From: Matthew Wilcox <mawilcox@linuxonhyperv.com>
To: linux-kernel@vger.kernel.org,
        Andrew Morton <akpm@linux-foundation.org>,
        Konstantin Khlebnikov <koct9i@gmail.com>,
        Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: linux-fsdevel@vger.kernel.org, Matthew Wilcox <willy@infradead.org>,
        linux-mm@kvack.org,
        "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Subject: [PATCH 04/29] radix tree test suite: Free preallocated nodes
Date: Wed, 16 Nov 2016 16:16:29 -0800
Message-Id: <1479341856-30320-5-git-send-email-mawilcox@linuxonhyperv.com>
In-Reply-To: <1479341856-30320-1-git-send-email-mawilcox@linuxonhyperv.com>
References: <1479341856-30320-1-git-send-email-mawilcox@linuxonhyperv.com>
Sender: linux-kernel-owner@vger.kernel.org
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From: Matthew Wilcox <willy@infradead.org>

It can be a source of mild concern when the test suite shows that we're
leaking nodes.  While poring over the source code looking for leaks
can lead to some fascinating bugs being discovered, sometimes the leak
is simply that these nodes were preallocated and are sitting on the
per-CPU list.  Free them by faking a CPU_DEAD event.

Signed-off-by: Matthew Wilcox <willy@infradead.org>
---
 tools/testing/radix-tree/main.c | 3 +++
 tools/testing/radix-tree/test.h | 4 ++++
 2 files changed, 7 insertions(+)

diff --git a/tools/testing/radix-tree/main.c b/tools/testing/radix-tree/main.c
index 64ffe67..2930560 100644
--- a/tools/testing/radix-tree/main.c
+++ b/tools/testing/radix-tree/main.c
@@ -344,6 +344,9 @@ int main(int argc, char **argv)
 	iteration_test();
 	single_thread_tests(long_run);
 
+	/* Free any remaining preallocated nodes */
+	radix_tree_callback(NULL, CPU_DEAD, NULL);
+
 	sleep(1);
 	printf("after sleep(1): %d allocated, preempt %d\n",
 		nr_allocated, preempt_count);
diff --git a/tools/testing/radix-tree/test.h b/tools/testing/radix-tree/test.h
index 217fb24..8cd666a 100644
--- a/tools/testing/radix-tree/test.h
+++ b/tools/testing/radix-tree/test.h
@@ -2,6 +2,8 @@
 #include <linux/types.h>
 #include <linux/radix-tree.h>
 #include <linux/rcupdate.h>
+#include <linux/notifier.h>
+#include <linux/cpu.h>
 
 struct item {
 	unsigned long index;
@@ -44,3 +46,5 @@ void radix_tree_dump(struct radix_tree_root *root);
 int root_tag_get(struct radix_tree_root *root, unsigned int tag);
 unsigned long node_maxindex(struct radix_tree_node *);
 unsigned long shift_maxindex(unsigned int shift);
+int radix_tree_callback(struct notifier_block *nfb,
+			unsigned long action, void *hcpu);
-- 
2.10.2