Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934936Ab2JaDqn (ORCPT ); Tue, 30 Oct 2012 23:46:43 -0400 Received: from e36.co.us.ibm.com ([32.97.110.154]:53942 "EHLO e36.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932436Ab2JaDql (ORCPT ); Tue, 30 Oct 2012 23:46:41 -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, joe.korty@ccur.com, "Paul E. McKenney" , "Paul E. McKenney" Subject: [PATCH tip/core/rcu 2/2] rcu: Separate accounting of callbacks from callback-free CPUs Date: Tue, 30 Oct 2012 20:46:31 -0700 Message-Id: <1351655191-2648-2-git-send-email-paulmck@linux.vnet.ibm.com> X-Mailer: git-send-email 1.7.8 In-Reply-To: <1351655191-2648-1-git-send-email-paulmck@linux.vnet.ibm.com> References: <20121031034552.GA1999@linux.vnet.ibm.com> <1351655191-2648-1-git-send-email-paulmck@linux.vnet.ibm.com> X-Content-Scanned: Fidelis XPS MAILER x-cbid: 12103103-7606-0000-0000-000004F21D2B Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2809 Lines: 68 From: "Paul E. McKenney" Currently, callback invocations from callback-free CPUs are accounted to the CPU that registered the callback, but using the same field that is used for normal callbacks. This makes it impossible to determine from debugfs output whether callbacks are in fact being diverted. This commit therefore adds a separate ->n_nocbs_invoked field in the rcu_data structure in which diverted callback invocations are counted. RCU's debugfs tracing still displays normal callback invocations using ci=, but displayed diverted callbacks with nci=. Signed-off-by: Paul E. McKenney Signed-off-by: Paul E. McKenney --- kernel/rcutree.h | 1 + kernel/rcutree_plugin.h | 2 +- kernel/rcutree_trace.c | 5 +++-- 3 files changed, 5 insertions(+), 3 deletions(-) diff --git a/kernel/rcutree.h b/kernel/rcutree.h index 79954bb..db9bec8 100644 --- a/kernel/rcutree.h +++ b/kernel/rcutree.h @@ -287,6 +287,7 @@ struct rcu_data { long qlen_last_fqs_check; /* qlen at last check for QS forcing */ unsigned long n_cbs_invoked; /* count of RCU cbs invoked. */ + unsigned long n_nocbs_invoked; /* count of no-CBs RCU cbs invoked. */ unsigned long n_cbs_orphaned; /* RCU cbs orphaned by dying CPU */ unsigned long n_cbs_adopted; /* RCU cbs adopted from dying CPU */ unsigned long n_force_qs_snap; diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h index ea960c4..31d3a95 100644 --- a/kernel/rcutree_plugin.h +++ b/kernel/rcutree_plugin.h @@ -2406,7 +2406,7 @@ static int rcu_nocb_kthread(void *arg) trace_rcu_batch_end(rdp->rsp->name, c, !!list, 0, 0, 1); ACCESS_ONCE(rdp->nocb_p_count) -= c; ACCESS_ONCE(rdp->nocb_p_count_lazy) -= cl; - rdp->n_cbs_invoked += c; + rdp->n_nocbs_invoked += c; } return 0; } diff --git a/kernel/rcutree_trace.c b/kernel/rcutree_trace.c index 5e9ca3e..167375d 100644 --- a/kernel/rcutree_trace.c +++ b/kernel/rcutree_trace.c @@ -146,8 +146,9 @@ static void print_one_rcu_data(struct seq_file *m, struct rcu_data *rdp) per_cpu(rcu_cpu_kthread_loops, rdp->cpu) & 0xffff); #endif /* #ifdef CONFIG_RCU_BOOST */ seq_printf(m, " b=%ld", rdp->blimit); - seq_printf(m, " ci=%lu co=%lu ca=%lu\n", - rdp->n_cbs_invoked, rdp->n_cbs_orphaned, rdp->n_cbs_adopted); + seq_printf(m, " ci=%lu nci=%lu co=%lu ca=%lu\n", + rdp->n_cbs_invoked, rdp->n_nocbs_invoked, + rdp->n_cbs_orphaned, rdp->n_cbs_adopted); } static int show_rcudata(struct seq_file *m, void *v) -- 1.7.8 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/