+++ /dev/null
-From foo@baz Wed May 2 08:55:24 PDT 2018
-From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
-Date: Mon, 8 Jan 2018 14:35:52 -0800
-Subject: rcu: Create RCU-specific workqueues with rescuers
-
-From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
-
-[ Upstream commit ad7c946b35ad455417fdd4bc0e17deda4011841b ]
-
-RCU's expedited grace periods can participate in out-of-memory deadlocks
-due to all available system_wq kthreads being blocked and there not being
-memory available to create more. This commit prevents such deadlocks
-by allocating an RCU-specific workqueue_struct at early boot time, and
-providing it with a rescuer to ensure forward progress. This uses the
-shiny new init_rescuer() function provided by Tejun (but indirectly).
-
-This commit also causes SRCU to use this new RCU-specific
-workqueue_struct. Note that SRCU's use of workqueues never blocks them
-waiting for readers, so this should be safe from a forward-progress
-viewpoint. Note that this moves SRCU from system_power_efficient_wq
-to a normal workqueue. In the unlikely event that this results in
-measurable degradation, a separate power-efficient workqueue will be
-creates for SRCU.
-
-Reported-by: Prateek Sood <prsood@codeaurora.org>
-Reported-by: Tejun Heo <tj@kernel.org>
-Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
-Acked-by: Tejun Heo <tj@kernel.org>
-Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
-Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
----
- kernel/rcu/rcu.h | 1 +
- kernel/rcu/srcutree.c | 8 +++-----
- kernel/rcu/tree.c | 6 ++++++
- kernel/rcu/tree_exp.h | 2 +-
- 4 files changed, 11 insertions(+), 6 deletions(-)
-
---- a/kernel/rcu/rcu.h
-+++ b/kernel/rcu/rcu.h
-@@ -474,6 +474,7 @@ void show_rcu_gp_kthreads(void);
- void rcu_force_quiescent_state(void);
- void rcu_bh_force_quiescent_state(void);
- void rcu_sched_force_quiescent_state(void);
-+extern struct workqueue_struct *rcu_gp_wq;
- #endif /* #else #ifdef CONFIG_TINY_RCU */
-
- #ifdef CONFIG_RCU_NOCB_CPU
---- a/kernel/rcu/srcutree.c
-+++ b/kernel/rcu/srcutree.c
-@@ -465,8 +465,7 @@ static bool srcu_queue_delayed_work_on(i
- */
- static void srcu_schedule_cbs_sdp(struct srcu_data *sdp, unsigned long delay)
- {
-- srcu_queue_delayed_work_on(sdp->cpu, system_power_efficient_wq,
-- &sdp->work, delay);
-+ srcu_queue_delayed_work_on(sdp->cpu, rcu_gp_wq, &sdp->work, delay);
- }
-
- /*
-@@ -664,8 +663,7 @@ static void srcu_funnel_gp_start(struct
- rcu_seq_state(sp->srcu_gp_seq) == SRCU_STATE_IDLE) {
- WARN_ON_ONCE(ULONG_CMP_GE(sp->srcu_gp_seq, sp->srcu_gp_seq_needed));
- srcu_gp_start(sp);
-- queue_delayed_work(system_power_efficient_wq, &sp->work,
-- srcu_get_delay(sp));
-+ queue_delayed_work(rcu_gp_wq, &sp->work, srcu_get_delay(sp));
- }
- raw_spin_unlock_irqrestore_rcu_node(sp, flags);
- }
-@@ -1198,7 +1196,7 @@ static void srcu_reschedule(struct srcu_
- raw_spin_unlock_irq_rcu_node(sp);
-
- if (pushgp)
-- queue_delayed_work(system_power_efficient_wq, &sp->work, delay);
-+ queue_delayed_work(rcu_gp_wq, &sp->work, delay);
- }
-
- /*
---- a/kernel/rcu/tree.c
-+++ b/kernel/rcu/tree.c
-@@ -4176,6 +4176,8 @@ static void __init rcu_dump_rcu_node_tre
- pr_cont("\n");
- }
-
-+struct workqueue_struct *rcu_gp_wq;
-+
- void __init rcu_init(void)
- {
- int cpu;
-@@ -4203,6 +4205,10 @@ void __init rcu_init(void)
- if (IS_ENABLED(CONFIG_TREE_SRCU))
- srcu_online_cpu(cpu);
- }
-+
-+ /* Create workqueue for expedited GPs and for Tree SRCU. */
-+ rcu_gp_wq = alloc_workqueue("rcu_gp", WQ_MEM_RECLAIM, 0);
-+ WARN_ON(!rcu_gp_wq);
- }
-
- #include "tree_exp.h"
---- a/kernel/rcu/tree_exp.h
-+++ b/kernel/rcu/tree_exp.h
-@@ -606,7 +606,7 @@ static void _synchronize_rcu_expedited(s
- rew.rew_rsp = rsp;
- rew.rew_s = s;
- INIT_WORK_ONSTACK(&rew.rew_work, wait_rcu_exp_gp);
-- schedule_work(&rew.rew_work);
-+ queue_work(rcu_gp_wq, &rew.rew_work);
- }
-
- /* Wait for expedited grace period to complete. */
bluetooth-btusb-add-device-id-for-rtl8822be.patch
kdb-make-mdr-command-repeat.patch
xhci-show-what-usb-release-number-the-xhc-supports-from-protocol-capablity.patch
-rcu-create-rcu-specific-workqueues-with-rescuers.patch
+++ /dev/null
-From foo@baz Wed May 2 08:55:03 PDT 2018
-From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
-Date: Mon, 8 Jan 2018 14:35:52 -0800
-Subject: rcu: Create RCU-specific workqueues with rescuers
-
-From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
-
-[ Upstream commit ad7c946b35ad455417fdd4bc0e17deda4011841b ]
-
-RCU's expedited grace periods can participate in out-of-memory deadlocks
-due to all available system_wq kthreads being blocked and there not being
-memory available to create more. This commit prevents such deadlocks
-by allocating an RCU-specific workqueue_struct at early boot time, and
-providing it with a rescuer to ensure forward progress. This uses the
-shiny new init_rescuer() function provided by Tejun (but indirectly).
-
-This commit also causes SRCU to use this new RCU-specific
-workqueue_struct. Note that SRCU's use of workqueues never blocks them
-waiting for readers, so this should be safe from a forward-progress
-viewpoint. Note that this moves SRCU from system_power_efficient_wq
-to a normal workqueue. In the unlikely event that this results in
-measurable degradation, a separate power-efficient workqueue will be
-creates for SRCU.
-
-Reported-by: Prateek Sood <prsood@codeaurora.org>
-Reported-by: Tejun Heo <tj@kernel.org>
-Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
-Acked-by: Tejun Heo <tj@kernel.org>
-Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
-Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
----
- kernel/rcu/rcu.h | 1 +
- kernel/rcu/srcutree.c | 8 +++-----
- kernel/rcu/tree.c | 6 ++++++
- kernel/rcu/tree_exp.h | 2 +-
- 4 files changed, 11 insertions(+), 6 deletions(-)
-
---- a/kernel/rcu/rcu.h
-+++ b/kernel/rcu/rcu.h
-@@ -470,6 +470,7 @@ void show_rcu_gp_kthreads(void);
- void rcu_force_quiescent_state(void);
- void rcu_bh_force_quiescent_state(void);
- void rcu_sched_force_quiescent_state(void);
-+extern struct workqueue_struct *rcu_gp_wq;
- #endif /* #else #ifdef CONFIG_TINY_RCU */
-
- #ifdef CONFIG_RCU_NOCB_CPU
---- a/kernel/rcu/srcutree.c
-+++ b/kernel/rcu/srcutree.c
-@@ -492,8 +492,7 @@ static bool srcu_queue_delayed_work_on(i
- */
- static void srcu_schedule_cbs_sdp(struct srcu_data *sdp, unsigned long delay)
- {
-- srcu_queue_delayed_work_on(sdp->cpu, system_power_efficient_wq,
-- &sdp->work, delay);
-+ srcu_queue_delayed_work_on(sdp->cpu, rcu_gp_wq, &sdp->work, delay);
- }
-
- /*
-@@ -691,8 +690,7 @@ static void srcu_funnel_gp_start(struct
- rcu_seq_state(sp->srcu_gp_seq) == SRCU_STATE_IDLE) {
- WARN_ON_ONCE(ULONG_CMP_GE(sp->srcu_gp_seq, sp->srcu_gp_seq_needed));
- srcu_gp_start(sp);
-- queue_delayed_work(system_power_efficient_wq, &sp->work,
-- srcu_get_delay(sp));
-+ queue_delayed_work(rcu_gp_wq, &sp->work, srcu_get_delay(sp));
- }
- spin_unlock_irqrestore_rcu_node(sp, flags);
- }
-@@ -1225,7 +1223,7 @@ static void srcu_reschedule(struct srcu_
- spin_unlock_irq_rcu_node(sp);
-
- if (pushgp)
-- queue_delayed_work(system_power_efficient_wq, &sp->work, delay);
-+ queue_delayed_work(rcu_gp_wq, &sp->work, delay);
- }
-
- /*
---- a/kernel/rcu/tree.c
-+++ b/kernel/rcu/tree.c
-@@ -4193,6 +4193,8 @@ static void __init rcu_dump_rcu_node_tre
- pr_cont("\n");
- }
-
-+struct workqueue_struct *rcu_gp_wq;
-+
- void __init rcu_init(void)
- {
- int cpu;
-@@ -4219,6 +4221,10 @@ void __init rcu_init(void)
- rcu_cpu_starting(cpu);
- rcutree_online_cpu(cpu);
- }
-+
-+ /* Create workqueue for expedited GPs and for Tree SRCU. */
-+ rcu_gp_wq = alloc_workqueue("rcu_gp", WQ_MEM_RECLAIM, 0);
-+ WARN_ON(!rcu_gp_wq);
- }
-
- #include "tree_exp.h"
---- a/kernel/rcu/tree_exp.h
-+++ b/kernel/rcu/tree_exp.h
-@@ -606,7 +606,7 @@ static void _synchronize_rcu_expedited(s
- rew.rew_rsp = rsp;
- rew.rew_s = s;
- INIT_WORK_ONSTACK(&rew.rew_work, wait_rcu_exp_gp);
-- schedule_work(&rew.rew_work);
-+ queue_work(rcu_gp_wq, &rew.rew_work);
- }
-
- /* Wait for expedited grace period to complete. */
bluetooth-btusb-add-support-for-intel-bluetooth-device-22560.patch
kdb-make-mdr-command-repeat.patch
xhci-show-what-usb-release-number-the-xhc-supports-from-protocol-capablity.patch
-rcu-create-rcu-specific-workqueues-with-rescuers.patch
projects / thirdparty / kernel / stable-queue.git / commitdiff
