[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH v8 03/11] accel: collecting JIT statistics
From: |
Alex Bennée |
Subject: |
Re: [Qemu-devel] [PATCH v8 03/11] accel: collecting JIT statistics |
Date: |
Fri, 30 Aug 2019 14:10:01 +0100 |
User-agent: |
mu4e 1.3.4; emacs 27.0.50 |
vandersonmr <address@hidden> writes:
> If a TB has a TBS (TBStatistics) with the TB_JIT_STATS
> enabled then we collect statistics of its translation
> processes and code translation.
>
> Collecting the number of host instructions seems to be
> not simple as it would imply in having to modify several
> target source files. So, for now, we are only collecting
> the size of the host gen code.
>
> Reviewed-by: Alex Bennée <address@hidden>
> Signed-off-by: Vanderson M. do Rosario <address@hidden>
> ---
> accel/tcg/translate-all.c | 15 ++++++++++++++-
> accel/tcg/translator.c | 4 ++++
> include/exec/tb-stats.h | 15 +++++++++++++++
> tcg/tcg.c | 23 +++++++++++++++++++++++
> tcg/tcg.h | 2 ++
> 5 files changed, 58 insertions(+), 1 deletion(-)
>
> diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c
> index e72aeba682..fb2fe0fa1f 100644
> --- a/accel/tcg/translate-all.c
> +++ b/accel/tcg/translate-all.c
> @@ -1705,6 +1705,7 @@ static TBStatistics *tb_get_stats(tb_page_addr_t
> phys_pc, target_ulong pc,
> * then just make the new TB point to the older TBStatistic
> */
> g_free(new_stats);
> + ((TBStatistics *) existing_stats)->tb = current_tb;
This seems out of place and again I can't see what we are doing with
this information yet.
> return existing_stats;
> } else {
> return new_stats;
> @@ -1785,13 +1786,18 @@ TranslationBlock *tb_gen_code(CPUState *cpu,
> */
> if (tb_stats_collection_enabled()) {
> tb->tb_stats = tb_get_stats(phys_pc, pc, cs_base, flags, tb);
> + uint32_t flag = get_default_tbstats_flag();
>
> if (qemu_log_in_addr_range(tb->pc)) {
> - uint32_t flag = get_default_tbstats_flag();
> if (flag & TB_EXEC_STATS) {
> tb->tb_stats->stats_enabled |= TB_EXEC_STATS;
> }
> }
> +
> + if (flag & TB_JIT_STATS) {
> + tb->tb_stats->stats_enabled |= TB_JIT_STATS;
> + atomic_inc(&tb->tb_stats->translations.total);
> + }
> } else {
> tb->tb_stats = NULL;
> }
> @@ -1869,6 +1875,10 @@ TranslationBlock *tb_gen_code(CPUState *cpu,
> atomic_set(&prof->search_out_len, prof->search_out_len + search_size);
> #endif
>
> + if (tb_stats_enabled(tb, TB_JIT_STATS)) {
> + atomic_add(&tb->tb_stats->code.out_len, gen_code_size);
> + }
> +
> #ifdef DEBUG_DISAS
> if (qemu_loglevel_mask(CPU_LOG_TB_OUT_ASM) &&
> qemu_log_in_addr_range(tb->pc)) {
> @@ -1926,6 +1936,9 @@ TranslationBlock *tb_gen_code(CPUState *cpu,
> phys_page2 = -1;
> if ((pc & TARGET_PAGE_MASK) != virt_page2) {
> phys_page2 = get_page_addr_code(env, virt_page2);
> + if (tb_stats_enabled(tb, TB_JIT_STATS)) {
> + atomic_inc(&tb->tb_stats->translations.spanning);
> + }
> }
> /*
> * No explicit memory barrier is required -- tb_link_page() makes the
> diff --git a/accel/tcg/translator.c b/accel/tcg/translator.c
> index ec6bd829a0..9b2e248b09 100644
> --- a/accel/tcg/translator.c
> +++ b/accel/tcg/translator.c
> @@ -116,6 +116,10 @@ void translator_loop(const TranslatorOps *ops,
> DisasContextBase *db,
> db->tb->size = db->pc_next - db->pc_first;
> db->tb->icount = db->num_insns;
>
> + if (tb_stats_enabled(tb, TB_JIT_STATS)) {
> + atomic_add(&db->tb->tb_stats->code.num_guest_inst, db->num_insns);
> + }
> +
> #ifdef DEBUG_DISAS
> if (qemu_loglevel_mask(CPU_LOG_TB_IN_ASM)
> && qemu_log_in_addr_range(db->pc_first)) {
> diff --git a/include/exec/tb-stats.h b/include/exec/tb-stats.h
> index c4a8715400..b68edd5d24 100644
> --- a/include/exec/tb-stats.h
> +++ b/include/exec/tb-stats.h
> @@ -58,6 +58,20 @@ struct TBStatistics {
> unsigned long atomic;
> } executions;
>
> + struct {
> + unsigned num_guest_inst;
> + unsigned num_tcg_ops;
> + unsigned num_tcg_ops_opt;
> + unsigned spills;
> + unsigned out_len;
> + } code;
> +
> + struct {
> + unsigned long total;
> + unsigned long uncached;
> + unsigned long spanning;
> + } translations;
> +
> /* current TB linked to this TBStatistics */
> TranslationBlock *tb;
> };
> @@ -71,6 +85,7 @@ enum TBStatsStatus { TB_STATS_RUNNING, TB_STATS_PAUSED,
> TB_STATS_STOPPED };
>
> #define TB_NOTHING (1 << 0)
> #define TB_EXEC_STATS (1 << 1)
> +#define TB_JIT_STATS (1 << 2)
>
> extern int tcg_collect_tb_stats;
> extern uint32_t default_tbstats_flag;
> diff --git a/tcg/tcg.c b/tcg/tcg.c
> index 0458eaec57..ae3e7a2217 100644
> --- a/tcg/tcg.c
> +++ b/tcg/tcg.c
> @@ -3125,6 +3125,11 @@ static void temp_sync(TCGContext *s, TCGTemp *ts,
> TCGRegSet allocated_regs,
> case TEMP_VAL_REG:
> tcg_out_st(s, ts->type, ts->reg,
> ts->mem_base->reg, ts->mem_offset);
> +
> + /* Count number of spills */
> + if (tb_stats_enabled(s->current_tb, TB_JIT_STATS)) {
> + atomic_inc(&s->current_tb->tb_stats->code.spills);
> + }
> break;
>
> case TEMP_VAL_MEM:
> @@ -3996,6 +4001,8 @@ int tcg_gen_code(TCGContext *s, TranslationBlock *tb)
> int i, num_insns;
> TCGOp *op;
>
> + s->current_tb = tb;
> +
> #ifdef CONFIG_PROFILER
> {
> int n = 0;
> @@ -4027,6 +4034,14 @@ int tcg_gen_code(TCGContext *s, TranslationBlock *tb)
> }
> #endif
>
> + if (tb_stats_enabled(tb, TB_JIT_STATS)) {
> + int n = 0;
> + QTAILQ_FOREACH(op, &s->ops, link) {
> + n++;
> + }
> + atomic_add(&tb->tb_stats->code.num_tcg_ops, n);
> + }
> +
> #ifdef CONFIG_DEBUG_TCG
> /* Ensure all labels referenced have been emitted. */
> {
> @@ -4093,6 +4108,14 @@ int tcg_gen_code(TCGContext *s, TranslationBlock *tb)
> }
> #endif
>
> + if (tb_stats_enabled(tb, TB_JIT_STATS)) {
> + int n = 0;
> + QTAILQ_FOREACH(op, &s->ops, link) {
> + n++;
> + }
> + atomic_add(&tb->tb_stats->code.num_tcg_ops_opt, n);
> + }
> +
> tcg_reg_alloc_start(s);
>
> s->code_buf = tb->tc.ptr;
> diff --git a/tcg/tcg.h b/tcg/tcg.h
> index 529acb2ed8..b4601162f8 100644
> --- a/tcg/tcg.h
> +++ b/tcg/tcg.h
> @@ -740,6 +740,8 @@ struct TCGContext {
>
> uint16_t gen_insn_end_off[TCG_MAX_INSNS];
> target_ulong gen_insn_data[TCG_MAX_INSNS][TARGET_INSN_START_WORDS];
> +
> + TranslationBlock *current_tb;
As we are only using this to get to tb_stats why not skip the middle man
and go directly to:
TBStatistics *current_stats;
?
You already have a tbs_stats_enabled() helper
> };
>
> extern TCGContext tcg_init_ctx;
--
Alex Bennée
- [Qemu-devel] [PATCH v8 00/11] Measure Tiny Code Generation Quality, vandersonmr, 2019/08/29
- [Qemu-devel] [PATCH v8 03/11] accel: collecting JIT statistics, vandersonmr, 2019/08/29
- Re: [Qemu-devel] [PATCH v8 03/11] accel: collecting JIT statistics,
Alex Bennée <=
- [Qemu-devel] [PATCH v8 04/11] accel: replacing part of CONFIG_PROFILER with TBStats, vandersonmr, 2019/08/29
- [Qemu-devel] [PATCH v8 06/11] Adding -d tb_stats to control TBStatistics collection:, vandersonmr, 2019/08/29
- [Qemu-devel] [PATCH v8 05/11] accel: adding TB_JIT_TIME and full replacing CONFIG_PROFILER, vandersonmr, 2019/08/29
- [Qemu-devel] [PATCH v8 07/11] monitor: adding tb_stats hmp command, vandersonmr, 2019/08/29
- [Qemu-devel] [PATCH v8 08/11] Adding tb_stats [start|pause|stop|filter] command to hmp., vandersonmr, 2019/08/29
- [Qemu-devel] [PATCH v8 10/11] monitor: adding new info cfg command, vandersonmr, 2019/08/29