[PATCH] Log LRU attempts where no candidate objects were found, and add a varnishstat counter for these events.

[Martin Blix Grydeland]

---
 bin/varnishd/cache/cache_expire.c |    3 +++
 include/tbl/vsc_f_main.h          |    4 ++++
 2 files changed, 7 insertions(+)

diff --git a/bin/varnishd/cache/cache_expire.c b/bin/varnishd/cache/cache_expire.c
index 3d18d78..daf8f88 100644
--- a/bin/varnishd/cache/cache_expire.c
+++ b/bin/varnishd/cache/cache_expire.c
@@ -446,6 +446,9 @@ EXP_NukeOne(struct busyobj *bo, struct lru *lru)
 		binheap_delete(exp_heap, oc->timer_idx);
 		assert(oc->timer_idx == BINHEAP_NOIDX);
 		VSC_C_main->n_lru_nuked++;
+	} else {
+		VSLb(bo->vsl, SLT_ExpKill, "LRU no candidates");
+		VSC_C_main->n_lru_no_candidates++;
 	}
 	Lck_Unlock(&exp_mtx);
 	Lck_Unlock(&lru->mtx);
diff --git a/include/tbl/vsc_f_main.h b/include/tbl/vsc_f_main.h
index d9c78ce..9aed160 100644
--- a/include/tbl/vsc_f_main.h
+++ b/include/tbl/vsc_f_main.h
@@ -314,6 +314,10 @@ VSC_F(n_lru_moved,		uint64_t, 0, 'i',
     "N LRU moved objects",
 	""
 )
+VSC_F(n_lru_no_candidates,	uint64_t, 0, 'c',
+    "LRU attemps with no candidates",
+      "Count of LRU attempts where no possible candidate objects were found"
+)
 
 VSC_F(losthdr,			uint64_t, 0, 'a',
     "HTTP header overflows",
-- 
1.7.9.5