From patchwork Thu Sep 20 18:48:08 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Paul E. McKenney" X-Patchwork-Id: 11599 Return-Path: X-Original-To: patchwork@peony.canonical.com Delivered-To: patchwork@peony.canonical.com Received: from fiordland.canonical.com (fiordland.canonical.com [91.189.94.145]) by peony.canonical.com (Postfix) with ESMTP id 2B93623E54 for ; Thu, 20 Sep 2012 18:49:00 +0000 (UTC) Received: from mail-ie0-f180.google.com (mail-ie0-f180.google.com [209.85.223.180]) by fiordland.canonical.com (Postfix) with ESMTP id 5AF07A1823C for ; Thu, 20 Sep 2012 18:48:59 +0000 (UTC) Received: by ieje10 with SMTP id e10so3420758iej.11 for ; Thu, 20 Sep 2012 11:48:58 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=x-forwarded-to:x-forwarded-for:delivered-to:received-spf:from:to:cc :subject:date:message-id:x-mailer:in-reply-to:references :x-content-scanned:x-cbid:x-gm-message-state; bh=BPuFJmTdt3zIaFqTuXA66IEY2lRYodIWOfDmOWE1m+Q=; b=X/strhJwiCZcbAEDnE9rXGcE93zSIBVdudysp/pVNIXy2NKBmlWLq1lUJFrudo1KN6 eEsASu0wlQCQqtfEkvnc8NTUJdAdq7u0SX1QfYLAwKYyY0ySeb7g+xQTNxNlzBALVK92 aikdUw22yYf3BuM6Q0GSaOy/EU9XGk+YuqkhJ8p9983ONJb3ai/k3Cn5G8qPoe3IFI9Y O8K1xaPzzqfySELJYWaQ3scTHZK+v/15/A5YGbaKcUWKoXfLTu+BONv7R+Vb7h9Pnr28 fezutnR4plXDVbs/KeZ/fJdOiGNQekEVQlFJS2jG/WdoMibvnFNt3/kCmnteGla2dHLe D32g== Received: by 10.50.184.129 with SMTP id eu1mr2658724igc.0.1348166938751; Thu, 20 Sep 2012 11:48:58 -0700 (PDT) X-Forwarded-To: linaro-patchwork@canonical.com X-Forwarded-For: patch@linaro.org linaro-patchwork@canonical.com Delivered-To: patches@linaro.org Received: by 10.50.184.232 with SMTP id ex8csp92225igc; Thu, 20 Sep 2012 11:48:57 -0700 (PDT) Received: by 10.50.171.100 with SMTP id at4mr3256961igc.73.1348166937457; Thu, 20 Sep 2012 11:48:57 -0700 (PDT) Received: from e35.co.us.ibm.com (e35.co.us.ibm.com. [32.97.110.153]) by mx.google.com with ESMTPS id t6si25455697igb.3.2012.09.20.11.48.57 (version=TLSv1/SSLv3 cipher=OTHER); Thu, 20 Sep 2012 11:48:57 -0700 (PDT) Received-SPF: pass (google.com: domain of paulmck@linux.vnet.ibm.com designates 32.97.110.153 as permitted sender) client-ip=32.97.110.153; Authentication-Results: mx.google.com; spf=pass (google.com: domain of paulmck@linux.vnet.ibm.com designates 32.97.110.153 as permitted sender) smtp.mail=paulmck@linux.vnet.ibm.com Received: from /spool/local by e35.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 20 Sep 2012 12:48:55 -0600 Received: from d03dlp02.boulder.ibm.com (9.17.202.178) by e35.co.us.ibm.com (192.168.1.135) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; Thu, 20 Sep 2012 12:48:45 -0600 Received: from d03relay04.boulder.ibm.com (d03relay04.boulder.ibm.com [9.17.195.106]) by d03dlp02.boulder.ibm.com (Postfix) with ESMTP id 3A21B3E4003D for ; Thu, 20 Sep 2012 12:48:39 -0600 (MDT) Received: from d03av01.boulder.ibm.com (d03av01.boulder.ibm.com [9.17.195.167]) by d03relay04.boulder.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id q8KImaFa132054 for ; Thu, 20 Sep 2012 12:48:36 -0600 Received: from d03av01.boulder.ibm.com (loopback [127.0.0.1]) by d03av01.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id q8KImPg3020961 for ; Thu, 20 Sep 2012 12:48:36 -0600 Received: from paulmck-ThinkPad-W500 ([9.47.24.72]) by d03av01.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVin) with ESMTP id q8KImNCq020799; Thu, 20 Sep 2012 12:48:24 -0600 Received: by paulmck-ThinkPad-W500 (Postfix, from userid 1000) id 4B38BEC52E; Thu, 20 Sep 2012 11:48:22 -0700 (PDT) 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, eric.dumazet@gmail.com, darren@dvhart.com, fweisbec@gmail.com, sbw@mit.edu, patches@linaro.org, "Paul E. McKenney" Subject: [PATCH tip/core/rcu 12/23] rcu: Adjust debugfs tracing for kthread-based quiescent-state forcing Date: Thu, 20 Sep 2012 11:48:08 -0700 Message-Id: <1348166900-18716-12-git-send-email-paulmck@linux.vnet.ibm.com> X-Mailer: git-send-email 1.7.8 In-Reply-To: <1348166900-18716-1-git-send-email-paulmck@linux.vnet.ibm.com> References: <20120920184751.GA18657@linux.vnet.ibm.com> <1348166900-18716-1-git-send-email-paulmck@linux.vnet.ibm.com> X-Content-Scanned: Fidelis XPS MAILER x-cbid: 12092018-6148-0000-0000-000009DB202B X-Gm-Message-State: ALoCoQkEwg3cshIIAgl8qbQThbjdbjd2leTlw6YnPX/yrZLo/DjpvMVqG+ESaCp5mWb9vgJd2O/O From: "Paul E. McKenney" Moving quiescent-state forcing into a kthread dispenses with the need for the ->n_rp_need_fqs field, so this commit removes it. Signed-off-by: Paul E. McKenney Reviewed-by: Josh Triplett --- Documentation/RCU/trace.txt | 43 ++++++++++++++++--------------------------- kernel/rcutree.h | 1 - kernel/rcutree_trace.c | 3 +-- 3 files changed, 17 insertions(+), 30 deletions(-) diff --git a/Documentation/RCU/trace.txt b/Documentation/RCU/trace.txt index f6f15ce..672d190 100644 --- a/Documentation/RCU/trace.txt +++ b/Documentation/RCU/trace.txt @@ -333,23 +333,23 @@ o Each element of the form "1/1 0:127 ^0" represents one struct The output of "cat rcu/rcu_pending" looks as follows: rcu_sched: - 0 np=255892 qsp=53936 rpq=85 cbr=0 cng=14417 gpc=10033 gps=24320 nf=6445 nn=146741 - 1 np=261224 qsp=54638 rpq=33 cbr=0 cng=25723 gpc=16310 gps=2849 nf=5912 nn=155792 - 2 np=237496 qsp=49664 rpq=23 cbr=0 cng=2762 gpc=45478 gps=1762 nf=1201 nn=136629 - 3 np=236249 qsp=48766 rpq=98 cbr=0 cng=286 gpc=48049 gps=1218 nf=207 nn=137723 - 4 np=221310 qsp=46850 rpq=7 cbr=0 cng=26 gpc=43161 gps=4634 nf=3529 nn=123110 - 5 np=237332 qsp=48449 rpq=9 cbr=0 cng=54 gpc=47920 gps=3252 nf=201 nn=137456 - 6 np=219995 qsp=46718 rpq=12 cbr=0 cng=50 gpc=42098 gps=6093 nf=4202 nn=120834 - 7 np=249893 qsp=49390 rpq=42 cbr=0 cng=72 gpc=38400 gps=17102 nf=41 nn=144888 + 0 np=255892 qsp=53936 rpq=85 cbr=0 cng=14417 gpc=10033 gps=24320 nn=146741 + 1 np=261224 qsp=54638 rpq=33 cbr=0 cng=25723 gpc=16310 gps=2849 nn=155792 + 2 np=237496 qsp=49664 rpq=23 cbr=0 cng=2762 gpc=45478 gps=1762 nn=136629 + 3 np=236249 qsp=48766 rpq=98 cbr=0 cng=286 gpc=48049 gps=1218 nn=137723 + 4 np=221310 qsp=46850 rpq=7 cbr=0 cng=26 gpc=43161 gps=4634 nn=123110 + 5 np=237332 qsp=48449 rpq=9 cbr=0 cng=54 gpc=47920 gps=3252 nn=137456 + 6 np=219995 qsp=46718 rpq=12 cbr=0 cng=50 gpc=42098 gps=6093 nn=120834 + 7 np=249893 qsp=49390 rpq=42 cbr=0 cng=72 gpc=38400 gps=17102 nn=144888 rcu_bh: - 0 np=146741 qsp=1419 rpq=6 cbr=0 cng=6 gpc=0 gps=0 nf=2 nn=145314 - 1 np=155792 qsp=12597 rpq=3 cbr=0 cng=0 gpc=4 gps=8 nf=3 nn=143180 - 2 np=136629 qsp=18680 rpq=1 cbr=0 cng=0 gpc=7 gps=6 nf=0 nn=117936 - 3 np=137723 qsp=2843 rpq=0 cbr=0 cng=0 gpc=10 gps=7 nf=0 nn=134863 - 4 np=123110 qsp=12433 rpq=0 cbr=0 cng=0 gpc=4 gps=2 nf=0 nn=110671 - 5 np=137456 qsp=4210 rpq=1 cbr=0 cng=0 gpc=6 gps=5 nf=0 nn=133235 - 6 np=120834 qsp=9902 rpq=2 cbr=0 cng=0 gpc=6 gps=3 nf=2 nn=110921 - 7 np=144888 qsp=26336 rpq=0 cbr=0 cng=0 gpc=8 gps=2 nf=0 nn=118542 + 0 np=146741 qsp=1419 rpq=6 cbr=0 cng=6 gpc=0 gps=0 nn=145314 + 1 np=155792 qsp=12597 rpq=3 cbr=0 cng=0 gpc=4 gps=8 nn=143180 + 2 np=136629 qsp=18680 rpq=1 cbr=0 cng=0 gpc=7 gps=6 nn=117936 + 3 np=137723 qsp=2843 rpq=0 cbr=0 cng=0 gpc=10 gps=7 nn=134863 + 4 np=123110 qsp=12433 rpq=0 cbr=0 cng=0 gpc=4 gps=2 nn=110671 + 5 np=137456 qsp=4210 rpq=1 cbr=0 cng=0 gpc=6 gps=5 nn=133235 + 6 np=120834 qsp=9902 rpq=2 cbr=0 cng=0 gpc=6 gps=3 nn=110921 + 7 np=144888 qsp=26336 rpq=0 cbr=0 cng=0 gpc=8 gps=2 nn=118542 As always, this is once again split into "rcu_sched" and "rcu_bh" portions, with CONFIG_TREE_PREEMPT_RCU kernels having an additional @@ -377,17 +377,6 @@ o "gpc" is the number of times that an old grace period had o "gps" is the number of times that a new grace period had started, but this CPU was not yet aware of it. -o "nf" is the number of times that this CPU suspected that the - current grace period had run for too long, and thus needed to - be forced. - - Please note that "forcing" consists of sending resched IPIs - to holdout CPUs. If that CPU really still is in an old RCU - read-side critical section, then we really do have to wait for it. - The assumption behing "forcing" is that the CPU is not still in - an old RCU read-side critical section, but has not yet responded - for some other reason. - o "nn" is the number of times that this CPU needed nothing. Alert readers will note that the rcu "nn" number for a given CPU very closely matches the rcu_bh "np" number for that same CPU. This diff --git a/kernel/rcutree.h b/kernel/rcutree.h index 2d04106..7fb93ce 100644 --- a/kernel/rcutree.h +++ b/kernel/rcutree.h @@ -312,7 +312,6 @@ struct rcu_data { unsigned long n_rp_cpu_needs_gp; unsigned long n_rp_gp_completed; unsigned long n_rp_gp_started; - unsigned long n_rp_need_fqs; unsigned long n_rp_need_nothing; /* 6) _rcu_barrier() and OOM callbacks. */ diff --git a/kernel/rcutree_trace.c b/kernel/rcutree_trace.c index abffb48..f54f0ce 100644 --- a/kernel/rcutree_trace.c +++ b/kernel/rcutree_trace.c @@ -386,10 +386,9 @@ static void print_one_rcu_pending(struct seq_file *m, struct rcu_data *rdp) rdp->n_rp_report_qs, rdp->n_rp_cb_ready, rdp->n_rp_cpu_needs_gp); - seq_printf(m, "gpc=%ld gps=%ld nf=%ld nn=%ld\n", + seq_printf(m, "gpc=%ld gps=%ld nn=%ld\n", rdp->n_rp_gp_completed, rdp->n_rp_gp_started, - rdp->n_rp_need_fqs, rdp->n_rp_need_nothing); }