Richard Henderson writes: > On 09/10/2017 09:35 AM, Lluís Vilanova wrote: >> Signed-off-by: Lluís Vilanova <vilan...@ac.upc.edu> >> --- >> accel/tcg/translator.c | 23 ++++++++++++++++++----- >> trace-events | 8 ++++++++ >> 2 files changed, 26 insertions(+), 5 deletions(-) >> >> diff --git a/accel/tcg/translator.c b/accel/tcg/translator.c >> index d66d601c89..c010aeee45 100644 >> --- a/accel/tcg/translator.c >> +++ b/accel/tcg/translator.c >> @@ -35,7 +35,8 @@ void translator_loop_temp_check(DisasContextBase *db) >> void translator_loop(const TranslatorOps *ops, DisasContextBase *db, >> CPUState *cpu, TranslationBlock *tb) >> { >> - target_ulong pc_bbl; >> + target_ulong pc_bbl, pc_insn = 0; >> + bool translated_insn = false; >> int max_insns; >> >> /* Initialize DisasContext */ >> @@ -75,10 +76,15 @@ void translator_loop(const TranslatorOps *ops, >> DisasContextBase *db, >> tcg_debug_assert(db->is_jmp == DISAS_NEXT); /* no early exit */ >> >> while (true) { >> - target_ulong pc_insn = db->pc_next; >> TCGv_i32 insn_size_tcg = 0; >> int insn_size_opcode_idx; >> >> + /* Tracing after (previous instruction) */ >> + if (db->num_insns > 0) { >> + trace_guest_inst_after_tcg(cpu, tcg_ctx.tcg_env, pc_insn); >> + }
> How does this differ from "guest_inst"? Why would you need two trace points? I assume you mean how it differs from guest_inst_before. The two main ideas are: * To be able to get a trace an execution-time event only after the instruction or TB have finished executing successfully (i.e., there could be an exception). * Some values are only known *after* the instruction is translated (like the instruction size, or other extra information we might add in the future), so an efficient way to collect that is to trace guest_bbl_* and guest_insn_after at translation time (to build a TB "dictionary" as some call it), and trace guest_bbl_before at execution time (and use the detailed info above that you got at translation time). > Why are you placing this at the beginning of the while loop rather than the > end? Yeah, that'll be much clearer. >> @@ -164,6 +172,9 @@ void translator_loop(const TranslatorOps *ops, >> DisasContextBase *db, >> >> gen_set_inline_region_begin(tcg_ctx.disas.inline_label); >> >> + if (TRACE_GUEST_INST_AFTER_ENABLED && translated_insn) { >> + trace_guest_inst_after_tcg(cpu, tcg_ctx.tcg_env, pc_insn); >> + } >> if (TRACE_GUEST_BBL_AFTER_ENABLED) { >> trace_guest_bbl_after_tcg(cpu, tcg_ctx.tcg_env, pc_bbl); >> } > I think I'm finally beginning to understand what you're after with your > inlining. But I still think this should be doable in the appropriate opcode > generating functions. I'm not sure we can if we want to avoid having the duplicate translation-time events I said in a previous response (since TB can have two exit points and we're detecting them through goto_tb). Thanks, Lluis