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OpenCloudOS-Kernel/kernel/rcu/rcuscale.c

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// SPDX-License-Identifier: GPL-2.0+
/*
* Read-Copy Update module-based scalability-test facility
*
* Copyright (C) IBM Corporation, 2015
*
* Authors: Paul E. McKenney <paulmck@linux.ibm.com>
*/
#define pr_fmt(fmt) fmt
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/kthread.h>
#include <linux/err.h>
#include <linux/spinlock.h>
#include <linux/smp.h>
#include <linux/rcupdate.h>
#include <linux/interrupt.h>
#include <linux/sched.h>
#include <uapi/linux/sched/types.h>
#include <linux/atomic.h>
#include <linux/bitops.h>
#include <linux/completion.h>
#include <linux/moduleparam.h>
#include <linux/percpu.h>
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <linux/freezer.h>
#include <linux/cpu.h>
#include <linux/delay.h>
#include <linux/stat.h>
#include <linux/srcu.h>
#include <linux/slab.h>
#include <asm/byteorder.h>
#include <linux/torture.h>
#include <linux/vmalloc.h>
#include "rcu.h"
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Paul E. McKenney <paulmck@linux.ibm.com>");
#define SCALE_FLAG "-scale:"
#define SCALEOUT_STRING(s) \
pr_alert("%s" SCALE_FLAG " %s\n", scale_type, s)
#define VERBOSE_SCALEOUT_STRING(s) \
do { if (verbose) pr_alert("%s" SCALE_FLAG " %s\n", scale_type, s); } while (0)
#define VERBOSE_SCALEOUT_ERRSTRING(s) \
do { if (verbose) pr_alert("%s" SCALE_FLAG "!!! %s\n", scale_type, s); } while (0)
/*
* The intended use cases for the nreaders and nwriters module parameters
* are as follows:
*
* 1. Specify only the nr_cpus kernel boot parameter. This will
* set both nreaders and nwriters to the value specified by
* nr_cpus for a mixed reader/writer test.
*
* 2. Specify the nr_cpus kernel boot parameter, but set
* rcuscale.nreaders to zero. This will set nwriters to the
* value specified by nr_cpus for an update-only test.
*
* 3. Specify the nr_cpus kernel boot parameter, but set
* rcuscale.nwriters to zero. This will set nreaders to the
* value specified by nr_cpus for a read-only test.
*
* Various other use cases may of course be specified.
*
* Note that this test's readers are intended only as a test load for
* the writers. The reader scalability statistics will be overly
* pessimistic due to the per-critical-section interrupt disabling,
* test-end checks, and the pair of calls through pointers.
*/
#ifdef MODULE
# define RCUSCALE_SHUTDOWN 0
#else
# define RCUSCALE_SHUTDOWN 1
#endif
torture_param(bool, gp_async, false, "Use asynchronous GP wait primitives");
torture_param(int, gp_async_max, 1000, "Max # outstanding waits per reader");
torture_param(bool, gp_exp, false, "Use expedited GP wait primitives");
torture_param(int, holdoff, 10, "Holdoff time before test start (s)");
torture_param(int, nreaders, -1, "Number of RCU reader threads");
torture_param(int, nwriters, -1, "Number of RCU updater threads");
torture_param(bool, shutdown, RCUSCALE_SHUTDOWN,
"Shutdown at end of scalability tests.");
torture_param(int, verbose, 1, "Enable verbose debugging printk()s");
torture_param(int, writer_holdoff, 0, "Holdoff (us) between GPs, zero to disable");
torture_param(int, kfree_rcu_test, 0, "Do we run a kfree_rcu() scale test?");
torture_param(int, kfree_mult, 1, "Multiple of kfree_obj size to allocate.");
static char *scale_type = "rcu";
module_param(scale_type, charp, 0444);
MODULE_PARM_DESC(scale_type, "Type of RCU to scalability-test (rcu, srcu, ...)");
static int nrealreaders;
static int nrealwriters;
static struct task_struct **writer_tasks;
static struct task_struct **reader_tasks;
static struct task_struct *shutdown_task;
static u64 **writer_durations;
static int *writer_n_durations;
static atomic_t n_rcu_scale_reader_started;
static atomic_t n_rcu_scale_writer_started;
static atomic_t n_rcu_scale_writer_finished;
static wait_queue_head_t shutdown_wq;
static u64 t_rcu_scale_writer_started;
static u64 t_rcu_scale_writer_finished;
static unsigned long b_rcu_gp_test_started;
static unsigned long b_rcu_gp_test_finished;
static DEFINE_PER_CPU(atomic_t, n_async_inflight);
#define MAX_MEAS 10000
#define MIN_MEAS 100
/*
* Operations vector for selecting different types of tests.
*/
struct rcu_scale_ops {
int ptype;
void (*init)(void);
void (*cleanup)(void);
int (*readlock)(void);
void (*readunlock)(int idx);
unsigned long (*get_gp_seq)(void);
unsigned long (*gp_diff)(unsigned long new, unsigned long old);
unsigned long (*exp_completed)(void);
void (*async)(struct rcu_head *head, rcu_callback_t func);
void (*gp_barrier)(void);
void (*sync)(void);
void (*exp_sync)(void);
const char *name;
};
static struct rcu_scale_ops *cur_ops;
/*
* Definitions for rcu scalability testing.
*/
static int rcu_scale_read_lock(void) __acquires(RCU)
{
rcu_read_lock();
return 0;
}
static void rcu_scale_read_unlock(int idx) __releases(RCU)
{
rcu_read_unlock();
}
static unsigned long __maybe_unused rcu_no_completed(void)
{
return 0;
}
static void rcu_sync_scale_init(void)
{
}
static struct rcu_scale_ops rcu_ops = {
.ptype = RCU_FLAVOR,
.init = rcu_sync_scale_init,
.readlock = rcu_scale_read_lock,
.readunlock = rcu_scale_read_unlock,
.get_gp_seq = rcu_get_gp_seq,
.gp_diff = rcu_seq_diff,
.exp_completed = rcu_exp_batches_completed,
.async = call_rcu,
.gp_barrier = rcu_barrier,
.sync = synchronize_rcu,
.exp_sync = synchronize_rcu_expedited,
.name = "rcu"
};
/*
* Definitions for srcu scalability testing.
*/
DEFINE_STATIC_SRCU(srcu_ctl_scale);
static struct srcu_struct *srcu_ctlp = &srcu_ctl_scale;
static int srcu_scale_read_lock(void) __acquires(srcu_ctlp)
{
return srcu_read_lock(srcu_ctlp);
}
static void srcu_scale_read_unlock(int idx) __releases(srcu_ctlp)
{
srcu_read_unlock(srcu_ctlp, idx);
}
static unsigned long srcu_scale_completed(void)
{
return srcu_batches_completed(srcu_ctlp);
}
static void srcu_call_rcu(struct rcu_head *head, rcu_callback_t func)
{
call_srcu(srcu_ctlp, head, func);
}
static void srcu_rcu_barrier(void)
{
srcu_barrier(srcu_ctlp);
}
static void srcu_scale_synchronize(void)
{
synchronize_srcu(srcu_ctlp);
}
static void srcu_scale_synchronize_expedited(void)
{
synchronize_srcu_expedited(srcu_ctlp);
}
static struct rcu_scale_ops srcu_ops = {
.ptype = SRCU_FLAVOR,
.init = rcu_sync_scale_init,
.readlock = srcu_scale_read_lock,
.readunlock = srcu_scale_read_unlock,
.get_gp_seq = srcu_scale_completed,
.gp_diff = rcu_seq_diff,
.exp_completed = srcu_scale_completed,
.async = srcu_call_rcu,
.gp_barrier = srcu_rcu_barrier,
.sync = srcu_scale_synchronize,
.exp_sync = srcu_scale_synchronize_expedited,
.name = "srcu"
};
static struct srcu_struct srcud;
static void srcu_sync_scale_init(void)
{
srcu_ctlp = &srcud;
init_srcu_struct(srcu_ctlp);
}
static void srcu_sync_scale_cleanup(void)
{
cleanup_srcu_struct(srcu_ctlp);
}
static struct rcu_scale_ops srcud_ops = {
.ptype = SRCU_FLAVOR,
.init = srcu_sync_scale_init,
.cleanup = srcu_sync_scale_cleanup,
.readlock = srcu_scale_read_lock,
.readunlock = srcu_scale_read_unlock,
.get_gp_seq = srcu_scale_completed,
.gp_diff = rcu_seq_diff,
.exp_completed = srcu_scale_completed,
.async = srcu_call_rcu,
.gp_barrier = srcu_rcu_barrier,
.sync = srcu_scale_synchronize,
.exp_sync = srcu_scale_synchronize_expedited,
.name = "srcud"
};
/*
* Definitions for RCU-tasks scalability testing.
*/
static int tasks_scale_read_lock(void)
{
return 0;
}
static void tasks_scale_read_unlock(int idx)
{
}
static struct rcu_scale_ops tasks_ops = {
.ptype = RCU_TASKS_FLAVOR,
.init = rcu_sync_scale_init,
.readlock = tasks_scale_read_lock,
.readunlock = tasks_scale_read_unlock,
.get_gp_seq = rcu_no_completed,
.gp_diff = rcu_seq_diff,
.async = call_rcu_tasks,
.gp_barrier = rcu_barrier_tasks,
.sync = synchronize_rcu_tasks,
.exp_sync = synchronize_rcu_tasks,
.name = "tasks"
};
static unsigned long rcuscale_seq_diff(unsigned long new, unsigned long old)
{
if (!cur_ops->gp_diff)
return new - old;
return cur_ops->gp_diff(new, old);
}
/*
* If scalability tests complete, wait for shutdown to commence.
*/
static void rcu_scale_wait_shutdown(void)
{
cond_resched_tasks_rcu_qs();
if (atomic_read(&n_rcu_scale_writer_finished) < nrealwriters)
return;
while (!torture_must_stop())
schedule_timeout_uninterruptible(1);
}
/*
* RCU scalability reader kthread. Repeatedly does empty RCU read-side
* critical section, minimizing update-side interference. However, the
* point of this test is not to evaluate reader scalability, but instead
* to serve as a test load for update-side scalability testing.
*/
static int
rcu_scale_reader(void *arg)
{
unsigned long flags;
int idx;
long me = (long)arg;
VERBOSE_SCALEOUT_STRING("rcu_scale_reader task started");
set_cpus_allowed_ptr(current, cpumask_of(me % nr_cpu_ids));
set_user_nice(current, MAX_NICE);
atomic_inc(&n_rcu_scale_reader_started);
do {
local_irq_save(flags);
idx = cur_ops->readlock();
cur_ops->readunlock(idx);
local_irq_restore(flags);
rcu_scale_wait_shutdown();
} while (!torture_must_stop());
torture_kthread_stopping("rcu_scale_reader");
return 0;
}
/*
* Callback function for asynchronous grace periods from rcu_scale_writer().
*/
static void rcu_scale_async_cb(struct rcu_head *rhp)
{
atomic_dec(this_cpu_ptr(&n_async_inflight));
kfree(rhp);
}
/*
* RCU scale writer kthread. Repeatedly does a grace period.
*/
static int
rcu_scale_writer(void *arg)
{
int i = 0;
int i_max;
long me = (long)arg;
struct rcu_head *rhp = NULL;
bool started = false, done = false, alldone = false;
u64 t;
u64 *wdp;
u64 *wdpp = writer_durations[me];
VERBOSE_SCALEOUT_STRING("rcu_scale_writer task started");
WARN_ON(!wdpp);
set_cpus_allowed_ptr(current, cpumask_of(me % nr_cpu_ids));
sched_set_fifo_low(current);
if (holdoff)
schedule_timeout_uninterruptible(holdoff * HZ);
/*
* Wait until rcu_end_inkernel_boot() is called for normal GP tests
* so that RCU is not always expedited for normal GP tests.
* The system_state test is approximate, but works well in practice.
*/
while (!gp_exp && system_state != SYSTEM_RUNNING)
schedule_timeout_uninterruptible(1);
t = ktime_get_mono_fast_ns();
if (atomic_inc_return(&n_rcu_scale_writer_started) >= nrealwriters) {
t_rcu_scale_writer_started = t;
if (gp_exp) {
b_rcu_gp_test_started =
cur_ops->exp_completed() / 2;
} else {
b_rcu_gp_test_started = cur_ops->get_gp_seq();
}
}
do {
if (writer_holdoff)
udelay(writer_holdoff);
wdp = &wdpp[i];
*wdp = ktime_get_mono_fast_ns();
if (gp_async) {
retry:
if (!rhp)
rhp = kmalloc(sizeof(*rhp), GFP_KERNEL);
if (rhp && atomic_read(this_cpu_ptr(&n_async_inflight)) < gp_async_max) {
atomic_inc(this_cpu_ptr(&n_async_inflight));
cur_ops->async(rhp, rcu_scale_async_cb);
rhp = NULL;
} else if (!kthread_should_stop()) {
cur_ops->gp_barrier();
goto retry;
} else {
kfree(rhp); /* Because we are stopping. */
}
} else if (gp_exp) {
cur_ops->exp_sync();
} else {
cur_ops->sync();
}
t = ktime_get_mono_fast_ns();
*wdp = t - *wdp;
i_max = i;
if (!started &&
atomic_read(&n_rcu_scale_writer_started) >= nrealwriters)
started = true;
if (!done && i >= MIN_MEAS) {
done = true;
sched_set_normal(current, 0);
pr_alert("%s%s rcu_scale_writer %ld has %d measurements\n",
scale_type, SCALE_FLAG, me, MIN_MEAS);
if (atomic_inc_return(&n_rcu_scale_writer_finished) >=
nrealwriters) {
schedule_timeout_interruptible(10);
rcu_ftrace_dump(DUMP_ALL);
SCALEOUT_STRING("Test complete");
t_rcu_scale_writer_finished = t;
if (gp_exp) {
b_rcu_gp_test_finished =
cur_ops->exp_completed() / 2;
} else {
b_rcu_gp_test_finished =
cur_ops->get_gp_seq();
}
if (shutdown) {
smp_mb(); /* Assign before wake. */
wake_up(&shutdown_wq);
}
}
}
if (done && !alldone &&
atomic_read(&n_rcu_scale_writer_finished) >= nrealwriters)
alldone = true;
if (started && !alldone && i < MAX_MEAS - 1)
i++;
rcu_scale_wait_shutdown();
} while (!torture_must_stop());
if (gp_async) {
cur_ops->gp_barrier();
}
writer_n_durations[me] = i_max;
torture_kthread_stopping("rcu_scale_writer");
return 0;
}
static void
rcu_scale_print_module_parms(struct rcu_scale_ops *cur_ops, const char *tag)
{
pr_alert("%s" SCALE_FLAG
"--- %s: nreaders=%d nwriters=%d verbose=%d shutdown=%d\n",
scale_type, tag, nrealreaders, nrealwriters, verbose, shutdown);
}
static void
rcu_scale_cleanup(void)
{
int i;
int j;
int ngps = 0;
u64 *wdp;
u64 *wdpp;
/*
* Would like warning at start, but everything is expedited
* during the mid-boot phase, so have to wait till the end.
*/
if (rcu_gp_is_expedited() && !rcu_gp_is_normal() && !gp_exp)
VERBOSE_SCALEOUT_ERRSTRING("All grace periods expedited, no normal ones to measure!");
if (rcu_gp_is_normal() && gp_exp)
VERBOSE_SCALEOUT_ERRSTRING("All grace periods normal, no expedited ones to measure!");
if (gp_exp && gp_async)
VERBOSE_SCALEOUT_ERRSTRING("No expedited async GPs, so went with async!");
if (torture_cleanup_begin())
return;
if (!cur_ops) {
torture_cleanup_end();
return;
}
if (reader_tasks) {
for (i = 0; i < nrealreaders; i++)
torture_stop_kthread(rcu_scale_reader,
reader_tasks[i]);
kfree(reader_tasks);
}
if (writer_tasks) {
for (i = 0; i < nrealwriters; i++) {
torture_stop_kthread(rcu_scale_writer,
writer_tasks[i]);
if (!writer_n_durations)
continue;
j = writer_n_durations[i];
pr_alert("%s%s writer %d gps: %d\n",
scale_type, SCALE_FLAG, i, j);
ngps += j;
}
pr_alert("%s%s start: %llu end: %llu duration: %llu gps: %d batches: %ld\n",
scale_type, SCALE_FLAG,
t_rcu_scale_writer_started, t_rcu_scale_writer_finished,
t_rcu_scale_writer_finished -
t_rcu_scale_writer_started,
ngps,
rcuscale_seq_diff(b_rcu_gp_test_finished,
b_rcu_gp_test_started));
for (i = 0; i < nrealwriters; i++) {
if (!writer_durations)
break;
if (!writer_n_durations)
continue;
wdpp = writer_durations[i];
if (!wdpp)
continue;
for (j = 0; j <= writer_n_durations[i]; j++) {
wdp = &wdpp[j];
pr_alert("%s%s %4d writer-duration: %5d %llu\n",
scale_type, SCALE_FLAG,
i, j, *wdp);
if (j % 100 == 0)
schedule_timeout_uninterruptible(1);
}
kfree(writer_durations[i]);
}
kfree(writer_tasks);
kfree(writer_durations);
kfree(writer_n_durations);
}
/* Do torture-type-specific cleanup operations. */
if (cur_ops->cleanup != NULL)
cur_ops->cleanup();
torture_cleanup_end();
}
/*
* Return the number if non-negative. If -1, the number of CPUs.
* If less than -1, that much less than the number of CPUs, but
* at least one.
*/
static int compute_real(int n)
{
int nr;
if (n >= 0) {
nr = n;
} else {
nr = num_online_cpus() + 1 + n;
if (nr <= 0)
nr = 1;
}
return nr;
}
/*
* RCU scalability shutdown kthread. Just waits to be awakened, then shuts
* down system.
*/
static int
rcu_scale_shutdown(void *arg)
{
wait_event(shutdown_wq,
atomic_read(&n_rcu_scale_writer_finished) >= nrealwriters);
smp_mb(); /* Wake before output. */
rcu_scale_cleanup();
kernel_power_off();
return -EINVAL;
}
/*
* kfree_rcu() scalability tests: Start a kfree_rcu() loop on all CPUs for number
* of iterations and measure total time and number of GP for all iterations to complete.
*/
torture_param(int, kfree_nthreads, -1, "Number of threads running loops of kfree_rcu().");
torture_param(int, kfree_alloc_num, 8000, "Number of allocations and frees done in an iteration.");
torture_param(int, kfree_loops, 10, "Number of loops doing kfree_alloc_num allocations and frees.");
static struct task_struct **kfree_reader_tasks;
static int kfree_nrealthreads;
static atomic_t n_kfree_scale_thread_started;
static atomic_t n_kfree_scale_thread_ended;
struct kfree_obj {
char kfree_obj[8];
struct rcu_head rh;
};
static int
kfree_scale_thread(void *arg)
{
int i, loop = 0;
long me = (long)arg;
struct kfree_obj *alloc_ptr;
u64 start_time, end_time;
long long mem_begin, mem_during = 0;
VERBOSE_SCALEOUT_STRING("kfree_scale_thread task started");
set_cpus_allowed_ptr(current, cpumask_of(me % nr_cpu_ids));
set_user_nice(current, MAX_NICE);
start_time = ktime_get_mono_fast_ns();
if (atomic_inc_return(&n_kfree_scale_thread_started) >= kfree_nrealthreads) {
if (gp_exp)
b_rcu_gp_test_started = cur_ops->exp_completed() / 2;
else
b_rcu_gp_test_started = cur_ops->get_gp_seq();
}
do {
if (!mem_during) {
mem_during = mem_begin = si_mem_available();
} else if (loop % (kfree_loops / 4) == 0) {
mem_during = (mem_during + si_mem_available()) / 2;
}
for (i = 0; i < kfree_alloc_num; i++) {
alloc_ptr = kmalloc(kfree_mult * sizeof(struct kfree_obj), GFP_KERNEL);
if (!alloc_ptr)
return -ENOMEM;
kfree_rcu(alloc_ptr, rh);
}
cond_resched();
} while (!torture_must_stop() && ++loop < kfree_loops);
if (atomic_inc_return(&n_kfree_scale_thread_ended) >= kfree_nrealthreads) {
end_time = ktime_get_mono_fast_ns();
if (gp_exp)
b_rcu_gp_test_finished = cur_ops->exp_completed() / 2;
else
b_rcu_gp_test_finished = cur_ops->get_gp_seq();
pr_alert("Total time taken by all kfree'ers: %llu ns, loops: %d, batches: %ld, memory footprint: %lldMB\n",
(unsigned long long)(end_time - start_time), kfree_loops,
rcuscale_seq_diff(b_rcu_gp_test_finished, b_rcu_gp_test_started),
(mem_begin - mem_during) >> (20 - PAGE_SHIFT));
if (shutdown) {
smp_mb(); /* Assign before wake. */
wake_up(&shutdown_wq);
}
}
torture_kthread_stopping("kfree_scale_thread");
return 0;
}
static void
kfree_scale_cleanup(void)
{
int i;
if (torture_cleanup_begin())
return;
if (kfree_reader_tasks) {
for (i = 0; i < kfree_nrealthreads; i++)
torture_stop_kthread(kfree_scale_thread,
kfree_reader_tasks[i]);
kfree(kfree_reader_tasks);
}
torture_cleanup_end();
}
/*
* shutdown kthread. Just waits to be awakened, then shuts down system.
*/
static int
kfree_scale_shutdown(void *arg)
{
wait_event(shutdown_wq,
atomic_read(&n_kfree_scale_thread_ended) >= kfree_nrealthreads);
smp_mb(); /* Wake before output. */
kfree_scale_cleanup();
kernel_power_off();
return -EINVAL;
}
static int __init
kfree_scale_init(void)
{
long i;
int firsterr = 0;
kfree_nrealthreads = compute_real(kfree_nthreads);
/* Start up the kthreads. */
if (shutdown) {
init_waitqueue_head(&shutdown_wq);
firsterr = torture_create_kthread(kfree_scale_shutdown, NULL,
shutdown_task);
if (firsterr)
goto unwind;
schedule_timeout_uninterruptible(1);
}
pr_alert("kfree object size=%zu\n", kfree_mult * sizeof(struct kfree_obj));
kfree_reader_tasks = kcalloc(kfree_nrealthreads, sizeof(kfree_reader_tasks[0]),
GFP_KERNEL);
if (kfree_reader_tasks == NULL) {
firsterr = -ENOMEM;
goto unwind;
}
for (i = 0; i < kfree_nrealthreads; i++) {
firsterr = torture_create_kthread(kfree_scale_thread, (void *)i,
kfree_reader_tasks[i]);
if (firsterr)
goto unwind;
}
while (atomic_read(&n_kfree_scale_thread_started) < kfree_nrealthreads)
schedule_timeout_uninterruptible(1);
torture_init_end();
return 0;
unwind:
torture_init_end();
kfree_scale_cleanup();
return firsterr;
}
static int __init
rcu_scale_init(void)
{
long i;
int firsterr = 0;
static struct rcu_scale_ops *scale_ops[] = {
&rcu_ops, &srcu_ops, &srcud_ops, &tasks_ops,
};
if (!torture_init_begin(scale_type, verbose))
return -EBUSY;
/* Process args and announce that the scalability'er is on the job. */
for (i = 0; i < ARRAY_SIZE(scale_ops); i++) {
cur_ops = scale_ops[i];
if (strcmp(scale_type, cur_ops->name) == 0)
break;
}
if (i == ARRAY_SIZE(scale_ops)) {
pr_alert("rcu-scale: invalid scale type: \"%s\"\n", scale_type);
pr_alert("rcu-scale types:");
for (i = 0; i < ARRAY_SIZE(scale_ops); i++)
pr_cont(" %s", scale_ops[i]->name);
pr_cont("\n");
WARN_ON(!IS_MODULE(CONFIG_RCU_SCALE_TEST));
firsterr = -EINVAL;
cur_ops = NULL;
goto unwind;
}
if (cur_ops->init)
cur_ops->init();
if (kfree_rcu_test)
return kfree_scale_init();
nrealwriters = compute_real(nwriters);
nrealreaders = compute_real(nreaders);
atomic_set(&n_rcu_scale_reader_started, 0);
atomic_set(&n_rcu_scale_writer_started, 0);
atomic_set(&n_rcu_scale_writer_finished, 0);
rcu_scale_print_module_parms(cur_ops, "Start of test");
/* Start up the kthreads. */
if (shutdown) {
init_waitqueue_head(&shutdown_wq);
firsterr = torture_create_kthread(rcu_scale_shutdown, NULL,
shutdown_task);
if (firsterr)
goto unwind;
schedule_timeout_uninterruptible(1);
}
reader_tasks = kcalloc(nrealreaders, sizeof(reader_tasks[0]),
GFP_KERNEL);
if (reader_tasks == NULL) {
VERBOSE_SCALEOUT_ERRSTRING("out of memory");
firsterr = -ENOMEM;
goto unwind;
}
for (i = 0; i < nrealreaders; i++) {
firsterr = torture_create_kthread(rcu_scale_reader, (void *)i,
reader_tasks[i]);
if (firsterr)
goto unwind;
}
while (atomic_read(&n_rcu_scale_reader_started) < nrealreaders)
schedule_timeout_uninterruptible(1);
writer_tasks = kcalloc(nrealwriters, sizeof(reader_tasks[0]),
GFP_KERNEL);
writer_durations = kcalloc(nrealwriters, sizeof(*writer_durations),
GFP_KERNEL);
writer_n_durations =
kcalloc(nrealwriters, sizeof(*writer_n_durations),
GFP_KERNEL);
if (!writer_tasks || !writer_durations || !writer_n_durations) {
VERBOSE_SCALEOUT_ERRSTRING("out of memory");
firsterr = -ENOMEM;
goto unwind;
}
for (i = 0; i < nrealwriters; i++) {
writer_durations[i] =
kcalloc(MAX_MEAS, sizeof(*writer_durations[i]),
GFP_KERNEL);
if (!writer_durations[i]) {
firsterr = -ENOMEM;
goto unwind;
}
firsterr = torture_create_kthread(rcu_scale_writer, (void *)i,
writer_tasks[i]);
if (firsterr)
goto unwind;
}
torture_init_end();
return 0;
unwind:
torture_init_end();
rcu_scale_cleanup();
return firsterr;
}
module_init(rcu_scale_init);
module_exit(rcu_scale_cleanup);
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