From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965132Ab2J3RdE (ORCPT ); Tue, 30 Oct 2012 13:33:04 -0400 Received: from e9.ny.us.ibm.com ([32.97.182.139]:60099 "EHLO e9.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964929Ab2J3Rc7 (ORCPT ); Tue, 30 Oct 2012 13:32:59 -0400 From: "Paul E. McKenney" To: linux-kernel@vger.kernel.org Cc: mingo@elte.hu, laijs@cn.fujitsu.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@polymtl.ca, josh@joshtriplett.org, niv@us.ibm.com, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, Valdis.Kletnieks@vt.edu, dhowells@redhat.com, edumazet@google.com, darren@dvhart.com, fweisbec@gmail.com, sbw@mit.edu, patches@linaro.org, Michael Wang , "Paul E. McKenney" Subject: [PATCH tip/core/rcu 05/14] rcu: Optimize the 'rcu_pending' for RCU trace Date: Tue, 30 Oct 2012 10:05:04 -0700 Message-Id: <1351616713-26930-5-git-send-email-paulmck@linux.vnet.ibm.com> X-Mailer: git-send-email 1.7.8 In-Reply-To: <1351616713-26930-1-git-send-email-paulmck@linux.vnet.ibm.com> References: <20121030170454.GA25712@linux.vnet.ibm.com> <1351616713-26930-1-git-send-email-paulmck@linux.vnet.ibm.com> X-Content-Scanned: Fidelis XPS MAILER x-cbid: 12103017-7182-0000-0000-000002FDE6C0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Michael Wang This patch implements the new 'rcu_pending' interface under each rsp directory, by using the 'CPU units sequence reading', thus avoiding loss of tracing data. Signed-off-by: Michael Wang Signed-off-by: Paul E. McKenney --- kernel/rcutree_trace.c | 41 +++++++++++++++++++++++++++++++++++------ 1 files changed, 35 insertions(+), 6 deletions(-) diff --git a/kernel/rcutree_trace.c b/kernel/rcutree_trace.c index e387a64..8b24867 100644 --- a/kernel/rcutree_trace.c +++ b/kernel/rcutree_trace.c @@ -467,6 +467,8 @@ static const struct file_operations rcugp_fops = { static void print_one_rcu_pending(struct seq_file *m, struct rcu_data *rdp) { + if (!rdp->beenonline) + return; seq_printf(m, "%3d%cnp=%ld ", rdp->cpu, cpu_is_offline(rdp->cpu) ? '!' : ' ', @@ -485,16 +487,12 @@ static void print_one_rcu_pending(struct seq_file *m, struct rcu_data *rdp) static int show_rcu_pending(struct seq_file *m, void *unused) { int cpu; - struct rcu_data *rdp; struct rcu_state *rsp; for_each_rcu_flavor(rsp) { seq_printf(m, "%s:\n", rsp->name); - for_each_possible_cpu(cpu) { - rdp = per_cpu_ptr(rsp->rda, cpu); - if (rdp->beenonline) - print_one_rcu_pending(m, rdp); - } + for_each_possible_cpu(cpu) + print_one_rcu_pending(m, per_cpu_ptr(rsp->rda, cpu)); } return 0; } @@ -512,6 +510,32 @@ static const struct file_operations rcu_pending_fops = { .release = single_release, }; +static int new_show_rcu_pending(struct seq_file *m, void *v) +{ + print_one_rcu_pending(m, (struct rcu_data *)v); + return 0; +} + +static const struct seq_operations new_rcu_pending_op = { + .start = r_start, + .next = r_next, + .stop = r_stop, + .show = new_show_rcu_pending, +}; + +static int new_rcu_pending_open(struct inode *inode, struct file *file) +{ + return r_open(inode, file, &new_rcu_pending_op); +} + +static const struct file_operations new_rcu_pending_fops = { + .owner = THIS_MODULE, + .open = new_rcu_pending_open, + .read = seq_read, + .llseek = no_llseek, + .release = seq_release, +}; + static int show_rcutorture(struct seq_file *m, void *unused) { seq_printf(m, "rcutorture test sequence: %lu %s\n", @@ -561,6 +585,11 @@ static int __init rcutree_trace_init(void) rspdir, rsp, &new_rcudata_csv_fops); if (!retval) goto free_out; + + retval = debugfs_create_file("rcu_pending", 0444, + rspdir, rsp, &new_rcu_pending_fops); + if (!retval) + goto free_out; } retval = debugfs_create_file("rcubarrier", 0444, rcudir, -- 1.7.8