[PATCH -mm 13/13] mm, THP, swap: Add THP swapping out fallback counting

From: Huang Ying When swapping out THP (Transparent Huge Page), instead of swapping out the THP as a whole, sometimes we have to fallback to split the THP into normal pages before swapping, because no free swap clusters are available, or cgroup limit is exceeded, etc. To

[PATCH -mm 13/13] mm, THP, swap: Add THP swapping out fallback counting

From: Huang Ying When swapping out THP (Transparent Huge Page), instead of swapping out the THP as a whole, sometimes we have to fallback to split the THP into normal pages before swapping, because no free swap clusters are available, or cgroup limit is exceeded, etc. To count the number of the