PERFORCE change 127589 for review

[Marko Zec]

http://perforce.freebsd.org/chv.cgi?CH=127589

Change 127589 by zec at zec_tpx32 on 2007/10/16 10:20:39

	Implement per process group accounting of average CPU usage.
	
	Two average values are maintained per process group: avg1
	loses half of its value after around 62.5 ms, while for avg2
	the same should happen after roughly 0.5 s.  Internally the
	values are maintained in a 16.16 bit fixed point format stored
	in a uint (portability XXX).  Each 62.5 ms the entire list
	of process group containers is scanned for deccay processing.
	
	This is very experimental, needs more thought about locking,
	as well as more experimentation accross wide variety of HZ
	values on both UP and SMP machines.

Affected files ...

.. //depot/projects/vimage/src/sys/kern/kern_clock.c#9 edit
.. //depot/projects/vimage/src/sys/kern/kern_vimage.c#43 edit
.. //depot/projects/vimage/src/sys/sys/vimage.h#42 edit

Differences ...

==== //depot/projects/vimage/src/sys/kern/kern_clock.c#9 (text+ko) ====

@@ -167,6 +167,11 @@
 int	ticks;
 int	psratio;
 
+#ifdef VIMAGE
+u_int	tot_acc_statcalls;
+int	last_acc_ticks;
+#endif
+
 /*
  * Initialize clock frequencies and start both clocks running.
  */
@@ -416,7 +421,8 @@
 	td = curthread;
 	p = td->td_proc;
 #ifdef VIMAGE
-	INIT_VPROCG(p->p_ucred->cr_vimage->v_procg);
+	INIT_VPROCG(td->td_ucred->cr_vimage->v_procg);
+	INIT_VCPU(td->td_ucred->cr_vimage->v_cpu);
 	struct vprocg *vprocg_iter;
 #endif
 
@@ -468,10 +474,41 @@
 #ifdef VIMAGE
 	if (sel != CP_INTR)
 		sel = CP_IDLE;
-	/* XXX list locking?  sched_lock is held here... */
+	/* XXX list locking? */
 	LIST_FOREACH(vprocg_iter, &vprocg_head, vprocg_le)
 		if (vprocg != vprocg_iter)
 			atomic_add_long(&vprocg_iter->_cp_time[sel], 1);
+
+	/* Per-vcpu average accounting */
+	/* LOCKING!!!! XXX */
+	tot_acc_statcalls++;
+	if (!TD_IS_IDLETHREAD(td))
+		V_acc_statcalls++;
+	if (last_acc_ticks + (hz >> 4) <= ticks) {
+		u_int weight_fixp;
+		u_int avg0;
+
+		last_acc_ticks = ticks;
+		/*
+		 * 0x10000 == 1.0 in 16:16 fixed point notation;
+		 * a few extra LS bits are added in an attempt to
+		 * compensate for truncation errors.
+		 */
+		weight_fixp = 0x010007 / tot_acc_statcalls;
+		LIST_FOREACH(vcpu, &vcpu_head, vcpu_le) {
+			avg0 = weight_fixp * V_acc_statcalls;
+			V_avg1_fixp = (V_avg1_fixp + avg0 + 1) >> 1;
+			V_avg2_fixp = (15 * V_avg2_fixp + avg0 + 15) >> 4;
+			V_acc_statcalls = 0;
+			/*
+			 * Convert fixp notation to percents for export to
+			 * userspace via sysctls - this will go away soon.
+			 */
+			V_avg1_uint = (V_avg1_fixp * 100 + 0x8000) >> 16;
+			V_avg2_uint = (V_avg2_fixp * 100 + 0x8000) >> 16;
+		}
+		tot_acc_statcalls = 0;
+	}
 #endif
 
 	/* Update resource usage integrals and maximums. */

==== //depot/projects/vimage/src/sys/kern/kern_vimage.c#43 (text+ko) ====

@@ -43,6 +43,7 @@
 #include <sys/sched.h>
 #include <sys/sockio.h>
 #include <sys/sx.h>
+#include <sys/sysctl.h>
 #include <sys/vimage.h>
 
 #ifdef DDB
@@ -130,6 +131,11 @@
 static TAILQ_HEAD(vnet_modlink_head, vnet_modlink) vnet_modlink_head;
 static TAILQ_HEAD(vnet_modpending_head, vnet_modlink) vnet_modpending_head;
 
+SYSCTL_V_INT(V_CPU, vcpu, _kern, OID_AUTO, avg1_uint, CTLFLAG_RD,
+    avg1_uint, 0, "Average CPU usage");
+SYSCTL_V_INT(V_CPU, vcpu, _kern, OID_AUTO, avg2_uint, CTLFLAG_RD,
+    avg2_uint, 0, "Average CPU usage");
+
 void vnet_mod_register(vmi)
 	const struct vnet_modinfo *vmi;
 {

==== //depot/projects/vimage/src/sys/sys/vimage.h#42 (text+ko) ====

@@ -104,6 +104,7 @@
 #define V_MOD_vnet_ipsec	VNET_MOD_IPSEC
 
 #define V_MOD_vprocg		0
+#define V_MOD_vcpu		0
 
 struct vnet {
 	void	*mod_data[VNET_MOD_MAX];
@@ -272,6 +273,8 @@
 #define VPROCG_ITERLOOP_END()						\
 	}								\
 
+#define INIT_VCPU(arg)		struct vcpu *vcpu = (arg);
+
 #else /* !VIMAGE */
 
 /* Non-VIMAGE null-macros */
@@ -290,10 +293,13 @@
 #define INIT_VPROCG(arg)
 #define VPROCG_ITERLOOP_BEGIN()
 #define VPROCG_ITERLOOP_END()
+#define INIT_VCPU(arg)
 
 #endif /* !VIMAGE */
 
+/* XXX those defines bellow should probably go into vprocg.h and vcpu.h */
 #define VPROCG(sym)		VSYM(vprocg, sym)
+#define VCPU(sym)		VSYM(vcpu, sym)
 
 #define V_cp_time		VPROCG(cp_time)
 #define V_hostname		VPROCG(hostname)
@@ -303,6 +309,12 @@
 #define V_sched_tdcnt		VPROCG(sched_tdcnt)
 #define V_tdq_load		VPROCG(tdq_load)
 
+#define V_acc_statcalls		VCPU(acc_statcalls)
+#define V_avg1_fixp		VCPU(avg1_fixp)
+#define V_avg2_fixp		VCPU(avg2_fixp)
+#define V_avg1_uint		VCPU(avg1_uint)
+#define V_avg2_uint		VCPU(avg2_uint)
+
 #ifdef VIMAGE
 void vnet_mod_register(const struct vnet_modinfo *);
 void vnet_mod_deregister(const struct vnet_modinfo *);
@@ -408,10 +420,13 @@
 	u_int	vcpu_ref;		/* reference count */
 	u_int	vcpu_id;		/* ID num */
 
+	u_int	_acc_statcalls;		/* statclocks since last avg update*/
+	u_int	_avg1_fixp;		/* "fast" avg in 16:16 bit fixedpoint */
+	u_int	_avg2_fixp;		/* "slow" avg in 16:16 bit fixedpoint */
+	u_int	_avg1_uint;		/* (avg1_fixp * 100) >> 16 */
+	u_int	_avg2_uint;		/* (avg2_fixp * 100) >> 16 */
+
 #if 0
-	u_int	cp_time_avg[CPUSTATES];
-	u_int	cp_time_avg1[CPUSTATES];
-
 	u_int	cpu_min;		/* Guaranteed CPU share */
 	u_int	cpu_max;		/* Maximum average CPU usage */
 	u_int	intr_limit;		/* Limit on CPU usage in intr ctx */