From: Xuehan Xu <xuxuehan@360.cn>
Date: Sat, 6 Jan 2018 02:40:33 +0000 (+0800)
Subject: common: compute SimpleLRU's size with contents.size() instead of lru.size()
X-Git-Tag: v13.0.2~567^2
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=7e0a27a5c8b7d12d378de4d700ed7a95af7860c3;p=ceph.git

common: compute SimpleLRU's size with contents.size() instead of lru.size()

As libstdc++ earlier than version 5 implement the list::size() as a O(n) operation,
this should be needed to avoid regression of various ceph component's performance.

Signed-off-by: Xuehan Xu <xuxuehan@360.cn>
---

diff --git a/src/common/simple_cache.hpp b/src/common/simple_cache.hpp
index 1ff4ae911cd..4006576d00b 100644
--- a/src/common/simple_cache.hpp
+++ b/src/common/simple_cache.hpp
@@ -27,7 +27,7 @@ class SimpleLRU {
   map<K, V, C> pinned;
 
   void trim_cache() {
-    while (lru.size() > max_size) {
+    while (contents.size() > max_size) {
       contents.erase(lru.back().first);
       lru.pop_back();
     }