Sergey Fedorov <sergey.fedo...@linaro.org> writes:
> From: Sergey Fedorov <serge.f...@gmail.com>
>
> Move tb_add_jump() call and surrounding code from cpu_exec() into
> tb_find_fast(). That simplifies cpu_exec() a little by hiding the direct
> chaining optimization details into tb_find_fast(). It also allows to
> move tb_lock()/tb_unlock() pair into tb_find_fast(), putting it closer
> to tb_find_slow() which also manipulates the lock.
>
> Suggested-by: Alex Bennée <alex.ben...@linaro.org>
> Signed-off-by: Sergey Fedorov <serge.f...@gmail.com>
> Signed-off-by: Sergey Fedorov <sergey.fedo...@linaro.org>
> ---
>
> Changes in v6:
> * Fixed rebase conflicts
>
> cpu-exec.c | 35 +++++++++++++++++++----------------
> 1 file changed, 19 insertions(+), 16 deletions(-)
>
> diff --git a/cpu-exec.c b/cpu-exec.c
> index f49a436e1a5a..5f23c0660d6e 100644
> --- a/cpu-exec.c
> +++ b/cpu-exec.c
> @@ -320,7 +320,9 @@ found:
> return tb;
> }
>
> -static inline TranslationBlock *tb_find_fast(CPUState *cpu)
> +static inline TranslationBlock *tb_find_fast(CPUState *cpu,
> + TranslationBlock **last_tb,
> + int tb_exit)
> {
> CPUArchState *env = (CPUArchState *)cpu->env_ptr;
> TranslationBlock *tb;
> @@ -331,11 +333,24 @@ static inline TranslationBlock *tb_find_fast(CPUState
> *cpu)
> always be the same before a given translated block
> is executed. */
> cpu_get_tb_cpu_state(env, &pc, &cs_base, &flags);
> + tb_lock();
> tb = cpu->tb_jmp_cache[tb_jmp_cache_hash_func(pc)];
> if (unlikely(!tb || tb->pc != pc || tb->cs_base != cs_base ||
> tb->flags != flags)) {
> tb = tb_find_slow(cpu, pc, cs_base, flags);
> }
> + if (cpu->tb_flushed) {
> + /* Ensure that no TB jump will be modified as the
> + * translation buffer has been flushed.
> + */
> + *last_tb = NULL;
> + cpu->tb_flushed = false;
> + }
> + /* See if we can patch the calling TB. */
> + if (*last_tb && qemu_loglevel_mask(CPU_LOG_TB_NOCHAIN)) {
This should be !qemu_loglevel_mask(CPU_LOG_TB_NOCHAIN)
> + tb_add_jump(*last_tb, tb_exit, tb);
> + }
> + tb_unlock();
> return tb;
> }
>
> @@ -441,7 +456,8 @@ int cpu_exec(CPUState *cpu)
> } else if (replay_has_exception()
> && cpu->icount_decr.u16.low + cpu->icount_extra == 0)
> {
> /* try to cause an exception pending in the log */
> - cpu_exec_nocache(cpu, 1, tb_find_fast(cpu), true);
> + last_tb = NULL; /* Avoid chaining TBs */
> + cpu_exec_nocache(cpu, 1, tb_find_fast(cpu, &last_tb, 0),
> true);
> ret = -1;
> break;
> #endif
> @@ -511,20 +527,7 @@ int cpu_exec(CPUState *cpu)
> cpu->exception_index = EXCP_INTERRUPT;
> cpu_loop_exit(cpu);
> }
> - tb_lock();
> - tb = tb_find_fast(cpu);
> - if (cpu->tb_flushed) {
> - /* Ensure that no TB jump will be modified as the
> - * translation buffer has been flushed.
> - */
> - last_tb = NULL;
> - cpu->tb_flushed = false;
> - }
> - /* See if we can patch the calling TB. */
> - if (last_tb && !qemu_loglevel_mask(CPU_LOG_TB_NOCHAIN)) {
> - tb_add_jump(last_tb, tb_exit, tb);
> - }
> - tb_unlock();
> + tb = tb_find_fast(cpu, &last_tb, tb_exit);
> if (likely(!cpu->exit_request)) {
> uintptr_t ret;
> trace_exec_tb(tb, tb->pc);
--
Alex Bennée
