rgw_file: fix hiwat behavior

Removed logic to skip reclaim processing conditionally on hiwat,
this probably meant to be related to a lowat value, which does
not exist.

Having exercised the hiwat reclaim behavior, noticed that the
path which moves unreachable objects to LRU, could and probably
should remove them altogether when q.size exceeds hiwat.  Now
the max unreachable float is lane hiwat, for all lanes.

Signed-off-by: Matt Benjamin <mbenjamin@redhat.com>
(cherry picked from commit b8791b2217e9ca87b2d17b51f283fa14bd68b581)
Signed-off-by: Matt Benjamin <mbenjamin@redhat.com>

diff --git a/src/common/cohort_lru.h b/src/common/cohort_lru.h
index 2c997ff683604524bd9da18379ead7ab4933f4ac..8a8b766997261d17f07128923cb1c658ec789981 100644 (file)
--- a/src/common/cohort_lru.h
+++ b/src/common/cohort_lru.h
@@ -131,17 +131,7 @@ namespace cohort {
        for (int ix = 0; ix < n_lanes; ++ix,
               lane_ix = next_evict_lane()) {
          Lane& lane = qlane[lane_ix];
-         /* hiwat check */
-         /* XXX try the hiwat check unlocked, then recheck locked */
-         if (lane.q.size() > lane_hiwat) {
-           lane.lock.lock();
-           if (lane.q.size() <= lane_hiwat) {
-             lane.lock.unlock();
-             continue;
-           }
-         } else
-           continue;
-         // XXXX if object at LRU has refcnt==1, take it
+         /* if object at LRU has refcnt==1, it may be reclaimable */
          Object* o = &(lane.q.back());
 #if 0 /* XXX save for refactor */
          std::cout << __func__
@@ -228,7 +218,12 @@ namespace cohort {
            Object::Queue::iterator it =
              Object::Queue::s_iterator_to(*o);
            lane.q.erase(it);
-           lane.q.push_back(*o);
+           /* hiwat check */
+           if (lane.q.size() > lane_hiwat) {
+             delete o;
+           } else {
+             lane.q.push_back(*o);
+           }
          }
          lane.lock.unlock();
        }