summaryrefslogtreecommitdiffstats
path: root/arch/mips/kernel/spinlock_test.c
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2010-02-27 16:19:22 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2010-02-27 16:19:22 -0800
commitf1dd6ad599732fc89f36fdd65a2c2cf3c63a8711 (patch)
tree5092207128e47cba99dc0fe373fff6a36f4cb4b8 /arch/mips/kernel/spinlock_test.c
parent8d37a371b6869920e6c40c495c68eabba1ef3909 (diff)
parente10b234b3c4e255d3300a486c4ac15b43253ac6d (diff)
Merge branch 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus
* 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus: (141 commits) MIPS: Alchemy: defconfig updates MIPS: Alchemy: Fix Au1100 ethernet build failure MIPS: Alchemy: Repair db1500/bosporus builds MIPS: ARC: Cleanup unused definitions from sgialib.h MIPS: Cobalt: convert legacy port addresses to GT-64111 bus addresses MIPS: Alchemy: use 36bit addresses for PCMCIA resources. MIPS: Cobalt: Fix theoretical port aliasing issue MIPS: Use ALIGN(x, bytes) instead of __ALIGN_MASK(x, bytes - 1) MIPS: Crazy spinlock speed test. MIPS: Optimize spinlocks. MIPS: Alchemy: devboard PM needs to save CPLD registers. MIPS: PowerTV: Eliminate duplicate opcode definition macros MIPS: Lemote 2F: Move printks out of port_access_lock. MIPS: PNX833x: Convert IRQ controller locks to raw spinlocks. MIPS: Octeon: Replace spinlock with raw_spinlocks in dma-octeon.c. MIPS: Octeon: Replace rwlocks in irq_chip handlers with raw_spinlocks. MIPS: Octeon: Convert octeon_irq_msi_lock to raw spinlock. MIPS: Loongson: Remove pointless sample_lock from oprofile code. MIPS: SNI: Convert sni_rm200_i8259A_lock to raw spinlock. MIPS: i8259: Convert IRQ controller lock to raw spinlock. ...
Diffstat (limited to 'arch/mips/kernel/spinlock_test.c')
-rw-r--r--arch/mips/kernel/spinlock_test.c141
1 files changed, 141 insertions, 0 deletions
diff --git a/arch/mips/kernel/spinlock_test.c b/arch/mips/kernel/spinlock_test.c
new file mode 100644
index 00000000000..da61134dfc5
--- /dev/null
+++ b/arch/mips/kernel/spinlock_test.c
@@ -0,0 +1,141 @@
+#include <linux/init.h>
+#include <linux/kthread.h>
+#include <linux/hrtimer.h>
+#include <linux/fs.h>
+#include <linux/debugfs.h>
+#include <linux/module.h>
+#include <linux/spinlock.h>
+
+
+static int ss_get(void *data, u64 *val)
+{
+ ktime_t start, finish;
+ int loops;
+ int cont;
+ DEFINE_RAW_SPINLOCK(ss_spin);
+
+ loops = 1000000;
+ cont = 1;
+
+ start = ktime_get();
+
+ while (cont) {
+ raw_spin_lock(&ss_spin);
+ loops--;
+ if (loops == 0)
+ cont = 0;
+ raw_spin_unlock(&ss_spin);
+ }
+
+ finish = ktime_get();
+
+ *val = ktime_us_delta(finish, start);
+
+ return 0;
+}
+
+DEFINE_SIMPLE_ATTRIBUTE(fops_ss, ss_get, NULL, "%llu\n");
+
+
+
+struct spin_multi_state {
+ raw_spinlock_t lock;
+ atomic_t start_wait;
+ atomic_t enter_wait;
+ atomic_t exit_wait;
+ int loops;
+};
+
+struct spin_multi_per_thread {
+ struct spin_multi_state *state;
+ ktime_t start;
+};
+
+static int multi_other(void *data)
+{
+ int loops;
+ int cont;
+ struct spin_multi_per_thread *pt = data;
+ struct spin_multi_state *s = pt->state;
+
+ loops = s->loops;
+ cont = 1;
+
+ atomic_dec(&s->enter_wait);
+
+ while (atomic_read(&s->enter_wait))
+ ; /* spin */
+
+ pt->start = ktime_get();
+
+ atomic_dec(&s->start_wait);
+
+ while (atomic_read(&s->start_wait))
+ ; /* spin */
+
+ while (cont) {
+ raw_spin_lock(&s->lock);
+ loops--;
+ if (loops == 0)
+ cont = 0;
+ raw_spin_unlock(&s->lock);
+ }
+
+ atomic_dec(&s->exit_wait);
+ while (atomic_read(&s->exit_wait))
+ ; /* spin */
+ return 0;
+}
+
+static int multi_get(void *data, u64 *val)
+{
+ ktime_t finish;
+ struct spin_multi_state ms;
+ struct spin_multi_per_thread t1, t2;
+
+ ms.lock = __RAW_SPIN_LOCK_UNLOCKED("multi_get");
+ ms.loops = 1000000;
+
+ atomic_set(&ms.start_wait, 2);
+ atomic_set(&ms.enter_wait, 2);
+ atomic_set(&ms.exit_wait, 2);
+ t1.state = &ms;
+ t2.state = &ms;
+
+ kthread_run(multi_other, &t2, "multi_get");
+
+ multi_other(&t1);
+
+ finish = ktime_get();
+
+ *val = ktime_us_delta(finish, t1.start);
+
+ return 0;
+}
+
+DEFINE_SIMPLE_ATTRIBUTE(fops_multi, multi_get, NULL, "%llu\n");
+
+
+extern struct dentry *mips_debugfs_dir;
+static int __init spinlock_test(void)
+{
+ struct dentry *d;
+
+ if (!mips_debugfs_dir)
+ return -ENODEV;
+
+ d = debugfs_create_file("spin_single", S_IRUGO,
+ mips_debugfs_dir, NULL,
+ &fops_ss);
+ if (!d)
+ return -ENOMEM;
+
+ d = debugfs_create_file("spin_multi", S_IRUGO,
+ mips_debugfs_dir, NULL,
+ &fops_multi);
+ if (!d)
+ return -ENOMEM;
+
+ return 0;
+}
+device_initcall(spinlock_test);