On 2022/12/23 19:42, Lianbo Jiang wrote: > Kernel commit d42f3245c7e2 ("mm: memcg: convert vmstat slab counters to > bytes"), which is contained in linux v5.9-rc1 and later kernels, renamed > NR_SLAB_{RECLAIMABLE,UNRECLAIMABLE} to NR_SLAB_{RECLAIMABLE,UNRECLAIMABLE}_B. > > Without the patch, "kmem -i" command will display incorrect SLAB > statistics: > > crash> kmem -i | grep -e PAGES -e SLAB > PAGES TOTAL PERCENTAGE > SLAB 89458 349.4 MB 0% of TOTAL MEM > ^^^^^ ^^^^^ > > With the patch, the actual result is: > crash> kmem -i | grep -e PAGES -e SLAB > PAGES TOTAL PERCENTAGE > SLAB 261953 1023.3 MB 0% of TOTAL MEM Good catch! This kind of no error issue is hard to detect.. > > Reported-by: Buland Kumar Singh <bsingh(a)redhat.com&gt; > Signed-off-by: Lianbo Jiang <lijiang(a)redhat.com&gt; > --- > memory.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/memory.c b/memory.c > index 9d003713534b..a8f08f1a4d09 100644 > --- a/memory.c > +++ b/memory.c > @@ -8382,9 +8382,11 @@ dump_kmeminfo(void) > if (vm_stat_init()) { > if (dump_vm_stat("NR_SLAB", &nr_slab, 0)) > get_slabs = nr_slab; > - else if (dump_vm_stat("NR_SLAB_RECLAIMABLE", &nr_slab, 0)) { > + else if (dump_vm_stat("NR_SLAB_RECLAIMABLE", &nr_slab, 0) || > + dump_vm_stat("NR_SLAB_RECLAIMABLE_B", &nr_slab, 0)) { > get_slabs = nr_slab; > - if (dump_vm_stat("NR_SLAB_UNRECLAIMABLE", &nr_slab, 0)) > + if (dump_vm_stat("NR_SLAB_UNRECLAIMABLE", &nr_slab, 0) || > + dump_vm_stat("NR_SLAB_UNRECLAIMABLE_B", &nr_slab, 0)) > get_slabs += nr_slab; > } > } Isn't this better? If no NR_SLAB_RECLAIMABLE, there is no need to search for NR_SLAB_UNRECLAIMABLE.

+++ b/memory.c @@ -8457,6 +8457,11 @@ dump_kmeminfo(void) get_slabs = nr_slab; if (dump_vm_stat("NR_SLAB_UNRECLAIMABLE", &nr_slab, 0)) get_slabs += nr_slab; + } else if (dump_vm_stat("NR_SLAB_RECLAIMABLE_B", &nr_slab, 0)) { + /* 5.9 and later */ + get_slabs = nr_slab; + if (dump_vm_stat("NR_SLAB_UNRECLAIMABLE_B", &nr_slab, 0)) + get_slabs += nr_slab; } } Thanks, Kazu