From: Dave Dykstra <dwd@fnal.gov>
Date: Wed, 30 Mar 2016 11:55:02 +0000 (+1300)
Subject: Bug 4312: Support disabling collapsed forwarding SMP cooperation
X-Git-Tag: SQUID_4_0_8~9
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=8f7dbf74048f3950f8931e5ea38480b5d35b641e;p=thirdparty%2Fsquid.git

Bug 4312: Support disabling collapsed forwarding SMP cooperation
---

diff --git a/src/SquidConfig.h b/src/SquidConfig.h
index 5c03b2ffc7..97842d81ff 100644
--- a/src/SquidConfig.h
+++ b/src/SquidConfig.h
@@ -341,6 +341,8 @@ public:
 #endif
     } onoff;
 
+    int64_t collapsed_forwarding_shared_entries_limit;
+
     int pipeline_max_prefetch;
 
     int forward_max_tries;
diff --git a/src/Transients.cc b/src/Transients.cc
index 98963eb261..acb5029e5f 100644
--- a/src/Transients.cc
+++ b/src/Transients.cc
@@ -370,7 +370,7 @@ Transients::EntryLimit()
     if (!UsingSmp() || !Config.onoff.collapsed_forwarding)
         return 0; // no SMP collapsed forwarding possible or needed
 
-    return 16*1024; // TODO: make configurable?
+    return Config.collapsed_forwarding_shared_entries_limit;
 }
 
 /// initializes shared memory segment used by Transients
diff --git a/src/cache_cf.cc b/src/cache_cf.cc
index 40c6c41da2..699d06697f 100644
--- a/src/cache_cf.cc
+++ b/src/cache_cf.cc
@@ -2456,6 +2456,26 @@ free_int(int *var)
     *var = 0;
 }
 
+static void
+dump_int64_t(StoreEntry * entry, const char *name, int64_t var)
+{
+    storeAppendPrintf(entry, "%s %" PRId64 "\n", name, var);
+}
+
+void
+parse_int64_t(int64_t *var)
+{
+    int64_t i;
+    i = GetInteger64();
+    *var = i;
+}
+
+static void
+free_int64_t(int64_t *var)
+{
+    *var = 0;
+}
+
 static void
 dump_onoff(StoreEntry * entry, const char *name, int var)
 {
diff --git a/src/cf.data.depend b/src/cf.data.depend
index e36332eee3..6f325a7388 100644
--- a/src/cf.data.depend
+++ b/src/cf.data.depend
@@ -51,6 +51,7 @@ icap_service_failure_limit
 icmp
 ecap_service_type
 int
+int64_t
 kb_int64_t
 kb_size_t
 logformat
diff --git a/src/cf.data.pre b/src/cf.data.pre
index d9741dcc79..6c3c3fb685 100644
--- a/src/cf.data.pre
+++ b/src/cf.data.pre
@@ -6189,6 +6189,27 @@ DOC_START
        simultenous refresh requests] outweigh losses from such delays.
 DOC_END
 
+NAME: collapsed_forwarding_shared_entries_limit
+COMMENT: (number of entries)
+TYPE: int64_t
+LOC: Config.collapsed_forwarding_shared_entries_limit
+DEFAULT: 16384
+DOC_START
+	This limits the size of a table used for sharing information
+	about collapsible entries among SMP workers. Limiting sharing
+	too much results in cache content duplication and missed
+	collapsing opportunities. Using excessively large values
+	wastes shared memory.
+
+	The limit should be significantly larger then the number of
+	concurrent collapsible entries one wants to share. For a cache
+	that handles less than 5000 concurrent requests, the default
+	setting of 16384 should be plenty.
+
+	If the limit is set to zero, it disables sharing of collapsed
+	forwarding between SMP workers.
+DOC_END
+
 COMMENT_START
  TIMEOUTS
  -----------------------------------------------------------------------------