mirror of
https://github.com/torvalds/linux.git
synced 2024-11-05 11:32:04 +00:00
623fd8072c
Tests various percpu operations. Enable with CONFIG_PERCPU_TEST=m. Signed-off-by: Greg Thelen <gthelen@google.com> Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
139 lines
3.2 KiB
C
139 lines
3.2 KiB
C
#include <linux/module.h>
|
|
|
|
/* validate @native and @pcp counter values match @expected */
|
|
#define CHECK(native, pcp, expected) \
|
|
do { \
|
|
WARN((native) != (expected), \
|
|
"raw %ld (0x%lx) != expected %lld (0x%llx)", \
|
|
(native), (native), \
|
|
(long long)(expected), (long long)(expected)); \
|
|
WARN(__this_cpu_read(pcp) != (expected), \
|
|
"pcp %ld (0x%lx) != expected %lld (0x%llx)", \
|
|
__this_cpu_read(pcp), __this_cpu_read(pcp), \
|
|
(long long)(expected), (long long)(expected)); \
|
|
} while (0)
|
|
|
|
static DEFINE_PER_CPU(long, long_counter);
|
|
static DEFINE_PER_CPU(unsigned long, ulong_counter);
|
|
|
|
static int __init percpu_test_init(void)
|
|
{
|
|
/*
|
|
* volatile prevents compiler from optimizing it uses, otherwise the
|
|
* +ul_one/-ul_one below would replace with inc/dec instructions.
|
|
*/
|
|
volatile unsigned int ui_one = 1;
|
|
long l = 0;
|
|
unsigned long ul = 0;
|
|
|
|
pr_info("percpu test start\n");
|
|
|
|
preempt_disable();
|
|
|
|
l += -1;
|
|
__this_cpu_add(long_counter, -1);
|
|
CHECK(l, long_counter, -1);
|
|
|
|
l += 1;
|
|
__this_cpu_add(long_counter, 1);
|
|
CHECK(l, long_counter, 0);
|
|
|
|
ul = 0;
|
|
__this_cpu_write(ulong_counter, 0);
|
|
|
|
ul += 1UL;
|
|
__this_cpu_add(ulong_counter, 1UL);
|
|
CHECK(ul, ulong_counter, 1);
|
|
|
|
ul += -1UL;
|
|
__this_cpu_add(ulong_counter, -1UL);
|
|
CHECK(ul, ulong_counter, 0);
|
|
|
|
ul += -(unsigned long)1;
|
|
__this_cpu_add(ulong_counter, -(unsigned long)1);
|
|
CHECK(ul, ulong_counter, -1);
|
|
|
|
ul = 0;
|
|
__this_cpu_write(ulong_counter, 0);
|
|
|
|
ul -= 1;
|
|
__this_cpu_dec(ulong_counter);
|
|
CHECK(ul, ulong_counter, -1);
|
|
CHECK(ul, ulong_counter, ULONG_MAX);
|
|
|
|
l += -ui_one;
|
|
__this_cpu_add(long_counter, -ui_one);
|
|
CHECK(l, long_counter, 0xffffffff);
|
|
|
|
l += ui_one;
|
|
__this_cpu_add(long_counter, ui_one);
|
|
CHECK(l, long_counter, (long)0x100000000LL);
|
|
|
|
|
|
l = 0;
|
|
__this_cpu_write(long_counter, 0);
|
|
|
|
l -= ui_one;
|
|
__this_cpu_sub(long_counter, ui_one);
|
|
CHECK(l, long_counter, -1);
|
|
|
|
l = 0;
|
|
__this_cpu_write(long_counter, 0);
|
|
|
|
l += ui_one;
|
|
__this_cpu_add(long_counter, ui_one);
|
|
CHECK(l, long_counter, 1);
|
|
|
|
l += -ui_one;
|
|
__this_cpu_add(long_counter, -ui_one);
|
|
CHECK(l, long_counter, (long)0x100000000LL);
|
|
|
|
l = 0;
|
|
__this_cpu_write(long_counter, 0);
|
|
|
|
l -= ui_one;
|
|
this_cpu_sub(long_counter, ui_one);
|
|
CHECK(l, long_counter, -1);
|
|
CHECK(l, long_counter, ULONG_MAX);
|
|
|
|
ul = 0;
|
|
__this_cpu_write(ulong_counter, 0);
|
|
|
|
ul += ui_one;
|
|
__this_cpu_add(ulong_counter, ui_one);
|
|
CHECK(ul, ulong_counter, 1);
|
|
|
|
ul = 0;
|
|
__this_cpu_write(ulong_counter, 0);
|
|
|
|
ul -= ui_one;
|
|
__this_cpu_sub(ulong_counter, ui_one);
|
|
CHECK(ul, ulong_counter, -1);
|
|
CHECK(ul, ulong_counter, ULONG_MAX);
|
|
|
|
ul = 3;
|
|
__this_cpu_write(ulong_counter, 3);
|
|
|
|
ul = this_cpu_sub_return(ulong_counter, ui_one);
|
|
CHECK(ul, ulong_counter, 2);
|
|
|
|
ul = __this_cpu_sub_return(ulong_counter, ui_one);
|
|
CHECK(ul, ulong_counter, 1);
|
|
|
|
preempt_enable();
|
|
|
|
pr_info("percpu test done\n");
|
|
return -EAGAIN; /* Fail will directly unload the module */
|
|
}
|
|
|
|
static void __exit percpu_test_exit(void)
|
|
{
|
|
}
|
|
|
|
module_init(percpu_test_init)
|
|
module_exit(percpu_test_exit)
|
|
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_AUTHOR("Greg Thelen");
|
|
MODULE_DESCRIPTION("percpu operations test");
|