On Tue, 18 Feb 2020, Kirill A. Shutemov wrote: > On Mon, Feb 17, 2020 at 09:41:40PM -0800, David Rientjes wrote: > > The thp_fault_fallback stat in either /proc/vmstat is incremented if > > either the hugepage allocation fails through the page allocator or the > > hugepage charge fails through mem cgroup. > > > > This patch leaves this field untouched but adds a new field, > > thp_fault_fallback_charge, which is incremented only when the mem cgroup > > charge fails. > > > > This distinguishes between faults that want to be backed by hugepages but > > fail due to fragmentation (or low memory conditions) and those that fail > > due to mem cgroup limits. That can be used to determine the impact of > > fragmentation on the system by excluding faults that failed due to memcg > > usage. > > > > Signed-off-by: David Rientjes <rientjes@xxxxxxxxxx> > > The patch looks good to me, but I noticed that we miss THP_FAULT_FALLBACK > (and THP_FAULT_FALLBACK_CHARGE) accounting in shmem_getpage_gfp(). > > Could you fix this while you are there? Sure, I'll add it as a predecessor and also count THP_FAULT_ALLOC for consistency.
