From: Dave Barach <dbarach@cisco.com>
Date: Sun, 10 Mar 2019 13:44:51 +0000 (-0400)
Subject: Perf tune get_frame_size_info
X-Git-Tag: v19.04-rc1~269
X-Git-Url: https://gerrit.fd.io/r/gitweb?a=commitdiff_plain;h=593eedf2561f639703d366cd21ab0c3ae03bdb0c;p=vpp.git

Perf tune get_frame_size_info

It turns out that for scalar sizes 0..24, frames are always the same
size. That range includes all current use-cases - and then some - so
get rid of the hash table. Old code preserved under #ifdef
VLIB_SUPPORTS_ARBITRARY_SCALAR_SIZES.

Change-Id: Ic005c7143c9639f77d1a0fadd2fc0e90dccb68c1
Signed-off-by: Dave Barach <dbarach@cisco.com>
---

diff --git a/src/vlib/main.c b/src/vlib/main.c
index c5cb155b1ee..4dcf63e0f9c 100644
--- a/src/vlib/main.c
+++ b/src/vlib/main.c
@@ -91,10 +91,11 @@ vlib_frame_find_magic (vlib_frame_t * f, vlib_node_t * node)
   return p;
 }
 
-static vlib_frame_size_t *
+static inline vlib_frame_size_t *
 get_frame_size_info (vlib_node_main_t * nm,
 		     u32 n_scalar_bytes, u32 n_vector_bytes)
 {
+#ifdef VLIB_SUPPORTS_ARBITRARY_SCALAR_SIZES
   uword key = (n_scalar_bytes << 16) | n_vector_bytes;
   uword *p, i;
 
@@ -109,6 +110,11 @@ get_frame_size_info (vlib_node_main_t * nm,
     }
 
   return vec_elt_at_index (nm->frame_sizes, i);
+#else
+  ASSERT (vlib_frame_bytes (n_scalar_bytes, n_vector_bytes)
+	  == (vlib_frame_bytes (0, 4)));
+  return vec_elt_at_index (nm->frame_sizes, 0);
+#endif
 }
 
 static u32
diff --git a/src/vlib/node.c b/src/vlib/node.c
index 69f505143b2..af323c4d63c 100644
--- a/src/vlib/node.c
+++ b/src/vlib/node.c
@@ -635,7 +635,10 @@ vlib_node_main_init (vlib_main_t * vm)
   vlib_node_t *n;
   uword ni;
 
+  nm->frame_sizes = vec_new (vlib_frame_size_t, 1);
+#ifdef VLIB_SUPPORTS_ARBITRARY_SCALAR_SIZES
   nm->frame_size_hash = hash_create (0, sizeof (uword));
+#endif
   nm->flags |= VLIB_NODE_MAIN_RUNTIME_STARTED;
 
   /* Generate sibling relationships */
diff --git a/src/vlib/threads.c b/src/vlib/threads.c
index e2f7d2634b9..7d17c7b37cc 100644
--- a/src/vlib/threads.c
+++ b/src/vlib/threads.c
@@ -866,9 +866,11 @@ start_workers (vlib_main_t * vm)
 	      nm_clone->processes = vec_dup_aligned (nm->processes,
 						     CLIB_CACHE_LINE_BYTES);
 
-	      /* zap the (per worker) frame freelists, etc */
-	      nm_clone->frame_sizes = 0;
+	      /* Create per-thread frame freelist */
+	      nm_clone->frame_sizes = vec_new (vlib_frame_size_t, 1);
+#ifdef VLIB_SUPPORTS_ARBITRARY_SCALAR_SIZES
 	      nm_clone->frame_size_hash = hash_create (0, sizeof (uword));
+#endif
 
 	      /* Packet trace buffers are guaranteed to be empty, nothing to do here */