vppinfra: bihash improvements

Template instances can allocate BIHASH_KVP_PER_PAGE data records
tangent to the bucket, to remove a dependent read / prefetch.

Template instances can ask for immediate memory allocation, to avoid
several branches in the lookup path.

Clean up l2 fib, gpb plugin codes: use clib_bihash_get_bucket(...)

Use hugepages for bihash allocation arenas

Type: improvement

Signed-off-by: Dave Barach <dave@barachs.net>
Signed-off-by: Damjan Marion <damarion@cisco.com>
Change-Id: I92fc11bc58e48d84e2d61f44580916dd1c56361c

1 files changed, 40 insertions, 13 deletions

diff --git a/src/vppinfra/bihash_template.h b/src/vppinfra/bihash_template.h
index 6abe7a36b27..13a348fbcf4 100644
--- a/src/vppinfra/bihash_template.h
+++ b/src/vppinfra/bihash_template.h
@@ -44,6 +44,11 @@
 #define BIHASH_FREELIST_LENGTH 17
 #endif
 
+/* default is 2MB, use 30 for 1GB */
+#ifndef BIHASH_LOG2_HUGEPAGE_SIZE
+#define BIHASH_LOG2_HUGEPAGE_SIZE 21
+#endif
+
 #define _bv(a,b) a##b
 #define __bv(a,b) _bv(a,b)
 #define BV(a) __bv(a,BIHASH_TYPE)
@@ -103,6 +108,7 @@ typedef CLIB_PACKED (struct {
    */
   u64 alloc_arena_next;	/* Next offset from alloc_arena to allocate, definitely NOT a constant */
   u64 alloc_arena_size;	/* Size of the arena */
+  u64 alloc_arena_mapped;	/* Size of the mapped memory in the arena */
   /* Two SVM pointers stored as 8-byte integers */
   u64 alloc_lock_as_u64;
   u64 buckets_as_u64;
@@ -111,7 +117,7 @@ typedef CLIB_PACKED (struct {
   u32 nbuckets;	/* Number of buckets */
   /* Set when header valid */
   volatile u32 ready;
-  u64 pad[2];
+  u64 pad[1];
 }) BVT (clib_bihash_shared_header);
 /* *INDENT-ON* */
 
@@ -175,19 +181,23 @@ extern void **clib_all_bihashes;
 #if BIHASH_32_64_SVM
 #undef alloc_arena_next
 #undef alloc_arena_size
+#undef alloc_arena_mapped
 #undef alloc_arena
 #undef CLIB_BIHASH_READY_MAGIC
 #define alloc_arena_next(h) (((h)->sh)->alloc_arena_next)
 #define alloc_arena_size(h) (((h)->sh)->alloc_arena_size)
+#define alloc_arena_mapped(h) (((h)->sh)->alloc_arena_mapped)
 #define alloc_arena(h) ((h)->alloc_arena)
 #define CLIB_BIHASH_READY_MAGIC 0xFEEDFACE
 #else
 #undef alloc_arena_next
 #undef alloc_arena_size
+#undef alloc_arena_mapped
 #undef alloc_arena
 #undef CLIB_BIHASH_READY_MAGIC
 #define alloc_arena_next(h) ((h)->sh.alloc_arena_next)
 #define alloc_arena_size(h) ((h)->sh.alloc_arena_size)
+#define alloc_arena_mapped(h) ((h)->sh.alloc_arena_mapped)
 #define alloc_arena(h) ((h)->alloc_arena)
 #define CLIB_BIHASH_READY_MAGIC 0
 #endif
@@ -285,7 +295,10 @@ static inline int BV (clib_bihash_bucket_is_empty)
   (BVT (clib_bihash_bucket) * b)
 {
   /* Note: applied to locked buckets, test offset */
-  return b->offset == 0;
+  if (BIHASH_KVP_AT_BUCKET_LEVEL == 0)
+    return b->offset == 0;
+  else
+    return (b->log2_pages == 0 && b->refcnt == 1);
 }
 
 static inline uword BV (clib_bihash_get_offset) (BVT (clib_bihash) * h,
@@ -345,19 +358,34 @@ format_function_t BV (format_bihash);
 format_function_t BV (format_bihash_kvp);
 format_function_t BV (format_bihash_lru);
 
+static inline
+BVT (clib_bihash_bucket) *
+BV (clib_bihash_get_bucket) (BVT (clib_bihash) * h, u64 hash)
+{
+#if BIHASH_KVP_AT_BUCKET_LEVEL
+  uword offset;
+  offset = (hash & (h->nbuckets - 1));
+  offset = offset * (sizeof (BVT (clib_bihash_bucket))
+		     + (BIHASH_KVP_PER_PAGE * sizeof (BVT (clib_bihash_kv))));
+  return ((BVT (clib_bihash_bucket) *) (((u8 *) h->buckets) + offset));
+#endif
+
+  return h->buckets + (hash & (h->nbuckets - 1));
+}
+
 static inline int BV (clib_bihash_search_inline_with_hash)
   (BVT (clib_bihash) * h, u64 hash, BVT (clib_bihash_kv) * key_result)
 {
-  u32 bucket_index;
   BVT (clib_bihash_value) * v;
   BVT (clib_bihash_bucket) * b;
   int i, limit;
 
+#if BIHASH_LAZY_INSTANTIATE
   if (PREDICT_FALSE (alloc_arena (h) == 0))
     return -1;
+#endif
 
-  bucket_index = hash & (h->nbuckets - 1);
-  b = &h->buckets[bucket_index];
+  b = BV (clib_bihash_get_bucket) (h, hash);
 
   if (PREDICT_FALSE (BV (clib_bihash_bucket_is_empty) (b)))
     return -1;
@@ -400,17 +428,12 @@ static inline int BV (clib_bihash_search_inline)
   return BV (clib_bihash_search_inline_with_hash) (h, hash, key_result);
 }
 
-static inline
-BVT (clib_bihash_bucket) *
-BV (clib_bihash_get_bucket) (BVT (clib_bihash) * h, u64 hash)
-{
-  return h->buckets + (hash & (h->nbuckets - 1));
-}
-
 static inline void BV (clib_bihash_prefetch_bucket)
   (BVT (clib_bihash) * h, u64 hash)
 {
-  clib_prefetch_load (BV (clib_bihash_get_bucket) (h, hash));
+  CLIB_PREFETCH (BV (clib_bihash_get_bucket) (h, hash),
+		 BIHASH_BUCKET_PREFETCH_CACHE_LINES * CLIB_CACHE_LINE_BYTES,
+		 LOAD);
 }
 
 static inline void BV (clib_bihash_prefetch_data)
@@ -419,8 +442,10 @@ static inline void BV (clib_bihash_prefetch_data)
   BVT (clib_bihash_value) * v;
   BVT (clib_bihash_bucket) * b;
 
+#if BIHASH_LAZY_INSTANTIATE
   if (PREDICT_FALSE (alloc_arena (h) == 0))
     return;
+#endif
 
   b = BV (clib_bihash_get_bucket) (h, hash);
 
@@ -445,8 +470,10 @@ static inline int BV (clib_bihash_search_inline_2_with_hash)
 
   ASSERT (valuep);
 
+#if BIHASH_LAZY_INSTANTIATE
   if (PREDICT_FALSE (alloc_arena (h) == 0))
     return -1;
+#endif
 
   b = BV (clib_bihash_get_bucket) (h, hash);