Add new eventlog events for various heap and GC statistics

They cover much the same info as is available via the GHC.Stats module
or via the '+RTS -s' textual output, but via the eventlog and with a
better sampling frequency.

We have three new generic heap info events and two very GHC-specific
ones. (The hope is the general ones are usable by other implementations
that use the same eventlog system, or indeed not so sensitive to changes
in GHC itself.)

The general ones are:

 * total heap mem allocated since prog start, on a per-HEC basis
 * current size of the heap (MBlocks reserved from OS for the heap)
 * current size of live data in the heap

Currently these are all emitted by GHC at GC time (live data only at
major GC).

The GHC specific ones are:

 * an event giving various static heap paramaters:
   * number of generations (usually 2)
   * max size if any
   * nursary size
   * MBlock and block sizes
 * a event emitted on each GC containing:
   * GC generation (usually just 0,1)
   * total bytes copied
   * bytes lost to heap slop and fragmentation
   * the number of threads in the parallel GC (1 for serial)
   * the maximum number of bytes copied by any par GC thread
   * the total number of bytes copied by all par GC threads
     (these last three can be used to calculate an estimate of the
      work balance in parallel GCs)

1 files changed, 140 insertions, 2 deletions

diff --git a/rts/Trace.h b/rts/Trace.h
index dcb0b00621..18856d9721 100644
--- a/rts/Trace.h
+++ b/rts/Trace.h
@@ -37,8 +37,9 @@ typedef StgWord16 CapsetType;
 enum CapsetType { CapsetTypeCustom = CAPSET_TYPE_CUSTOM,
                   CapsetTypeOsProcess = CAPSET_TYPE_OSPROCESS,
                   CapsetTypeClockdomain = CAPSET_TYPE_CLOCKDOMAIN };
-#define CAPSET_OSPROCESS_DEFAULT 0
-#define CAPSET_CLOCKDOMAIN_DEFAULT 1
+#define CAPSET_OSPROCESS_DEFAULT   ((CapsetID)0)
+#define CAPSET_HEAP_DEFAULT        ((CapsetID)0)   /* reusing the same capset */
+#define CAPSET_CLOCKDOMAIN_DEFAULT ((CapsetID)1)
 
 // -----------------------------------------------------------------------------
 // Message classes
@@ -113,6 +114,35 @@ void traceSchedEvent_ (Capability *cap, EventTypeNum tag,
 void traceGcEvent_ (Capability *cap, EventTypeNum tag);
 
 /* 
+ * Record a heap event
+ */
+#define traceHeapEvent(cap, tag, heap_capset, info1) \
+    if (RTS_UNLIKELY(TRACE_gc)) { \
+        traceHeapEvent_(cap, tag, heap_capset, info1);  \
+    }
+void traceHeapEvent_ (Capability   *cap,
+                      EventTypeNum  tag,
+                      CapsetID      heap_capset,
+                      lnat          info1);
+
+void traceEventHeapInfo_ (CapsetID    heap_capset,
+                          nat         gens,
+                          lnat        maxHeapSize,
+                          lnat        allocAreaSize,
+                          lnat        mblockSize,
+                          lnat        blockSize);
+
+void traceEventGcStats_  (Capability *cap,
+                          CapsetID    heap_capset,
+                          nat         gen,
+                          lnat        copied,
+                          lnat        slop,
+                          lnat        fragmentation,
+                          nat         par_n_threads,
+                          lnat        par_max_copied,
+                          lnat        par_tot_copied);
+
+/* 
  * Record a spark event
  */
 #define traceSparkEvent(cap, tag)         \
@@ -227,6 +257,13 @@ void traceSparkCounters_ (Capability *cap,
 #define traceSchedEvent(cap, tag, tso, other) /* nothing */
 #define traceSchedEvent2(cap, tag, tso, other, info) /* nothing */
 #define traceGcEvent(cap, tag) /* nothing */
+#define traceEventGcStats_(cap, heap_capset, gen, \
+                           copied, slop, fragmentation, \
+                           par_n_threads, par_max_copied, par_tot_copied) /* nothing */
+#define traceHeapEvent(cap, tag, heap_capset, info1) /* nothing */
+#define traceEventHeapInfo_(heap_capset, gens, \
+                            maxHeapSize, allocAreaSize, \
+                            mblockSize, blockSize) /* nothing */
 #define traceSparkEvent(cap, tag) /* nothing */
 #define traceSparkEvent2(cap, tag, other) /* nothing */
 #define traceCap(class, cap, msg, ...) /* nothing */
@@ -302,6 +339,31 @@ INLINE_HEADER void dtraceStartup (int num_caps) {
     HASKELLEVENT_GC_WORK(cap)
 #define dtraceGcDone(cap)                               \
     HASKELLEVENT_GC_DONE(cap)
+#define dtraceEventGcStats(heap_capset, gens,           \
+                           copies, slop, fragmentation, \
+                           par_n_threads,               \
+                           par_max_copied,              \
+                           par_tot_copied)              \
+    HASKELLEVENT_GC_STATS(heap_capset, gens,            \
+                           copies, slop, fragmentation, \
+                           par_n_threads,               \
+                           par_max_copied,              \
+                           par_tot_copied)              \
+#define dtraceHeapInfo(heap_capset, gens,               \
+                       maxHeapSize, allocAreaSize,      \
+                       mblockSize, blockSize)           \
+    HASKELLEVENT_HEAP_INFO(heap_capset, gens,           \
+                           maxHeapSize, allocAreaSize,  \
+                           mblockSize, blockSize)
+#define dtraceEventHeapAllocated(cap, heap_capset,      \
+                                 allocated)             \
+    HASKELLEVENT_HEAP_ALLOCATED(cap, heap_capset,       \
+                                allocated)
+#define dtraceEventHeapSize(heap_capset, size)          \
+    HASKELLEVENT_HEAP_LIVE(heap_capset, size)
+#define dtraceEventHeapLive(heap_capset, live)          \
+    HASKELLEVENT_HEAP_LIVE(heap_capset, live)
+
 #define dtraceCapsetCreate(capset, capset_type)         \
     HASKELLEVENT_CAPSET_CREATE(capset, capset_type)
 #define dtraceCapsetDelete(capset)                      \
@@ -346,6 +408,18 @@ INLINE_HEADER void dtraceStartup (int num_caps STG_UNUSED) {};
 #define dtraceGcIdle(cap)                               /* nothing */
 #define dtraceGcWork(cap)                               /* nothing */
 #define dtraceGcDone(cap)                               /* nothing */
+#define dtraceEventGcStats(heap_capset, gens,           \
+                           copies, slop, fragmentation, \
+                           par_n_threads,               \
+                           par_max_copied,              \
+                           par_tot_copied)              /* nothing */
+#define dtraceHeapInfo(heap_capset, gens,               \
+                       maxHeapSize, allocAreaSize,      \
+                       mblockSize, blockSize)           /* nothing */
+#define dtraceEventHeapAllocated(cap, heap_capset,      \
+                                 allocated)             /* nothing */
+#define dtraceEventHeapSize(heap_capset, size)          /* nothing */
+#define dtraceEventHeapLive(heap_capset, live)          /* nothing */
 #define dtraceCapCreate(cap)                            /* nothing */
 #define dtraceCapDelete(cap)                            /* nothing */
 #define dtraceCapEnable(cap)                            /* nothing */
@@ -511,6 +585,70 @@ INLINE_HEADER void traceEventGcDone(Capability *cap STG_UNUSED)
     dtraceGcDone((EventCapNo)cap->no);
 }
 
+INLINE_HEADER void traceEventGcStats(Capability *cap            STG_UNUSED,
+                                     CapsetID    heap_capset    STG_UNUSED,
+                                     nat         gen            STG_UNUSED,
+                                     lnat        copied         STG_UNUSED,
+                                     lnat        slop           STG_UNUSED,
+                                     lnat        fragmentation  STG_UNUSED,
+                                     nat         par_n_threads  STG_UNUSED,
+                                     lnat        par_max_copied STG_UNUSED,
+                                     lnat        par_tot_copied STG_UNUSED)
+{
+    if (RTS_UNLIKELY(TRACE_gc)) {
+        traceEventGcStats_(cap, heap_capset, gen,
+                           copied, slop, fragmentation,
+                           par_n_threads, par_max_copied, par_tot_copied);
+    }
+    dtraceEventGcStats(heap_capset, gens,
+                       copies, slop, fragmentation,
+                       par_n_threads, par_max_copied, par_tot_copied);
+}
+
+INLINE_HEADER void traceEventHeapInfo(CapsetID    heap_capset   STG_UNUSED,
+                                      nat         gens          STG_UNUSED,
+                                      lnat        maxHeapSize   STG_UNUSED,
+                                      lnat        allocAreaSize STG_UNUSED,
+                                      lnat        mblockSize    STG_UNUSED,
+                                      lnat        blockSize     STG_UNUSED)
+{
+    if (RTS_UNLIKELY(TRACE_gc)) {
+        traceEventHeapInfo_(heap_capset, gens,
+                            maxHeapSize, allocAreaSize,
+                            mblockSize, blockSize);
+    }
+    dtraceHeapInfo(heap_capset, gens,
+                   maxHeapSize, allocAreaSize,
+                   mblockSize, blockSize);
+}
+
+INLINE_HEADER void traceEventHeapAllocated(Capability *cap         STG_UNUSED,
+                                           CapsetID    heap_capset STG_UNUSED,
+                                           lnat        allocated   STG_UNUSED)
+{
+    traceHeapEvent(cap, EVENT_HEAP_ALLOCATED, heap_capset, allocated);
+    dtraceEventHeapAllocated((EventCapNo)cap->no, heap_capset, allocated);
+}
+
+INLINE_HEADER void traceEventHeapSize(Capability *cap         STG_UNUSED,
+                                      CapsetID    heap_capset STG_UNUSED,
+                                      lnat        heap_size   STG_UNUSED)
+{
+    traceHeapEvent(cap, EVENT_HEAP_SIZE, heap_capset, heap_size);
+    dtraceEventHeapSize(heap_capset, heap_size);
+}
+
+INLINE_HEADER void traceEventHeapLive(Capability *cap         STG_UNUSED,
+                                      CapsetID    heap_capset STG_UNUSED,
+                                      lnat        heap_live   STG_UNUSED)
+{
+    traceHeapEvent(cap, EVENT_HEAP_LIVE, heap_capset, heap_live);
+    dtraceEventHeapLive(heap_capset, heap_live);
+}
+
+/* TODO: at some point we should remove this event, it's covered by
+ * the cap create/delete events.
+ */
 INLINE_HEADER void traceEventStartup(void)
 {
     int n_caps;