[PATCH v5 net-next 05/10] net: Clean up __sk_mem_raise_allocated().

Kuniyuki Iwashima posted 10 patches 5 months, 3 weeks ago
[PATCH v5 net-next 05/10] net: Clean up __sk_mem_raise_allocated().
Posted by Kuniyuki Iwashima 5 months, 3 weeks ago
In __sk_mem_raise_allocated(), charged is initialised as true due
to the weird condition removed in the previous patch.

It makes the variable unreliable by itself, so we have to check
another variable, memcg, in advance.

Also, we will factorise the common check below for memcg later.

    if (mem_cgroup_sockets_enabled && sk->sk_memcg)

As a prep, let's initialise charged as false and memcg as NULL.

Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
---
 net/core/sock.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/net/core/sock.c b/net/core/sock.c
index 380bc1aa6982..000940ecf360 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -3263,15 +3263,16 @@ EXPORT_SYMBOL(sk_wait_data);
  */
 int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind)
 {
-	struct mem_cgroup *memcg = mem_cgroup_sockets_enabled ? sk->sk_memcg : NULL;
 	struct proto *prot = sk->sk_prot;
-	bool charged = true;
+	struct mem_cgroup *memcg = NULL;
+	bool charged = false;
 	long allocated;
 
 	sk_memory_allocated_add(sk, amt);
 	allocated = sk_memory_allocated(sk);
 
-	if (memcg) {
+	if (mem_cgroup_sockets_enabled && sk->sk_memcg) {
+		memcg = sk->sk_memcg;
 		charged = mem_cgroup_charge_skmem(memcg, amt, gfp_memcg_charge());
 		if (!charged)
 			goto suppress_allocation;
@@ -3358,7 +3359,7 @@ int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind)
 
 	sk_memory_allocated_sub(sk, amt);
 
-	if (memcg && charged)
+	if (charged)
 		mem_cgroup_uncharge_skmem(memcg, amt);
 
 	return 0;
-- 
2.51.0.rc1.163.g2494970778-goog
Re: [PATCH v5 net-next 05/10] net: Clean up __sk_mem_raise_allocated().
Posted by Shakeel Butt 5 months, 3 weeks ago
On Fri, Aug 15, 2025 at 08:16:13PM +0000, Kuniyuki Iwashima wrote:
> In __sk_mem_raise_allocated(), charged is initialised as true due
> to the weird condition removed in the previous patch.
> 
> It makes the variable unreliable by itself, so we have to check
> another variable, memcg, in advance.
> 
> Also, we will factorise the common check below for memcg later.
> 
>     if (mem_cgroup_sockets_enabled && sk->sk_memcg)
> 
> As a prep, let's initialise charged as false and memcg as NULL.
> 
> Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
> Reviewed-by: Eric Dumazet <edumazet@google.com>

Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev>