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-rw-r--r--module/spl/spl-mutex.c295
-rw-r--r--module/spl/spl-proc.c172
-rw-r--r--module/splat/splat-mutex.c464
3 files changed, 268 insertions, 663 deletions
diff --git a/module/spl/spl-mutex.c b/module/spl/spl-mutex.c
index f0389f5d1..0af74571d 100644
--- a/module/spl/spl-mutex.c
+++ b/module/spl/spl-mutex.c
@@ -1,7 +1,7 @@
/*
* This file is part of the SPL: Solaris Porting Layer.
*
- * Copyright (c) 2008 Lawrence Livermore National Security, LLC.
+ * Copyright (c) 2009 Lawrence Livermore National Security, LLC.
* Produced at Lawrence Livermore National Laboratory
* Written by:
* Brian Behlendorf <[email protected]>,
@@ -32,277 +32,46 @@
#define DEBUG_SUBSYSTEM S_MUTEX
-/* Mutex implementation based on those found in Solaris. This means
- * they the MUTEX_DEFAULT type is an adaptive mutex. When calling
- * mutex_enter() your process will spin waiting for the lock if it's
- * likely the lock will be free'd shortly. If it looks like the
- * lock will be held for a longer time we schedule and sleep waiting
- * for it. This determination is made by checking if the holder of
- * the lock is currently running on cpu or sleeping waiting to be
- * scheduled. If the holder is currently running it's likely the
- * lock will be shortly dropped.
+/*
+ * While a standard mutex implementation has been available in the kernel
+ * for quite some time. It was not until 2.6.29 and latter kernels that
+ * adaptive mutexs were embraced and integrated with the scheduler. This
+ * brought a significant performance improvement, but just as importantly
+ * it added a lock owner to the generic mutex outside CONFIG_DEBUG_MUTEXES
+ * builds. This is critical for correctly supporting the mutex_owner()
+ * Solaris primitive. When the owner is available we use a pure Linux
+ * mutex implementation. When the owner is not available we still use
+ * Linux mutexs as a base but also reserve space for an owner field right
+ * after the mutex structure.
*
- * XXX: This is basically a rough implementation to see if this
- * helps our performance. If it does a more careful implementation
- * should be done, perhaps in assembly.
+ * In the case when HAVE_MUTEX_OWNER is not defined your code may
+ * still me able to leverage adaptive mutexs. As long as the task_curr()
+ * symbol is exported this code will provide a poor mans adaptive mutex
+ * implementation. However, this is not required and if the symbol is
+ * unavailable we provide a standard mutex.
*/
-/* 0: Never spin when trying to aquire lock
- * -1: Spin until aquired or holder yeilds without dropping lock
+#ifndef HAVE_MUTEX_OWNER
+#ifdef HAVE_TASK_CURR
+/*
+ * mutex_spin_max = { 0, -1, 1-MAX_INT }
+ * 0: Never spin when trying to acquire lock
+ * -1: Spin until acquired or holder yields without dropping lock
* 1-MAX_INT: Spin for N attempts before sleeping for lock
*/
int mutex_spin_max = 0;
-
-#ifdef DEBUG_MUTEX
-int mutex_stats[MUTEX_STATS_SIZE] = { 0 };
-spinlock_t mutex_stats_lock;
-struct list_head mutex_stats_list;
-#endif
-
-int
-__spl_mutex_init(kmutex_t *mp, char *name, int type, void *ibc)
-{
- int flags = KM_SLEEP;
-
- ASSERT(mp);
- ASSERT(name);
- ASSERT(ibc == NULL);
-
- mp->km_name = NULL;
- mp->km_name_size = strlen(name) + 1;
-
- switch (type) {
- case MUTEX_DEFAULT:
- mp->km_type = MUTEX_ADAPTIVE;
- break;
- case MUTEX_SPIN:
- case MUTEX_ADAPTIVE:
- mp->km_type = type;
- break;
- default:
- SBUG();
- }
-
- /* We may be called when there is a non-zero preempt_count or
- * interrupts are disabled is which case we must not sleep.
- */
- if (current_thread_info()->preempt_count || irqs_disabled())
- flags = KM_NOSLEEP;
-
- /* Semaphore kmem_alloc'ed to keep struct size down (<64b) */
- mp->km_sem = kmem_alloc(sizeof(struct semaphore), flags);
- if (mp->km_sem == NULL)
- return -ENOMEM;
-
- mp->km_name = kmem_alloc(mp->km_name_size, flags);
- if (mp->km_name == NULL) {
- kmem_free(mp->km_sem, sizeof(struct semaphore));
- return -ENOMEM;
- }
-
- sema_init(mp->km_sem, 1);
- strncpy(mp->km_name, name, mp->km_name_size);
-
-#ifdef DEBUG_MUTEX
- mp->km_stats = kmem_zalloc(sizeof(int) * MUTEX_STATS_SIZE, flags);
- if (mp->km_stats == NULL) {
- kmem_free(mp->km_name, mp->km_name_size);
- kmem_free(mp->km_sem, sizeof(struct semaphore));
- return -ENOMEM;
- }
-
- /* XXX - This appears to be a much more contended lock than I
- * would have expected. To run with this debugging enabled and
- * get reasonable performance we may need to be more clever and
- * do something like hash the mutex ptr on to one of several
- * lists to ease this single point of contention.
- */
- spin_lock(&mutex_stats_lock);
- list_add_tail(&mp->km_list, &mutex_stats_list);
- spin_unlock(&mutex_stats_lock);
-#endif
- mp->km_magic = KM_MAGIC;
- mp->km_owner = NULL;
-
- return 0;
-}
-EXPORT_SYMBOL(__spl_mutex_init);
-
-void
-__spl_mutex_destroy(kmutex_t *mp)
-{
- ASSERT(mp);
- ASSERT(mp->km_magic == KM_MAGIC);
-
-#ifdef DEBUG_MUTEX
- spin_lock(&mutex_stats_lock);
- list_del_init(&mp->km_list);
- spin_unlock(&mutex_stats_lock);
-
- kmem_free(mp->km_stats, sizeof(int) * MUTEX_STATS_SIZE);
-#endif
- kmem_free(mp->km_name, mp->km_name_size);
- kmem_free(mp->km_sem, sizeof(struct semaphore));
-
- memset(mp, KM_POISON, sizeof(*mp));
-}
-EXPORT_SYMBOL(__spl_mutex_destroy);
-
-/* Return 1 if we acquired the mutex, else zero. */
-int
-__mutex_tryenter(kmutex_t *mp)
-{
- int rc;
- ENTRY;
-
- ASSERT(mp);
- ASSERT(mp->km_magic == KM_MAGIC);
- MUTEX_STAT_INC(mutex_stats, MUTEX_TRYENTER_TOTAL);
- MUTEX_STAT_INC(mp->km_stats, MUTEX_TRYENTER_TOTAL);
-
- rc = down_trylock(mp->km_sem);
- if (rc == 0) {
- ASSERT(mp->km_owner == NULL);
- mp->km_owner = current;
- MUTEX_STAT_INC(mutex_stats, MUTEX_TRYENTER_NOT_HELD);
- MUTEX_STAT_INC(mp->km_stats, MUTEX_TRYENTER_NOT_HELD);
- }
-
- RETURN(!rc);
-}
-EXPORT_SYMBOL(__mutex_tryenter);
-
-#ifndef HAVE_TASK_CURR
-#define task_curr(owner) 0
-#endif
-
-
-static void
-mutex_enter_adaptive(kmutex_t *mp)
-{
- struct task_struct *owner;
- int count = 0;
-
- /* Lock is not held so we expect to aquire the lock */
- if ((owner = mp->km_owner) == NULL) {
- down(mp->km_sem);
- MUTEX_STAT_INC(mutex_stats, MUTEX_ENTER_NOT_HELD);
- MUTEX_STAT_INC(mp->km_stats, MUTEX_ENTER_NOT_HELD);
- } else {
- /* The lock is held by a currently running task which
- * we expect will drop the lock before leaving the
- * head of the runqueue. So the ideal thing to do
- * is spin until we aquire the lock and avoid a
- * context switch. However it is also possible the
- * task holding the lock yields the processor with
- * out dropping lock. In which case, we know it's
- * going to be a while so we stop spinning and go
- * to sleep waiting for the lock to be available.
- * This should strike the optimum balance between
- * spinning and sleeping waiting for a lock.
- */
- while (task_curr(owner) && (count <= mutex_spin_max)) {
- if (down_trylock(mp->km_sem) == 0) {
- MUTEX_STAT_INC(mutex_stats, MUTEX_ENTER_SPIN);
- MUTEX_STAT_INC(mp->km_stats, MUTEX_ENTER_SPIN);
- GOTO(out, count);
- }
- count++;
- }
-
- /* The lock is held by a sleeping task so it's going to
- * cost us minimally one context switch. We might as
- * well sleep and yield the processor to other tasks.
- */
- down(mp->km_sem);
- MUTEX_STAT_INC(mutex_stats, MUTEX_ENTER_SLEEP);
- MUTEX_STAT_INC(mp->km_stats, MUTEX_ENTER_SLEEP);
- }
-out:
- MUTEX_STAT_INC(mutex_stats, MUTEX_ENTER_TOTAL);
- MUTEX_STAT_INC(mp->km_stats, MUTEX_ENTER_TOTAL);
-}
-
-void
-__mutex_enter(kmutex_t *mp)
-{
- ENTRY;
- ASSERT(mp);
- ASSERT(mp->km_magic == KM_MAGIC);
-
- switch (mp->km_type) {
- case MUTEX_SPIN:
- while (down_trylock(mp->km_sem));
- MUTEX_STAT_INC(mutex_stats, MUTEX_ENTER_SPIN);
- MUTEX_STAT_INC(mp->km_stats, MUTEX_ENTER_SPIN);
- break;
- case MUTEX_ADAPTIVE:
- mutex_enter_adaptive(mp);
- break;
- }
-
- ASSERT(mp->km_owner == NULL);
- mp->km_owner = current;
-
- EXIT;
-}
-EXPORT_SYMBOL(__mutex_enter);
-
-void
-__mutex_exit(kmutex_t *mp)
-{
- ENTRY;
- ASSERT(mp);
- ASSERT(mp->km_magic == KM_MAGIC);
- ASSERT(mp->km_owner == current);
- mp->km_owner = NULL;
- up(mp->km_sem);
- EXIT;
-}
-EXPORT_SYMBOL(__mutex_exit);
-
-/* Return 1 if mutex is held by current process, else zero. */
-int
-__mutex_owned(kmutex_t *mp)
-{
- ENTRY;
- ASSERT(mp);
- ASSERT(mp->km_magic == KM_MAGIC);
- RETURN(mp->km_owner == current);
-}
-EXPORT_SYMBOL(__mutex_owned);
-
-/* Return owner if mutex is owned, else NULL. */
-kthread_t *
-__spl_mutex_owner(kmutex_t *mp)
-{
- ENTRY;
- ASSERT(mp);
- ASSERT(mp->km_magic == KM_MAGIC);
- RETURN(mp->km_owner);
-}
-EXPORT_SYMBOL(__spl_mutex_owner);
+module_param(mutex_spin_max, int, 0644);
+MODULE_PARM_DESC(mutex_spin_max, "Spin a maximum of N times to acquire lock");
int
-spl_mutex_init(void)
+spl_mutex_spin_max(void)
{
- ENTRY;
-#ifdef DEBUG_MUTEX
- spin_lock_init(&mutex_stats_lock);
- INIT_LIST_HEAD(&mutex_stats_list);
-#endif
- RETURN(0);
+ return mutex_spin_max;
}
+EXPORT_SYMBOL(spl_mutex_spin_max);
-void
-spl_mutex_fini(void)
-{
- ENTRY;
-#ifdef DEBUG_MUTEX
- ASSERT(list_empty(&mutex_stats_list));
-#endif
- EXIT;
-}
+#endif /* HAVE_TASK_CURR */
+#endif /* !HAVE_MUTEX_OWNER */
-module_param(mutex_spin_max, int, 0644);
-MODULE_PARM_DESC(mutex_spin_max, "Spin a maximum of N times to aquire lock");
+int spl_mutex_init(void) { return 0; }
+void spl_mutex_fini(void) { }
diff --git a/module/spl/spl-proc.c b/module/spl/spl-proc.c
index 5dd7884f6..690f2991e 100644
--- a/module/spl/spl-proc.c
+++ b/module/spl/spl-proc.c
@@ -41,12 +41,8 @@ static unsigned long table_max = ~0;
static struct ctl_table_header *spl_header = NULL;
#endif /* CONFIG_SYSCTL */
-#if defined(DEBUG_MUTEX) || defined(DEBUG_KMEM) || defined(DEBUG_KSTAT)
+#if defined(DEBUG_KMEM) || defined(DEBUG_KSTAT)
static struct proc_dir_entry *proc_spl = NULL;
-#ifdef DEBUG_MUTEX
-static struct proc_dir_entry *proc_spl_mutex = NULL;
-static struct proc_dir_entry *proc_spl_mutex_stats = NULL;
-#endif /* DEBUG_MUTEX */
#ifdef DEBUG_KMEM
static struct proc_dir_entry *proc_spl_kmem = NULL;
static struct proc_dir_entry *proc_spl_kmem_slab = NULL;
@@ -54,7 +50,7 @@ static struct proc_dir_entry *proc_spl_kmem_slab = NULL;
#ifdef DEBUG_KSTAT
struct proc_dir_entry *proc_spl_kstat = NULL;
#endif /* DEBUG_KSTAT */
-#endif /* DEBUG_MUTEX || DEBUG_KMEM || DEBUG_KSTAT */
+#endif /* DEBUG_KMEM || DEBUG_KSTAT */
#ifdef HAVE_CTL_UNNUMBERED
@@ -105,10 +101,6 @@ struct proc_dir_entry *proc_spl_kstat = NULL;
#define CTL_KMEM_ALLOC_FAILED CTL_UNNUMBERED /* Cache allocations failed */
#endif
-#define CTL_MUTEX_STATS CTL_UNNUMBERED /* Global mutex statistics */
-#define CTL_MUTEX_STATS_PER CTL_UNNUMBERED /* Per mutex statistics */
-#define CTL_MUTEX_SPIN_MAX CTL_UNNUMBERED /* Max mutex spin iterations */
-
#else /* HAVE_CTL_UNNUMBERED */
enum {
@@ -159,10 +151,6 @@ enum {
CTL_KMEM_VMEMUSED, /* Alloc'd vmem bytes */
CTL_KMEM_VMEMMAX, /* Max alloc'd by vmem bytes */
#endif
-
- CTL_MUTEX_STATS, /* Global mutex statistics */
- CTL_MUTEX_STATS_PER, /* Per mutex statistics */
- CTL_MUTEX_SPIN_MAX, /* Maximum mutex spin iterations */
};
#endif /* HAVE_CTL_UNNUMBERED */
@@ -589,103 +577,6 @@ proc_dofreemem(struct ctl_table *table, int write, struct file *filp,
RETURN(rc);
}
-#ifdef DEBUG_MUTEX
-static void
-mutex_seq_show_headers(struct seq_file *f)
-{
- seq_printf(f, "%-36s %-4s %-16s\t"
- "e_tot\te_nh\te_sp\te_sl\tte_tot\tte_nh\n",
- "name", "type", "owner");
-}
-
-static int
-mutex_seq_show(struct seq_file *f, void *p)
-{
- kmutex_t *mp = p;
- char t = 'X';
- int i;
-
- ASSERT(mp->km_magic == KM_MAGIC);
-
- switch (mp->km_type) {
- case MUTEX_DEFAULT: t = 'D'; break;
- case MUTEX_SPIN: t = 'S'; break;
- case MUTEX_ADAPTIVE: t = 'A'; break;
- default:
- SBUG();
- }
- seq_printf(f, "%-36s %c ", mp->km_name, t);
- if (mp->km_owner)
- seq_printf(f, "%p\t", mp->km_owner);
- else
- seq_printf(f, "%-16s\t", "<not held>");
-
- for (i = 0; i < MUTEX_STATS_SIZE; i++)
- seq_printf(f, "%d%c", mp->km_stats[i],
- (i + 1 == MUTEX_STATS_SIZE) ? '\n' : '\t');
-
- return 0;
-}
-
-static void *
-mutex_seq_start(struct seq_file *f, loff_t *pos)
-{
- struct list_head *p;
- loff_t n = *pos;
- ENTRY;
-
- spin_lock(&mutex_stats_lock);
- if (!n)
- mutex_seq_show_headers(f);
-
- p = mutex_stats_list.next;
- while (n--) {
- p = p->next;
- if (p == &mutex_stats_list)
- RETURN(NULL);
- }
-
- RETURN(list_entry(p, kmutex_t, km_list));
-}
-
-static void *
-mutex_seq_next(struct seq_file *f, void *p, loff_t *pos)
-{
- kmutex_t *mp = p;
- ENTRY;
-
- ++*pos;
- RETURN((mp->km_list.next == &mutex_stats_list) ?
- NULL : list_entry(mp->km_list.next, kmutex_t, km_list));
-}
-
-static void
-mutex_seq_stop(struct seq_file *f, void *v)
-{
- spin_unlock(&mutex_stats_lock);
-}
-
-static struct seq_operations mutex_seq_ops = {
- .show = mutex_seq_show,
- .start = mutex_seq_start,
- .next = mutex_seq_next,
- .stop = mutex_seq_stop,
-};
-
-static int
-proc_mutex_open(struct inode *inode, struct file *filp)
-{
- return seq_open(filp, &mutex_seq_ops);
-}
-
-static struct file_operations proc_mutex_operations = {
- .open = proc_mutex_open,
- .read = seq_read,
- .llseek = seq_lseek,
- .release = seq_release,
-};
-#endif /* DEBUG_MUTEX */
-
#ifdef DEBUG_KMEM
static void
slab_seq_show_headers(struct seq_file *f)
@@ -968,28 +859,6 @@ static struct ctl_table spl_vm_table[] = {
{0},
};
-#ifdef DEBUG_MUTEX
-static struct ctl_table spl_mutex_table[] = {
- {
- .ctl_name = CTL_MUTEX_STATS,
- .procname = "stats",
- .data = &mutex_stats,
- .maxlen = sizeof(int) * MUTEX_STATS_SIZE,
- .mode = 0444,
- .proc_handler = &proc_dointvec,
- },
- {
- .ctl_name = CTL_MUTEX_SPIN_MAX,
- .procname = "spin_max",
- .data = &mutex_spin_max,
- .maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = &proc_dointvec,
- },
- {0},
-};
-#endif /* DEBUG_MUTEX */
-
#ifdef DEBUG_KMEM
static struct ctl_table spl_kmem_table[] = {
{
@@ -1088,14 +957,6 @@ static struct ctl_table spl_table[] = {
.mode = 0555,
.child = spl_vm_table,
},
-#ifdef DEBUG_MUTEX
- {
- .ctl_name = CTL_SPL_MUTEX,
- .procname = "mutex",
- .mode = 0555,
- .child = spl_mutex_table,
- },
-#endif
#ifdef DEBUG_KMEM
{
.ctl_name = CTL_SPL_KMEM,
@@ -1180,24 +1041,11 @@ proc_init(void)
RETURN(-EUNATCH);
#endif /* CONFIG_SYSCTL */
-#if defined(DEBUG_MUTEX) || defined(DEBUG_KMEM) || defined(DEBUG_KSTAT)
+#if defined(DEBUG_KMEM) || defined(DEBUG_KSTAT)
proc_spl = proc_mkdir("spl", NULL);
if (proc_spl == NULL)
GOTO(out, rc = -EUNATCH);
-#ifdef DEBUG_MUTEX
- proc_spl_mutex = proc_mkdir("mutex", proc_spl);
- if (proc_spl_mutex == NULL)
- GOTO(out, rc = -EUNATCH);
-
- proc_spl_mutex_stats = create_proc_entry("stats_per", 0444,
- proc_spl_mutex);
- if (proc_spl_mutex_stats == NULL)
- GOTO(out, rc = -EUNATCH);
-
- proc_spl_mutex_stats->proc_fops = &proc_mutex_operations;
-#endif /* DEBUG_MUTEX */
-
#ifdef DEBUG_KMEM
proc_spl_kmem = proc_mkdir("kmem", proc_spl);
if (proc_spl_kmem == NULL)
@@ -1223,16 +1071,12 @@ out:
remove_proc_entry("slab", proc_spl_kmem);
#endif
remove_proc_entry("kmem", proc_spl);
-#ifdef DEBUG_MUTEX
- remove_proc_entry("stats_per", proc_spl_mutex);
-#endif
- remove_proc_entry("mutex", proc_spl);
remove_proc_entry("spl", NULL);
#ifdef CONFIG_SYSCTL
spl_unregister_sysctl_table(spl_header);
#endif /* CONFIG_SYSCTL */
}
-#endif /* DEBUG_MUTEX || DEBUG_KMEM || DEBUG_KSTAT */
+#endif /* DEBUG_KMEM || DEBUG_KSTAT */
RETURN(rc);
}
@@ -1242,18 +1086,14 @@ proc_fini(void)
{
ENTRY;
-#if defined(DEBUG_MUTEX) || defined(DEBUG_KMEM) || defined(DEBUG_KSTAT)
+#if defined(DEBUG_KMEM) || defined(DEBUG_KSTAT)
remove_proc_entry("kstat", proc_spl);
#ifdef DEBUG_KMEM
remove_proc_entry("slab", proc_spl_kmem);
#endif
remove_proc_entry("kmem", proc_spl);
-#ifdef DEBUG_MUTEX
- remove_proc_entry("stats_per", proc_spl_mutex);
-#endif
- remove_proc_entry("mutex", proc_spl);
remove_proc_entry("spl", NULL);
-#endif /* DEBUG_MUTEX || DEBUG_KMEM || DEBUG_KSTAT */
+#endif /* DEBUG_KMEM || DEBUG_KSTAT */
#ifdef CONFIG_SYSCTL
ASSERT(spl_header != NULL);
diff --git a/module/splat/splat-mutex.c b/module/splat/splat-mutex.c
index 3d8f94213..72fa32c81 100644
--- a/module/splat/splat-mutex.c
+++ b/module/splat/splat-mutex.c
@@ -26,296 +26,292 @@
#include "splat-internal.h"
-#define SPLAT_MUTEX_NAME "mutex"
-#define SPLAT_MUTEX_DESC "Kernel Mutex Tests"
+#define SPLAT_MUTEX_NAME "mutex"
+#define SPLAT_MUTEX_DESC "Kernel Mutex Tests"
-#define SPLAT_MUTEX_TEST1_ID 0x0401
-#define SPLAT_MUTEX_TEST1_NAME "tryenter"
-#define SPLAT_MUTEX_TEST1_DESC "Validate mutex_tryenter() correctness"
+#define SPLAT_MUTEX_TEST1_ID 0x0401
+#define SPLAT_MUTEX_TEST1_NAME "tryenter"
+#define SPLAT_MUTEX_TEST1_DESC "Validate mutex_tryenter() correctness"
-#define SPLAT_MUTEX_TEST2_ID 0x0402
-#define SPLAT_MUTEX_TEST2_NAME "race"
-#define SPLAT_MUTEX_TEST2_DESC "Many threads entering/exiting the mutex"
+#define SPLAT_MUTEX_TEST2_ID 0x0402
+#define SPLAT_MUTEX_TEST2_NAME "race"
+#define SPLAT_MUTEX_TEST2_DESC "Many threads entering/exiting the mutex"
-#define SPLAT_MUTEX_TEST3_ID 0x0403
-#define SPLAT_MUTEX_TEST3_NAME "owned"
-#define SPLAT_MUTEX_TEST3_DESC "Validate mutex_owned() correctness"
+#define SPLAT_MUTEX_TEST3_ID 0x0403
+#define SPLAT_MUTEX_TEST3_NAME "owned"
+#define SPLAT_MUTEX_TEST3_DESC "Validate mutex_owned() correctness"
-#define SPLAT_MUTEX_TEST4_ID 0x0404
-#define SPLAT_MUTEX_TEST4_NAME "owner"
-#define SPLAT_MUTEX_TEST4_DESC "Validate mutex_owner() correctness"
+#define SPLAT_MUTEX_TEST4_ID 0x0404
+#define SPLAT_MUTEX_TEST4_NAME "owner"
+#define SPLAT_MUTEX_TEST4_DESC "Validate mutex_owner() correctness"
-#define SPLAT_MUTEX_TEST_MAGIC 0x115599DDUL
-#define SPLAT_MUTEX_TEST_NAME "mutex_test"
-#define SPLAT_MUTEX_TEST_TASKQ "mutex_taskq"
-#define SPLAT_MUTEX_TEST_COUNT 128
+#define SPLAT_MUTEX_TEST_MAGIC 0x115599DDUL
+#define SPLAT_MUTEX_TEST_NAME "mutex_test"
+#define SPLAT_MUTEX_TEST_TASKQ "mutex_taskq"
+#define SPLAT_MUTEX_TEST_COUNT 128
typedef struct mutex_priv {
unsigned long mp_magic;
struct file *mp_file;
- kmutex_t mp_mtx;
- int mp_rc;
+ kmutex_t mp_mtx;
+ int mp_rc;
} mutex_priv_t;
static void
splat_mutex_test1_func(void *arg)
{
- mutex_priv_t *mp = (mutex_priv_t *)arg;
- ASSERT(mp->mp_magic == SPLAT_MUTEX_TEST_MAGIC);
-
- if (mutex_tryenter(&mp->mp_mtx)) {
- mp->mp_rc = 0;
- mutex_exit(&mp->mp_mtx);
- } else {
- mp->mp_rc = -EBUSY;
- }
+ mutex_priv_t *mp = (mutex_priv_t *)arg;
+ ASSERT(mp->mp_magic == SPLAT_MUTEX_TEST_MAGIC);
+
+ if (mutex_tryenter(&mp->mp_mtx)) {
+ mp->mp_rc = 0;
+ mutex_exit(&mp->mp_mtx);
+ } else {
+ mp->mp_rc = -EBUSY;
+ }
}
static int
splat_mutex_test1(struct file *file, void *arg)
{
- mutex_priv_t *mp;
- taskq_t *tq;
- int id, rc = 0;
-
- mp = (mutex_priv_t *)kmalloc(sizeof(*mp), GFP_KERNEL);
- if (mp == NULL)
- return -ENOMEM;
-
- tq = taskq_create(SPLAT_MUTEX_TEST_TASKQ, 1, maxclsyspri,
- 50, INT_MAX, TASKQ_PREPOPULATE);
- if (tq == NULL) {
- rc = -ENOMEM;
- goto out2;
- }
-
- mp->mp_magic = SPLAT_MUTEX_TEST_MAGIC;
- mp->mp_file = file;
- mutex_init(&mp->mp_mtx, SPLAT_MUTEX_TEST_NAME, MUTEX_DEFAULT, NULL);
- mutex_enter(&mp->mp_mtx);
-
- /*
- * Schedule a task function which will try and acquire the mutex via
- * mutex_tryenter() while it's held. This should fail and the task
- * function will indicate this status in the passed private data.
- */
- mp->mp_rc = -EINVAL;
- id = taskq_dispatch(tq, splat_mutex_test1_func, mp, TQ_SLEEP);
- if (id == 0) {
- mutex_exit(&mp->mp_mtx);
- splat_vprint(file, SPLAT_MUTEX_TEST1_NAME, "%s",
- "taskq_dispatch() failed\n");
- rc = -EINVAL;
- goto out;
- }
-
- taskq_wait_id(tq, id);
- mutex_exit(&mp->mp_mtx);
-
- /* Task function successfully acquired mutex, very bad! */
- if (mp->mp_rc != -EBUSY) {
- splat_vprint(file, SPLAT_MUTEX_TEST1_NAME,
- "mutex_trylock() incorrectly succeeded when "
- "the mutex was held, %d/%d\n", id, mp->mp_rc);
- rc = -EINVAL;
- goto out;
- } else {
- splat_vprint(file, SPLAT_MUTEX_TEST1_NAME, "%s",
- "mutex_trylock() correctly failed when "
- "the mutex was held\n");
- }
-
- /*
- * Schedule a task function which will try and acquire the mutex via
- * mutex_tryenter() while it is not held. This should succeed and
- * can be verified by checking the private data.
- */
- mp->mp_rc = -EINVAL;
- id = taskq_dispatch(tq, splat_mutex_test1_func, mp, TQ_SLEEP);
- if (id == 0) {
- splat_vprint(file, SPLAT_MUTEX_TEST1_NAME, "%s",
- "taskq_dispatch() failed\n");
- rc = -EINVAL;
- goto out;
- }
-
- taskq_wait_id(tq, id);
-
- /* Task function failed to acquire mutex, very bad! */
- if (mp->mp_rc != 0) {
- splat_vprint(file, SPLAT_MUTEX_TEST1_NAME,
- "mutex_trylock() incorrectly failed when "
- "the mutex was not held, %d/%d\n", id, mp->mp_rc);
- rc = -EINVAL;
- } else {
- splat_vprint(file, SPLAT_MUTEX_TEST1_NAME, "%s",
- "mutex_trylock() correctly succeeded "
- "when the mutex was not held\n");
- }
+ mutex_priv_t *mp;
+ taskq_t *tq;
+ int id, rc = 0;
+
+ mp = (mutex_priv_t *)kmalloc(sizeof(*mp), GFP_KERNEL);
+ if (mp == NULL)
+ return -ENOMEM;
+
+ tq = taskq_create(SPLAT_MUTEX_TEST_TASKQ, 1, maxclsyspri,
+ 50, INT_MAX, TASKQ_PREPOPULATE);
+ if (tq == NULL) {
+ rc = -ENOMEM;
+ goto out2;
+ }
+
+ mp->mp_magic = SPLAT_MUTEX_TEST_MAGIC;
+ mp->mp_file = file;
+ mutex_init(&mp->mp_mtx, SPLAT_MUTEX_TEST_NAME, MUTEX_DEFAULT, NULL);
+ mutex_enter(&mp->mp_mtx);
+
+ /*
+ * Schedule a task function which will try and acquire the mutex via
+ * mutex_tryenter() while it's held. This should fail and the task
+ * function will indicate this status in the passed private data.
+ */
+ mp->mp_rc = -EINVAL;
+ id = taskq_dispatch(tq, splat_mutex_test1_func, mp, TQ_SLEEP);
+ if (id == 0) {
+ mutex_exit(&mp->mp_mtx);
+ splat_vprint(file, SPLAT_MUTEX_TEST1_NAME, "%s",
+ "taskq_dispatch() failed\n");
+ rc = -EINVAL;
+ goto out;
+ }
+
+ taskq_wait_id(tq, id);
+ mutex_exit(&mp->mp_mtx);
+
+ /* Task function successfully acquired mutex, very bad! */
+ if (mp->mp_rc != -EBUSY) {
+ splat_vprint(file, SPLAT_MUTEX_TEST1_NAME,
+ "mutex_trylock() incorrectly succeeded when "
+ "the mutex was held, %d/%d\n", id, mp->mp_rc);
+ rc = -EINVAL;
+ goto out;
+ } else {
+ splat_vprint(file, SPLAT_MUTEX_TEST1_NAME, "%s",
+ "mutex_trylock() correctly failed when "
+ "the mutex was held\n");
+ }
+
+ /*
+ * Schedule a task function which will try and acquire the mutex via
+ * mutex_tryenter() while it is not held. This should succeed and
+ * can be verified by checking the private data.
+ */
+ mp->mp_rc = -EINVAL;
+ id = taskq_dispatch(tq, splat_mutex_test1_func, mp, TQ_SLEEP);
+ if (id == 0) {
+ splat_vprint(file, SPLAT_MUTEX_TEST1_NAME, "%s",
+ "taskq_dispatch() failed\n");
+ rc = -EINVAL;
+ goto out;
+ }
+
+ taskq_wait_id(tq, id);
+
+ /* Task function failed to acquire mutex, very bad! */
+ if (mp->mp_rc != 0) {
+ splat_vprint(file, SPLAT_MUTEX_TEST1_NAME,
+ "mutex_trylock() incorrectly failed when "
+ "the mutex was not held, %d/%d\n", id, mp->mp_rc);
+ rc = -EINVAL;
+ } else {
+ splat_vprint(file, SPLAT_MUTEX_TEST1_NAME, "%s",
+ "mutex_trylock() correctly succeeded "
+ "when the mutex was not held\n");
+ }
out:
- taskq_destroy(tq);
- mutex_destroy(&(mp->mp_mtx));
+ taskq_destroy(tq);
+ mutex_destroy(&(mp->mp_mtx));
out2:
- kfree(mp);
- return rc;
+ kfree(mp);
+ return rc;
}
static void
splat_mutex_test2_func(void *arg)
{
- mutex_priv_t *mp = (mutex_priv_t *)arg;
- int rc;
- ASSERT(mp->mp_magic == SPLAT_MUTEX_TEST_MAGIC);
-
- /* Read the value before sleeping and write it after we wake up to
- * maximize the chance of a race if mutexs are not working properly */
- mutex_enter(&mp->mp_mtx);
- rc = mp->mp_rc;
- set_current_state(TASK_INTERRUPTIBLE);
- schedule_timeout(HZ / 100); /* 1/100 of a second */
- VERIFY(mp->mp_rc == rc);
- mp->mp_rc = rc + 1;
- mutex_exit(&mp->mp_mtx);
+ mutex_priv_t *mp = (mutex_priv_t *)arg;
+ int rc;
+ ASSERT(mp->mp_magic == SPLAT_MUTEX_TEST_MAGIC);
+
+ /* Read the value before sleeping and write it after we wake up to
+ * maximize the chance of a race if mutexs are not working properly */
+ mutex_enter(&mp->mp_mtx);
+ rc = mp->mp_rc;
+ set_current_state(TASK_INTERRUPTIBLE);
+ schedule_timeout(HZ / 100); /* 1/100 of a second */
+ VERIFY(mp->mp_rc == rc);
+ mp->mp_rc = rc + 1;
+ mutex_exit(&mp->mp_mtx);
}
static int
splat_mutex_test2(struct file *file, void *arg)
{
- mutex_priv_t *mp;
- taskq_t *tq;
- int i, rc = 0;
-
- mp = (mutex_priv_t *)kmalloc(sizeof(*mp), GFP_KERNEL);
- if (mp == NULL)
- return -ENOMEM;
-
- /* Create several threads allowing tasks to race with each other */
- tq = taskq_create(SPLAT_MUTEX_TEST_TASKQ, num_online_cpus(),
- maxclsyspri, 50, INT_MAX, TASKQ_PREPOPULATE);
- if (tq == NULL) {
- rc = -ENOMEM;
- goto out;
- }
-
- mp->mp_magic = SPLAT_MUTEX_TEST_MAGIC;
- mp->mp_file = file;
- mutex_init(&(mp->mp_mtx), SPLAT_MUTEX_TEST_NAME, MUTEX_DEFAULT, NULL);
- mp->mp_rc = 0;
-
- /*
- * Schedule N work items to the work queue each of which enters the
- * mutex, sleeps briefly, then exits the mutex. On a multiprocessor
- * box these work items will be handled by all available CPUs. The
- * task function checks to ensure the tracked shared variable is
- * always only incremented by one. Additionally, the mutex itself
- * is instrumented such that if any two processors are in the
- * critical region at the same time the system will panic. If the
- * mutex is implemented right this will never happy, that's a pass.
- */
- for (i = 0; i < SPLAT_MUTEX_TEST_COUNT; i++) {
- if (!taskq_dispatch(tq, splat_mutex_test2_func, mp, TQ_SLEEP)) {
- splat_vprint(file, SPLAT_MUTEX_TEST2_NAME,
- "Failed to queue task %d\n", i);
- rc = -EINVAL;
- }
- }
-
- taskq_wait(tq);
-
- if (mp->mp_rc == SPLAT_MUTEX_TEST_COUNT) {
- splat_vprint(file, SPLAT_MUTEX_TEST2_NAME, "%d racing threads "
- "correctly entered/exited the mutex %d times\n",
- num_online_cpus(), mp->mp_rc);
- } else {
- splat_vprint(file, SPLAT_MUTEX_TEST2_NAME, "%d racing threads "
- "only processed %d/%d mutex work items\n",
- num_online_cpus(),mp->mp_rc,SPLAT_MUTEX_TEST_COUNT);
- rc = -EINVAL;
- }
-
- taskq_destroy(tq);
- mutex_destroy(&(mp->mp_mtx));
+ mutex_priv_t *mp;
+ taskq_t *tq;
+ int i, rc = 0;
+
+ mp = (mutex_priv_t *)kmalloc(sizeof(*mp), GFP_KERNEL);
+ if (mp == NULL)
+ return -ENOMEM;
+
+ /* Create several threads allowing tasks to race with each other */
+ tq = taskq_create(SPLAT_MUTEX_TEST_TASKQ, num_online_cpus(),
+ maxclsyspri, 50, INT_MAX, TASKQ_PREPOPULATE);
+ if (tq == NULL) {
+ rc = -ENOMEM;
+ goto out;
+ }
+
+ mp->mp_magic = SPLAT_MUTEX_TEST_MAGIC;
+ mp->mp_file = file;
+ mutex_init(&(mp->mp_mtx), SPLAT_MUTEX_TEST_NAME, MUTEX_DEFAULT, NULL);
+ mp->mp_rc = 0;
+
+ /*
+ * Schedule N work items to the work queue each of which enters the
+ * mutex, sleeps briefly, then exits the mutex. On a multiprocessor
+ * box these work items will be handled by all available CPUs. The
+ * task function checks to ensure the tracked shared variable is
+ * always only incremented by one. Additionally, the mutex itself
+ * is instrumented such that if any two processors are in the
+ * critical region at the same time the system will panic. If the
+ * mutex is implemented right this will never happy, that's a pass.
+ */
+ for (i = 0; i < SPLAT_MUTEX_TEST_COUNT; i++) {
+ if (!taskq_dispatch(tq, splat_mutex_test2_func, mp, TQ_SLEEP)) {
+ splat_vprint(file, SPLAT_MUTEX_TEST2_NAME,
+ "Failed to queue task %d\n", i);
+ rc = -EINVAL;
+ }
+ }
+
+ taskq_wait(tq);
+
+ if (mp->mp_rc == SPLAT_MUTEX_TEST_COUNT) {
+ splat_vprint(file, SPLAT_MUTEX_TEST2_NAME, "%d racing threads "
+ "correctly entered/exited the mutex %d times\n",
+ num_online_cpus(), mp->mp_rc);
+ } else {
+ splat_vprint(file, SPLAT_MUTEX_TEST2_NAME, "%d racing threads "
+ "only processed %d/%d mutex work items\n",
+ num_online_cpus(),mp->mp_rc,SPLAT_MUTEX_TEST_COUNT);
+ rc = -EINVAL;
+ }
+
+ taskq_destroy(tq);
+ mutex_destroy(&(mp->mp_mtx));
out:
- kfree(mp);
- return rc;
+ kfree(mp);
+ return rc;
}
static int
splat_mutex_test3(struct file *file, void *arg)
{
kmutex_t mtx;
- int rc = 0;
+ int rc = 0;
- mutex_init(&mtx, SPLAT_MUTEX_TEST_NAME, MUTEX_DEFAULT, NULL);
+ mutex_init(&mtx, SPLAT_MUTEX_TEST_NAME, MUTEX_DEFAULT, NULL);
+ mutex_enter(&mtx);
- mutex_enter(&mtx);
+ /* Mutex should be owned by current */
+ if (!mutex_owned(&mtx)) {
+ splat_vprint(file, SPLAT_MUTEX_TEST3_NAME, "Unowned mutex "
+ "should be owned by pid %d\n", current->pid);
+ rc = -EINVAL;
+ goto out;
+ }
- /* Mutex should be owned by current */
- if (!mutex_owned(&mtx)) {
- splat_vprint(file, SPLAT_MUTEX_TEST3_NAME, "Mutex should "
- "be owned by pid %d but is owned by pid %d\n",
- current->pid, mtx.km_owner ? mtx.km_owner->pid : -1);
- rc = -EINVAL;
- goto out;
- }
+ mutex_exit(&mtx);
- mutex_exit(&mtx);
-
- /* Mutex should not be owned by any task */
- if (mutex_owned(&mtx)) {
- splat_vprint(file, SPLAT_MUTEX_TEST3_NAME, "Mutex should "
- "not be owned but is owned by pid %d\n",
- mtx.km_owner ? mtx.km_owner->pid : -1);
- rc = -EINVAL;
- goto out;
- }
+ /* Mutex should not be owned by any task */
+ if (mutex_owned(&mtx)) {
+ splat_vprint(file, SPLAT_MUTEX_TEST3_NAME, "Mutex owned by "
+ "pid %d should be unowned\b", current->pid);
+ rc = -EINVAL;
+ goto out;
+ }
splat_vprint(file, SPLAT_MUTEX_TEST3_NAME, "%s",
- "Correct mutex_owned() behavior\n");
+ "Correct mutex_owned() behavior\n");
out:
- mutex_destroy(&mtx);
+ mutex_destroy(&mtx);
- return rc;
+ return rc;
}
static int
splat_mutex_test4(struct file *file, void *arg)
{
kmutex_t mtx;
- kthread_t *owner;
- int rc = 0;
-
- mutex_init(&mtx, SPLAT_MUTEX_TEST_NAME, MUTEX_DEFAULT, NULL);
-
- mutex_enter(&mtx);
-
- /* Mutex should be owned by current */
- owner = mutex_owner(&mtx);
- if (current != owner) {
- splat_vprint(file, SPLAT_MUTEX_TEST3_NAME, "Mutex should "
- "be owned by pid %d but is owned by pid %d\n",
- current->pid, owner ? owner->pid : -1);
- rc = -EINVAL;
- goto out;
- }
-
- mutex_exit(&mtx);
-
- /* Mutex should not be owned by any task */
- owner = mutex_owner(&mtx);
- if (owner) {
- splat_vprint(file, SPLAT_MUTEX_TEST3_NAME, "Mutex should not "
- "be owned but is owned by pid %d\n", owner->pid);
- rc = -EINVAL;
- goto out;
- }
+ kthread_t *owner;
+ int rc = 0;
+
+ mutex_init(&mtx, SPLAT_MUTEX_TEST_NAME, MUTEX_DEFAULT, NULL);
+ mutex_enter(&mtx);
+
+ /* Mutex should be owned by current */
+ owner = mutex_owner(&mtx);
+ if (current != owner) {
+ splat_vprint(file, SPLAT_MUTEX_TEST3_NAME, "Mutex should "
+ "be owned by pid %d but is owned by pid %d\n",
+ current->pid, owner ? owner->pid : -1);
+ rc = -EINVAL;
+ goto out;
+ }
+
+ mutex_exit(&mtx);
+
+ /* Mutex should not be owned by any task */
+ owner = mutex_owner(&mtx);
+ if (owner) {
+ splat_vprint(file, SPLAT_MUTEX_TEST3_NAME, "Mutex should not "
+ "be owned but is owned by pid %d\n", owner->pid);
+ rc = -EINVAL;
+ goto out;
+ }
splat_vprint(file, SPLAT_MUTEX_TEST3_NAME, "%s",
- "Correct mutex_owner() behavior\n");
+ "Correct mutex_owner() behavior\n");
out:
- mutex_destroy(&mtx);
+ mutex_destroy(&mtx);
- return rc;
+ return rc;
}
splat_subsystem_t *
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-26 18:28:14 +0000