From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755351AbcIFCax (ORCPT ); Mon, 5 Sep 2016 22:30:53 -0400 Received: from mail-it0-f66.google.com ([209.85.214.66]:35698 "EHLO mail-it0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755132AbcIFCal (ORCPT ); Mon, 5 Sep 2016 22:30:41 -0400 From: Jia He To: netdev@vger.kernel.org Cc: linux-sctp@vger.kernel.org, linux-kernel@vger.kernel.org, davem@davemloft.net, Alexey Kuznetsov , James Morris , Hideaki YOSHIFUJI , Patrick McHardy , Vlad Yasevich , Neil Horman , Steffen Klassert , Herbert Xu , Jia He Subject: [RFC PATCH v2 4/6] proc: Reduce cache miss in xfrm_statistics_seq_show Date: Tue, 6 Sep 2016 10:30:07 +0800 Message-Id: <1473129009-20478-5-git-send-email-hejianet@gmail.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1473129009-20478-1-git-send-email-hejianet@gmail.com> References: <1473129009-20478-1-git-send-email-hejianet@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch exchanges the two loop for collecting the percpu statistics data. This can reduce cache misses by going through all the items of each cpu sequentially. Signed-off-by: Jia He --- net/xfrm/xfrm_proc.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) diff --git a/net/xfrm/xfrm_proc.c b/net/xfrm/xfrm_proc.c index 9c4fbd8..c9df546 100644 --- a/net/xfrm/xfrm_proc.c +++ b/net/xfrm/xfrm_proc.c @@ -51,11 +51,20 @@ static const struct snmp_mib xfrm_mib_list[] = { static int xfrm_statistics_seq_show(struct seq_file *seq, void *v) { struct net *net = seq->private; - int i; - for (i = 0; xfrm_mib_list[i].name; i++) + int i, c; + unsigned long buff[LINUX_MIB_XFRMMAX]; + + memset(buff, 0, sizeof(unsigned long) * LINUX_MIB_XFRMMAX); + + for_each_possible_cpu(c) + for (i = 0; xfrm_mib_list[i].name != NULL; i++) + buff[i] += snmp_get_cpu_field( + net->mib.xfrm_statistics, + c, xfrm_mib_list[i].entry); + for (i = 0; xfrm_mib_list[i].name != NULL; i++) seq_printf(seq, "%-24s\t%lu\n", xfrm_mib_list[i].name, - snmp_fold_field(net->mib.xfrm_statistics, - xfrm_mib_list[i].entry)); + buff[i]); + return 0; } -- 1.8.3.1