On Fri, 18 Oct, at 11:56:03AM, Mel Gorman wrote: > A private report stated that system CPU usage was excessive on an AMD > EPYC 2 machine while building kernels with much longer build times than > expected. The issue is partially explained by high zone lock contention > due to the per-cpu page allocator batch and high limits being calculated > incorrectly. This series addresses a large chunk of the problem. Patch 1 > is mostly cosmetic but prepares for patch 2 which is the real fix. Patch > 3 is definiely cosmetic but was noticed while implementing the fix. Proper > details are in the changelog for patch 2. > > include/linux/mm.h | 3 --- > mm/internal.h | 3 +++ > mm/page_alloc.c | 33 ++++++++++++++++++++------------- > 3 files changed, 23 insertions(+), 16 deletions(-) Just to confirm, these patches don't fix the issue we're seeing on the EPYC 2 machines, but they do return the batch sizes to sensible values.