The following commit has been merged into the core/rcu branch of tip: Commit-ID: e9b800db96fa40170c5607d8968b2ec6212c2026 Gitweb: https://git.kernel.org/tip/e9b800db96fa40170c5607d8968b2ec6212c2026 Author: Paul E. McKenney <paulmck@xxxxxxxxxx> AuthorDate: Wed, 10 Mar 2021 18:02:36 -08:00 Committer: Paul E. McKenney <paulmck@xxxxxxxxxx> CommitterDate: Mon, 10 May 2021 16:05:05 -07:00 refscale: Add acqrel, lock, and lock-irq This commit adds scale_type of acqrel, lock, and lock-irq to test acquisition and release. Note that the refscale.nreaders=1 module parameter is required if you wish to test uncontended locking. In contrast, acqrel uses a per-CPU variable, so should be just fine with large values of the refscale.nreaders=1 module parameter. Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx> --- kernel/rcu/refscale.c | 109 ++++++++++++++++++++++++++++++++++++++++- 1 file changed, 107 insertions(+), 2 deletions(-) diff --git a/kernel/rcu/refscale.c b/kernel/rcu/refscale.c index 02dd976..313d454 100644 --- a/kernel/rcu/refscale.c +++ b/kernel/rcu/refscale.c @@ -362,6 +362,111 @@ static struct ref_scale_ops rwsem_ops = { .name = "rwsem" }; +// Definitions for global spinlock +static DEFINE_SPINLOCK(test_lock); + +static void ref_lock_section(const int nloops) +{ + int i; + + preempt_disable(); + for (i = nloops; i >= 0; i--) { + spin_lock(&test_lock); + spin_unlock(&test_lock); + } + preempt_enable(); +} + +static void ref_lock_delay_section(const int nloops, const int udl, const int ndl) +{ + int i; + + preempt_disable(); + for (i = nloops; i >= 0; i--) { + spin_lock(&test_lock); + un_delay(udl, ndl); + spin_unlock(&test_lock); + } + preempt_enable(); +} + +static struct ref_scale_ops lock_ops = { + .readsection = ref_lock_section, + .delaysection = ref_lock_delay_section, + .name = "lock" +}; + +// Definitions for global irq-save spinlock + +static void ref_lock_irq_section(const int nloops) +{ + unsigned long flags; + int i; + + preempt_disable(); + for (i = nloops; i >= 0; i--) { + spin_lock_irqsave(&test_lock, flags); + spin_unlock_irqrestore(&test_lock, flags); + } + preempt_enable(); +} + +static void ref_lock_irq_delay_section(const int nloops, const int udl, const int ndl) +{ + unsigned long flags; + int i; + + preempt_disable(); + for (i = nloops; i >= 0; i--) { + spin_lock_irqsave(&test_lock, flags); + un_delay(udl, ndl); + spin_unlock_irqrestore(&test_lock, flags); + } + preempt_enable(); +} + +static struct ref_scale_ops lock_irq_ops = { + .readsection = ref_lock_irq_section, + .delaysection = ref_lock_irq_delay_section, + .name = "lock-irq" +}; + +// Definitions acquire-release. +static DEFINE_PER_CPU(unsigned long, test_acqrel); + +static void ref_acqrel_section(const int nloops) +{ + unsigned long x; + int i; + + preempt_disable(); + for (i = nloops; i >= 0; i--) { + x = smp_load_acquire(this_cpu_ptr(&test_acqrel)); + smp_store_release(this_cpu_ptr(&test_acqrel), x + 1); + } + preempt_enable(); +} + +static void ref_acqrel_delay_section(const int nloops, const int udl, const int ndl) +{ + unsigned long x; + int i; + + preempt_disable(); + for (i = nloops; i >= 0; i--) { + x = smp_load_acquire(this_cpu_ptr(&test_acqrel)); + un_delay(udl, ndl); + smp_store_release(this_cpu_ptr(&test_acqrel), x + 1); + } + preempt_enable(); +} + +static struct ref_scale_ops acqrel_ops = { + .readsection = ref_acqrel_section, + .delaysection = ref_acqrel_delay_section, + .name = "acqrel" +}; + static void rcu_scale_one_reader(void) { if (readdelay <= 0) @@ -653,8 +758,8 @@ ref_scale_init(void) long i; int firsterr = 0; static struct ref_scale_ops *scale_ops[] = { - &rcu_ops, &srcu_ops, &rcu_trace_ops, &rcu_tasks_ops, - &refcnt_ops, &rwlock_ops, &rwsem_ops, + &rcu_ops, &srcu_ops, &rcu_trace_ops, &rcu_tasks_ops, &refcnt_ops, &rwlock_ops, + &rwsem_ops, &lock_ops, &lock_irq_ops, &acqrel_ops, }; if (!torture_init_begin(scale_type, verbose))
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