Re: [PULL 3/5] tcg: add perfmap and jitdump

[Philippe Mathieu-Daudé]

Hi Richard, Alex,

On 16/1/23 23:36, Richard Henderson wrote:
> From: Ilya Leoshkevich <iii@linux.ibm.com>
>
> Add ability to dump /tmp/perf-<pid>.map and jit-<pid>.dump.
> The first one allows the perf tool to map samples to each individual
> translation block. The second one adds the ability to resolve symbol
> names, line numbers and inspect JITed code.
>
> Example of use:
>
>      perf record qemu-x86_64 -perfmap ./a.out
>      perf report
>
> or
>
>      perf record -k 1 qemu-x86_64 -jitdump ./a.out
>      DEBUGINFOD_URLS= perf inject -j -i perf.data -o perf.data.jitted
>      perf report -i perf.data.jitted
>
> Co-developed-by: Vanderson M. do Rosario <vandersonmr2@gmail.com>
> Co-developed-by: Alex Bennée <alex.bennee@linaro.org>
> Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
> Message-Id: <20230112152013.125680-4-iii@linux.ibm.com>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>   docs/devel/tcg.rst        |  23 +++
>   accel/tcg/perf.h          |  49 +++++
>   accel/tcg/perf.c          | 375 ++++++++++++++++++++++++++++++++++++++
>   accel/tcg/translate-all.c |   7 +
>   linux-user/exit.c         |   2 +
>   linux-user/main.c         |  15 ++
>   softmmu/vl.c              |  11 ++
>   tcg/tcg.c                 |   2 +
>   accel/tcg/meson.build     |   1 +
>   qemu-options.hx           |  20 ++
>   10 files changed, 505 insertions(+)
>   create mode 100644 accel/tcg/perf.h
>   create mode 100644 accel/tcg/perf.c


> diff --git a/tcg/tcg.c b/tcg/tcg.c
> index da91779890..9b7df71e7a 100644
> --- a/tcg/tcg.c
> +++ b/tcg/tcg.c
> @@ -61,6 +61,7 @@
>   #include "exec/log.h"
>   #include "tcg/tcg-ldst.h"
>   #include "tcg-internal.h"
> +#include "accel/tcg/perf.h"

Is it OK to include an header from QEMU's accel/tcg/ here?
I thought we wanted to keep tcg/ kinda independant (or maybe
this is already too late and this isn't a concern anymore).

>   /* Forward declarations for functions declared in tcg-target.c.inc and
>      used here. */
> @@ -913,6 +914,7 @@ void tcg_prologue_init(TCGContext *s)
>   #endif
>   
>       prologue_size = tcg_current_code_size(s);
> +    perf_report_prologue(s->code_gen_ptr, prologue_size);