PGPool::update: optimize with interval_set.swap

Use constant complexity swap instead of linear complexity
assignment.

Signed-off-by: Zac Medico <zmedico@gmail.com>
(cherry picked from commit ae64179a63351ac3966e70a074776188ddba5b84)

diff --git a/src/osd/PG.cc b/src/osd/PG.cc
index 9e45796b89a77c523afd77409827d203dd2e3f47..04f2d92828d957a4fb1d931f5266ab7de9571926 100644 (file)
--- a/src/osd/PG.cc
+++ b/src/osd/PG.cc
@@ -247,7 +247,7 @@ void PGPool::update(OSDMapRef map)
         lgeneric_subdout(cct, osd, 0) << __func__
           << " cached_removed_snaps shrank from " << cached_removed_snaps
           << " to " << newly_removed_snaps << dendl;
-        cached_removed_snaps = newly_removed_snaps;
+        cached_removed_snaps.swap(newly_removed_snaps);
         newly_removed_snaps.clear();
     }
     snapc = pi->get_snap_context();