Commit f9ca2820 authored by Jakub Kicinski's avatar Jakub Kicinski
Browse files

Merge branch 'net-memcg-gather-memcg-code-under-config_memcg' 

Kuniyuki Iwashima says:

====================
net-memcg: Gather memcg code under CONFIG_MEMCG.

This series converts most sk->sk_memcg access to helper functions
under CONFIG_MEMCG and finally defines sk_memcg under CONFIG_MEMCG.

This is v5 of the series linked below but without core changes
that decoupled memcg and global socket memory accounting.

I will defer the changes to a follow-up series that will use BPF
to store a flag in sk->sk_memcg.

Overview of the series:

  patch 1 is a trivial fix for MPTCP
  patch 2 ~ 9 move sk->sk_memcg accesses to a single place
  patch 10 moves sk_memcg under CONFIG_MEMCG

v4: https://lore.kernel.org/20250814200912.1040628-1-kuniyu@google.com
v3: https://lore.kernel.org/20250812175848.512446-1-kuniyu@google.com
v2: https://lore.kernel.org/20250811173116.2829786-1-kuniyu@google.com
v1: https://lore.kernel.org/20250721203624.3807041-1-kuniyu@google.com
====================

Link: https://patch.msgid.link/20250815201712.1745332-1-kuniyu@google.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parents 5c69e0b3 bf64002c

include/linux/memcontrol.h

+26 −19
Original line number Diff line number Diff line
@@ -1596,14 +1596,16 @@ static inline void mem_cgroup_flush_foreign(struct bdi_writeback *wb) 
#endif	/* CONFIG_CGROUP_WRITEBACK */



struct sock;

bool mem_cgroup_charge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages,

			     gfp_t gfp_mask);

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

#ifdef CONFIG_MEMCG

extern struct static_key_false memcg_sockets_enabled_key;

#define mem_cgroup_sockets_enabled static_branch_unlikely(&memcg_sockets_enabled_key)



void mem_cgroup_sk_alloc(struct sock *sk);

void mem_cgroup_sk_free(struct sock *sk);

void mem_cgroup_sk_inherit(const struct sock *sk, struct sock *newsk);

bool mem_cgroup_sk_charge(const struct sock *sk, unsigned int nr_pages,

			  gfp_t gfp_mask);

void mem_cgroup_sk_uncharge(const struct sock *sk, unsigned int nr_pages);



#if BITS_PER_LONG < 64

static inline void mem_cgroup_set_socket_pressure(struct mem_cgroup *memcg)
@@ -1640,32 +1642,37 @@ static inline u64 mem_cgroup_get_socket_pressure(struct mem_cgroup *memcg) 
}

#endif



static inline bool mem_cgroup_under_socket_pressure(struct mem_cgroup *memcg)

{

#ifdef CONFIG_MEMCG_V1

	if (!cgroup_subsys_on_dfl(memory_cgrp_subsys))

		return !!memcg->tcpmem_pressure;

#endif /* CONFIG_MEMCG_V1 */

	do {

		if (time_before64(get_jiffies_64(), mem_cgroup_get_socket_pressure(memcg)))

			return true;

	} while ((memcg = parent_mem_cgroup(memcg)));

	return false;

}



int alloc_shrinker_info(struct mem_cgroup *memcg);

void free_shrinker_info(struct mem_cgroup *memcg);

void set_shrinker_bit(struct mem_cgroup *memcg, int nid, int shrinker_id);

void reparent_shrinker_deferred(struct mem_cgroup *memcg);

#else

#define mem_cgroup_sockets_enabled 0

static inline void mem_cgroup_sk_alloc(struct sock *sk) { };

static inline void mem_cgroup_sk_free(struct sock *sk) { };

static inline bool mem_cgroup_under_socket_pressure(struct mem_cgroup *memcg)



static inline void mem_cgroup_sk_alloc(struct sock *sk)

{

}



static inline void mem_cgroup_sk_free(struct sock *sk)

{

}



static inline void mem_cgroup_sk_inherit(const struct sock *sk, struct sock *newsk)

{

}



static inline bool mem_cgroup_sk_charge(const struct sock *sk,

					unsigned int nr_pages,

					gfp_t gfp_mask)

{

	return false;

}



static inline void mem_cgroup_sk_uncharge(const struct sock *sk,

					  unsigned int nr_pages)

{

}



static inline void set_shrinker_bit(struct mem_cgroup *memcg,

				    int nid, int shrinker_id)

{

include/net/proto_memory.h

+2 −2
Original line number Diff line number Diff line
@@ -31,8 +31,8 @@ static inline bool sk_under_memory_pressure(const struct sock *sk) 
	if (!sk->sk_prot->memory_pressure)

		return false;



	if (mem_cgroup_sockets_enabled && sk->sk_memcg &&

	    mem_cgroup_under_socket_pressure(sk->sk_memcg))

	if (mem_cgroup_sk_enabled(sk) &&

	    mem_cgroup_sk_under_memory_pressure(sk))

		return true;



	return !!READ_ONCE(*sk->sk_prot->memory_pressure);

include/net/sock.h

+46 −0
Original line number Diff line number Diff line
@@ -443,7 +443,9 @@ struct sock { 
	__cacheline_group_begin(sock_read_rxtx);

	int			sk_err;

	struct socket		*sk_socket;

#ifdef CONFIG_MEMCG

	struct mem_cgroup	*sk_memcg;

#endif

#ifdef CONFIG_XFRM

	struct xfrm_policy __rcu *sk_policy[2];

#endif
@@ -2594,6 +2596,50 @@ static inline gfp_t gfp_memcg_charge(void) 
	return in_softirq() ? GFP_ATOMIC : GFP_KERNEL;

}



#ifdef CONFIG_MEMCG

static inline struct mem_cgroup *mem_cgroup_from_sk(const struct sock *sk)

{

	return sk->sk_memcg;

}



static inline bool mem_cgroup_sk_enabled(const struct sock *sk)

{

	return mem_cgroup_sockets_enabled && mem_cgroup_from_sk(sk);

}



static inline bool mem_cgroup_sk_under_memory_pressure(const struct sock *sk)

{

	struct mem_cgroup *memcg = mem_cgroup_from_sk(sk);



#ifdef CONFIG_MEMCG_V1

	if (!cgroup_subsys_on_dfl(memory_cgrp_subsys))

		return !!memcg->tcpmem_pressure;

#endif /* CONFIG_MEMCG_V1 */



	do {

		if (time_before64(get_jiffies_64(), mem_cgroup_get_socket_pressure(memcg)))

			return true;

	} while ((memcg = parent_mem_cgroup(memcg)));



	return false;

}

#else

static inline struct mem_cgroup *mem_cgroup_from_sk(const struct sock *sk)

{

	return NULL;

}



static inline bool mem_cgroup_sk_enabled(const struct sock *sk)

{

	return false;

}



static inline bool mem_cgroup_sk_under_memory_pressure(const struct sock *sk)

{

	return false;

}

#endif



static inline long sock_rcvtimeo(const struct sock *sk, bool noblock)

{

	return noblock ? 0 : READ_ONCE(sk->sk_rcvtimeo);

include/net/tcp.h

+2 −2
Original line number Diff line number Diff line
@@ -275,8 +275,8 @@ extern unsigned long tcp_memory_pressure; 
/* optimized version of sk_under_memory_pressure() for TCP sockets */

static inline bool tcp_under_memory_pressure(const struct sock *sk)

{

	if (mem_cgroup_sockets_enabled && sk->sk_memcg &&

	    mem_cgroup_under_socket_pressure(sk->sk_memcg))

	if (mem_cgroup_sk_enabled(sk) &&

	    mem_cgroup_sk_under_memory_pressure(sk))

		return true;



	return READ_ONCE(tcp_memory_pressure);

mm/memcontrol.c

+31 −9
Original line number Diff line number Diff line
@@ -5020,22 +5020,42 @@ void mem_cgroup_sk_alloc(struct sock *sk) 


void mem_cgroup_sk_free(struct sock *sk)

{

	if (sk->sk_memcg)

		css_put(&sk->sk_memcg->css);

	struct mem_cgroup *memcg = mem_cgroup_from_sk(sk);



	if (memcg)

		css_put(&memcg->css);

}



void mem_cgroup_sk_inherit(const struct sock *sk, struct sock *newsk)

{

	struct mem_cgroup *memcg;



	if (sk->sk_memcg == newsk->sk_memcg)

		return;



	mem_cgroup_sk_free(newsk);



	memcg = mem_cgroup_from_sk(sk);

	if (memcg)

		css_get(&memcg->css);



	newsk->sk_memcg = sk->sk_memcg;

}



/**

 * mem_cgroup_charge_skmem - charge socket memory

 * @memcg: memcg to charge

 * mem_cgroup_sk_charge - charge socket memory

 * @sk: socket in memcg to charge

 * @nr_pages: number of pages to charge

 * @gfp_mask: reclaim mode

 *

 * Charges @nr_pages to @memcg. Returns %true if the charge fit within

 * @memcg's configured limit, %false if it doesn't.

 */

bool mem_cgroup_charge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages,

bool mem_cgroup_sk_charge(const struct sock *sk, unsigned int nr_pages,

			  gfp_t gfp_mask)

{

	struct mem_cgroup *memcg = mem_cgroup_from_sk(sk);



	if (!cgroup_subsys_on_dfl(memory_cgrp_subsys))

		return memcg1_charge_skmem(memcg, nr_pages, gfp_mask);
@@ -5048,12 +5068,14 @@ bool mem_cgroup_charge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages, 
}



/**

 * mem_cgroup_uncharge_skmem - uncharge socket memory

 * @memcg: memcg to uncharge

 * mem_cgroup_sk_uncharge - uncharge socket memory

 * @sk: socket in memcg to uncharge

 * @nr_pages: number of pages to uncharge

 */

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

void mem_cgroup_sk_uncharge(const struct sock *sk, unsigned int nr_pages)

{

	struct mem_cgroup *memcg = mem_cgroup_from_sk(sk);



	if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) {

		memcg1_uncharge_skmem(memcg, nr_pages);

		return;