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[apple/xnu.git] / osfmk / kern / sched_average.c
index e20ddff7384db45c178617093605b20dfaad479e..b3edb3d9cc77acd72e13418bb5f4dda6bb94282d 100644 (file)
 #include <kern/assert.h>
 #include <kern/processor.h>
 #include <kern/thread.h>
+#if CONFIG_TELEMETRY
+#include <kern/telemetry.h>
+#endif
        
 uint32_t       avenrun[3] = {0, 0, 0};
 uint32_t       mach_factor[3] = {0, 0, 0};
 
+#if defined(CONFIG_SCHED_TRADITIONAL)
 /*
  * Values are scaled by LOAD_SCALE, defined in processor_info.h
  */
@@ -87,33 +91,45 @@ static uint32_t             fract[3] = {
 #undef base
 #undef frac
 
+#endif /* CONFIG_SCHED_TRADITIONAL */
+
 static unsigned int            sched_nrun;
 
 typedef void   (*sched_avg_comp_t)(
                                        void                    *param);
 
-#define SCHED_AVG_SECS(n)      ((n) << SCHED_TICK_SHIFT)
-
 static struct sched_average {
        sched_avg_comp_t        comp;
-       void                            *param;
-       int                                     period;
-       int                                     tick;                   
+       void                    *param;
+       int                     period; /* in seconds */
+       uint64_t                deadline;
 } sched_average[] = {
-       { compute_averunnable, &sched_nrun, SCHED_AVG_SECS(5), 0 },
-       { compute_stack_target, NULL, SCHED_AVG_SECS(5), 1 },
-       { compute_memory_pressure, NULL, SCHED_AVG_SECS(1), 0 },
+       { compute_averunnable, &sched_nrun, 5, 0 },
+       { compute_stack_target, NULL, 5, 1 },
+       { compute_memory_pressure, NULL, 1, 0 },
+       { compute_zone_gc_throttle, NULL, 60, 0 },
+       { compute_pageout_gc_throttle, NULL, 1, 0 },
+       { compute_pmap_gc_throttle, NULL, 60, 0 },
+#if CONFIG_TELEMETRY
+       { compute_telemetry, NULL, 1, 0 },
+#endif
        { NULL, NULL, 0, 0 }
 };
 
 typedef struct sched_average   *sched_average_t;
 
+/* The "stdelta" parameter represents the number of scheduler maintenance
+ * "ticks" that have elapsed since the last invocation, subject to
+ * integer division imprecision.
+ */
+
 void
-compute_averages(void)
+compute_averages(uint64_t stdelta)
 {
-       int                                     ncpus, nthreads, nshared;
-       uint32_t                        factor_now, average_now, load_now = 0;
+       int                     ncpus, nthreads, nshared, nbackground, nshared_non_bg;
+       uint32_t                factor_now, average_now, load_now = 0, background_load_now = 0, combined_fgbg_load_now = 0;
        sched_average_t         avg;
+       uint64_t                abstime, index;
 
        /*
         *      Retrieve counts, ignoring
@@ -122,6 +138,7 @@ compute_averages(void)
        ncpus = processor_avail_count;
        nthreads = sched_run_count - 1;
        nshared = sched_share_count;
+       nbackground = sched_background_count;
 
        /*
         *      Load average and mach factor calculations for
@@ -134,26 +151,67 @@ compute_averages(void)
        else
                factor_now = (ncpus - nthreads) * LOAD_SCALE;
 
-       sched_mach_factor =     ((sched_mach_factor << 2) + factor_now) / 5;
-       sched_load_average = ((sched_load_average << 2) + average_now) / 5;
-
+       /* For those statistics that formerly relied on being recomputed
+        * on timer ticks, advance by the approximate number of corresponding
+        * elapsed intervals, thus compensating for potential idle intervals.
+        */
+       for (index = 0; index < stdelta; index++) {
+               sched_mach_factor = ((sched_mach_factor << 2) + factor_now) / 5;
+               sched_load_average = ((sched_load_average << 2) + average_now) / 5;
+       }
        /*
-        *      Compute the timeshare priority
-        *      conversion factor based on loading.
+        * Compute the timeshare priority conversion factor based on loading.
+        * Because our counters may be incremented and accessed
+        * concurrently with respect to each other, we may have
+        * windows where the invariant nthreads >= nshared >= nbackground
+        * is broken, so truncate values in these cases.
         */
+
        if (nshared > nthreads)
                nshared = nthreads;
 
-       if (nshared > ncpus) {
+       if (nbackground > nshared)
+               nbackground = nshared;
+
+       nshared_non_bg = nshared - nbackground;
+
+       if (nshared_non_bg > ncpus) {
                if (ncpus > 1)
-                       load_now = nshared / ncpus;
+                       load_now = nshared_non_bg / ncpus;
                else
-                       load_now = nshared;
+                       load_now = nshared_non_bg;
 
                if (load_now > NRQS - 1)
                        load_now = NRQS - 1;
        }
 
+       if (nbackground > ncpus) {
+               if (ncpus > 1)
+                       background_load_now = nbackground / ncpus;
+               else
+                       background_load_now = nbackground;
+
+               if (background_load_now > NRQS - 1)
+                       background_load_now = NRQS - 1;
+       }
+
+       if (nshared > ncpus) {
+               if (ncpus > 1)
+                       combined_fgbg_load_now = nshared / ncpus;
+               else
+                       combined_fgbg_load_now = nshared;
+
+               if (combined_fgbg_load_now > NRQS - 1)
+                       combined_fgbg_load_now = NRQS - 1;
+       }
+
+       /*
+        *      Sample total running threads.
+        */
+       sched_nrun = nthreads;
+       
+#if defined(CONFIG_SCHED_TRADITIONAL)
+
        /*
         *      The conversion factor consists of
         *      two components: a fixed value based
@@ -166,16 +224,14 @@ compute_averages(void)
         *      are discarded.
         */
        sched_pri_shift = sched_fixed_shift - sched_load_shifts[load_now];
-
-       /*
-        *      Sample total running threads.
-        */
-       sched_nrun = nthreads;
+       sched_background_pri_shift = sched_fixed_shift - sched_load_shifts[background_load_now];
+       sched_combined_fgbg_pri_shift = sched_fixed_shift - sched_load_shifts[combined_fgbg_load_now];
 
        /*
         * Compute old-style Mach load averages.
         */
-       {
+
+       for (index = 0; index < stdelta; index++) {
                register int            i;
 
                for (i = 0; i < 3; i++) {
@@ -186,14 +242,24 @@ compute_averages(void)
                                                (average_now * (LOAD_SCALE - fract[i]))) / LOAD_SCALE;
                }
        }
+#endif /* CONFIG_SCHED_TRADITIONAL */
 
        /*
         *      Compute averages in other components.
         */
+       abstime = mach_absolute_time();
        for (avg = sched_average; avg->comp != NULL; ++avg) {
-               if (++avg->tick >= avg->period) {
-                       (*avg->comp)(avg->param);
-                       avg->tick = 0;
+               if (abstime >= avg->deadline) {
+                       uint64_t period_abs = (avg->period * sched_one_second_interval);
+                       uint64_t ninvokes = 1;
+
+                       ninvokes += (abstime - avg->deadline) / period_abs;
+                       ninvokes = MIN(ninvokes, SCHED_TICK_MAX_DELTA);
+
+                       for (index = 0; index < ninvokes; index++) {
+                               (*avg->comp)(avg->param);
+                       }
+                       avg->deadline = abstime + period_abs;
                }
        }
 }