From aacb5d91ab1bfbb0e8123da59a2e333d52ba7f60 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Sun, 28 Oct 2018 10:32:51 -0700 Subject: srcu: Use "ssp" instead of "sp" for srcu_struct pointer In RCU, the distinction between "rsp", "rnp", and "rdp" has served well for a great many years, but in SRCU, "sp" vs. "sdp" has proven confusing. This commit therefore renames SRCU's "sp" pointers to "ssp", so that there is "ssp" for srcu_struct pointer, "snp" for srcu_node pointer, and "sdp" for srcu_data pointer. Signed-off-by: Paul E. McKenney --- include/linux/srcutree.h | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'include/linux/srcutree.h') diff --git a/include/linux/srcutree.h b/include/linux/srcutree.h index 0ae91b3a7406..6f292bd3e7db 100644 --- a/include/linux/srcutree.h +++ b/include/linux/srcutree.h @@ -51,7 +51,7 @@ struct srcu_data { unsigned long grpmask; /* Mask for leaf srcu_node */ /* ->srcu_data_have_cbs[]. */ int cpu; - struct srcu_struct *sp; + struct srcu_struct *ssp; }; /* @@ -138,8 +138,8 @@ struct srcu_struct { #define DEFINE_SRCU(name) __DEFINE_SRCU(name, /* not static */) #define DEFINE_STATIC_SRCU(name) __DEFINE_SRCU(name, static) -void synchronize_srcu_expedited(struct srcu_struct *sp); -void srcu_barrier(struct srcu_struct *sp); -void srcu_torture_stats_print(struct srcu_struct *sp, char *tt, char *tf); +void synchronize_srcu_expedited(struct srcu_struct *ssp); +void srcu_barrier(struct srcu_struct *ssp); +void srcu_torture_stats_print(struct srcu_struct *ssp, char *tt, char *tf); #endif -- cgit v1.2.3 From e81baf4cb19a9b428ba477fd0423f81672a58817 Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Tue, 11 Dec 2018 12:12:38 +0100 Subject: srcu: Remove srcu_queue_delayed_work_on() srcu_queue_delayed_work_on() disables preemption (and therefore CPU hotplug in RCU's case) and then checks based on its own accounting if a CPU is online. If the CPU is online it uses queue_delayed_work_on() otherwise it fallbacks to queue_delayed_work(). The problem here is that queue_work() on -RT does not work with disabled preemption. queue_work_on() works also on an offlined CPU. queue_delayed_work_on() has the problem that it is possible to program a timer on an offlined CPU. This timer will fire once the CPU is online again. But until then, the timer remains programmed and nothing will happen. Add a local timer which will fire (as requested per delay) on the local CPU and then enqueue the work on the specific CPU. RCUtorture testing with SRCU-P for 24h showed no problems. Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Paul E. McKenney --- include/linux/srcutree.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'include/linux/srcutree.h') diff --git a/include/linux/srcutree.h b/include/linux/srcutree.h index 6f292bd3e7db..0faa978c9880 100644 --- a/include/linux/srcutree.h +++ b/include/linux/srcutree.h @@ -45,7 +45,8 @@ struct srcu_data { unsigned long srcu_gp_seq_needed; /* Furthest future GP needed. */ unsigned long srcu_gp_seq_needed_exp; /* Furthest future exp GP. */ bool srcu_cblist_invoking; /* Invoking these CBs? */ - struct delayed_work work; /* Context for CB invoking. */ + struct timer_list delay_work; /* Delay for CB invoking */ + struct work_struct work; /* Context for CB invoking. */ struct rcu_head srcu_barrier_head; /* For srcu_barrier() use. */ struct srcu_node *mynode; /* Leaf srcu_node. */ unsigned long grpmask; /* Mask for leaf srcu_node */ -- cgit v1.2.3 From 8c366db05b1f27fac01a7dbf9e4904d499bd5d55 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Thu, 17 Jan 2019 10:39:22 -0800 Subject: linux/srcu: Convert to SPDX license identifier Replace the license boiler plate with a SPDX license identifier. While in the area, update an email address. Signed-off-by: Paul E. McKenney [ paulmck: Update ,h SPDX format per Joe Perches. ] Reviewed-by: Thomas Gleixner --- include/linux/srcutree.h | 17 ++--------------- 1 file changed, 2 insertions(+), 15 deletions(-) (limited to 'include/linux/srcutree.h') diff --git a/include/linux/srcutree.h b/include/linux/srcutree.h index 6f292bd3e7db..de7a42116b2e 100644 --- a/include/linux/srcutree.h +++ b/include/linux/srcutree.h @@ -1,24 +1,11 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ /* * Sleepable Read-Copy Update mechanism for mutual exclusion, * tree variant. * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, you can access it online at - * http://www.gnu.org/licenses/gpl-2.0.html. - * * Copyright (C) IBM Corporation, 2017 * - * Author: Paul McKenney + * Author: Paul McKenney */ #ifndef _LINUX_SRCU_TREE_H -- cgit v1.2.3