From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yafang Shao Subject: [PATCH net-next] net, mm: avoid unnecessary memcg charge skmem Date: Sat, 30 Jun 2018 18:09:57 +0800 Message-ID: <1530353397-12948-1-git-send-email-laoar.shao@gmail.com> Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id; bh=0fBxVKiB6P7zFYgm5gVeN4Vt+kQXtyxhsPRM1/V59iQ=; b=R8OvG1zQXGpBJ5lB5gdhIdL00tjoUfwHWN4VbIOzdLtwXjlsZznNSZzXZID+Nl+Z+D XlWjYW1C7ZWfjpRSWccxMCt4jjp2Dcv7mOCDrmIgsaQ+3yiUOHQvg+8xwRL/eJ6OB+05 MK2oKTe29PqwBHdiFzW061Q4ym76zrTmfnLcgIpGL9q5XVEelKB/f6sunZ0IWW8l58HF xvxBo4Q+aApxYJ74lMZxmCDwB84eLq5HQPpJzEEhERiu4CUy93guwBvqhCmkxwLhhAsy rupLaJQPkS5ANiXMNQjjysnpSvPI4t1H5704VZsnp589b+MNMSd8qiZFMK9BGXmCkCUr eL+g== Sender: linux-kernel-owner@vger.kernel.org List-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: davem@davemloft.net Cc: hannes@cmpxchg.org, mhocko@kernel.org, cgroups@vger.kernel.org, linux-mm@kvack.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Yafang Shao In __sk_mem_raise_allocated(), if mem_cgroup_charge_skmem() return false, mem_cgroup_uncharge_skmem will be executed. The logic is as bellow, __sk_mem_raise_allocated ret = mem_cgroup_uncharge_skmem try_charge(memcg, gfp_mask|__GFP_NOFAIL, nr_pages); return false if (!ret) mem_cgroup_uncharge_skmem(sk->sk_memcg, amt); So it is unnecessary to charge if it is not forced. Signed-off-by: Yafang Shao --- include/linux/memcontrol.h | 3 ++- mm/memcontrol.c | 12 +++++++++--- net/core/sock.c | 5 +++-- net/ipv4/tcp_output.c | 2 +- 4 files changed, 15 insertions(+), 7 deletions(-) diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index 6c6fb11..56c07c9 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -1160,7 +1160,8 @@ static inline void mem_cgroup_wb_stats(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, + bool force); 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/mm/memcontrol.c b/mm/memcontrol.c index e6f0d5e..1122be2 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -5929,7 +5929,8 @@ void mem_cgroup_sk_free(struct sock *sk) * Charges @nr_pages to @memcg. Returns %true if the charge fit within * @memcg's configured limit, %false if the charge had to be forced. */ -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, + bool force) { gfp_t gfp_mask = GFP_KERNEL; @@ -5940,7 +5941,10 @@ 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); + + if (force) + page_counter_charge(&memcg->tcpmem, nr_pages); + memcg->tcpmem_pressure = 1; return false; } @@ -5954,7 +5958,9 @@ bool mem_cgroup_charge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages) if (try_charge(memcg, gfp_mask, nr_pages) == 0) return true; - try_charge(memcg, gfp_mask|__GFP_NOFAIL, nr_pages); + if (force) + try_charge(memcg, gfp_mask|__GFP_NOFAIL, nr_pages); + return false; } diff --git a/net/core/sock.c b/net/core/sock.c index bcc4182..148a840 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -2401,9 +2401,10 @@ 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 charged = false; if (mem_cgroup_sockets_enabled && sk->sk_memcg && - !mem_cgroup_charge_skmem(sk->sk_memcg, amt)) + !(charged = mem_cgroup_charge_skmem(sk->sk_memcg, amt, false))) goto suppress_allocation; /* Under limit. */ @@ -2465,7 +2466,7 @@ int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind) sk_memory_allocated_sub(sk, amt); - if (mem_cgroup_sockets_enabled && sk->sk_memcg) + if (mem_cgroup_sockets_enabled && sk->sk_memcg && charged) mem_cgroup_uncharge_skmem(sk->sk_memcg, amt); return 0; diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index f8f6129..9b741d4 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -3014,7 +3014,7 @@ 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, true); } /* Send a FIN. The caller locks the socket for us. -- 1.8.3.1