Commit 1d8f136a authored by Joshua Hahn's avatar Joshua Hahn Committed by Andrew Morton
Browse files

memcg/hugetlb: remove memcg hugetlb try-commit-cancel protocol 

This patch fully removes the mem_cgroup_{try, commit, cancel}_charge
functions, as well as their hugetlb variants.

Link: https://lkml.kernel.org/r/20241211203951.764733-4-joshua.hahnjy@gmail.com


Signed-off-by: default avatarJoshua Hahn <joshua.hahnjy@gmail.com>
Acked-by: default avatarShakeel Butt <shakeel.butt@linux.dev>
Reviewed-by: default avatarNhat Pham <nphamcs@gmail.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 99113577

include/linux/memcontrol.h

+0 −22
Original line number Diff line number Diff line
@@ -620,8 +620,6 @@ static inline bool mem_cgroup_below_min(struct mem_cgroup *target, 
		page_counter_read(&memcg->memory);

}



void mem_cgroup_commit_charge(struct folio *folio, struct mem_cgroup *memcg);



int __mem_cgroup_charge(struct folio *folio, struct mm_struct *mm, gfp_t gfp);



/**
@@ -646,9 +644,6 @@ static inline int mem_cgroup_charge(struct folio *folio, struct mm_struct *mm, 
	return __mem_cgroup_charge(folio, mm, gfp);

}



int mem_cgroup_hugetlb_try_charge(struct mem_cgroup *memcg, gfp_t gfp,

		long nr_pages);



int mem_cgroup_charge_hugetlb(struct folio* folio, gfp_t gfp);



int mem_cgroup_swapin_charge_folio(struct folio *folio, struct mm_struct *mm,
@@ -679,7 +674,6 @@ static inline void mem_cgroup_uncharge_folios(struct folio_batch *folios) 
	__mem_cgroup_uncharge_folios(folios);

}



void mem_cgroup_cancel_charge(struct mem_cgroup *memcg, unsigned int nr_pages);

void mem_cgroup_replace_folio(struct folio *old, struct folio *new);

void mem_cgroup_migrate(struct folio *old, struct folio *new);
@@ -1154,23 +1148,12 @@ static inline bool mem_cgroup_below_min(struct mem_cgroup *target, 
	return false;

}



static inline void mem_cgroup_commit_charge(struct folio *folio,

		struct mem_cgroup *memcg)

{

}



static inline int mem_cgroup_charge(struct folio *folio,

		struct mm_struct *mm, gfp_t gfp)

{

	return 0;

}



static inline int mem_cgroup_hugetlb_try_charge(struct mem_cgroup *memcg,

		gfp_t gfp, long nr_pages)

{

	return 0;

}



static inline int mem_cgroup_charge_hugetlb(struct folio* folio, gfp_t gfp)

{

        return 0;
@@ -1194,11 +1177,6 @@ static inline void mem_cgroup_uncharge_folios(struct folio_batch *folios) 
{

}



static inline void mem_cgroup_cancel_charge(struct mem_cgroup *memcg,

		unsigned int nr_pages)

{

}



static inline void mem_cgroup_replace_folio(struct folio *old,

		struct folio *new)

{

mm/memcontrol.c

+3 −62
Original line number Diff line number Diff line
@@ -2383,21 +2383,6 @@ int try_charge_memcg(struct mem_cgroup *memcg, gfp_t gfp_mask, 
	return 0;

}



/**

 * mem_cgroup_cancel_charge() - cancel an uncommitted try_charge() call.

 * @memcg: memcg previously charged.

 * @nr_pages: number of pages previously charged.

 */

void mem_cgroup_cancel_charge(struct mem_cgroup *memcg, unsigned int nr_pages)

{

	if (mem_cgroup_is_root(memcg))

		return;



	page_counter_uncharge(&memcg->memory, nr_pages);

	if (do_memsw_account())

		page_counter_uncharge(&memcg->memsw, nr_pages);

}



static void commit_charge(struct folio *folio, struct mem_cgroup *memcg)

{

	VM_BUG_ON_FOLIO(folio_memcg_charged(folio), folio);
@@ -2411,18 +2396,6 @@ static void commit_charge(struct folio *folio, struct mem_cgroup *memcg) 
	folio->memcg_data = (unsigned long)memcg;

}



/**

 * mem_cgroup_commit_charge - commit a previously successful try_charge().

 * @folio: folio to commit the charge to.

 * @memcg: memcg previously charged.

 */

void mem_cgroup_commit_charge(struct folio *folio, struct mem_cgroup *memcg)

{

	css_get(&memcg->css);

	commit_charge(folio, memcg);

	memcg1_commit_charge(folio, memcg);

}



static inline void __mod_objcg_mlstate(struct obj_cgroup *objcg,

				       struct pglist_data *pgdat,

				       enum node_stat_item idx, int nr)
@@ -4510,7 +4483,9 @@ static int charge_memcg(struct folio *folio, struct mem_cgroup *memcg, 
	if (ret)

		goto out;



	mem_cgroup_commit_charge(folio, memcg);

	css_get(&memcg->css);

	commit_charge(folio, memcg);

	memcg1_commit_charge(folio, memcg);

out:

	return ret;

}
@@ -4527,40 +4502,6 @@ int __mem_cgroup_charge(struct folio *folio, struct mm_struct *mm, gfp_t gfp) 
	return ret;

}



/**

 * mem_cgroup_hugetlb_try_charge - try to charge the memcg for a hugetlb folio

 * @memcg: memcg to charge.

 * @gfp: reclaim mode.

 * @nr_pages: number of pages to charge.

 *

 * This function is called when allocating a huge page folio to determine if

 * the memcg has the capacity for it. It does not commit the charge yet,

 * as the hugetlb folio itself has not been obtained from the hugetlb pool.

 *

 * Once we have obtained the hugetlb folio, we can call

 * mem_cgroup_commit_charge() to commit the charge. If we fail to obtain the

 * folio, we should instead call mem_cgroup_cancel_charge() to undo the effect

 * of try_charge().

 *

 * Returns 0 on success. Otherwise, an error code is returned.

 */

int mem_cgroup_hugetlb_try_charge(struct mem_cgroup *memcg, gfp_t gfp,

			long nr_pages)

{

	/*

	 * If hugetlb memcg charging is not enabled, do not fail hugetlb allocation,

	 * but do not attempt to commit charge later (or cancel on error) either.

	 */

	if (mem_cgroup_disabled() || !memcg ||

		!cgroup_subsys_on_dfl(memory_cgrp_subsys) || !memcg_accounts_hugetlb())

		return -EOPNOTSUPP;



	if (try_charge(memcg, gfp, nr_pages))

		return -ENOMEM;



	return 0;

}



/**

 * mem_cgroup_charge_hugetlb - charge the memcg for a hugetlb folio

 * @folio: folio being charged