From: Roman Gushchin <guro@xxxxxx> Subject: mm: kmem: cleanup (__)memcg_kmem_charge_memcg() arguments Patch series "mm: memcg: kmem API cleanup", v2. This patchset aims to clean up the kernel memory charging API. It doesn't bring any functional changes, just removes unused arguments, renames some functions and fixes some comments. Currently it's not obvious which functions are most basic (memcg_kmem_(un)charge_memcg()) and which are based on them (memcg_kmem_(un)charge()). The patchset renames these functions and removes unused arguments: TL;DR: was: memcg_kmem_charge_memcg(page, gfp, order, memcg) memcg_kmem_uncharge_memcg(memcg, nr_pages) memcg_kmem_charge(page, gfp, order) memcg_kmem_uncharge(page, order) now: memcg_kmem_charge(memcg, gfp, nr_pages) memcg_kmem_uncharge(memcg, nr_pages) memcg_kmem_charge_page(page, gfp, order) memcg_kmem_uncharge_page(page, order) This patch (of 6): The first argument of memcg_kmem_charge_memcg() and __memcg_kmem_charge_memcg() is the page pointer and it's not used. Let's drop it. Memcg pointer is passed as the last argument. Move it to the first place for consistency with other memcg functions, e.g. __memcg_kmem_uncharge_memcg() or try_charge(). Link: http://lkml.kernel.org/r/20200109202659.752357-2-guro@xxxxxx Signed-off-by: Roman Gushchin <guro@xxxxxx> Reviewed-by: Shakeel Butt <shakeelb@xxxxxxxxxx> Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxxxx> Cc: Vladimir Davydov <vdavydov.dev@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/memcontrol.h | 9 ++++----- mm/memcontrol.c | 8 +++----- mm/slab.h | 2 +- 3 files changed, 8 insertions(+), 11 deletions(-) --- a/include/linux/memcontrol.h~mm-kmem-cleanup-__memcg_kmem_charge_memcg-arguments +++ a/include/linux/memcontrol.h @@ -1369,8 +1369,7 @@ void memcg_kmem_put_cache(struct kmem_ca #ifdef CONFIG_MEMCG_KMEM int __memcg_kmem_charge(struct page *page, gfp_t gfp, int order); void __memcg_kmem_uncharge(struct page *page, int order); -int __memcg_kmem_charge_memcg(struct page *page, gfp_t gfp, int order, - struct mem_cgroup *memcg); +int __memcg_kmem_charge_memcg(struct mem_cgroup *memcg, gfp_t gfp, int order); void __memcg_kmem_uncharge_memcg(struct mem_cgroup *memcg, unsigned int nr_pages); @@ -1407,11 +1406,11 @@ static inline void memcg_kmem_uncharge(s __memcg_kmem_uncharge(page, order); } -static inline int memcg_kmem_charge_memcg(struct page *page, gfp_t gfp, - int order, struct mem_cgroup *memcg) +static inline int memcg_kmem_charge_memcg(struct mem_cgroup *memcg, gfp_t gfp, + int order) { if (memcg_kmem_enabled()) - return __memcg_kmem_charge_memcg(page, gfp, order, memcg); + return __memcg_kmem_charge_memcg(memcg, gfp, order); return 0; } --- a/mm/memcontrol.c~mm-kmem-cleanup-__memcg_kmem_charge_memcg-arguments +++ a/mm/memcontrol.c @@ -2882,15 +2882,13 @@ void memcg_kmem_put_cache(struct kmem_ca /** * __memcg_kmem_charge_memcg: charge a kmem page - * @page: page to charge + * @memcg: memory cgroup to charge * @gfp: reclaim mode * @order: allocation order - * @memcg: memory cgroup to charge * * Returns 0 on success, an error code on failure. */ -int __memcg_kmem_charge_memcg(struct page *page, gfp_t gfp, int order, - struct mem_cgroup *memcg) +int __memcg_kmem_charge_memcg(struct mem_cgroup *memcg, gfp_t gfp, int order) { unsigned int nr_pages = 1 << order; struct page_counter *counter; @@ -2936,7 +2934,7 @@ int __memcg_kmem_charge(struct page *pag memcg = get_mem_cgroup_from_current(); if (!mem_cgroup_is_root(memcg)) { - ret = __memcg_kmem_charge_memcg(page, gfp, order, memcg); + ret = __memcg_kmem_charge_memcg(memcg, gfp, order); if (!ret) { page->mem_cgroup = memcg; __SetPageKmemcg(page); --- a/mm/slab.h~mm-kmem-cleanup-__memcg_kmem_charge_memcg-arguments +++ a/mm/slab.h @@ -365,7 +365,7 @@ static __always_inline int memcg_charge_ return 0; } - ret = memcg_kmem_charge_memcg(page, gfp, order, memcg); + ret = memcg_kmem_charge_memcg(memcg, gfp, order); if (ret) goto out; _
