From 847d357635ce4c63b8901ab81333586a0f115fa5 Mon Sep 17 00:00:00 2001
From: Matthew Wilcox <willy@infradead.org>
Date: Wed, 14 Dec 2016 15:08:02 -0800
Subject: [PATCH] radix tree test suite: track preempt_count
Rather than simply NOP out preempt_enable() and preempt_disable(), keep
track of preempt_count and display it regularly in case either the test
suite or the code under test is forgetting to balance the enables &
disables. Only found a test-case that was forgetting to re-enable
preemption, but it's a possibility worth checking.
Link: http://lkml.kernel.org/r/1480369871-5271-39-git-send-email-mawilcox@linuxonhyperv.com
Signed-off-by: Matthew Wilcox <willy@infradead.org>
Tested-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
tools/testing/radix-tree/linux.c | 1 +
tools/testing/radix-tree/linux/preempt.h | 6 ++---
tools/testing/radix-tree/main.c | 30 ++++++++++++++++--------
3 files changed, 24 insertions(+), 13 deletions(-)
diff --git a/tools/testing/radix-tree/linux.c b/tools/testing/radix-tree/linux.c
index 3cfb04e98e2f3..1f32a16a3848c 100644
--- a/tools/testing/radix-tree/linux.c
+++ b/tools/testing/radix-tree/linux.c
@@ -9,6 +9,7 @@
#include <urcu/uatomic.h>
int nr_allocated;
+int preempt_count;
void *mempool_alloc(mempool_t *pool, int gfp_mask)
{
diff --git a/tools/testing/radix-tree/linux/preempt.h b/tools/testing/radix-tree/linux/preempt.h
index 6210672e3baa5..65c04c226965d 100644
--- a/tools/testing/radix-tree/linux/preempt.h
+++ b/tools/testing/radix-tree/linux/preempt.h
@@ -1,4 +1,4 @@
-/* */
+extern int preempt_count;
-#define preempt_disable() do { } while (0)
-#define preempt_enable() do { } while (0)
+#define preempt_disable() uatomic_inc(&preempt_count)
+#define preempt_enable() uatomic_dec(&preempt_count)
diff --git a/tools/testing/radix-tree/main.c b/tools/testing/radix-tree/main.c
index daa9010693e83..64ffe67605d46 100644
--- a/tools/testing/radix-tree/main.c
+++ b/tools/testing/radix-tree/main.c
@@ -293,27 +293,36 @@ static void single_thread_tests(bool long_run)
{
int i;
- printf("starting single_thread_tests: %d allocated\n", nr_allocated);
+ printf("starting single_thread_tests: %d allocated, preempt %d\n",
+ nr_allocated, preempt_count);
multiorder_checks();
- printf("after multiorder_check: %d allocated\n", nr_allocated);
+ printf("after multiorder_check: %d allocated, preempt %d\n",
+ nr_allocated, preempt_count);
locate_check();
- printf("after locate_check: %d allocated\n", nr_allocated);
+ printf("after locate_check: %d allocated, preempt %d\n",
+ nr_allocated, preempt_count);
tag_check();
- printf("after tag_check: %d allocated\n", nr_allocated);
+ printf("after tag_check: %d allocated, preempt %d\n",
+ nr_allocated, preempt_count);
gang_check();
- printf("after gang_check: %d allocated\n", nr_allocated);
+ printf("after gang_check: %d allocated, preempt %d\n",
+ nr_allocated, preempt_count);
add_and_check();
- printf("after add_and_check: %d allocated\n", nr_allocated);
+ printf("after add_and_check: %d allocated, preempt %d\n",
+ nr_allocated, preempt_count);
dynamic_height_check();
- printf("after dynamic_height_check: %d allocated\n", nr_allocated);
+ printf("after dynamic_height_check: %d allocated, preempt %d\n",
+ nr_allocated, preempt_count);
big_gang_check(long_run);
- printf("after big_gang_check: %d allocated\n", nr_allocated);
+ printf("after big_gang_check: %d allocated, preempt %d\n",
+ nr_allocated, preempt_count);
for (i = 0; i < (long_run ? 2000 : 3); i++) {
copy_tag_check();
printf("%d ", i);
fflush(stdout);
}
- printf("after copy_tag_check: %d allocated\n", nr_allocated);
+ printf("after copy_tag_check: %d allocated, preempt %d\n",
+ nr_allocated, preempt_count);
}
int main(int argc, char **argv)
@@ -336,7 +345,8 @@ int main(int argc, char **argv)
single_thread_tests(long_run);
sleep(1);
- printf("after sleep(1): %d allocated\n", nr_allocated);
+ printf("after sleep(1): %d allocated, preempt %d\n",
+ nr_allocated, preempt_count);
rcu_unregister_thread();
exit(0);
--
2.30.2