Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932214AbbLEBE2 (ORCPT ); Fri, 4 Dec 2015 20:04:28 -0500 Received: from relay4-d.mail.gandi.net ([217.70.183.196]:40859 "EHLO relay4-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932087AbbLEBE0 (ORCPT ); Fri, 4 Dec 2015 20:04:26 -0500 Date: Fri, 4 Dec 2015 17:04:21 -0800 From: Josh Triplett To: "Paul E. McKenney" Cc: linux-kernel@vger.kernel.org, mingo@kernel.org, jiangshanlai@gmail.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@efficios.com, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, dhowells@redhat.com, edumazet@google.com, dvhart@linux.intel.com, fweisbec@gmail.com, oleg@redhat.com, bobby.prani@gmail.com Subject: Re: [PATCH tip/core/rcu 6/8] rcutorture: Print symbolic name for ->gp_state Message-ID: <20151205010421.GC27128@cloud> References: <20151205002331.GA27249@linux.vnet.ibm.com> <1449275032-28206-6-git-send-email-paulmck@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1449275032-28206-6-git-send-email-paulmck@linux.vnet.ibm.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3057 Lines: 84 On Fri, Dec 04, 2015 at 04:23:50PM -0800, Paul E. McKenney wrote: > Currently, ->gp_state is printed as an integer, which slows debugging. > This commit therefore prints a symbolic name in addition to the integer. > > Signed-off-by: Paul E. McKenney > [ Updated to fix relational operator called out by Dan Carpenter. ] > --- > kernel/rcu/tree.c | 15 +++++++++++++-- > kernel/rcu/tree.h | 9 +++++++++ > 2 files changed, 22 insertions(+), 2 deletions(-) > > diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c > index 7b78c88e19a3..491c99a73996 100644 > --- a/kernel/rcu/tree.c > +++ b/kernel/rcu/tree.c > @@ -1187,6 +1187,16 @@ static void record_gp_stall_check_time(struct rcu_state *rsp) > } > > /* > + * Convert a ->gp_state value to a character string. > + */ > +static char *gp_state_getname(short gs) Same comment about "const char *" > +{ > + if (gs < 0 || gs >= ARRAY_SIZE(gp_state_names)) > + return "???"; > + return gp_state_names[gs]; > +} > + > +/* > * Complain about starvation of grace-period kthread. > */ > static void rcu_check_gp_kthread_starvation(struct rcu_state *rsp) > @@ -1197,10 +1207,11 @@ static void rcu_check_gp_kthread_starvation(struct rcu_state *rsp) > j = jiffies; > gpa = READ_ONCE(rsp->gp_activity); > if (j - gpa > 2 * HZ) { > - pr_err("%s kthread starved for %ld jiffies! g%lu c%lu f%#x s%d ->state=%#lx\n", > + pr_err("%s kthread starved for %ld jiffies! g%lu c%lu f%#x %s(%d) ->state=%#lx\n", > rsp->name, j - gpa, > rsp->gpnum, rsp->completed, > - rsp->gp_flags, rsp->gp_state, > + rsp->gp_flags, > + gp_state_getname(rsp->gp_state), rsp->gp_state, > rsp->gp_kthread ? rsp->gp_kthread->state : ~0); > if (rsp->gp_kthread) > sched_show_task(rsp->gp_kthread); > diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h > index f32bebb6bc90..f0304988e3f8 100644 > --- a/kernel/rcu/tree.h > +++ b/kernel/rcu/tree.h > @@ -544,6 +544,15 @@ struct rcu_state { > #define RCU_GP_DOING_FQS 4 /* Wait done for force-quiescent-state time. */ > #define RCU_GP_CLEANUP 5 /* Grace-period cleanup started. */ > #define RCU_GP_CLEANED 6 /* Grace-period cleanup complete. */ > +static char * const gp_state_names[] = { Same comment about "const char * const", but also, should this really go in a header file? Do any circumstances exist where this header could get included in more than one source file in a given build? If so, multiple copies of this array could potentially end up in the binary, if the compiler fails to merge them. > + "RCU_GP_IDLE", > + "RCU_GP_WAIT_GPS", > + "RCU_GP_DONE_GPS", > + "RCU_GP_WAIT_FQS", > + "RCU_GP_DOING_FQS", > + "RCU_GP_CLEANUP", > + "RCU_GP_CLEANED", > +}; > > extern struct list_head rcu_struct_flavors; > > -- > 2.5.2 > -- 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/