From patchwork Sun May 1 13:21:06 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Paul E. McKenney" X-Patchwork-Id: 1267 Return-Path: Delivered-To: unknown Received: from imap.gmail.com (74.125.159.109) by localhost6.localdomain6 with IMAP4-SSL; 08 Jun 2011 14:50:38 -0000 Delivered-To: patches@linaro.org Received: by 10.224.2.73 with SMTP id 9cs230870qai; Sun, 1 May 2011 06:22:24 -0700 (PDT) Received: by 10.236.146.230 with SMTP id r66mr8214516yhj.98.1304256144506; Sun, 01 May 2011 06:22:24 -0700 (PDT) Received: from e3.ny.us.ibm.com (e3.ny.us.ibm.com [32.97.182.143]) by mx.google.com with ESMTPS id i8si14546391anm.92.2011.05.01.06.22.23 (version=TLSv1/SSLv3 cipher=OTHER); Sun, 01 May 2011 06:22:23 -0700 (PDT) Received-SPF: pass (google.com: domain of paulmck@linux.vnet.ibm.com designates 32.97.182.143 as permitted sender) client-ip=32.97.182.143; Authentication-Results: mx.google.com; spf=pass (google.com: domain of paulmck@linux.vnet.ibm.com designates 32.97.182.143 as permitted sender) smtp.mail=paulmck@linux.vnet.ibm.com Received: from d01relay04.pok.ibm.com (d01relay04.pok.ibm.com [9.56.227.236]) by e3.ny.us.ibm.com (8.14.4/8.13.1) with ESMTP id p41D0uK8026744; Sun, 1 May 2011 09:00:56 -0400 Received: from d01av01.pok.ibm.com (d01av01.pok.ibm.com [9.56.224.215]) by d01relay04.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id p41DMMTM059928; Sun, 1 May 2011 09:22:22 -0400 Received: from d01av01.pok.ibm.com (loopback [127.0.0.1]) by d01av01.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id p41DMG7g019544; Sun, 1 May 2011 09:22:22 -0400 Received: from paulmck-ThinkPad-W500 (sig-9-65-224-93.mts.ibm.com [9.65.224.93]) by d01av01.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVin) with ESMTP id p41DMDpm019206; Sun, 1 May 2011 09:22:14 -0400 Received: by paulmck-ThinkPad-W500 (Postfix, from userid 1000) id 6C7FD13F808; Sun, 1 May 2011 06:22:08 -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, patches@linaro.org, "Paul E. McKenney" , "Paul E. McKenney" Subject: [PATCH tip/core/rcu 26/86] rcu: remove useless ->boosted_this_gp field Date: Sun, 1 May 2011 06:21:06 -0700 Message-Id: <1304256126-26015-26-git-send-email-paulmck@linux.vnet.ibm.com> X-Mailer: git-send-email 1.7.3.2 In-Reply-To: <20110501132142.GA25494@linux.vnet.ibm.com> References: <20110501132142.GA25494@linux.vnet.ibm.com> From: Paul E. McKenney The ->boosted_this_gp field is a holdover from an earlier design that was to carry out multiple boost operations in parallel. It is not required by the current design, which boosts one task at a time. Signed-off-by: Paul E. McKenney Signed-off-by: Paul E. McKenney --- kernel/rcutiny_plugin.h | 35 ++++------------------------------- 1 files changed, 4 insertions(+), 31 deletions(-) diff --git a/kernel/rcutiny_plugin.h b/kernel/rcutiny_plugin.h index 0bc9f73..2b8d529 100644 --- a/kernel/rcutiny_plugin.h +++ b/kernel/rcutiny_plugin.h @@ -100,7 +100,6 @@ struct rcu_preempt_ctrlblk { u8 completed; /* Last grace period completed. */ /* If all three are equal, RCU is idle. */ #ifdef CONFIG_RCU_BOOST - s8 boosted_this_gp; /* Has boosting already happened? */ unsigned long boost_time; /* When to start boosting (jiffies) */ #endif /* #ifdef CONFIG_RCU_BOOST */ #ifdef CONFIG_RCU_TRACE @@ -112,7 +111,6 @@ struct rcu_preempt_ctrlblk { unsigned long n_normal_balk_blkd_tasks; unsigned long n_normal_balk_gp_tasks; unsigned long n_normal_balk_boost_tasks; - unsigned long n_normal_balk_boosted; unsigned long n_normal_balk_notyet; unsigned long n_normal_balk_nos; unsigned long n_exp_balk_blkd_tasks; @@ -219,36 +217,19 @@ static void show_tiny_preempt_stats(struct seq_file *m) "N."[!rcu_preempt_ctrlblk.gp_tasks], "E."[!rcu_preempt_ctrlblk.exp_tasks]); #ifdef CONFIG_RCU_BOOST - seq_printf(m, " ttb=%c btg=", - "B."[!rcu_preempt_ctrlblk.boost_tasks]); - switch (rcu_preempt_ctrlblk.boosted_this_gp) { - case -1: - seq_puts(m, "exp"); - break; - case 0: - seq_puts(m, "no"); - break; - case 1: - seq_puts(m, "begun"); - break; - case 2: - seq_puts(m, "done"); - break; - default: - seq_printf(m, "?%d?", rcu_preempt_ctrlblk.boosted_this_gp); - } - seq_printf(m, " ntb=%lu neb=%lu nnb=%lu j=%04x bt=%04x\n", + seq_printf(m, "%sttb=%c ntb=%lu neb=%lu nnb=%lu j=%04x bt=%04x\n", + " ", + "B."[!rcu_preempt_ctrlblk.boost_tasks], rcu_preempt_ctrlblk.n_tasks_boosted, rcu_preempt_ctrlblk.n_exp_boosts, rcu_preempt_ctrlblk.n_normal_boosts, (int)(jiffies & 0xffff), (int)(rcu_preempt_ctrlblk.boost_time & 0xffff)); - seq_printf(m, " %s: nt=%lu gt=%lu bt=%lu b=%lu ny=%lu nos=%lu\n", + seq_printf(m, " %s: nt=%lu gt=%lu bt=%lu ny=%lu nos=%lu\n", "normal balk", rcu_preempt_ctrlblk.n_normal_balk_blkd_tasks, rcu_preempt_ctrlblk.n_normal_balk_gp_tasks, rcu_preempt_ctrlblk.n_normal_balk_boost_tasks, - rcu_preempt_ctrlblk.n_normal_balk_boosted, rcu_preempt_ctrlblk.n_normal_balk_notyet, rcu_preempt_ctrlblk.n_normal_balk_nos); seq_printf(m, " exp balk: bt=%lu nos=%lu\n", @@ -277,7 +258,6 @@ static int rcu_boost(void) if (rcu_preempt_ctrlblk.boost_tasks == NULL) return 0; /* Nothing to boost. */ raw_local_irq_save(flags); - rcu_preempt_ctrlblk.boosted_this_gp++; t = container_of(rcu_preempt_ctrlblk.boost_tasks, struct task_struct, rcu_node_entry); np = rcu_next_node_entry(t); @@ -287,7 +267,6 @@ static int rcu_boost(void) raw_local_irq_restore(flags); rt_mutex_lock(&mtx); RCU_TRACE(rcu_preempt_ctrlblk.n_tasks_boosted++); - rcu_preempt_ctrlblk.boosted_this_gp++; rt_mutex_unlock(&mtx); return rcu_preempt_ctrlblk.boost_tasks != NULL; } @@ -310,7 +289,6 @@ static int rcu_initiate_boost(void) } if (rcu_preempt_ctrlblk.gp_tasks != NULL && rcu_preempt_ctrlblk.boost_tasks == NULL && - rcu_preempt_ctrlblk.boosted_this_gp == 0 && ULONG_CMP_GE(jiffies, rcu_preempt_ctrlblk.boost_time)) { rcu_preempt_ctrlblk.boost_tasks = rcu_preempt_ctrlblk.gp_tasks; invoke_rcu_kthread(); @@ -331,7 +309,6 @@ static void rcu_initiate_expedited_boost(void) if (!list_empty(&rcu_preempt_ctrlblk.blkd_tasks)) { rcu_preempt_ctrlblk.boost_tasks = rcu_preempt_ctrlblk.blkd_tasks.next; - rcu_preempt_ctrlblk.boosted_this_gp = -1; invoke_rcu_kthread(); RCU_TRACE(rcu_preempt_ctrlblk.n_exp_boosts++); } else @@ -347,8 +324,6 @@ static void rcu_initiate_expedited_boost(void) static void rcu_preempt_boost_start_gp(void) { rcu_preempt_ctrlblk.boost_time = jiffies + RCU_BOOST_DELAY_JIFFIES; - if (rcu_preempt_ctrlblk.boosted_this_gp > 0) - rcu_preempt_ctrlblk.boosted_this_gp = 0; } #else /* #ifdef CONFIG_RCU_BOOST */ @@ -934,8 +909,6 @@ static void rcu_initiate_boost_trace(void) rcu_preempt_ctrlblk.n_normal_balk_gp_tasks++; else if (rcu_preempt_ctrlblk.boost_tasks != NULL) rcu_preempt_ctrlblk.n_normal_balk_boost_tasks++; - else if (rcu_preempt_ctrlblk.boosted_this_gp != 0) - rcu_preempt_ctrlblk.n_normal_balk_boosted++; else if (!ULONG_CMP_GE(jiffies, rcu_preempt_ctrlblk.boost_time)) rcu_preempt_ctrlblk.n_normal_balk_notyet++; else