commit 5cdde5c25a0e71d923a6d56e5c94e058887f95d8
author jaszha03 <jason.zhang2@arm.com> Thu Jul 11 20:47:24 2019 +0000
committer Dave Barach <openvpp@barachs.net> Wed Jul 31 13:53:55 2019 +0000
tree c54eeb5a91ce67417806fabd1fca8d287993e71d
parent 9a4e631890a70978d414b4937cb94b50cfd778e6

vppinfra: refactor test_and_set spinlocks to use clib_spinlock_t

Spinlock performance improved when implemented with compare_and_exchange
instead of test_and_set. All instances of test_and_set locks were refactored
to use clib_spinlock_t when possible. Some locks e.g. ssvm synchronize
between processes rather than threads, so they cannot directly use
clib_spinlock_t.

Type: refactor

Change-Id: Ia16b5d4cd49209b2b57b8df6c94615c28b11bb60
Signed-off-by: Jason Zhang <jason.zhang2@arm.com>
Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
Reviewed-by: Lijian Zhang <Lijian.Zhang@arm.com>

src/vnet/classify/vnet_classify.c

diff --git a/src/vnet/classify/vnet_classify.c b/src/vnet/classify/vnet_classify.c
index f5e4949..b807a26 100755
--- a/src/vnet/classify/vnet_classify.c
+++ b/src/vnet/classify/vnet_classify.c
@@ -152,10 +152,7 @@
   vec_validate_aligned (t->buckets, nbuckets - 1, CLIB_CACHE_LINE_BYTES);
   oldheap = clib_mem_set_heap (t->mheap);
 
-  t->writer_lock = clib_mem_alloc_aligned (CLIB_CACHE_LINE_BYTES,
-					   CLIB_CACHE_LINE_BYTES);
-  t->writer_lock[0] = 0;
-
+  clib_spinlock_init (&t->writer_lock);
   clib_mem_set_heap (oldheap);
   return (t);
 }
@@ -193,7 +190,7 @@
   u32 required_length;
   void *oldheap;
 
-  ASSERT (t->writer_lock[0]);
+  CLIB_SPINLOCK_ASSERT_LOCKED (&t->writer_lock);
   required_length =
     (sizeof (vnet_classify_entry_t) + (t->match_n_vectors * sizeof (u32x4)))
     * t->entries_per_page * (1 << log2_pages);
@@ -222,7 +219,7 @@
 vnet_classify_entry_free (vnet_classify_table_t * t,
 			  vnet_classify_entry_t * v, u32 log2_pages)
 {
-  ASSERT (t->writer_lock[0]);
+  CLIB_SPINLOCK_ASSERT_LOCKED (&t->writer_lock);
 
   ASSERT (vec_len (t->freelists) > log2_pages);
 
@@ -447,8 +444,7 @@
 
   hash >>= t->log2_nbuckets;
 
-  while (clib_atomic_test_and_set (t->writer_lock))
-    CLIB_PAUSE ();
+  clib_spinlock_lock (&t->writer_lock);
 
   /* First elt in the bucket? */
   if (b->offset == 0)
@@ -640,7 +636,7 @@
   vnet_classify_entry_free (t, v, old_log2_pages);
 
 unlock:
-  clib_atomic_release (&t->writer_lock[0]);
+  clib_spinlock_unlock (&t->writer_lock);
   return rv;
 }