diff options
| -rw-r--r-- | kernel/ksysfs.c | 18 | ||||
| -rw-r--r-- | kernel/rcu.h | 2 | ||||
| -rw-r--r-- | kernel/rcupdate.c | 3 | ||||
| -rw-r--r-- | kernel/rcutiny_plugin.h | 5 | ||||
| -rw-r--r-- | kernel/rcutree.c | 12 | ||||
| -rw-r--r-- | kernel/rcutree_plugin.h | 7 | ||||
| -rw-r--r-- | kernel/srcu.c | 8 |
7 files changed, 48 insertions, 7 deletions
diff --git a/kernel/ksysfs.c b/kernel/ksysfs.c index 4e316e1acf5..8715a798aa7 100644 --- a/kernel/ksysfs.c +++ b/kernel/ksysfs.c @@ -141,6 +141,23 @@ static ssize_t fscaps_show(struct kobject *kobj, } KERNEL_ATTR_RO(fscaps); +int rcu_expedited; +static ssize_t rcu_expedited_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + return sprintf(buf, "%d\n", rcu_expedited); +} +static ssize_t rcu_expedited_store(struct kobject *kobj, + struct kobj_attribute *attr, + const char *buf, size_t count) +{ + if (kstrtoint(buf, 0, &rcu_expedited)) + return -EINVAL; + + return count; +} +KERNEL_ATTR_RW(rcu_expedited); + /* * Make /sys/kernel/notes give the raw contents of our kernel .notes section. */ @@ -182,6 +199,7 @@ static struct attribute * kernel_attrs[] = { &kexec_crash_size_attr.attr, &vmcoreinfo_attr.attr, #endif + &rcu_expedited_attr.attr, NULL }; diff --git a/kernel/rcu.h b/kernel/rcu.h index 8ba99cdc651..20dfba576c2 100644 --- a/kernel/rcu.h +++ b/kernel/rcu.h @@ -109,4 +109,6 @@ static inline bool __rcu_reclaim(char *rn, struct rcu_head *head) } } +extern int rcu_expedited; + #endif /* __LINUX_RCU_H */ diff --git a/kernel/rcupdate.c b/kernel/rcupdate.c index 29ca1c6da59..a2cf76177b4 100644 --- a/kernel/rcupdate.c +++ b/kernel/rcupdate.c @@ -46,12 +46,15 @@ #include <linux/export.h> #include <linux/hardirq.h> #include <linux/delay.h> +#include <linux/module.h> #define CREATE_TRACE_POINTS #include <trace/events/rcu.h> #include "rcu.h" +module_param(rcu_expedited, int, 0); + #ifdef CONFIG_PREEMPT_RCU /* diff --git a/kernel/rcutiny_plugin.h b/kernel/rcutiny_plugin.h index 3d019028220..f85016a2309 100644 --- a/kernel/rcutiny_plugin.h +++ b/kernel/rcutiny_plugin.h @@ -706,7 +706,10 @@ void synchronize_rcu(void) return; /* Once we get past the fastpath checks, same code as rcu_barrier(). */ - rcu_barrier(); + if (rcu_expedited) + synchronize_rcu_expedited(); + else + rcu_barrier(); } EXPORT_SYMBOL_GPL(synchronize_rcu); diff --git a/kernel/rcutree.c b/kernel/rcutree.c index 74df86bd920..f9c17c39953 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -2224,7 +2224,10 @@ void synchronize_sched(void) "Illegal synchronize_sched() in RCU-sched read-side critical section"); if (rcu_blocking_is_gp()) return; - wait_rcu_gp(call_rcu_sched); + if (rcu_expedited) + synchronize_sched_expedited(); + else + wait_rcu_gp(call_rcu_sched); } EXPORT_SYMBOL_GPL(synchronize_sched); @@ -2245,7 +2248,10 @@ void synchronize_rcu_bh(void) "Illegal synchronize_rcu_bh() in RCU-bh read-side critical section"); if (rcu_blocking_is_gp()) return; - wait_rcu_gp(call_rcu_bh); + if (rcu_expedited) + synchronize_rcu_bh_expedited(); + else + wait_rcu_gp(call_rcu_bh); } EXPORT_SYMBOL_GPL(synchronize_rcu_bh); @@ -2328,7 +2334,7 @@ void synchronize_sched_expedited(void) if (trycount++ < 10) { udelay(trycount * num_online_cpus()); } else { - synchronize_sched(); + wait_rcu_gp(call_rcu_sched); return; } diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h index f9211548818..c177ba0cce9 100644 --- a/kernel/rcutree_plugin.h +++ b/kernel/rcutree_plugin.h @@ -679,7 +679,10 @@ void synchronize_rcu(void) "Illegal synchronize_rcu() in RCU read-side critical section"); if (!rcu_scheduler_active) return; - wait_rcu_gp(call_rcu); + if (rcu_expedited) + synchronize_rcu_expedited(); + else + wait_rcu_gp(call_rcu); } EXPORT_SYMBOL_GPL(synchronize_rcu); @@ -831,7 +834,7 @@ void synchronize_rcu_expedited(void) udelay(trycount * num_online_cpus()); } else { put_online_cpus(); - synchronize_rcu(); + wait_rcu_gp(call_rcu); return; } } diff --git a/kernel/srcu.c b/kernel/srcu.c index 97c465ebd84..de9074047c9 100644 --- a/kernel/srcu.c +++ b/kernel/srcu.c @@ -34,6 +34,10 @@ #include <linux/delay.h> #include <linux/srcu.h> +#include <trace/events/rcu.h> + +#include "rcu.h" + /* * Initialize an rcu_batch structure to empty. */ @@ -464,7 +468,9 @@ static void __synchronize_srcu(struct srcu_struct *sp, int trycount) */ void synchronize_srcu(struct srcu_struct *sp) { - __synchronize_srcu(sp, SYNCHRONIZE_SRCU_TRYCOUNT); + __synchronize_srcu(sp, rcu_expedited + ? SYNCHRONIZE_SRCU_EXP_TRYCOUNT + : SYNCHRONIZE_SRCU_TRYCOUNT); } EXPORT_SYMBOL_GPL(synchronize_srcu); |