si_meminfo_node(struct sysinfo *val, int nid) val->totalram = managed_pages; val->sharedram = node_page_state(pgdat, NR_SHMEM); val->freeram = sum_zone_node_page_state(nid, NR_FREE_PAGES); + val->freeram = min(val->freeram, val->totalram); #ifdef CONFIG_HIGHMEM for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) { struct zone *zone = &pgdat->node_zones[zone_type]; -- 2.33.0