From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936258AbdCJMDU (ORCPT ); Fri, 10 Mar 2017 07:03:20 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:44634 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935916AbdCJLxf (ORCPT ); Fri, 10 Mar 2017 06:53:35 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Eric Dumazet" , "David S. Miller" Date: Fri, 10 Mar 2017 11:46:10 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 163/199] net: fix sk_mem_reclaim_partial() In-Reply-To: X-SA-Exim-Connect-IP: 82.70.136.246 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2.87-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet commit 1a24e04e4b50939daa3041682b38b82c896ca438 upstream. 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 Signed-off-by: David S. Miller [bwh: Backported to 3.2: - Keep using atomic_long_sub() directly, not sk_memory_allocated_sub() - Adjust context] Signed-off-by: Ben Hutchings --- include/net/sock.h | 6 +++--- net/core/sock.c | 9 +++++---- 2 files changed, 8 insertions(+), 7 deletions(-) --- a/include/net/sock.h +++ b/include/net/sock.h @@ -961,7 +961,7 @@ static inline struct inode *SOCK_INODE(s * Functions for memory accounting */ extern int __sk_mem_schedule(struct sock *sk, int size, int kind); -extern void __sk_mem_reclaim(struct sock *sk); +void __sk_mem_reclaim(struct sock *sk, int amount); #define SK_MEM_QUANTUM ((int)PAGE_SIZE) #define SK_MEM_QUANTUM_SHIFT ilog2(SK_MEM_QUANTUM) @@ -1000,7 +1000,7 @@ static inline void sk_mem_reclaim(struct if (!sk_has_account(sk)) return; if (sk->sk_forward_alloc >= SK_MEM_QUANTUM) - __sk_mem_reclaim(sk); + __sk_mem_reclaim(sk, sk->sk_forward_alloc); } static inline void sk_mem_reclaim_partial(struct sock *sk) @@ -1008,7 +1008,7 @@ static inline void sk_mem_reclaim_partia if (!sk_has_account(sk)) return; if (sk->sk_forward_alloc > SK_MEM_QUANTUM) - __sk_mem_reclaim(sk); + __sk_mem_reclaim(sk, sk->sk_forward_alloc - 1); } static inline void sk_mem_charge(struct sock *sk, int size) --- a/net/core/sock.c +++ b/net/core/sock.c @@ -1750,14 +1750,15 @@ 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) { struct proto *prot = sk->sk_prot; - atomic_long_sub(sk->sk_forward_alloc >> SK_MEM_QUANTUM_SHIFT, - prot->memory_allocated); - sk->sk_forward_alloc &= SK_MEM_QUANTUM - 1; + amount >>= SK_MEM_QUANTUM_SHIFT; + atomic_long_sub(amount, prot->memory_allocated); + sk->sk_forward_alloc -= amount << SK_MEM_QUANTUM_SHIFT; if (prot->memory_pressure && *prot->memory_pressure && (atomic_long_read(prot->memory_allocated) < prot->sysctl_mem[0]))