[PATCH v9 04/13] accel: replacing part of CONFIG_PROFILER with TBStats

[Alex Bennée]

From: "Vanderson M. do Rosario" <address@hidden>

We add some of the statistics collected in the TCGProfiler into the
TBStats, having the statistics not only for the whole emulation but
for each TB. Then, we removed these stats from TCGProfiler and
reconstruct the information for the "info jit" using the sum of all
TBStats statistics.

The goal is to have one unique and better way of collecting emulation
statistics. Moreover, checking dynamiclly if the profiling is enabled
showed to have an insignificant impact on the performance:
https://wiki.qemu.org/Internships/ProjectIdeas/TCGCodeQuality#Overheads.

Reviewed-by: Alex Bennée <address@hidden>
Signed-off-by: Vanderson M. do Rosario <address@hidden>
Message-Id: <address@hidden>
[AJB: fix authorship, use prof structure]
Signed-off-by: Alex Bennée <address@hidden>

---
AJB:
  - moving profiler stuff under jit_stats lock
  - keep TCGProf as per-ctx staging post for values
  - delete max counters as can be interfered.
---
 accel/tcg/tb-stats.c      |  95 ++++++++++++++++++++++++++++++++++
 accel/tcg/translate-all.c |  11 ++--
 include/exec/tb-stats.h   |  11 ++++
 tcg/tcg.c                 | 105 ++++----------------------------------
 tcg/tcg.h                 |   9 ++--
 5 files changed, 125 insertions(+), 106 deletions(-)

diff --git a/accel/tcg/tb-stats.c b/accel/tcg/tb-stats.c
index ee0506bff1..0e64c176b3 100644
--- a/accel/tcg/tb-stats.c
+++ b/accel/tcg/tb-stats.c
@@ -9,6 +9,10 @@
 #include "qemu/osdep.h"
 
 #include "disas/disas.h"
+#include "exec/exec-all.h"
+#include "tcg.h"
+
+#include "qemu/qemu-print.h"
 
 #include "exec/tb-stats.h"
 
@@ -18,6 +22,97 @@ enum TBStatsStatus { TB_STATS_RUNNING, TB_STATS_PAUSED, 
TB_STATS_STOPPED };
 static enum TBStatsStatus tcg_collect_tb_stats;
 static uint32_t default_tbstats_flag;
 
+struct jit_profile_info {
+    uint64_t translations;
+    uint64_t aborted;
+    uint64_t ops;
+    unsigned ops_max;
+    uint64_t del_ops;
+    uint64_t temps;
+    unsigned temps_max;
+    uint64_t host;
+    uint64_t guest;
+    uint64_t search_data;
+};
+
+/* accumulate the statistics from all TBs */
+static void collect_jit_profile_info(void *p, uint32_t hash, void *userp)
+{
+    struct jit_profile_info *jpi = userp;
+    TBStatistics *tbs = p;
+
+    jpi->translations += tbs->translations.total;
+    jpi->ops += tbs->code.num_tcg_ops;
+    if (stat_per_translation(tbs, code.num_tcg_ops) > jpi->ops_max) {
+        jpi->ops_max = stat_per_translation(tbs, code.num_tcg_ops);
+    }
+    jpi->del_ops += tbs->code.deleted_ops;
+    jpi->temps += tbs->code.temps;
+    if (stat_per_translation(tbs, code.temps) > jpi->temps_max) {
+        jpi->temps_max = stat_per_translation(tbs, code.temps);
+    }
+    jpi->host += tbs->code.out_len;
+    jpi->guest += tbs->code.in_len;
+    jpi->search_data += tbs->code.search_out_len;
+}
+
+/* dump JIT statisticis using TCGProfile and TBStats */
+void dump_jit_profile_info(TCGProfile *s)
+{
+    if (!tb_stats_collection_enabled()) {
+        return;
+    }
+
+    struct jit_profile_info *jpi = g_new0(struct jit_profile_info, 1);
+
+    qht_iter(&tb_ctx.tb_stats, collect_jit_profile_info, jpi);
+
+    if (jpi->translations) {
+        qemu_printf("translated TBs      %" PRId64 "\n", jpi->translations);
+        qemu_printf("avg ops/TB          %0.1f max=%d\n",
+                jpi->ops / (double) jpi->translations, jpi->ops_max);
+        qemu_printf("deleted ops/TB      %0.2f\n",
+                jpi->del_ops / (double) jpi->translations);
+        qemu_printf("avg temps/TB        %0.2f max=%d\n",
+                jpi->temps / (double) jpi->translations, jpi->temps_max);
+        qemu_printf("avg host code/TB    %0.1f\n",
+                jpi->host / (double) jpi->translations);
+        qemu_printf("avg search data/TB  %0.1f\n",
+                jpi->search_data / (double) jpi->translations);
+
+        if (s) {
+            int64_t tot = s->interm_time + s->code_time;
+            qemu_printf("JIT cycles          %" PRId64 " (%0.3f s at 2.4 
GHz)\n",
+                            tot, tot / 2.4e9);
+            qemu_printf("cycles/op           %0.1f\n",
+                        jpi->ops ? (double)tot / jpi->ops : 0);
+            qemu_printf("cycles/in byte      %0.1f\n",
+                        jpi->guest ? (double)tot / jpi->guest : 0);
+            qemu_printf("cycles/out byte     %0.1f\n",
+                        jpi->host ? (double)tot / jpi->host : 0);
+            qemu_printf("cycles/search byte     %0.1f\n",
+                        jpi->search_data ? (double)tot / jpi->search_data : 0);
+            if (tot == 0) {
+                tot = 1;
+            }
+            qemu_printf("  gen_interm time   %0.1f%%\n",
+                        (double)s->interm_time / tot * 100.0);
+            qemu_printf("  gen_code time     %0.1f%%\n",
+                        (double)s->code_time / tot * 100.0);
+            qemu_printf("optim./code time    %0.1f%%\n",
+                        (double)s->opt_time / (s->code_time ? s->code_time : 1)
+                        * 100.0);
+            qemu_printf("liveness/code time  %0.1f%%\n",
+                    (double)s->la_time / (s->code_time ? s->code_time : 1) * 
100.0);
+            qemu_printf("cpu_restore count   %" PRId64 "\n",
+                    s->restore_count);
+            qemu_printf("  avg cycles        %0.1f\n",
+                    s->restore_count ? (double)s->restore_time / 
s->restore_count : 0);
+        }
+    }
+    g_free(jpi);
+}
+
 void init_tb_stats_htable_if_not(void)
 {
     if (tb_stats_collection_enabled() && !tb_ctx.tb_stats.map) {
diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c
index 6fa9850a3a..84f759a829 100644
--- a/accel/tcg/translate-all.c
+++ b/accel/tcg/translate-all.c
@@ -1780,8 +1780,6 @@ TranslationBlock *tb_gen_code(CPUState *cpu,
  tb_overflow:
 
 #ifdef CONFIG_PROFILER
-    /* includes aborted translations because of exceptions */
-    atomic_set(&prof->tb_count1, prof->tb_count1 + 1);
     ti = profile_getclock();
 #endif
 
@@ -1807,6 +1805,7 @@ TranslationBlock *tb_gen_code(CPUState *cpu,
         tb->tb_stats = NULL;
     }
 
+
     tcg_func_start(tcg_ctx);
 
     tcg_ctx->cpu = env_cpu(env);
@@ -1828,7 +1827,6 @@ TranslationBlock *tb_gen_code(CPUState *cpu,
     }
 
 #ifdef CONFIG_PROFILER
-    atomic_set(&prof->tb_count, prof->tb_count + 1);
     atomic_set(&prof->interm_time, prof->interm_time + profile_getclock() - 
ti);
     ti = profile_getclock();
 #endif
@@ -1875,9 +1873,6 @@ TranslationBlock *tb_gen_code(CPUState *cpu,
 
 #ifdef CONFIG_PROFILER
     atomic_set(&prof->code_time, prof->code_time + profile_getclock() - ti);
-    atomic_set(&prof->code_in_len, prof->code_in_len + tb->size);
-    atomic_set(&prof->code_out_len, prof->code_out_len + gen_code_size);
-    atomic_set(&prof->search_out_len, prof->search_out_len + search_size);
 #endif
 
 #ifdef DEBUG_DISAS
@@ -1951,7 +1946,11 @@ TranslationBlock *tb_gen_code(CPUState *cpu,
         ts->code.num_tcg_ops += prof->translation.nb_ops_pre_opt;
         ts->code.num_tcg_ops_opt += tcg_ctx->nb_ops;
         ts->code.spills += prof->translation.nb_spills;
+        ts->code.temps += prof->translation.temp_count;
+        ts->code.deleted_ops += prof->translation.del_op_count;
+        ts->code.in_len += tb->size;
         ts->code.out_len += tb->tc.size;
+        ts->code.search_out_len += search_size;
 
         ts->translations.total++;
         if (phys_page2 != -1) {
diff --git a/include/exec/tb-stats.h b/include/exec/tb-stats.h
index 566ae0d2be..c779d6a183 100644
--- a/include/exec/tb-stats.h
+++ b/include/exec/tb-stats.h
@@ -33,6 +33,9 @@
 #define tb_stats_enabled(tb, JIT_STATS) \
     (tb && tb->tb_stats && (tb->tb_stats->stats_enabled & JIT_STATS))
 
+#define stat_per_translation(stat, name) \
+    (stat->translations.total ? stat->name / stat->translations.total : 0)
+
 typedef struct TBStatistics TBStatistics;
 
 /*
@@ -67,7 +70,13 @@ struct TBStatistics {
         unsigned num_tcg_ops;
         unsigned num_tcg_ops_opt;
         unsigned spills;
+
+        /* CONFIG_PROFILE */
+        unsigned temps;
+        unsigned deleted_ops;
+        unsigned in_len;
         unsigned out_len;
+        unsigned search_out_len;
     } code;
 
     struct {
@@ -87,6 +96,8 @@ bool tb_stats_cmp(const void *ap, const void *bp);
 
 void init_tb_stats_htable_if_not(void);
 
+void dump_jit_profile_info(TCGProfile *s);
+
 #define TB_NOTHING    (1 << 0)
 #define TB_EXEC_STATS (1 << 1)
 #define TB_JIT_STATS  (1 << 2)
diff --git a/tcg/tcg.c b/tcg/tcg.c
index fa2fef9f1a..9c199c8a40 100644
--- a/tcg/tcg.c
+++ b/tcg/tcg.c
@@ -1118,6 +1118,8 @@ void tcg_func_start(TCGContext *s)
     s->current_frame_offset = s->frame_start;
 
     s->prof.translation.nb_spills = 0;
+    s->prof.translation.del_op_count = 0;
+    s->prof.translation.temp_count = 0;
 #ifdef CONFIG_DEBUG_TCG
     s->goto_tb_issue_mask = 0;
 #endif
@@ -2294,10 +2296,8 @@ void tcg_op_remove(TCGContext *s, TCGOp *op)
     QTAILQ_REMOVE(&s->ops, op, link);
     QTAILQ_INSERT_TAIL(&s->free_ops, op, link);
     s->nb_ops--;
-
-#ifdef CONFIG_PROFILER
-    atomic_set(&s->prof.del_op_count, s->prof.del_op_count + 1);
-#endif
+    /* ? won't this end up op_opt - op = del_op_count ? */
+    s->prof.translation.del_op_count++;
 }
 
 static TCGOp *tcg_op_alloc(TCGOpcode opc)
@@ -3910,16 +3910,6 @@ void tcg_profile_snapshot(TCGProfile *prof, bool 
counters, bool table)
 
         if (counters) {
             PROF_ADD(prof, orig, cpu_exec_time);
-            PROF_ADD(prof, orig, tb_count1);
-            PROF_ADD(prof, orig, tb_count);
-            PROF_ADD(prof, orig, op_count);
-            PROF_MAX(prof, orig, op_count_max);
-            PROF_ADD(prof, orig, temp_count);
-            PROF_MAX(prof, orig, temp_count_max);
-            PROF_ADD(prof, orig, del_op_count);
-            PROF_ADD(prof, orig, code_in_len);
-            PROF_ADD(prof, orig, code_out_len);
-            PROF_ADD(prof, orig, search_out_len);
             PROF_ADD(prof, orig, interm_time);
             PROF_ADD(prof, orig, code_time);
             PROF_ADD(prof, orig, la_time);
@@ -3997,26 +3987,9 @@ int tcg_gen_code(TCGContext *s, TranslationBlock *tb)
     TCGOp *op;
 
     s->current_tb = tb;
-
-#ifdef CONFIG_PROFILER
-    {
-        int n = 0;
-
-        QTAILQ_FOREACH(op, &s->ops, link) {
-            n++;
-        }
-        atomic_set(&prof->op_count, prof->op_count + n);
-        if (n > prof->op_count_max) {
-            atomic_set(&prof->op_count_max, n);
-        }
-
-        n = s->nb_temps;
-        atomic_set(&prof->temp_count, prof->temp_count + n);
-        if (n > prof->temp_count_max) {
-            atomic_set(&prof->temp_count_max, n);
-        }
-    }
-#endif
+    /* save pre-optimisation op count */
+    prof->translation.nb_ops_pre_opt = s->nb_ops;
+    prof->translation.temp_count = s->nb_temps;
 
 #ifdef DEBUG_DISAS
     if (unlikely(qemu_loglevel_mask(CPU_LOG_TB_OP)
@@ -4029,8 +4002,6 @@ int tcg_gen_code(TCGContext *s, TranslationBlock *tb)
     }
 #endif
 
-    /* save pre-optimisation op count */
-    prof->translation.nb_ops_pre_opt = s->nb_ops;
 
 #ifdef CONFIG_DEBUG_TCG
     /* Ensure all labels referenced have been emitted.  */
@@ -4210,70 +4181,16 @@ int tcg_gen_code(TCGContext *s, TranslationBlock *tb)
     return tcg_current_code_size(s);
 }
 
-#ifdef CONFIG_PROFILER
 void tcg_dump_info(void)
 {
+    TCGProfile *s = NULL;
+#ifdef CONFIG_PROFILER
     TCGProfile prof = {};
-    const TCGProfile *s;
-    int64_t tb_count;
-    int64_t tb_div_count;
-    int64_t tot;
-
     tcg_profile_snapshot_counters(&prof);
     s = &prof;
-    tb_count = s->tb_count;
-    tb_div_count = tb_count ? tb_count : 1;
-    tot = s->interm_time + s->code_time;
-
-    qemu_printf("JIT cycles          %" PRId64 " (%0.3f s at 2.4 GHz)\n",
-                tot, tot / 2.4e9);
-    qemu_printf("translated TBs      %" PRId64 " (aborted=%" PRId64
-                " %0.1f%%)\n",
-                tb_count, s->tb_count1 - tb_count,
-                (double)(s->tb_count1 - s->tb_count)
-                / (s->tb_count1 ? s->tb_count1 : 1) * 100.0);
-    qemu_printf("avg ops/TB          %0.1f max=%d\n",
-                (double)s->op_count / tb_div_count, s->op_count_max);
-    qemu_printf("deleted ops/TB      %0.2f\n",
-                (double)s->del_op_count / tb_div_count);
-    qemu_printf("avg temps/TB        %0.2f max=%d\n",
-                (double)s->temp_count / tb_div_count, s->temp_count_max);
-    qemu_printf("avg host code/TB    %0.1f\n",
-                (double)s->code_out_len / tb_div_count);
-    qemu_printf("avg search data/TB  %0.1f\n",
-                (double)s->search_out_len / tb_div_count);
-    
-    qemu_printf("cycles/op           %0.1f\n",
-                s->op_count ? (double)tot / s->op_count : 0);
-    qemu_printf("cycles/in byte      %0.1f\n",
-                s->code_in_len ? (double)tot / s->code_in_len : 0);
-    qemu_printf("cycles/out byte     %0.1f\n",
-                s->code_out_len ? (double)tot / s->code_out_len : 0);
-    qemu_printf("cycles/search byte     %0.1f\n",
-                s->search_out_len ? (double)tot / s->search_out_len : 0);
-    if (tot == 0) {
-        tot = 1;
-    }
-    qemu_printf("  gen_interm time   %0.1f%%\n",
-                (double)s->interm_time / tot * 100.0);
-    qemu_printf("  gen_code time     %0.1f%%\n",
-                (double)s->code_time / tot * 100.0);
-    qemu_printf("optim./code time    %0.1f%%\n",
-                (double)s->opt_time / (s->code_time ? s->code_time : 1)
-                * 100.0);
-    qemu_printf("liveness/code time  %0.1f%%\n",
-                (double)s->la_time / (s->code_time ? s->code_time : 1) * 
100.0);
-    qemu_printf("cpu_restore count   %" PRId64 "\n",
-                s->restore_count);
-    qemu_printf("  avg cycles        %0.1f\n",
-                s->restore_count ? (double)s->restore_time / s->restore_count 
: 0);
-}
-#else
-void tcg_dump_info(void)
-{
-    qemu_printf("[TCG profiler not compiled]\n");
-}
 #endif
+    dump_jit_profile_info(s);
+}
 
 #ifdef ELF_HOST_MACHINE
 /* In order to use this feature, the backend needs to do three things:
diff --git a/tcg/tcg.h b/tcg/tcg.h
index 31571289cf..5296f7c075 100644
--- a/tcg/tcg.h
+++ b/tcg/tcg.h
@@ -573,16 +573,13 @@ typedef struct TCGProfile {
         int nb_guest_insns;
         int nb_spills;
         int nb_ops_pre_opt;
+
+        int del_op_count;
+        int temp_count;
     } translation;
 
     int64_t cpu_exec_time;
-    int64_t tb_count1;
-    int64_t tb_count;
     int64_t op_count; /* total insn count */
-    int op_count_max; /* max insn per TB */
-    int temp_count_max;
-    int64_t temp_count;
-    int64_t del_op_count;
     int64_t code_in_len;
     int64_t code_out_len;
     int64_t search_out_len;
-- 
2.20.1