On 03/27/2014 09:37 AM, alex.ben...@linaro.org wrote:
> From: Alex Bennée <alex.ben...@linaro.org>
>
> This allows the perf tool to map samples to each individual translation
> block. This could be expanded for user space but currently it gives
> enough information to find any hotblocks by other means.
Plausible, I suppose.
> TCGOpDef tcg_op_defs[] = {
> #define DEF(s, oargs, iargs, cargs, flags) { #s, oargs, iargs, cargs, iargs
> + oargs + cargs, flags },
> @@ -2575,6 +2579,8 @@ static inline int tcg_gen_code_common(TCGContext *s,
> uint64_t target_pc,
> the_end:
> /* Generate TB finalization at the end of block */
> tcg_out_tb_finalize(s);
> +
> + tcg_write_perfmap(gen_code_buf, s->code_ptr - gen_code_buf, target_pc);
> return -1;
> }
>
> @@ -2666,6 +2672,21 @@ void tcg_dump_info(FILE *f, fprintf_function
> cpu_fprintf)
> }
> #endif
>
> +static FILE *tcg_perfmap = NULL;
> +void qemu_tcg_enable_perfmap(void) {
> + gchar * map_file = g_strdup_printf("/tmp/perf-%d.map", getpid());
> + tcg_perfmap = g_fopen(map_file, "w");
> + g_free(map_file);
> +}
> +
> +static void tcg_write_perfmap(uint8_t *start, uint64_t size, uint64_t
> target_pc)
> +{
> + if (tcg_perfmap) {
> + g_fprintf(tcg_perfmap, "%lx %lx subject-0x%lx\n",
> + (uint64_t) start, size, target_pc);
> + }
> +}
Why oh why do you feel the need to use g_fprintf? That's just gratuitous glib
obfuscation, that.
For this small of a single-use function, I think it would be clearer to just do
the printf directly in tcg_gen_code_common. Certainly no need to use uint64_t
all over the place; ptrdiff_t and target_ulong are exactly the right thing.
r~
