We want to store statistics for each TB even after flushes.
We do not want to modify or grow the TB struct.
So we create a new struct to contain this statistics and
we link one of it to each TB as they are generated.
Signed-off-by: Vanderson M. do Rosario <vanderson...@gmail.com>
---
accel/tcg/translate-all.c | 60 +++++++++++++++++++++++++++++++++++++++
include/exec/exec-all.h | 46 ++++++++++++++++++++++++++++++
include/exec/tb-context.h | 1 +
include/exec/tb-hash.h | 7 +++++
include/qemu/log.h | 1 +
5 files changed, 115 insertions(+)
diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c
index 5d1e08b169..d05803a142 100644
--- a/accel/tcg/translate-all.c
+++ b/accel/tcg/translate-all.c
@@ -1132,11 +1132,31 @@ static bool tb_cmp(const void *ap, const void *bp)
a->page_addr[1] == b->page_addr[1];
}
+/*
+ * This is the more or less the same compare, but the data persists
+ * over tb_flush. We also aggregate the various variations of cflags
+ * under one record and ignore the details of page overlap (although
+ * we can count it).
+ */
+bool tb_stats_cmp(const void *ap, const void *bp)
+{
+ const TBStatistics *a = ap;
+ const TBStatistics *b = bp;
+
+ return a->phys_pc == b->phys_pc &&
+ a->pc == b->pc &&
+ a->cs_base == b->cs_base &&
+ a->flags == b->flags;
+}
+
static void tb_htable_init(void)
{
unsigned int mode = QHT_MODE_AUTO_RESIZE;
qht_init(&tb_ctx.htable, tb_cmp, CODE_GEN_HTABLE_SIZE, mode);
+ if (qemu_loglevel_mask(CPU_LOG_HOT_TBS)) {
+ qht_init(&tb_ctx.tb_stats, tb_stats_cmp, CODE_GEN_HTABLE_SIZE, mode);
+ }
}
/* Must be called before using the QEMU cpus. 'tb_size' is the size
@@ -1586,6 +1606,31 @@ static inline void tb_page_add(PageDesc *p,
TranslationBlock *tb,
#endif
}
+static TBStatistics *tb_get_stats(tb_page_addr_t phys_pc, target_ulong pc,
+ target_ulong cs_base, uint32_t flags)
+{
+ TBStatistics *new_stats = g_new0(TBStatistics, 1);
+ uint32_t hash = tb_stats_hash_func(phys_pc, pc, flags);
+ void *existing_stats = NULL;
+ new_stats->phys_pc = phys_pc;
+ new_stats->pc = pc;
+ new_stats->cs_base = cs_base;
+ new_stats->flags = flags;
+
+ qht_insert(&tb_ctx.tb_stats, new_stats, hash, &existing_stats);
+
+ if (unlikely(existing_stats)) {
+ /*
+ * If there is already a TBStatistic for this TB from a previous flush
+ * then just make the new TB point to the older TBStatistic
+ */
+ g_free(new_stats);
+ return existing_stats;
+ } else {
+ return new_stats;
+ }
+}
+
/* add a new TB and link it to the physical page tables. phys_page2 is
* (-1) to indicate that only one page contains the TB.
*
@@ -1732,6 +1777,21 @@ TranslationBlock *tb_gen_code(CPUState *cpu,
ti = profile_getclock();
#endif
+ /*
+ * We want to fetch the stats structure before we start code
+ * generation so we can count interesting things about this
+ * generation.
+ *
+ * XXX: using loglevel is fugly - we should have a general flag
+ */
+ if (qemu_loglevel_mask(CPU_LOG_HOT_TBS) && qemu_log_in_addr_range(tb->pc))
{
+ tb->tb_stats = tb_get_stats(phys_pc, pc, cs_base, flags);
+ /* XXX: should we lock and update in bulk? */
+ atomic_inc(&tb->tb_stats->translations.total);
+ } else {
+ tb->tb_stats = NULL;
+ }
+
tcg_func_start(tcg_ctx);
tcg_ctx->cpu = env_cpu(env);
diff --git a/include/exec/exec-all.h b/include/exec/exec-all.h
index 16034ee651..a4bcd9b6df 100644
--- a/include/exec/exec-all.h
+++ b/include/exec/exec-all.h
@@ -324,6 +324,49 @@ static inline void
tlb_flush_by_mmuidx_all_cpus_synced(CPUState *cpu,
#define CODE_GEN_AVG_BLOCK_SIZE 150
#endif
+typedef struct TBStatistics TBStatistics;
+
+/*
+ * This struct stores statistics such as execution count of the
+ * TranslationBlocks. Each sets of TBs for a given phys_pc/pc/flags
+ * has its own TBStatistics which will persist over tb_flush.
+ *
+ * We include additional counters to track number of translations as
+ * well as variants for compile flags.
+ */
+struct TBStatistics {
+ tb_page_addr_t phys_pc;
+ target_ulong pc;
+ uint32_t flags;
+ /* cs_base isn't included in the hash but we do check for matches */
+ target_ulong cs_base;
+
+ /* Translation stats */
+ struct {
+ unsigned long total;
+ unsigned long uncached;
+ unsigned long spanning;
+ /* XXX: count invalidation? */
+ } translations;
+
+ /* Execution stats */
+ struct {
+ unsigned long total;
+ unsigned long atomic;
+ } executions;
+
+ struct {
+ unsigned num_guest_inst;
+ unsigned num_host_inst;
+ unsigned num_tcg_inst;
+ } code;
+
+ /* HMP information - used for referring to previous search */
+ int display_id;
+};
+
+bool tb_stats_cmp(const void *ap, const void *bp);
+
/*
* Translation Cache-related fields of a TB.
* This struct exists just for convenience; we keep track of TB's in a binary
@@ -403,6 +446,9 @@ struct TranslationBlock {
uintptr_t jmp_list_head;
uintptr_t jmp_list_next[2];
uintptr_t jmp_dest[2];
+
+ /* Pointer to a struct where statistics from the TB is stored */
+ TBStatistics *tb_stats;
};
extern bool parallel_cpus;
diff --git a/include/exec/tb-context.h b/include/exec/tb-context.h
index feb585e0a7..a4decb5d1f 100644
--- a/include/exec/tb-context.h
+++ b/include/exec/tb-context.h
@@ -35,6 +35,7 @@ struct TBContext {
/* statistics */
unsigned tb_flush_count;
+ struct qht tb_stats;
};
extern TBContext tb_ctx;
diff --git a/include/exec/tb-hash.h b/include/exec/tb-hash.h
index 4f3a37d927..54c477fe79 100644
--- a/include/exec/tb-hash.h
+++ b/include/exec/tb-hash.h
@@ -64,4 +64,11 @@ uint32_t tb_hash_func(tb_page_addr_t phys_pc, target_ulong
pc, uint32_t flags,
return qemu_xxhash7(phys_pc, pc, flags, cf_mask, trace_vcpu_dstate);
}
+static inline
+uint32_t tb_stats_hash_func(tb_page_addr_t phys_pc, target_ulong pc,
+ uint32_t flags)
+{
+ return qemu_xxhash5(phys_pc, pc, flags);
+}
+
#endif
diff --git a/include/qemu/log.h b/include/qemu/log.h
index b097a6cae1..2fca65dd01 100644
--- a/include/qemu/log.h
+++ b/include/qemu/log.h
@@ -45,6 +45,7 @@ static inline bool qemu_log_separate(void)
/* LOG_TRACE (1 << 15) is defined in log-for-trace.h */
#define CPU_LOG_TB_OP_IND (1 << 16)
#define CPU_LOG_TB_FPU (1 << 17)
+#define CPU_LOG_HOT_TBS (1 << 18)
/* Lock output for a series of related logs. Since this is not needed
* for a single qemu_log / qemu_log_mask / qemu_log_mask_and_addr, we
--
2.22.0
