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
link it to each TB while they are created.
Signed-off-by: Vanderson M. do Rosario <vanderson...@gmail.com>
---
accel/tcg/translate-all.c | 40 +++++++++++++++++++++++++++++++++++++++
include/exec/exec-all.h | 21 ++++++++++++++++++++
include/exec/tb-context.h | 1 +
include/qemu/log.h | 1 +
4 files changed, 63 insertions(+)
diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c
index 5d1e08b169..f7e99f90e0 100644
--- a/accel/tcg/translate-all.c
+++ b/accel/tcg/translate-all.c
@@ -1118,6 +1118,18 @@ static inline void code_gen_alloc(size_t tb_size)
}
}
+static gint statistics_cmp(gconstpointer p1, gconstpointer p2)
+{
+ const TBStatistics *a = (TBStatistics *) p1;
+ const TBStatistics *b = (TBStatistics *) p2;
+
+ return (a->pc == b->pc &&
+ a->cs_base == b->cs_base &&
+ a->flags == b->flags &&
+ a->page_addr[0] == b->page_addr[0] &&
+ a->page_addr[1] == b->page_addr[1]) ? 0 : 1;
+}
+
static bool tb_cmp(const void *ap, const void *bp)
{
const TranslationBlock *a = ap;
@@ -1586,6 +1598,29 @@ static inline void tb_page_add(PageDesc *p,
TranslationBlock *tb,
#endif
}
+static void tb_insert_statistics_structure(TranslationBlock *tb) {
+ TBStatistics *new_stats = g_new0(TBStatistics, 1);
+ new_stats->pc = tb->pc;
+ new_stats->cs_base = tb->cs_base;
+ new_stats->flags = tb->flags;
+ new_stats->page_addr[0] = tb->page_addr[0];
+ new_stats->page_addr[1] = tb->page_addr[1];
+
+ GList *lookup_result = g_list_find_custom(tb_ctx.tb_statistics,
new_stats, statistics_cmp);
+
+ if (lookup_result) {
+ /* If there is already a TBStatistic for this TB from a
previous flush
+ * then just make the new TB point to the older TBStatistic
+ */
+ free(new_stats);
+ tb->tb_stats = lookup_result->data;
+ } else {
+ /* If not, then points to the new tb_statistics and add it to
the hash */
+ tb->tb_stats = new_stats;
+ tb_ctx.tb_statistics = g_list_prepend(tb_ctx.tb_statistics, 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.
*
@@ -1636,6 +1671,11 @@ tb_link_page(TranslationBlock *tb, tb_page_addr_t
phys_pc,
void *existing_tb = NULL;
uint32_t h;
+ if (qemu_loglevel_mask(CPU_LOG_HOT_TBS)) {
+ /* create and link to its TB a structure to store statistics */
+ tb_insert_statistics_structure(tb);
+ }
+
/* add in the hash table */
h = tb_hash_func(phys_pc, tb->pc, tb->flags, tb->cflags & CF_HASH_MASK,
tb->trace_vcpu_dstate);
diff --git a/include/exec/exec-all.h b/include/exec/exec-all.h
index 16034ee651..359100ef3b 100644
--- a/include/exec/exec-all.h
+++ b/include/exec/exec-all.h
@@ -324,6 +324,24 @@ 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 TB has its own TBStatistics. TBStatistics is suppose to live even
after
+ * flushes.
+ */
+struct TBStatistics {
+ target_ulong pc;
+ target_ulong cs_base;
+ uint32_t flags;
+ tb_page_addr_t page_addr[2];
+
+ // total number of times that the related TB have being executed
+ uint32_t exec_count;
+ uint32_t exec_count_overflows;
+};
+
/*
* Translation Cache-related fields of a TB.
* This struct exists just for convenience; we keep track of TB's in a binary
@@ -403,6 +421,9 @@ 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..a78ce92e60 100644
--- a/include/exec/tb-context.h
+++ b/include/exec/tb-context.h
@@ -35,6 +35,7 @@ struct TBContext {
/* statistics */
unsigned tb_flush_count;
+ GList *tb_statistics;
};
extern TBContext tb_ctx;
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
