Changelog since v1 o Parenthesise binary and boolean comparisons o Add reviewed-bys o Rebase to 5.12-rc2 This series introduces a bulk order-0 page allocator with sunrpc and the network page pool being the first users. The implementation is not particularly efficient and the intention is to iron out what the semantics of the API should have for users. Once the semantics are ironed out, it can be made more efficient. Improving the implementation requires fairly deep surgery in numerous places. The lock scope would need to be significantly reduced, particularly as vmstat, per-cpu and the buddy allocator have different locking protocol that overall -- e.g. all partially depend on irqs being disabled at various points. Secondly, the core of the allocator deals with single pages where as both the bulk allocator and per-cpu allocator operate in batches. All of that has to be reconciled with all the existing users and their constraints (memory offline, CMA and cpusets being the trickiest). Light testing passed, I'm relying on Chuck and Jesper to test the target users more aggressively but both report performance improvements with the initial RFC. Patch 1 of this series is a cleanup to sunrpc, it could be merged separately but is included here as a pre-requisite. Patch 2 is the prototype bulk allocator Patch 3 is the sunrpc user. Chuck also has a patch which further caches pages but is not included in this series. It's not directly related to the bulk allocator and as it caches pages, it might have other concerns (e.g. does it need a shrinker?) Patch 4 is a preparation patch only for the network user Patch 5 converts the net page pool to the bulk allocator for order-0 pages. There is no obvious impact to the existing paths as only new users of the API should notice a difference between multiple calls to the allocator and a single bulk allocation. include/linux/gfp.h | 13 +++++ mm/page_alloc.c | 113 +++++++++++++++++++++++++++++++++++++++++- net/core/page_pool.c | 102 +++++++++++++++++++++++--------------- net/sunrpc/svc_xprt.c | 47 ++++++++++++------ 4 files changed, 220 insertions(+), 55 deletions(-) -- 2.26.2
