On 10/08/2015 17:27, fred.kon...@greensocs.com wrote:
> diff --git a/cpu-exec.c b/cpu-exec.c
> index f3358a9..a012e9d 100644
> --- a/cpu-exec.c
> +++ b/cpu-exec.c
> @@ -131,6 +131,8 @@ static void init_delay_params(SyncClocks *sc, const
> CPUState *cpu)
> void cpu_loop_exit(CPUState *cpu)
> {
> cpu->current_tb = NULL;
> + /* Release those mutex before long jump so other thread can work. */
> + tb_lock_reset();
> siglongjmp(cpu->jmp_env, 1);
> }
>
> @@ -143,6 +145,8 @@ void cpu_resume_from_signal(CPUState *cpu, void *puc)
> /* XXX: restore cpu registers saved in host registers */
>
> cpu->exception_index = -1;
> + /* Release those mutex before long jump so other thread can work. */
> + tb_lock_reset();
> siglongjmp(cpu->jmp_env, 1);
> }
>
I think you should start easy and reuse the existing tb_lock code in
cpu-exec.c:
diff --git a/cpu-exec.c b/cpu-exec.c
index 9305f03..2909ec2 100644
--- a/cpu-exec.c
+++ b/cpu-exec.c
@@ -307,7 +307,6 @@ static TranslationBlock *tb_find_slow(CPUState *cpu,
target_ulong pc,
tb = tb_find_physical(cpu, pc, cs_base, flags);
if (!tb) {
- tb_lock();
/*
* Retry to get the TB in case a CPU just translate it to avoid having
* duplicated TB in the pool.
@@ -316,7 +315,6 @@ static TranslationBlock *tb_find_slow(CPUState *cpu,
target_ulong pc,
if (!tb) {
tb = tb_gen_code(cpu, pc, cs_base, flags, 0);
}
- tb_unlock();
}
/* we add the TB in the virtual pc hash table */
cpu->tb_jmp_cache[tb_jmp_cache_hash_func(pc)] = tb;
@@ -372,11 +372,6 @@ int cpu_exec(CPUState *cpu)
uintptr_t next_tb;
SyncClocks sc;
- /* This must be volatile so it is not trashed by longjmp() */
-#if defined(CONFIG_USER_ONLY)
- volatile bool have_tb_lock = false;
-#endif
-
if (cpu->halted) {
if (!cpu_has_work(cpu)) {
return EXCP_HALTED;
@@ -480,10 +475,7 @@ int cpu_exec(CPUState *cpu)
cpu->exception_index = EXCP_INTERRUPT;
cpu_loop_exit(cpu);
}
-#if defined(CONFIG_USER_ONLY)
- qemu_mutex_lock(&tcg_ctx.tb_ctx.tb_lock);
- have_tb_lock = true;
-#endif
+ tb_lock();
tb = tb_find_fast(cpu);
/* Note: we do it here to avoid a gcc bug on Mac OS X when
doing it in tb_find_slow */
@@ -505,10 +497,7 @@ int cpu_exec(CPUState *cpu)
tb_add_jump((TranslationBlock *)(next_tb & ~TB_EXIT_MASK),
next_tb & TB_EXIT_MASK, tb);
}
-#if defined(CONFIG_USER_ONLY)
- have_tb_lock = false;
- qemu_mutex_unlock(&tcg_ctx.tb_ctx.tb_lock);
-#endif
+ tb_unlock();
/* cpu_interrupt might be called while translating the
TB, but before it is linked into a potentially
infinite loop and becomes env->current_tb. Avoid
@@ -575,12 +564,7 @@ int cpu_exec(CPUState *cpu)
x86_cpu = X86_CPU(cpu);
env = &x86_cpu->env;
#endif
-#if defined(CONFIG_USER_ONLY)
- if (have_tb_lock) {
- qemu_mutex_unlock(&tcg_ctx.tb_ctx.tb_lock);
- have_tb_lock = false;
- }
-#endif
+ tb_lock_reset();
}
} /* for(;;) */
Optimizations should then come on top.
> diff --git a/target-arm/translate.c b/target-arm/translate.c
> index 69ac18c..960c75e 100644
> --- a/target-arm/translate.c
> +++ b/target-arm/translate.c
> @@ -11166,6 +11166,8 @@ static inline void
> gen_intermediate_code_internal(ARMCPU *cpu,
>
> dc->tb = tb;
>
> + tb_lock();
This locks twice, I think? Both cpu_restore_state_from_tb and
tb_gen_code (which calls cpu_gen_code) take the lock. How does it work?
> +
> dc->is_jmp = DISAS_NEXT;
> dc->pc = pc_start;
> dc->singlestep_enabled = cs->singlestep_enabled;
> @@ -11506,6 +11508,7 @@ done_generating:
> tb->size = dc->pc - pc_start;
> tb->icount = num_insns;
> }
> + tb_unlock();
> }
>
> +/* tb_lock must be help for tcg_malloc_internal. */
"Held", not "help".
Paolo
