diff mbox series

[COMMITTED,2/2] benchtests: Reallocate buffers for memset

Message ID 1505409959-6088-2-git-send-email-siddhesh@sourceware.org
State New
Headers show
Series [COMMITTED,1/2] benchtests: Make memset benchmarks print json | expand

Commit Message

Siddhesh Poyarekar Sept. 14, 2017, 5:25 p.m. UTC 
Keeping the same buffers along with copying the same size of data into
the same location means that the first routine is typically the
slowest since it has to bear the cost of fetching data into to cache.
Reallocating buffers stabilizes numbers by a bit.

	* benchtests/bench-string.h (realloc_bufs): New function.
	(test_init): Call it.
	* benchtests/bench-memset-large.c (do_test): Likewise.
	* benchtests/bench-memset.c (do_test): Likewise.
---
 benchtests/bench-memset-large.c |  5 ++++-
 benchtests/bench-memset.c       |  5 ++++-
 benchtests/bench-string.h       | 50 ++++++++++++++++++++++++++++++++---------
 3 files changed, 47 insertions(+), 13 deletions(-)
diff mbox series

Patch

diff --git a/benchtests/bench-memset-large.c b/benchtests/bench-memset-large.c
index c0f1974..6cd48c9 100644
--- a/benchtests/bench-memset-large.c
+++ b/benchtests/bench-memset-large.c
@@ -90,7 +90,10 @@  do_test (json_ctx_t *json_ctx, size_t align, int c, size_t len)
   json_array_begin (json_ctx, "timings");
 
   FOR_EACH_IMPL (impl, 0)
-    do_one_test (json_ctx, impl, (CHAR *) (buf1) + align, c, len);
+    {
+      do_one_test (json_ctx, impl, (CHAR *) (buf1) + align, c, len);
+      realloc_bufs ();
+    }
 
   json_array_end (json_ctx);
   json_element_object_end (json_ctx);
diff --git a/benchtests/bench-memset.c b/benchtests/bench-memset.c
index 107e2b7..724c105 100644
--- a/benchtests/bench-memset.c
+++ b/benchtests/bench-memset.c
@@ -132,7 +132,10 @@  do_test (json_ctx_t *json_ctx, size_t align, int c, size_t len)
   json_array_begin (json_ctx, "timings");
 
   FOR_EACH_IMPL (impl, 0)
-    do_one_test (json_ctx, impl, (CHAR *) (buf1) + align, c, len);
+    {
+      do_one_test (json_ctx, impl, (CHAR *) (buf1) + align, c, len);
+      realloc_bufs ();
+    }
 
   json_array_end (json_ctx);
   json_element_object_end (json_ctx);
diff --git a/benchtests/bench-string.h b/benchtests/bench-string.h
index 3aacfdf..40c735c 100644
--- a/benchtests/bench-string.h
+++ b/benchtests/bench-string.h
@@ -173,14 +173,8 @@  static impl_t *impl_array;
 # endif
 
 static void
-test_init (void)
+alloc_bufs (void)
 {
-# ifdef TEST_NAME
-  func_count = __libc_ifunc_impl_list (TEST_NAME, func_list,
-				       (sizeof func_list
-					/ sizeof func_list[0]));
-# endif
-
   page_size = 2 * getpagesize ();
 # ifdef MIN_PAGE_SIZE
   if (page_size < MIN_PAGE_SIZE)
@@ -189,15 +183,49 @@  test_init (void)
   buf1 = mmap (0, (BUF1PAGES + 1) * page_size, PROT_READ | PROT_WRITE,
 	       MAP_PRIVATE | MAP_ANON, -1, 0);
   if (buf1 == MAP_FAILED)
-    error (EXIT_FAILURE, errno, "mmap failed");
+    error (EXIT_FAILURE, errno, "mmap failed for buf1");
   if (mprotect (buf1 + BUF1PAGES * page_size, page_size, PROT_NONE))
-    error (EXIT_FAILURE, errno, "mprotect failed");
+    error (EXIT_FAILURE, errno, "mprotect failed for buf1");
   buf2 = mmap (0, 2 * page_size, PROT_READ | PROT_WRITE,
 	       MAP_PRIVATE | MAP_ANON, -1, 0);
   if (buf2 == MAP_FAILED)
-    error (EXIT_FAILURE, errno, "mmap failed");
+    error (EXIT_FAILURE, errno, "mmap failed for buf2");
   if (mprotect (buf2 + page_size, page_size, PROT_NONE))
-    error (EXIT_FAILURE, errno, "mprotect failed");
+    error (EXIT_FAILURE, errno, "mprotect failed for buf2");
+}
+
+static void
+__attribute__ ((unused))
+realloc_bufs (void)
+{
+  int ret = 0;
+
+  if (buf1)
+    ret = munmap (buf1, (BUF1PAGES + 1) * page_size);
+
+  if (ret != 0)
+    error (EXIT_FAILURE, errno, "munmap failed for buf1");
+
+  if (buf2)
+    ret = munmap (buf2, 2 * page_size);
+
+  if (ret != 0)
+    error (EXIT_FAILURE, errno, "munmap failed for buf2");
+
+  alloc_bufs ();
+}
+
+static void
+test_init (void)
+{
+# ifdef TEST_NAME
+  func_count = __libc_ifunc_impl_list (TEST_NAME, func_list,
+				       (sizeof func_list
+					/ sizeof func_list[0]));
+# endif
+
+  alloc_bufs ();
+
   if (do_srandom)
     {
       printf ("Setting seed to 0x%x\n", seed);