From 12d4536f7d911b6d87a766ad7300482ea663cea2 Mon Sep 17 00:00:00 2001 From: Anthony Liguori Date: Mon, 22 Aug 2011 08:24:58 -0500 Subject: main: force enabling of I/O thread Enabling the I/O thread by default seems like an important part of declaring 1.0. Besides allowing true SMP support with KVM, the I/O thread means that the TCG VCPU doesn't have to multiplex itself with the I/O dispatch routines which currently requires a (racey) signal based alarm system. I know there have been concerns about performance. I think so far the ones that have come up (virtio-net) are most likely due to secondary reasons like decreased batching. I think we ought to force enabling I/O thread early in 1.0 development and commit to resolving any lingering issues. Signed-off-by: Anthony Liguori --- cpus.c | 143 ----------------------------------------------------------------- 1 file changed, 143 deletions(-) (limited to 'cpus.c') diff --git a/cpus.c b/cpus.c index b163efe4a8..54c188cf5c 100644 --- a/cpus.c +++ b/cpus.c @@ -173,12 +173,9 @@ static void cpu_handle_guest_debug(CPUState *env) { gdb_set_stop_cpu(env); qemu_system_debug_request(); -#ifdef CONFIG_IOTHREAD env->stopped = 1; -#endif } -#ifdef CONFIG_IOTHREAD static void cpu_signal(int sig) { if (cpu_single_env) { @@ -186,7 +183,6 @@ static void cpu_signal(int sig) } exit_request = 1; } -#endif #ifdef CONFIG_LINUX static void sigbus_reraise(void) @@ -262,12 +258,6 @@ static void qemu_kvm_eat_signals(CPUState *env) exit(1); } } while (sigismember(&chkset, SIG_IPI) || sigismember(&chkset, SIGBUS)); - -#ifndef CONFIG_IOTHREAD - if (sigismember(&chkset, SIGIO) || sigismember(&chkset, SIGALRM)) { - qemu_notify_event(); - } -#endif } #else /* !CONFIG_LINUX */ @@ -390,7 +380,6 @@ static int qemu_signal_init(void) int sigfd; sigset_t set; -#ifdef CONFIG_IOTHREAD /* SIGUSR2 used by posix-aio-compat.c */ sigemptyset(&set); sigaddset(&set, SIGUSR2); @@ -409,18 +398,6 @@ static int qemu_signal_init(void) sigaddset(&set, SIGIO); sigaddset(&set, SIGALRM); sigaddset(&set, SIGBUS); -#else - sigemptyset(&set); - sigaddset(&set, SIGBUS); - if (kvm_enabled()) { - /* - * We need to process timer signals synchronously to avoid a race - * between exit_request check and KVM vcpu entry. - */ - sigaddset(&set, SIGIO); - sigaddset(&set, SIGALRM); - } -#endif pthread_sigmask(SIG_BLOCK, &set, NULL); sigfd = qemu_signalfd(&set); @@ -447,7 +424,6 @@ static void qemu_kvm_init_cpu_signals(CPUState *env) sigact.sa_handler = dummy_signal; sigaction(SIG_IPI, &sigact, NULL); -#ifdef CONFIG_IOTHREAD pthread_sigmask(SIG_BLOCK, NULL, &set); sigdelset(&set, SIG_IPI); sigdelset(&set, SIGBUS); @@ -456,17 +432,7 @@ static void qemu_kvm_init_cpu_signals(CPUState *env) fprintf(stderr, "kvm_set_signal_mask: %s\n", strerror(-r)); exit(1); } -#else - sigemptyset(&set); - sigaddset(&set, SIG_IPI); - sigaddset(&set, SIGIO); - sigaddset(&set, SIGALRM); - pthread_sigmask(SIG_BLOCK, &set, NULL); - pthread_sigmask(SIG_BLOCK, NULL, &set); - sigdelset(&set, SIGIO); - sigdelset(&set, SIGALRM); -#endif sigdelset(&set, SIG_IPI); sigdelset(&set, SIGBUS); r = kvm_set_signal_mask(env, &set); @@ -478,7 +444,6 @@ static void qemu_kvm_init_cpu_signals(CPUState *env) static void qemu_tcg_init_cpu_signals(void) { -#ifdef CONFIG_IOTHREAD sigset_t set; struct sigaction sigact; @@ -489,7 +454,6 @@ static void qemu_tcg_init_cpu_signals(void) sigemptyset(&set); sigaddset(&set, SIG_IPI); pthread_sigmask(SIG_UNBLOCK, &set, NULL); -#endif } #else /* _WIN32 */ @@ -535,106 +499,6 @@ static void qemu_tcg_init_cpu_signals(void) } #endif /* _WIN32 */ -#ifndef CONFIG_IOTHREAD -int qemu_init_main_loop(void) -{ - int ret; - - ret = qemu_signal_init(); - if (ret) { - return ret; - } - - qemu_init_sigbus(); - - return qemu_event_init(); -} - -void qemu_main_loop_start(void) -{ -} - -void qemu_init_vcpu(void *_env) -{ - CPUState *env = _env; - int r; - - env->nr_cores = smp_cores; - env->nr_threads = smp_threads; - - if (kvm_enabled()) { - r = kvm_init_vcpu(env); - if (r < 0) { - fprintf(stderr, "kvm_init_vcpu failed: %s\n", strerror(-r)); - exit(1); - } - qemu_kvm_init_cpu_signals(env); - } else { - qemu_tcg_init_cpu_signals(); - } -} - -int qemu_cpu_is_self(void *env) -{ - return 1; -} - -void run_on_cpu(CPUState *env, void (*func)(void *data), void *data) -{ - func(data); -} - -void resume_all_vcpus(void) -{ -} - -void pause_all_vcpus(void) -{ -} - -void qemu_cpu_kick(void *env) -{ -} - -void qemu_cpu_kick_self(void) -{ -#ifndef _WIN32 - assert(cpu_single_env); - - raise(SIG_IPI); -#else - abort(); -#endif -} - -void qemu_notify_event(void) -{ - CPUState *env = cpu_single_env; - - qemu_event_increment (); - if (env) { - cpu_exit(env); - } - if (next_cpu && env != next_cpu) { - cpu_exit(next_cpu); - } - exit_request = 1; -} - -void qemu_mutex_lock_iothread(void) {} -void qemu_mutex_unlock_iothread(void) {} - -void cpu_stop_current(void) -{ -} - -void vm_stop(int reason) -{ - do_vm_stop(reason); -} - -#else /* CONFIG_IOTHREAD */ - QemuMutex qemu_global_mutex; static QemuCond qemu_io_proceeded_cond; static bool iothread_requesting_mutex; @@ -1028,8 +892,6 @@ void vm_stop(int reason) do_vm_stop(reason); } -#endif - static int tcg_cpu_exec(CPUState *env) { int ret; @@ -1084,11 +946,6 @@ bool cpu_exec_all(void) qemu_clock_enable(vm_clock, (env->singlestep_enabled & SSTEP_NOTIMER) == 0); -#ifndef CONFIG_IOTHREAD - if (qemu_alarm_pending()) { - break; - } -#endif if (cpu_can_run(env)) { if (kvm_enabled()) { r = kvm_cpu_exec(env); -- cgit v1.2.1