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authorWei Wang <weiwan@google.com>2021-08-17 22:40:03 +0300
committerDavid S. Miller <davem@davemloft.net>2021-08-18 13:39:44 +0300
commit4b1327be9fe57443295ae86fe0fcf24a18469e9f (patch)
treecab0b45edc0c01d5fbac35ba3c63bdcd17428d7d
parentab44035d308227723b490487ff0feba521e87029 (diff)
downloadlinux-4b1327be9fe57443295ae86fe0fcf24a18469e9f.tar.xz
net-memcg: pass in gfp_t mask to mem_cgroup_charge_skmem()
Add gfp_t mask as an input parameter to mem_cgroup_charge_skmem(), to give more control to the networking stack and enable it to change memcg charging behavior. In the future, the networking stack may decide to avoid oom-kills when fallbacks are more appropriate. One behavior change in mem_cgroup_charge_skmem() by this patch is to avoid force charging by default and let the caller decide when and if force charging is needed through the presence or absence of __GFP_NOFAIL. Signed-off-by: Wei Wang <weiwan@google.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--include/linux/memcontrol.h3
-rw-r--r--include/net/sock.h5
-rw-r--r--mm/memcontrol.c24
-rw-r--r--net/core/sock.c16
-rw-r--r--net/ipv4/inet_connection_sock.c3
-rw-r--r--net/ipv4/tcp_output.c3
6 files changed, 34 insertions, 20 deletions
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index bfe5c486f4ad..f0ee30881ca9 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -1581,7 +1581,8 @@ 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);
+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;
diff --git a/include/net/sock.h b/include/net/sock.h
index 6e761451c927..95b25777b53e 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -2400,6 +2400,11 @@ static inline gfp_t gfp_any(void)
return in_softirq() ? GFP_ATOMIC : GFP_KERNEL;
}
+static inline gfp_t gfp_memcg_charge(void)
+{
+ return in_softirq() ? GFP_NOWAIT : GFP_KERNEL;
+}
+
static inline long sock_rcvtimeo(const struct sock *sk, bool noblock)
{
return noblock ? 0 : sk->sk_rcvtimeo;
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 8ef06f9e0db1..be585ceaba98 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -7048,14 +7048,14 @@ void mem_cgroup_sk_free(struct sock *sk)
* mem_cgroup_charge_skmem - charge socket memory
* @memcg: 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 the charge had to be forced.
+ * @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_charge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages,
+ gfp_t gfp_mask)
{
- gfp_t gfp_mask = GFP_KERNEL;
-
if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) {
struct page_counter *fail;
@@ -7063,21 +7063,19 @@ bool mem_cgroup_charge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages)
memcg->tcpmem_pressure = 0;
return true;
}
- page_counter_charge(&memcg->tcpmem, nr_pages);
memcg->tcpmem_pressure = 1;
+ if (gfp_mask & __GFP_NOFAIL) {
+ page_counter_charge(&memcg->tcpmem, nr_pages);
+ return true;
+ }
return false;
}
- /* Don't block in the packet receive path */
- if (in_softirq())
- gfp_mask = GFP_NOWAIT;
-
- mod_memcg_state(memcg, MEMCG_SOCK, nr_pages);
-
- if (try_charge(memcg, gfp_mask, nr_pages) == 0)
+ if (try_charge(memcg, gfp_mask, nr_pages) == 0) {
+ mod_memcg_state(memcg, MEMCG_SOCK, nr_pages);
return true;
+ }
- try_charge(memcg, gfp_mask|__GFP_NOFAIL, nr_pages);
return false;
}
diff --git a/net/core/sock.c b/net/core/sock.c
index aada649e07e8..950f1e70dbf5 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -2728,10 +2728,12 @@ int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind)
{
struct proto *prot = sk->sk_prot;
long allocated = sk_memory_allocated_add(sk, amt);
+ bool memcg_charge = mem_cgroup_sockets_enabled && sk->sk_memcg;
bool charged = true;
- if (mem_cgroup_sockets_enabled && sk->sk_memcg &&
- !(charged = mem_cgroup_charge_skmem(sk->sk_memcg, amt)))
+ if (memcg_charge &&
+ !(charged = mem_cgroup_charge_skmem(sk->sk_memcg, amt,
+ gfp_memcg_charge())))
goto suppress_allocation;
/* Under limit. */
@@ -2785,8 +2787,14 @@ suppress_allocation:
/* Fail only if socket is _under_ its sndbuf.
* In this case we cannot block, so that we have to fail.
*/
- if (sk->sk_wmem_queued + size >= sk->sk_sndbuf)
+ if (sk->sk_wmem_queued + size >= sk->sk_sndbuf) {
+ /* Force charge with __GFP_NOFAIL */
+ if (memcg_charge && !charged) {
+ mem_cgroup_charge_skmem(sk->sk_memcg, amt,
+ gfp_memcg_charge() | __GFP_NOFAIL);
+ }
return 1;
+ }
}
if (kind == SK_MEM_SEND || (kind == SK_MEM_RECV && charged))
@@ -2794,7 +2802,7 @@ suppress_allocation:
sk_memory_allocated_sub(sk, amt);
- if (mem_cgroup_sockets_enabled && sk->sk_memcg)
+ if (memcg_charge && charged)
mem_cgroup_uncharge_skmem(sk->sk_memcg, amt);
return 0;
diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
index 754013fa393b..f25d02ad4a8a 100644
--- a/net/ipv4/inet_connection_sock.c
+++ b/net/ipv4/inet_connection_sock.c
@@ -534,7 +534,8 @@ out:
atomic_read(&newsk->sk_rmem_alloc));
mem_cgroup_sk_alloc(newsk);
if (newsk->sk_memcg && amt)
- mem_cgroup_charge_skmem(newsk->sk_memcg, amt);
+ mem_cgroup_charge_skmem(newsk->sk_memcg, amt,
+ GFP_KERNEL | __GFP_NOFAIL);
release_sock(newsk);
}
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 29553fce8502..6d72f3ea48c4 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -3373,7 +3373,8 @@ void sk_forced_mem_schedule(struct sock *sk, int size)
sk_memory_allocated_add(sk, amt);
if (mem_cgroup_sockets_enabled && sk->sk_memcg)
- mem_cgroup_charge_skmem(sk->sk_memcg, amt);
+ mem_cgroup_charge_skmem(sk->sk_memcg, amt,
+ gfp_memcg_charge() | __GFP_NOFAIL);
}
/* Send a FIN. The caller locks the socket for us.