mirror_zfs/module/splat/splat-thread.c
Brian Behlendorf 62aa81a577 Add defclsyspri macro
Add a new defclsyspri macro which can be used to request the default
Linux scheduler priority.  Neither the minclsyspri or maxclsyspri map
to the default Linux kernel thread priority.  This makes it awkward to
create taskqs which run with the same priority as the rest of the kernel
threads on the system which can lead to performance issues.

All SPL callers which previously used minclsyspri or maxclsyspri have
been changed to use defclsyspri.  The vast majority of callers were
part of the test suite which won't have an external impact.  The few
places where it could impact performance the change was from maxclsyspri
to defclsyspri.  This makes it more likely the process will be scheduled
which may help performance.

To facilitate further performance analysis the spl_taskq_thread_priority
module option has been added.  When disabled (0) all newly created kernel
threads will use the default kernel thread priority.  When enabled (1)
the specified taskq priority will be used.  By default this value is
enabled (1).

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2015-07-23 13:25:49 -07:00

390 lines
11 KiB
C

/*****************************************************************************\
* Copyright (C) 2007-2010 Lawrence Livermore National Security, LLC.
* Copyright (C) 2007 The Regents of the University of California.
* Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
* Written by Brian Behlendorf <behlendorf1@llnl.gov>.
* UCRL-CODE-235197
*
* This file is part of the SPL, Solaris Porting Layer.
* For details, see <http://zfsonlinux.org/>.
*
* The SPL is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*
* The SPL is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* for more details.
*
* You should have received a copy of the GNU General Public License along
* with the SPL. If not, see <http://www.gnu.org/licenses/>.
*****************************************************************************
* Solaris Porting LAyer Tests (SPLAT) Thread Tests.
\*****************************************************************************/
#include <sys/thread.h>
#include <sys/random.h>
#include <linux/delay.h>
#include <linux/mm_compat.h>
#include <linux/slab.h>
#include "splat-internal.h"
#define SPLAT_THREAD_NAME "thread"
#define SPLAT_THREAD_DESC "Kernel Thread Tests"
#define SPLAT_THREAD_TEST1_ID 0x0601
#define SPLAT_THREAD_TEST1_NAME "create"
#define SPLAT_THREAD_TEST1_DESC "Validate thread creation"
#define SPLAT_THREAD_TEST2_ID 0x0602
#define SPLAT_THREAD_TEST2_NAME "exit"
#define SPLAT_THREAD_TEST2_DESC "Validate thread exit"
#define SPLAT_THREAD_TEST3_ID 0x6003
#define SPLAT_THREAD_TEST3_NAME "tsd"
#define SPLAT_THREAD_TEST3_DESC "Validate thread specific data"
#define SPLAT_THREAD_TEST_MAGIC 0x4488CC00UL
#define SPLAT_THREAD_TEST_KEYS 32
#define SPLAT_THREAD_TEST_THREADS 16
typedef struct thread_priv {
unsigned long tp_magic;
struct file *tp_file;
spinlock_t tp_lock;
wait_queue_head_t tp_waitq;
uint_t tp_keys[SPLAT_THREAD_TEST_KEYS];
int tp_rc;
int tp_count;
int tp_dtor_count;
} thread_priv_t;
static int
splat_thread_rc(thread_priv_t *tp, int rc)
{
int ret;
spin_lock(&tp->tp_lock);
ret = (tp->tp_rc == rc);
spin_unlock(&tp->tp_lock);
return ret;
}
static int
splat_thread_count(thread_priv_t *tp, int count)
{
int ret;
spin_lock(&tp->tp_lock);
ret = (tp->tp_count == count);
spin_unlock(&tp->tp_lock);
return ret;
}
static void
splat_thread_work1(void *priv)
{
thread_priv_t *tp = (thread_priv_t *)priv;
spin_lock(&tp->tp_lock);
ASSERT(tp->tp_magic == SPLAT_THREAD_TEST_MAGIC);
tp->tp_rc = 1;
wake_up(&tp->tp_waitq);
spin_unlock(&tp->tp_lock);
thread_exit();
}
static int
splat_thread_test1(struct file *file, void *arg)
{
thread_priv_t tp;
kthread_t *thr;
tp.tp_magic = SPLAT_THREAD_TEST_MAGIC;
tp.tp_file = file;
spin_lock_init(&tp.tp_lock);
init_waitqueue_head(&tp.tp_waitq);
tp.tp_rc = 0;
thr = (kthread_t *)thread_create(NULL, 0, splat_thread_work1, &tp, 0,
&p0, TS_RUN, defclsyspri);
/* Must never fail under Solaris, but we check anyway since this
* can happen in the linux SPL, we may want to change this behavior */
if (thr == NULL)
return -ESRCH;
/* Sleep until the thread sets tp.tp_rc == 1 */
wait_event(tp.tp_waitq, splat_thread_rc(&tp, 1));
splat_vprint(file, SPLAT_THREAD_TEST1_NAME, "%s",
"Thread successfully started properly\n");
return 0;
}
static void
splat_thread_work2(void *priv)
{
thread_priv_t *tp = (thread_priv_t *)priv;
spin_lock(&tp->tp_lock);
ASSERT(tp->tp_magic == SPLAT_THREAD_TEST_MAGIC);
tp->tp_rc = 1;
wake_up(&tp->tp_waitq);
spin_unlock(&tp->tp_lock);
thread_exit();
/* The following code is unreachable when thread_exit() is
* working properly, which is exactly what we're testing */
spin_lock(&tp->tp_lock);
tp->tp_rc = 2;
wake_up(&tp->tp_waitq);
spin_unlock(&tp->tp_lock);
}
static int
splat_thread_test2(struct file *file, void *arg)
{
thread_priv_t tp;
kthread_t *thr;
int rc = 0;
tp.tp_magic = SPLAT_THREAD_TEST_MAGIC;
tp.tp_file = file;
spin_lock_init(&tp.tp_lock);
init_waitqueue_head(&tp.tp_waitq);
tp.tp_rc = 0;
thr = (kthread_t *)thread_create(NULL, 0, splat_thread_work2, &tp, 0,
&p0, TS_RUN, defclsyspri);
/* Must never fail under Solaris, but we check anyway since this
* can happen in the linux SPL, we may want to change this behavior */
if (thr == NULL)
return -ESRCH;
/* Sleep until the thread sets tp.tp_rc == 1 */
wait_event(tp.tp_waitq, splat_thread_rc(&tp, 1));
/* Sleep until the thread sets tp.tp_rc == 2, or until we hit
* the timeout. If thread exit is working properly we should
* hit the timeout and never see to.tp_rc == 2. */
rc = wait_event_timeout(tp.tp_waitq, splat_thread_rc(&tp, 2), HZ / 10);
if (rc > 0) {
rc = -EINVAL;
splat_vprint(file, SPLAT_THREAD_TEST2_NAME, "%s",
"Thread did not exit properly at thread_exit()\n");
} else {
splat_vprint(file, SPLAT_THREAD_TEST2_NAME, "%s",
"Thread successfully exited at thread_exit()\n");
}
return rc;
}
static void
splat_thread_work3_common(thread_priv_t *tp)
{
ulong_t rnd;
int i, rc = 0;
/* set a unique value for each key using a random value */
get_random_bytes((void *)&rnd, 4);
for (i = 0; i < SPLAT_THREAD_TEST_KEYS; i++)
tsd_set(tp->tp_keys[i], (void *)(i + rnd));
/* verify the unique value for each key */
for (i = 0; i < SPLAT_THREAD_TEST_KEYS; i++)
if (tsd_get(tp->tp_keys[i]) != (void *)(i + rnd))
rc = -EINVAL;
/* set the value to thread_priv_t for use by the destructor */
for (i = 0; i < SPLAT_THREAD_TEST_KEYS; i++)
tsd_set(tp->tp_keys[i], (void *)tp);
spin_lock(&tp->tp_lock);
if (rc && !tp->tp_rc)
tp->tp_rc = rc;
tp->tp_count++;
wake_up_all(&tp->tp_waitq);
spin_unlock(&tp->tp_lock);
}
static void
splat_thread_work3_wait(void *priv)
{
thread_priv_t *tp = (thread_priv_t *)priv;
ASSERT(tp->tp_magic == SPLAT_THREAD_TEST_MAGIC);
splat_thread_work3_common(tp);
wait_event(tp->tp_waitq, splat_thread_count(tp, 0));
thread_exit();
}
static void
splat_thread_work3_exit(void *priv)
{
thread_priv_t *tp = (thread_priv_t *)priv;
ASSERT(tp->tp_magic == SPLAT_THREAD_TEST_MAGIC);
splat_thread_work3_common(tp);
thread_exit();
}
static void
splat_thread_dtor3(void *priv)
{
thread_priv_t *tp = (thread_priv_t *)priv;
ASSERT(tp->tp_magic == SPLAT_THREAD_TEST_MAGIC);
spin_lock(&tp->tp_lock);
tp->tp_dtor_count++;
spin_unlock(&tp->tp_lock);
}
/*
* Create threads which set and verify SPLAT_THREAD_TEST_KEYS number of
* keys. These threads may then exit by calling thread_exit() which calls
* tsd_exit() resulting in all their thread specific data being reclaimed.
* Alternately, the thread may block in which case the thread specific
* data will be reclaimed as part of tsd_destroy(). In either case all
* thread specific data must be reclaimed, this is verified by ensuring
* the registered destructor is called the correct number of times.
*/
static int
splat_thread_test3(struct file *file, void *arg)
{
int i, rc = 0, expected, wait_count = 0, exit_count = 0;
thread_priv_t tp;
tp.tp_magic = SPLAT_THREAD_TEST_MAGIC;
tp.tp_file = file;
spin_lock_init(&tp.tp_lock);
init_waitqueue_head(&tp.tp_waitq);
tp.tp_rc = 0;
tp.tp_count = 0;
tp.tp_dtor_count = 0;
for (i = 0; i < SPLAT_THREAD_TEST_KEYS; i++) {
tp.tp_keys[i] = 0;
tsd_create(&tp.tp_keys[i], splat_thread_dtor3);
}
/* Start tsd wait threads */
for (i = 0; i < SPLAT_THREAD_TEST_THREADS; i++) {
if (thread_create(NULL, 0, splat_thread_work3_wait,
&tp, 0, &p0, TS_RUN, defclsyspri))
wait_count++;
}
/* All wait threads have setup their tsd and are blocking. */
wait_event(tp.tp_waitq, splat_thread_count(&tp, wait_count));
if (tp.tp_dtor_count != 0) {
splat_vprint(file, SPLAT_THREAD_TEST3_NAME,
"Prematurely ran %d tsd destructors\n", tp.tp_dtor_count);
if (!rc)
rc = -ERANGE;
}
/* Start tsd exit threads */
for (i = 0; i < SPLAT_THREAD_TEST_THREADS; i++) {
if (thread_create(NULL, 0, splat_thread_work3_exit,
&tp, 0, &p0, TS_RUN, defclsyspri))
exit_count++;
}
/* All exit threads verified tsd and are in the process of exiting */
wait_event(tp.tp_waitq,splat_thread_count(&tp, wait_count+exit_count));
msleep(500);
expected = (SPLAT_THREAD_TEST_KEYS * exit_count);
if (tp.tp_dtor_count != expected) {
splat_vprint(file, SPLAT_THREAD_TEST3_NAME,
"Expected %d exit tsd destructors but saw %d\n",
expected, tp.tp_dtor_count);
if (!rc)
rc = -ERANGE;
}
/* Destroy all keys and associated tsd in blocked threads */
for (i = 0; i < SPLAT_THREAD_TEST_KEYS; i++)
tsd_destroy(&tp.tp_keys[i]);
expected = (SPLAT_THREAD_TEST_KEYS * (exit_count + wait_count));
if (tp.tp_dtor_count != expected) {
splat_vprint(file, SPLAT_THREAD_TEST3_NAME,
"Expected %d wait+exit tsd destructors but saw %d\n",
expected, tp.tp_dtor_count);
if (!rc)
rc = -ERANGE;
}
/* Release the remaining wait threads, sleep briefly while they exit */
spin_lock(&tp.tp_lock);
tp.tp_count = 0;
wake_up_all(&tp.tp_waitq);
spin_unlock(&tp.tp_lock);
msleep(500);
if (tp.tp_rc) {
splat_vprint(file, SPLAT_THREAD_TEST3_NAME,
"Thread tsd_get()/tsd_set() error %d\n", tp.tp_rc);
if (!rc)
rc = tp.tp_rc;
} else if (!rc) {
splat_vprint(file, SPLAT_THREAD_TEST3_NAME, "%s",
"Thread specific data verified\n");
}
return rc;
}
splat_subsystem_t *
splat_thread_init(void)
{
splat_subsystem_t *sub;
sub = kmalloc(sizeof(*sub), GFP_KERNEL);
if (sub == NULL)
return NULL;
memset(sub, 0, sizeof(*sub));
strncpy(sub->desc.name, SPLAT_THREAD_NAME, SPLAT_NAME_SIZE);
strncpy(sub->desc.desc, SPLAT_THREAD_DESC, SPLAT_DESC_SIZE);
INIT_LIST_HEAD(&sub->subsystem_list);
INIT_LIST_HEAD(&sub->test_list);
spin_lock_init(&sub->test_lock);
sub->desc.id = SPLAT_SUBSYSTEM_THREAD;
SPLAT_TEST_INIT(sub, SPLAT_THREAD_TEST1_NAME, SPLAT_THREAD_TEST1_DESC,
SPLAT_THREAD_TEST1_ID, splat_thread_test1);
SPLAT_TEST_INIT(sub, SPLAT_THREAD_TEST2_NAME, SPLAT_THREAD_TEST2_DESC,
SPLAT_THREAD_TEST2_ID, splat_thread_test2);
SPLAT_TEST_INIT(sub, SPLAT_THREAD_TEST3_NAME, SPLAT_THREAD_TEST3_DESC,
SPLAT_THREAD_TEST3_ID, splat_thread_test3);
return sub;
}
void
splat_thread_fini(splat_subsystem_t *sub)
{
ASSERT(sub);
SPLAT_TEST_FINI(sub, SPLAT_THREAD_TEST3_ID);
SPLAT_TEST_FINI(sub, SPLAT_THREAD_TEST2_ID);
SPLAT_TEST_FINI(sub, SPLAT_THREAD_TEST1_ID);
kfree(sub);
}
int
splat_thread_id(void) {
return SPLAT_SUBSYSTEM_THREAD;
}