lib/bsearch: Provide __always_inline variant

For code that needs the ultimate performance (it can inline the @cmp
function too) or simply needs to avoid calling external functions for
whatever reason, provide an __always_inline variant of bsearch().

[ tglx: Renamed to __inline_bsearch() as suggested by Andy ]

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Acked-by: Andy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/20200505135313.624443814@linutronix.de

diff --git a/include/linux/bsearch.h b/include/linux/bsearch.h
index 8ed53d7..e66b711 100644 (file)
--- a/include/linux/bsearch.h
+++ b/include/linux/bsearch.h
@@ -4,7 +4,29 @@
 
 #include <linux/types.h>
 
-void *bsearch(const void *key, const void *base, size_t num, size_t size,
-             cmp_func_t cmp);
+static __always_inline
+void *__inline_bsearch(const void *key, const void *base, size_t num, size_t size, cmp_func_t cmp)
+{
+       const char *pivot;
+       int result;
+
+       while (num > 0) {
+               pivot = base + (num >> 1) * size;
+               result = cmp(key, pivot);
+
+               if (result == 0)
+                       return (void *)pivot;
+
+               if (result > 0) {
+                       base = pivot + size;
+                       num--;
+               }
+               num >>= 1;
+       }
+
+       return NULL;
+}
+
+extern void *bsearch(const void *key, const void *base, size_t num, size_t size, cmp_func_t cmp);
 
 #endif /* _LINUX_BSEARCH_H */

diff --git a/lib/bsearch.c b/lib/bsearch.c
index 8b3aae5..bf86aa6 100644 (file)
--- a/lib/bsearch.c
+++ b/lib/bsearch.c
@@ -28,27 +28,9 @@
  * the key and elements in the array are of the same type, you can use
  * the same comparison function for both sort() and bsearch().
  */
-void *bsearch(const void *key, const void *base, size_t num, size_t size,
-             cmp_func_t cmp)
+void *bsearch(const void *key, const void *base, size_t num, size_t size, cmp_func_t cmp)
 {
-       const char *pivot;
-       int result;
-
-       while (num > 0) {
-               pivot = base + (num >> 1) * size;
-               result = cmp(key, pivot);
-
-               if (result == 0)
-                       return (void *)pivot;
-
-               if (result > 0) {
-                       base = pivot + size;
-                       num--;
-               }
-               num >>= 1;
-       }
-
-       return NULL;
+       return __inline_bsearch(key, base, num, size, cmp);
 }
 EXPORT_SYMBOL(bsearch);
 NOKPROBE_SYMBOL(bsearch);