net: fix sk_mem_reclaim_partial()

sk_mem_reclaim_partial() goal is to ensure each socket has
one SK_MEM_QUANTUM forward allocation. This is needed both for
performance and better handling of memory pressure situations in
follow up patches.

SK_MEM_QUANTUM is currently a page, but might be reduced to 4096 bytes
as some arches have 64KB pages.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 5 insertions, 4 deletions

diff --git a/net/core/sock.c b/net/core/sock.c
index c18738a795b0..29124fcdc42a 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -2069,12 +2069,13 @@ EXPORT_SYMBOL(__sk_mem_schedule);
 /**
  *      __sk_reclaim - reclaim memory_allocated
  *      @sk: socket
+ *      @amount: number of bytes (rounded down to a SK_MEM_QUANTUM multiple)
  */
-void __sk_mem_reclaim(struct sock *sk)
+void __sk_mem_reclaim(struct sock *sk, int amount)
 {
-        sk_memory_allocated_sub(sk,
-                                sk->sk_forward_alloc >> SK_MEM_QUANTUM_SHIFT);
-        sk->sk_forward_alloc &= SK_MEM_QUANTUM - 1;
+        amount >>= SK_MEM_QUANTUM_SHIFT;
+        sk_memory_allocated_sub(sk, amount);
+        sk->sk_forward_alloc -= amount << SK_MEM_QUANTUM_SHIFT;
 
         if (sk_under_memory_pressure(sk) &&
             (sk_memory_allocated(sk) < sk_prot_mem_limits(sk, 0)))