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cpu-exec: avoid cpu_loop_exit in cpu_handle_interrupt 

The siglongjmp goes straight back to the beginning of cpu_exec's
outermost loop.  We do not need a siglongjmp, we can simply
leave the inner TB execution loop.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Paolo Bonzini 2017-01-27 10:57:18 +01:00
parent a70fe14b7d
commit 209b71b60e
1 changed files with 12 additions and 11 deletions
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23
cpu-exec.c
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@ -461,7 +461,7 @@ static inline bool cpu_handle_exception(CPUState *cpu, int *ret)
return false;
}
static inline void cpu_handle_interrupt(CPUState *cpu,
static inline bool cpu_handle_interrupt(CPUState *cpu,
TranslationBlock **last_tb)
{
CPUClass *cc = CPU_GET_CLASS(cpu);
@ -475,7 +475,7 @@ static inline void cpu_handle_interrupt(CPUState *cpu,
if (interrupt_request & CPU_INTERRUPT_DEBUG) {
cpu->interrupt_request &= ~CPU_INTERRUPT_DEBUG;
cpu->exception_index = EXCP_DEBUG;
cpu_loop_exit(cpu);
return true;
}
if (replay_mode == REPLAY_MODE_PLAY && !replay_has_interrupt()) {
/* Do nothing */
@ -484,7 +484,7 @@ static inline void cpu_handle_interrupt(CPUState *cpu,
cpu->interrupt_request &= ~CPU_INTERRUPT_HALT;
cpu->halted = 1;
cpu->exception_index = EXCP_HLT;
cpu_loop_exit(cpu);
return true;
}
#if defined(TARGET_I386)
else if (interrupt_request & CPU_INTERRUPT_INIT) {
@ -494,13 +494,13 @@ static inline void cpu_handle_interrupt(CPUState *cpu,
cpu_svm_check_intercept_param(env, SVM_EXIT_INIT, 0);
do_cpu_init(x86_cpu);
cpu->exception_index = EXCP_HALTED;
cpu_loop_exit(cpu);
return true;
}
#else
else if (interrupt_request & CPU_INTERRUPT_RESET) {
replay_interrupt();
cpu_reset(cpu);
cpu_loop_exit(cpu);
return true;
}
#endif
/* The target hook has 3 exit conditions:
@ -526,8 +526,10 @@ static inline void cpu_handle_interrupt(CPUState *cpu,
if (unlikely(atomic_read(&cpu->exit_request) || replay_has_interrupt())) {
atomic_set(&cpu->exit_request, 0);
cpu->exception_index = EXCP_INTERRUPT;
cpu_loop_exit(cpu);
return true;
}
return false;
}
static inline void cpu_loop_exec_tb(CPUState *cpu, TranslationBlock *tb,
@ -625,7 +627,7 @@ int cpu_exec(CPUState *cpu)
for(;;) {
/* prepare setjmp context for exception handling */
if (sigsetjmp(cpu->jmp_env, 0) == 0) {
TranslationBlock *tb, *last_tb = NULL;
TranslationBlock *last_tb = NULL;
int tb_exit = 0;
/* if an exception is pending, we execute it here */
@ -633,14 +635,13 @@ int cpu_exec(CPUState *cpu)
break;
}
for(;;) {
cpu_handle_interrupt(cpu, &last_tb);
tb = tb_find(cpu, last_tb, tb_exit);
while (!cpu_handle_interrupt(cpu, &last_tb)) {
TranslationBlock *tb = tb_find(cpu, last_tb, tb_exit);
cpu_loop_exec_tb(cpu, tb, &last_tb, &tb_exit, &sc);
/* Try to align the host and virtual clocks
if the guest is in advance */
align_clocks(&sc, cpu);
} /* for(;;) */
}
} else {
#if defined(__clang__) || !QEMU_GNUC_PREREQ(4, 6)
/* Some compilers wrongly smash all local variables after