path: root/tools/testing/radix-tree/test.c
diff options
authorMatthew Wilcox <mawilcox@microsoft.com>2016-12-14 15:08:55 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2016-12-14 16:04:10 -0800
commit268f42de718128cd0301293177e79c08c38e39a6 (patch)
tree6668c85388c327f64ce9b51e77d70e245ec52b57 /tools/testing/radix-tree/test.c
parentradix-tree: delete radix_tree_locate_item() (diff)
radix-tree: delete radix_tree_range_tag_if_tagged()
This is an exceptionally complicated function with just one caller (tag_pages_for_writeback). We devote a large portion of the runtime of the test suite to testing this one function which has one caller. By introducing the new function radix_tree_iter_tag_set(), we can eliminate all of the complexity while keeping the performance. The caller can now use a fairly standard radix_tree_for_each() loop, and it doesn't need to worry about tricksy things like 'start' wrapping. The test suite continues to spend a large amount of time investigating this function, but now it's testing the underlying primitives such as radix_tree_iter_resume() and the radix_tree_for_each_tagged() iterator which are also used by other parts of the kernel. Link: http://lkml.kernel.org/r/1480369871-5271-57-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>
Diffstat (limited to 'tools/testing/radix-tree/test.c')
1 files changed, 34 insertions, 0 deletions
diff --git a/tools/testing/radix-tree/test.c b/tools/testing/radix-tree/test.c
index 88bf57f7175e..e5726e373646 100644
--- a/tools/testing/radix-tree/test.c
+++ b/tools/testing/radix-tree/test.c
@@ -151,6 +151,40 @@ void item_full_scan(struct radix_tree_root *root, unsigned long start,
assert(nfound == 0);
+/* Use the same pattern as tag_pages_for_writeback() in mm/page-writeback.c */
+int tag_tagged_items(struct radix_tree_root *root, pthread_mutex_t *lock,
+ unsigned long start, unsigned long end, unsigned batch,
+ unsigned iftag, unsigned thentag)
+ unsigned long tagged = 0;
+ struct radix_tree_iter iter;
+ void **slot;
+ if (batch == 0)
+ batch = 1;
+ if (lock)
+ pthread_mutex_lock(lock);
+ radix_tree_for_each_tagged(slot, root, &iter, start, iftag) {
+ if (iter.index > end)
+ break;
+ radix_tree_iter_tag_set(root, &iter, thentag);
+ tagged++;
+ if ((tagged % batch) != 0)
+ continue;
+ slot = radix_tree_iter_resume(slot, &iter);
+ if (lock) {
+ pthread_mutex_unlock(lock);
+ rcu_barrier();
+ pthread_mutex_lock(lock);
+ }
+ }
+ if (lock)
+ pthread_mutex_unlock(lock);
+ return tagged;
/* Use the same pattern as find_swap_entry() in mm/shmem.c */
unsigned long find_item(struct radix_tree_root *root, void *item)