From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6CD2A12C47A; Tue, 30 Apr 2024 10:48:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714474134; cv=none; b=jRJhYAD5usc8dJG/mjz/5RME3S84fmQAnEYyWGZ4lDCpBoL6NzCyPCJjwYi3UDycwLCzwubzJXB66ryw3M7scutPc5MqCq3gNvApwNhNRows6FWRfBl0sJzyHa+HQsHZhFR2JOl6Yrs7Xq22TC6Lws3Fz9+lGQoPdYo6QgqpOUE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714474134; c=relaxed/simple; bh=i6vNUYTL9E2k8sYQdsHuGN591249z3GfLaN/MwFnTNA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=rqQa7GUcZJOw22LwWKa33nP5PpfP1v9PP2gtWor+iZeGk/lEtXLIoynPDEl+i1G89yXL40MQochhuYwyPc65H2RHFtduW/bdSHDTm2hYPBQQFJnOtX7jSDZUfIbnQlHOeUWNtBc4+uusrdPE2zBucEYPb70LthGlRsiyhqeLLiQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=El/K+Bbd; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="El/K+Bbd" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E0AACC2BBFC; Tue, 30 Apr 2024 10:48:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1714474134; bh=i6vNUYTL9E2k8sYQdsHuGN591249z3GfLaN/MwFnTNA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=El/K+Bbd9D2+SPyRvXwizeFkEyJQTmvr2/TSNOYZMVaXfPpLpAyrSz3xlKaTnh/12 weyXHhwsDqMHkLHAaCR2mjJfIWeIL+KIGWNmSW/Gx4i/1PX4goVNWCVvItrACRERk3 aUIYDv7pR9kxkR2Nn1yz01vZAHKFPnWDwTxYvkSo= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Adam Li , "Christoph Lameter (Ampere)" , "David S. Miller" , Sasha Levin Subject: [PATCH 6.8 067/228] net: make SK_MEMORY_PCPU_RESERV tunable Date: Tue, 30 Apr 2024 12:37:25 +0200 Message-ID: <20240430103105.742204773@linuxfoundation.org> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240430103103.806426847@linuxfoundation.org> References: <20240430103103.806426847@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.8-stable review patch. If anyone has any objections, please let me know. ------------------ From: Adam Li [ Upstream commit 12a686c2e761f1f1f6e6e2117a9ab9c6de2ac8a7 ] This patch adds /proc/sys/net/core/mem_pcpu_rsv sysctl file, to make SK_MEMORY_PCPU_RESERV tunable. Commit 3cd3399dd7a8 ("net: implement per-cpu reserves for memory_allocated") introduced per-cpu forward alloc cache: "Implement a per-cpu cache of +1/-1 MB, to reduce number of changes to sk->sk_prot->memory_allocated, which would otherwise be cause of false sharing." sk_prot->memory_allocated points to global atomic variable: atomic_long_t tcp_memory_allocated ____cacheline_aligned_in_smp; If increasing the per-cpu cache size from 1MB to e.g. 16MB, changes to sk->sk_prot->memory_allocated can be further reduced. Performance may be improved on system with many cores. Signed-off-by: Adam Li Reviewed-by: Christoph Lameter (Ampere) Signed-off-by: David S. Miller Stable-dep-of: 3584718cf2ec ("net: fix sk_memory_allocated_{add|sub} vs softirqs") Signed-off-by: Sasha Levin --- Documentation/admin-guide/sysctl/net.rst | 5 +++++ include/net/sock.h | 5 +++-- net/core/sock.c | 1 + net/core/sysctl_net_core.c | 9 +++++++++ 4 files changed, 18 insertions(+), 2 deletions(-) diff --git a/Documentation/admin-guide/sysctl/net.rst b/Documentation/admin-guide/sysctl/net.rst index 3960916519557..7250c0542828b 100644 --- a/Documentation/admin-guide/sysctl/net.rst +++ b/Documentation/admin-guide/sysctl/net.rst @@ -206,6 +206,11 @@ Will increase power usage. Default: 0 (off) +mem_pcpu_rsv +------------ + +Per-cpu reserved forward alloc cache size in page units. Default 1MB per CPU. + rmem_default ------------ diff --git a/include/net/sock.h b/include/net/sock.h index 4afb4376c97e8..6855c50a70f1b 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -1429,6 +1429,7 @@ sk_memory_allocated(const struct sock *sk) /* 1 MB per cpu, in page units */ #define SK_MEMORY_PCPU_RESERVE (1 << (20 - PAGE_SHIFT)) +extern int sysctl_mem_pcpu_rsv; static inline void sk_memory_allocated_add(struct sock *sk, int amt) @@ -1437,7 +1438,7 @@ sk_memory_allocated_add(struct sock *sk, int amt) preempt_disable(); local_reserve = __this_cpu_add_return(*sk->sk_prot->per_cpu_fw_alloc, amt); - if (local_reserve >= SK_MEMORY_PCPU_RESERVE) { + if (local_reserve >= READ_ONCE(sysctl_mem_pcpu_rsv)) { __this_cpu_sub(*sk->sk_prot->per_cpu_fw_alloc, local_reserve); atomic_long_add(local_reserve, sk->sk_prot->memory_allocated); } @@ -1451,7 +1452,7 @@ sk_memory_allocated_sub(struct sock *sk, int amt) preempt_disable(); local_reserve = __this_cpu_sub_return(*sk->sk_prot->per_cpu_fw_alloc, amt); - if (local_reserve <= -SK_MEMORY_PCPU_RESERVE) { + if (local_reserve <= -READ_ONCE(sysctl_mem_pcpu_rsv)) { __this_cpu_sub(*sk->sk_prot->per_cpu_fw_alloc, local_reserve); atomic_long_add(local_reserve, sk->sk_prot->memory_allocated); } diff --git a/net/core/sock.c b/net/core/sock.c index 5e78798456fd8..9cf404e8038a4 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -283,6 +283,7 @@ __u32 sysctl_rmem_max __read_mostly = SK_RMEM_MAX; EXPORT_SYMBOL(sysctl_rmem_max); __u32 sysctl_wmem_default __read_mostly = SK_WMEM_MAX; __u32 sysctl_rmem_default __read_mostly = SK_RMEM_MAX; +int sysctl_mem_pcpu_rsv __read_mostly = SK_MEMORY_PCPU_RESERVE; int sysctl_tstamp_allow_data __read_mostly = 1; diff --git a/net/core/sysctl_net_core.c b/net/core/sysctl_net_core.c index 0f0cb1465e089..986f15e5d6c41 100644 --- a/net/core/sysctl_net_core.c +++ b/net/core/sysctl_net_core.c @@ -30,6 +30,7 @@ static int int_3600 = 3600; static int min_sndbuf = SOCK_MIN_SNDBUF; static int min_rcvbuf = SOCK_MIN_RCVBUF; static int max_skb_frags = MAX_SKB_FRAGS; +static int min_mem_pcpu_rsv = SK_MEMORY_PCPU_RESERVE; static int net_msg_warn; /* Unused, but still a sysctl */ @@ -407,6 +408,14 @@ static struct ctl_table net_core_table[] = { .proc_handler = proc_dointvec_minmax, .extra1 = &min_rcvbuf, }, + { + .procname = "mem_pcpu_rsv", + .data = &sysctl_mem_pcpu_rsv, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = &min_mem_pcpu_rsv, + }, { .procname = "dev_weight", .data = &weight_p, -- 2.43.0