About the "temperature histogram" of tier-agent

[YuFan Chen <wiz.chen@gmail.com>]

Hi,

   Before Jewel, the code uses "atime" to distinguish hot/cold data:

          agent_estimate_atime_temp() calculates the distance.
          It means colder data gets longer distance (larger value)


   In Jewel, it changes to use temperature with weight.
            So, colder data gets smaller value.

    However, it still use the "old semantics" to determine evicting or not in
           ReplicatedPG::agent_estimate_atime_temp();

    if (1000000 - temp_upper >= agent_state->evict_effort)
       return false;


     if there is no misunderstanding, should it change to that:

--- a/src/osd/ReplicatedPG.cc
+++ b/src/osd/ReplicatedPG.cc
@@ -12211,7 +12211,7 @@ bool
ReplicatedPG::agent_maybe_evict(ObjectContextRef& obc, bool
after_flush)
     delete f;
     *_dout << dendl;

-    if (1000000 - temp_upper >= agent_state->evict_effort)
+    if (temp_upper >= agent_state->evict_effort)
       return false;
   }

Yu Fan