diff options
| -rw-r--r-- | kernel/rcu/refperf.c | 108 |
1 files changed, 89 insertions, 19 deletions
diff --git a/kernel/rcu/refperf.c b/kernel/rcu/refperf.c index 7839237ffc17..57a750bbcaca 100644 --- a/kernel/rcu/refperf.c +++ b/kernel/rcu/refperf.c @@ -66,8 +66,8 @@ torture_param(long, loops, 10000000, "Number of loops per experiment."); torture_param(int, nreaders, -1, "Number of readers, -1 for 75% of CPUs."); // Number of runs. torture_param(int, nruns, 30, "Number of experiments to run."); -// Reader delay in nanoseconds, 0 for no delay. -torture_param(int, readdelay, 0, "Read-side delay in nanoseconds."); +// Reader delay in microseconds, 0 for no delay. +torture_param(int, readdelay, 0, "Read-side delay in microseconds."); #ifdef MODULE # define REFPERF_SHUTDOWN 0 @@ -111,6 +111,7 @@ struct ref_perf_ops { void (*init)(void); void (*cleanup)(void); void (*readsection)(const int nloops); + void (*delaysection)(const int nloops, const int ndelay); const char *name; }; @@ -126,6 +127,17 @@ static void ref_rcu_read_section(const int nloops) } } +static void ref_rcu_delay_section(const int nloops, const int ndelay) +{ + int i; + + for (i = nloops; i >= 0; i--) { + rcu_read_lock(); + udelay(ndelay); + rcu_read_unlock(); + } +} + static void rcu_sync_perf_init(void) { } @@ -133,6 +145,7 @@ static void rcu_sync_perf_init(void) static struct ref_perf_ops rcu_ops = { .init = rcu_sync_perf_init, .readsection = ref_rcu_read_section, + .delaysection = ref_rcu_delay_section, .name = "rcu" }; @@ -141,7 +154,7 @@ static struct ref_perf_ops rcu_ops = { DEFINE_STATIC_SRCU(srcu_refctl_perf); static struct srcu_struct *srcu_ctlp = &srcu_refctl_perf; -static void srcu_ref_perf_read_section(int nloops) +static void srcu_ref_perf_read_section(const int nloops) { int i; int idx; @@ -152,16 +165,29 @@ static void srcu_ref_perf_read_section(int nloops) } } +static void srcu_ref_perf_delay_section(const int nloops, const int ndelay) +{ + int i; + int idx; + + for (i = nloops; i >= 0; i--) { + idx = srcu_read_lock(srcu_ctlp); + udelay(ndelay); + srcu_read_unlock(srcu_ctlp, idx); + } +} + static struct ref_perf_ops srcu_ops = { .init = rcu_sync_perf_init, .readsection = srcu_ref_perf_read_section, + .delaysection = srcu_ref_perf_delay_section, .name = "srcu" }; // Definitions for reference count static atomic_t refcnt; -static void ref_perf_refcnt_section(const int nloops) +static void ref_refcnt_section(const int nloops) { int i; @@ -171,45 +197,69 @@ static void ref_perf_refcnt_section(const int nloops) } } +static void ref_refcnt_delay_section(const int nloops, const int ndelay) +{ + int i; + + for (i = nloops; i >= 0; i--) { + atomic_inc(&refcnt); + udelay(ndelay); + atomic_dec(&refcnt); + } +} + static struct ref_perf_ops refcnt_ops = { .init = rcu_sync_perf_init, - .readsection = ref_perf_refcnt_section, + .readsection = ref_refcnt_section, + .delaysection = ref_refcnt_delay_section, .name = "refcnt" }; // Definitions for rwlock static rwlock_t test_rwlock; -static void ref_perf_rwlock_init(void) +static void ref_rwlock_init(void) { rwlock_init(&test_rwlock); } -static void ref_perf_rwlock_section(const int nloops) +static void ref_rwlock_section(const int nloops) +{ + int i; + + for (i = nloops; i >= 0; i--) { + read_lock(&test_rwlock); + read_unlock(&test_rwlock); + } +} + +static void ref_rwlock_delay_section(const int nloops, const int ndelay) { int i; for (i = nloops; i >= 0; i--) { read_lock(&test_rwlock); + udelay(ndelay); read_unlock(&test_rwlock); } } static struct ref_perf_ops rwlock_ops = { - .init = ref_perf_rwlock_init, - .readsection = ref_perf_rwlock_section, + .init = ref_rwlock_init, + .readsection = ref_rwlock_section, + .delaysection = ref_rwlock_delay_section, .name = "rwlock" }; // Definitions for rwsem static struct rw_semaphore test_rwsem; -static void ref_perf_rwsem_init(void) +static void ref_rwsem_init(void) { init_rwsem(&test_rwsem); } -static void ref_perf_rwsem_section(const int nloops) +static void ref_rwsem_section(const int nloops) { int i; @@ -219,12 +269,32 @@ static void ref_perf_rwsem_section(const int nloops) } } +static void ref_rwsem_delay_section(const int nloops, const int ndelay) +{ + int i; + + for (i = nloops; i >= 0; i--) { + down_read(&test_rwsem); + udelay(ndelay); + up_read(&test_rwsem); + } +} + static struct ref_perf_ops rwsem_ops = { - .init = ref_perf_rwsem_init, - .readsection = ref_perf_rwsem_section, + .init = ref_rwsem_init, + .readsection = ref_rwsem_section, + .delaysection = ref_rwsem_delay_section, .name = "rwsem" }; +static void rcu_perf_one_reader(void) +{ + if (readdelay <= 0) + cur_ops->readsection(loops); + else + cur_ops->delaysection(loops, readdelay); +} + // Reader kthread. Repeatedly does empty RCU read-side // critical section, minimizing update-side interference. static int @@ -265,16 +335,16 @@ repeat: // To reduce noise, do an initial cache-warming invocation, check // in, and then keep warming until everyone has checked in. - cur_ops->readsection(loops); + rcu_perf_one_reader(); if (!atomic_dec_return(&n_warmedup)) while (atomic_read_acquire(&n_warmedup)) - cur_ops->readsection(loops); + rcu_perf_one_reader(); // Also keep interrupts disabled. This also has the effect // of preventing entries into slow path for rcu_read_unlock(). local_irq_save(flags); start = ktime_get_mono_fast_ns(); - cur_ops->readsection(loops); + rcu_perf_one_reader(); duration = ktime_get_mono_fast_ns() - start; local_irq_restore(flags); @@ -284,7 +354,7 @@ repeat: // everyone is done. if (!atomic_dec_return(&n_cooleddown)) while (atomic_read_acquire(&n_cooleddown)) - cur_ops->readsection(loops); + rcu_perf_one_reader(); if (atomic_dec_and_test(&nreaders_exp)) wake_up(&main_wq); @@ -449,8 +519,8 @@ static void ref_perf_print_module_parms(struct ref_perf_ops *cur_ops, const char *tag) { pr_alert("%s" PERF_FLAG - "--- %s: verbose=%d shutdown=%d holdoff=%d loops=%ld nreaders=%d nruns=%d\n", perf_type, tag, - verbose, shutdown, holdoff, loops, nreaders, nruns); + "--- %s: verbose=%d shutdown=%d holdoff=%d loops=%ld nreaders=%d nruns=%d readdelay=%d\n", perf_type, tag, + verbose, shutdown, holdoff, loops, nreaders, nruns, readdelay); } static void |