os/bluestore: leverage the type knowledge in BitMapAreaLeaf.

We're sure the only element type BitMapAreaLeaf aggregates is
BitMapZone. There is no business to go through vptrs and thus
prohibit compiler to inline in a method that is crucial for
overall performance of the BitMap allocator.

Signed-off-by: Radoslaw Zarzynski <rzarzynski@mirantis.com>

diff --git a/src/os/bluestore/BitAllocator.cc b/src/os/bluestore/BitAllocator.cc
index 238f5f36dfc9ae7c56cc30fa040d9bc0a0842a43..b5dea053cc799ddd91ff5b73734200474ef30be9 100644 (file)
--- a/src/os/bluestore/BitAllocator.cc
+++ b/src/os/bluestore/BitAllocator.cc
@@ -1095,7 +1095,9 @@ BitMapAreaLeaf::~BitMapAreaLeaf()
   unlock();
 }
 
-bool BitMapAreaLeaf::child_check_n_lock(BitMapArea *child, int64_t required, bool lock)
+bool BitMapAreaLeaf::child_check_n_lock(BitMapZone* const child,
+                                        const int64_t required,
+                                        const bool lock)
 {
   /* The exhausted check can be performed without acquiring the lock. This
    * is because 1) BitMapZone::is_exhausted() actually operates atomically
@@ -1120,22 +1122,20 @@ bool BitMapAreaLeaf::child_check_n_lock(BitMapArea *child, int64_t required, boo
   return true;
 }
 
-void BitMapAreaLeaf::child_unlock(BitMapArea *child)
-{
-  child->unlock();
-}
-
 int64_t BitMapAreaLeaf::alloc_blocks_dis_int(int64_t num_blocks, int64_t min_alloc, 
                                  int64_t hint, int64_t area_blk_off, ExtentList *block_list)
 {
-  BitMapArea *child = NULL;
+  BitMapZone* child = nullptr;
   int64_t allocated = 0;
   int64_t blk_off = 0;
 
   BmapEntityListIter iter = BmapEntityListIter(
         m_child_list, hint / m_child_size_blocks, false);
 
-  while ((child = (BitMapArea *) iter.next())) {
+  /* We're sure the only element type we aggregate is BitMapZone,
+   * so there is no business to go through vptr and thus prohibit
+   * compiler to inline the stuff. Consult BitMapAreaLeaf::init. */
+  while ((child = static_cast<BitMapZone*>(iter.next()))) {
     if (!child_check_n_lock(child, 1, false)) {
       hint = 0;
       continue;
@@ -1144,7 +1144,7 @@ int64_t BitMapAreaLeaf::alloc_blocks_dis_int(int64_t num_blocks, int64_t min_all
     blk_off = child->get_index() * m_child_size_blocks + area_blk_off;
     allocated += child->alloc_blocks_dis(num_blocks - allocated, min_alloc,
                                          hint % m_child_size_blocks, blk_off, block_list);
-    child_unlock(child);
+    child->unlock();
     if (allocated == num_blocks) {
       break;
     }

diff --git a/src/os/bluestore/BitAllocator.h b/src/os/bluestore/BitAllocator.h
index e12b256e2c876358d3eb104a45bb9fc871be3457..2b24a324fcee165ec6c87a89aca7ab7f7a77a64d 100644 (file)
--- a/src/os/bluestore/BitAllocator.h
+++ b/src/os/bluestore/BitAllocator.h
@@ -450,8 +450,7 @@ public:
     return false;
   }
 
-  bool child_check_n_lock(BitMapArea *child, int64_t required, bool lock);
-  void child_unlock(BitMapArea *child);
+  bool child_check_n_lock(BitMapZone* child, int64_t required, bool lock);
 
   int64_t alloc_blocks_int(int64_t num_blocks, int64_t hint, int64_t *start_block);
   int64_t alloc_blocks_dis_int(int64_t num_blocks, int64_t min_alloc, int64_t hint,