added a setting "$OptimizeForUniprocessor"

...to enable users to turn off pthread_yield calls which are
counter-productive on multiprocessor machines (but have been
shown to be useful on uniprocessors)

10 files changed, 49 insertions, 5 deletions

diff --git a/ChangeLog b/ChangeLog
index 41aef49f..6856c3e7 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -21,6 +21,9 @@ version before switching to this one.
   receive loop (aka receiving messsages at a high rate)
 - doc bugfix: queue doc had wrong parameter name for setting controlling
   worker thread shutdown period
+- added a setting "$OptimizeForUniprocessor" to enable users to turn off
+  pthread_yield calls which are counter-productive on multiprocessor 
+  machines (but have been shown to be useful on uniprocessors)
 ---------------------------------------------------------------------------
 Version 3.21.6  [DEVEL] (rgerhards), 2008-10-22
 - consolidated time calls during msg object creation, improves performance
diff --git a/doc/rsyslog_conf.html b/doc/rsyslog_conf.html
index 2b773476..be543833 100644
--- a/doc/rsyslog_conf.html
+++ b/doc/rsyslog_conf.html
@@ -236,8 +236,10 @@ supported in order to be compliant to the upcoming new syslog RFC series.
 <li><a href="rsconf1_modload.html">$ModLoad</a></li>
 <li><a href="rsconf1_repeatedmsgreduction.html">$RepeatedMsgReduction</a></li>
 <li><a href="rsconf1_resetconfigvariables.html">$ResetConfigVariables</a></li>
-<li>$WorkDirectory &lt;name&gt; (directory for spool
-and other work files)</li>
+<li><b>$OptimizeForUniprocessor</b> [on/<b>off</b>] - turns on optimizatons which lead to better
+performance on uniprocessors. If you run on multicore-machiens, turning this off lessens CPU load. The
+default may change as uniprocessor systems become less common.</li>
+<li>$WorkDirectory &lt;name&gt; (directory for spool and other work files)</li>
 <li>$UDPServerAddress &lt;IP&gt; (imudp) -- local IP
 address (or name) the UDP listens should bind to</li>
 <li>$UDPServerRun &lt;port&gt; (imudp) -- former
diff --git a/runtime/glbl.c b/runtime/glbl.c
index 1114fcd3..c752288f 100644
--- a/runtime/glbl.c
+++ b/runtime/glbl.c
@@ -51,6 +51,7 @@ DEFobjStaticHelpers
  * class...
  */
 static uchar *pszWorkDir = NULL;
+static int bOptimizeUniProc = 1;	/* enable uniprocessor optimizations */
 static int iMaxLine = 2048;		/* maximum length of a syslog message */
 static int iDefPFFamily = PF_UNSPEC;     /* protocol family (IPv4, IPv6 or both) */
 static int bDropMalPTRMsgs = 0;/* Drop messages which have malicious PTR records during DNS lookup */
@@ -85,6 +86,7 @@ static dataType Get##nameFunc(void) \
 	return(nameVar); \
 }
 
+SIMP_PROP(OptimizeUniProc, bOptimizeUniProc, int)
 SIMP_PROP(MaxLine, iMaxLine, int)
 SIMP_PROP(DefPFFamily, iDefPFFamily, int) /* note that in the future we may check the family argument */
 SIMP_PROP(DropMalPTRMsgs, bDropMalPTRMsgs, int)
@@ -173,6 +175,7 @@ CODESTARTobjQueryInterface(glbl)
 	pIf->Get##name = Get##name; \
 	pIf->Set##name = Set##name;
 	SIMP_PROP(MaxLine);
+	SIMP_PROP(OptimizeUniProc);
 	SIMP_PROP(DefPFFamily);
 	SIMP_PROP(DropMalPTRMsgs);
 	SIMP_PROP(Option_DisallowWarning);
@@ -216,6 +219,7 @@ static rsRetVal resetConfigVariables(uchar __attribute__((unused)) *pp, void __a
 		pszWorkDir = NULL;
 	}
 	bDropMalPTRMsgs = 0;
+	bOptimizeUniProc = 1;
 	return RS_RET_OK;
 }
 
@@ -235,6 +239,7 @@ BEGINAbstractObjClassInit(glbl, 1, OBJ_IS_CORE_MODULE) /* class, version */
 	CHKiRet(regCfSysLineHdlr((uchar *)"defaultnetstreamdrivercafile", 0, eCmdHdlrGetWord, NULL, &pszDfltNetstrmDrvrCAF, NULL));
 	CHKiRet(regCfSysLineHdlr((uchar *)"defaultnetstreamdriverkeyfile", 0, eCmdHdlrGetWord, NULL, &pszDfltNetstrmDrvrKeyFile, NULL));
 	CHKiRet(regCfSysLineHdlr((uchar *)"defaultnetstreamdrivercertfile", 0, eCmdHdlrGetWord, NULL, &pszDfltNetstrmDrvrCertFile, NULL));
+	CHKiRet(regCfSysLineHdlr((uchar *)"optimizeforuniprocessor", 0, eCmdHdlrBinary, NULL, &bOptimizeUniProc, NULL));
 	CHKiRet(regCfSysLineHdlr((uchar *)"resetconfigvariables", 1, eCmdHdlrCustomHandler, resetConfigVariables, NULL, NULL));
 ENDObjClassInit(glbl)
 
diff --git a/runtime/glbl.h b/runtime/glbl.h
index 0c83bdd5..0b871b3c 100644
--- a/runtime/glbl.h
+++ b/runtime/glbl.h
@@ -41,6 +41,7 @@ BEGINinterface(glbl) /* name must also be changed in ENDinterface macro! */
 	dataType (*Get##name)(void); \
 	rsRetVal (*Set##name)(dataType);
 	SIMP_PROP(MaxLine, int)
+	SIMP_PROP(OptimizeUniProc, int)
 	SIMP_PROP(DefPFFamily, int)
 	SIMP_PROP(DropMalPTRMsgs, int)
 	SIMP_PROP(Option_DisallowWarning, int)
diff --git a/runtime/queue.c b/runtime/queue.c
index 7fa2df91..a3e29a96 100644
--- a/runtime/queue.c
+++ b/runtime/queue.c
@@ -1285,6 +1285,7 @@ rsRetVal queueConstruct(queue_t **ppThis, queueType_t qType, int iWorkerThreads,
 
 	/* we have an object, so let's fill the properties */
 	objConstructSetObjInfo(pThis);
+	pThis->bOptimizeUniProc = glbl.GetOptimizeUniProc();
 	if((pThis->pszSpoolDir = (uchar*) strdup((char*)glbl.GetWorkDir())) == NULL)
 		ABORT_FINALIZE(RS_RET_OUT_OF_MEMORY);
 
@@ -2208,8 +2209,10 @@ finalize_it:
 		/* the following pthread_yield is experimental, but brought us performance
 		 * benefit. For details, please see http://kb.monitorware.com/post14216.html#p14216
 		 * rgerhards, 2008-10-09
+		 * but this is only true for uniprocessors, so we guard it with an optimize flag -- rgerhards, 2008-10-22
 		 */
-		pthread_yield();
+		if(pThis->bOptimizeUniProc)
+			pthread_yield();
 	}
 
 	RETiRet;
diff --git a/runtime/queue.h b/runtime/queue.h
index 9e75b31b..a2dd594f 100644
--- a/runtime/queue.h
+++ b/runtime/queue.h
@@ -58,6 +58,7 @@ typedef struct qWrkThrd_s {
 typedef struct queue_s {
 	BEGINobjInstance;
 	queueType_t	qType;
+	int	bOptimizeUniProc; /* cache for the equally-named global setting, pulled at time of queue creation */
 	int	bEnqOnly;	/* does queue run in enqueue-only mode (1) or not (0)? */
 	int	bSaveOnShutdown;/* persists everthing on shutdown (if DA!)? 1-yes, 0-no */
 	int	bQueueStarted;	/* has queueStart() been called on this queue? 1-yes, 0-no */
diff --git a/runtime/wti.c b/runtime/wti.c
index 4abca090..e8a77474 100644
--- a/runtime/wti.c
+++ b/runtime/wti.c
@@ -45,9 +45,11 @@
 #include "wtp.h"
 #include "wti.h"
 #include "obj.h"
+#include "glbl.h"
 
 /* static data */
 DEFobjStaticHelpers
+DEFobjCurrIf(glbl)
 
 /* forward-definitions */
 
@@ -202,6 +204,7 @@ ENDobjDestruct(wti)
 /* Standard-Constructor for the wti object
  */
 BEGINobjConstruct(wti) /* be sure to specify the object type also in END macro! */
+	pThis->bOptimizeUniProc = glbl.GetOptimizeUniProc();
 	pthread_cond_init(&pThis->condExitDone, NULL);
 	pthread_mutex_init(&pThis->mut, NULL);
 ENDobjConstruct(wti)
@@ -367,7 +370,8 @@ wtiWorker(wti_t *pThis)
 		wtpProcessThrdChanges(pWtp);
 		pthread_testcancel(); /* see big comment in function header */
 #		if !defined(__hpux) /* pthread_yield is missing there! */
-		pthread_yield(); /* see big comment in function header */
+		if(pThis->bOptimizeUniProc)
+			pthread_yield(); /* see big comment in function header */
 #		endif
 
 		/* if we have a rate-limiter set for this worker pool, let's call it. Please
@@ -466,6 +470,14 @@ finalize_it:
 /* dummy */
 rsRetVal wtiQueryInterface(void) { return RS_RET_NOT_IMPLEMENTED; }
 
+/* exit our class
+ */
+BEGINObjClassExit(wti, OBJ_IS_CORE_MODULE) /* CHANGE class also in END MACRO! */
+CODESTARTObjClassExit(nsdsel_gtls)
+	/* release objects we no longer need */
+	objRelease(glbl, CORE_COMPONENT);
+ENDObjClassExit(wti)
+
 
 /* Initialize the wti class. Must be called as the very first method
  * before anything else is called inside this class.
@@ -473,6 +485,7 @@ rsRetVal wtiQueryInterface(void) { return RS_RET_NOT_IMPLEMENTED; }
  */
 BEGINObjClassInit(wti, 1, OBJ_IS_CORE_MODULE) /* one is the object version (most important for persisting) */
 	/* request objects we use */
+	CHKiRet(objUse(glbl, CORE_COMPONENT));
 ENDObjClassInit(wti)
 
 /*
diff --git a/runtime/wti.h b/runtime/wti.h
index 0cd6744e..6b60b833 100644
--- a/runtime/wti.h
+++ b/runtime/wti.h
@@ -31,6 +31,7 @@
 /* the worker thread instance class */
 typedef struct wti_s {
 	BEGINobjInstance;
+	int bOptimizeUniProc; /* cache for the equally-named global setting, pulled at time of queue creation */
 	pthread_t thrdID;  /* thread ID */
 	qWrkCmd_t tCurrCmd; /* current command to be carried out by worker */
 	obj_t *pUsrp;		/* pointer to an object meaningful for current user pointer (e.g. queue pUsr data elemt) */
diff --git a/runtime/wtp.c b/runtime/wtp.c
index 45034fa7..06173e04 100644
--- a/runtime/wtp.c
+++ b/runtime/wtp.c
@@ -46,9 +46,11 @@
 #include "wtp.h"
 #include "wti.h"
 #include "obj.h"
+#include "glbl.h"
 
 /* static data */
 DEFobjStaticHelpers
+DEFobjCurrIf(glbl)
 
 /* forward-definitions */
 
@@ -75,6 +77,7 @@ static rsRetVal NotImplementedDummy() { return RS_RET_OK; }
 /* Standard-Constructor for the wtp object
  */
 BEGINobjConstruct(wtp) /* be sure to specify the object type also in END macro! */
+	pThis->bOptimizeUniProc = glbl.GetOptimizeUniProc();
 	pthread_mutex_init(&pThis->mut, NULL);
 	pthread_cond_init(&pThis->condThrdTrm, NULL);
 	/* set all function pointers to "not implemented" dummy so that we can safely call them */
@@ -484,7 +487,8 @@ wtpStartWrkr(wtp_t *pThis, int bLockMutex)
  	 * hold the queue's mutex, but at least it has a chance to start on a single-CPU system.
  	 */
 #	if !defined(__hpux) /* pthread_yield is missing there! */
-	pthread_yield();
+	if(pThis->bOptimizeUniProc)
+		pthread_yield();
 #	endif
 
 	/* indicate we just started a worker and would like to see it running */
@@ -617,12 +621,22 @@ finalize_it:
 /* dummy */
 rsRetVal wtpQueryInterface(void) { return RS_RET_NOT_IMPLEMENTED; }
 
+/* exit our class
+ */
+BEGINObjClassExit(wtp, OBJ_IS_CORE_MODULE) /* CHANGE class also in END MACRO! */
+CODESTARTObjClassExit(nsdsel_gtls)
+	/* release objects we no longer need */
+	objRelease(glbl, CORE_COMPONENT);
+ENDObjClassExit(wtp)
+
+
 /* Initialize the stream class. Must be called as the very first method
  * before anything else is called inside this class.
  * rgerhards, 2008-01-09
  */
 BEGINObjClassInit(wtp, 1, OBJ_IS_CORE_MODULE)
 	/* request objects we use */
+	CHKiRet(objUse(glbl, CORE_COMPONENT));
 ENDObjClassInit(wtp)
 
 /*
diff --git a/runtime/wtp.h b/runtime/wtp.h
index 13ebe536..88d88afd 100644
--- a/runtime/wtp.h
+++ b/runtime/wtp.h
@@ -52,6 +52,7 @@ typedef enum {
 /* the worker thread pool (wtp) object */
 typedef struct wtp_s {
 	BEGINobjInstance;
+	int	bOptimizeUniProc; /* cache for the equally-named global setting, pulled at time of queue creation */
 	wtpState_t wtpState;
 	int 	iNumWorkerThreads;/* number of worker threads to use */
 	int 	iCurNumWrkThrd;/* current number of active worker threads */