Re: [Qemu-devel] [PATCH v2 4/4] adding -d hot_tbs:limit command line option

["Alex Bennée" <alex.bennee@linaro.org>]

vandersonmr <vandersonmr2@gmail.com> writes:

> add option to dump the N most hot TB blocks.
> -d hot_tbs:N
>
> Signed-off-by: vandersonmr <vandersonmr2@gmail.com>
> ---
>  include/qemu/log-for-trace.h | 2 ++
>  linux-user/exit.c            | 3 +++
>  util/log.c                   | 9 +++++++++
>  3 files changed, 14 insertions(+)
>
> diff --git a/include/qemu/log-for-trace.h b/include/qemu/log-for-trace.h
> index 2f0a5b080e..d65eb83037 100644
> --- a/include/qemu/log-for-trace.h
> +++ b/include/qemu/log-for-trace.h
> @@ -21,6 +21,8 @@
>  /* Private global variable, don't use */
>  extern int qemu_loglevel;
>
> +extern int32_t max_num_hot_tbs_to_dump;
> +

This might as well be an int (especially as your using atoi to scan it).

>  #define LOG_TRACE          (1 << 15)
>
>  /* Returns true if a bit is set in the current loglevel mask */
> diff --git a/linux-user/exit.c b/linux-user/exit.c
> index bdda720553..08b86dfd61 100644
> --- a/linux-user/exit.c
> +++ b/linux-user/exit.c
> @@ -28,6 +28,9 @@ extern void __gcov_dump(void);
>
>  void preexit_cleanup(CPUArchState *env, int code)
>  {
> +    if (qemu_loglevel_mask(CPU_LOG_HOT_TBS)) {
> +        tb_dump_exec_freq(max_num_hot_tbs_to_dump);
> +    }

Rather than baking the individual flags here and the fact you'll need to
duplicate the test for system emulation why not have a common helper
which you call unconditionally here and in the tail end of vl.c's main:

  qemu_do_exit_logs()

where:

void qemu_do_exit_logs(void)
{
    if (qemu_loglevel_mask(CPU_LOG_HOT_TBS)) {
        tb_dump_exec_freq(max_num_hot_tbs_to_dump);
    }
}

and we can extend that for other reports later...


>  #ifdef TARGET_GPROF
>          _mcleanup();
>  #endif
> diff --git a/util/log.c b/util/log.c
> index 1d1b33f7d9..e71c663143 100644
> --- a/util/log.c
> +++ b/util/log.c
> @@ -30,6 +30,7 @@ FILE *qemu_logfile;
>  int qemu_loglevel;
>  static int log_append = 0;
>  static GArray *debug_regions;
> +int32_t max_num_hot_tbs_to_dump;
>
>  /* Return the number of characters emitted.  */
>  int qemu_log(const char *fmt, ...)
> @@ -273,6 +274,9 @@ const QEMULogItem qemu_log_items[] = {
>      { CPU_LOG_TB_NOCHAIN, "nochain",
>        "do not chain compiled TBs so that \"exec\" and \"cpu\" show\n"
>        "complete traces" },
> +    { CPU_LOG_HOT_TBS, "hot_tbs(:limit)",
> +      "show TBs (until given a limit) ordered by their hotness.\n"
> +      "(if no limit is given, show all)" },
>      { 0, NULL, NULL },
>  };
>
> @@ -294,6 +298,11 @@ int qemu_str_to_log_mask(const char *str)
>              trace_enable_events((*tmp) + 6);
>              mask |= LOG_TRACE;
>  #endif
> +        } else if (g_str_has_prefix(*tmp, "hot_tbs")) {
> +            if (g_str_has_prefix(*tmp, "hot_tbs:") && (*tmp)[8] != '\0') {
> +                max_num_hot_tbs_to_dump = atoi((*tmp) + 8);
> +            }
> +            mask |= CPU_LOG_HOT_TBS;
>          } else {
>              for (item = qemu_log_items; item->mask != 0; item++) {
>                  if (g_str_equal(*tmp, item->name)) {


--
Alex Bennée