From patchwork Mon Aug 22 13:24:58 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anthony Liguori X-Patchwork-Id: 110920 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [140.186.70.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 85E1BB6F00 for ; Mon, 22 Aug 2011 23:25:21 +1000 (EST) Received: from localhost ([::1]:51314 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QvUVA-0005lW-Hb for incoming@patchwork.ozlabs.org; Mon, 22 Aug 2011 09:25:16 -0400 Received: from eggs.gnu.org ([140.186.70.92]:60612) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QvUV4-0005lQ-Ds for qemu-devel@nongnu.org; Mon, 22 Aug 2011 09:25:11 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1QvUV2-0002lx-Mb for qemu-devel@nongnu.org; Mon, 22 Aug 2011 09:25:10 -0400 Received: from e7.ny.us.ibm.com ([32.97.182.137]:55978) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QvUV2-0002lZ-CT for qemu-devel@nongnu.org; Mon, 22 Aug 2011 09:25:08 -0400 Received: from d01relay04.pok.ibm.com (d01relay04.pok.ibm.com [9.56.227.236]) by e7.ny.us.ibm.com (8.14.4/8.13.1) with ESMTP id p7MCwVLn016056 for ; Mon, 22 Aug 2011 08:58:31 -0400 Received: from d03av04.boulder.ibm.com (d03av04.boulder.ibm.com [9.17.195.170]) by d01relay04.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id p7MDP51G185684 for ; Mon, 22 Aug 2011 09:25:05 -0400 Received: from d03av04.boulder.ibm.com (loopback [127.0.0.1]) by d03av04.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id p7M7P4f4002431 for ; Mon, 22 Aug 2011 01:25:04 -0600 Received: from titi.austin.rr.com ([9.57.82.90]) by d03av04.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVin) with ESMTP id p7M7P1ag002251; Mon, 22 Aug 2011 01:25:02 -0600 From: Anthony Liguori To: qemu-devel@nongnu.org Date: Mon, 22 Aug 2011 08:24:58 -0500 Message-Id: <1314019498-8550-1-git-send-email-aliguori@us.ibm.com> X-Mailer: git-send-email 1.7.4.1 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6, seldom 2.4 (older, 4) X-Received-From: 32.97.182.137 Cc: Blue Swirl , Paolo Bonzini , Anthony Liguori , Aurelien Jarno , Jan Kiszka Subject: [Qemu-devel] [PATCH] main: force enabling of I/O thread X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org 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 --- configure | 13 ----- cpus.c | 143 ---------------------------------------------------------- hw/qxl.c | 4 -- kvm-all.c | 2 +- qemu-timer.c | 53 --------------------- vl.c | 17 ------- 6 files changed, 1 insertions(+), 231 deletions(-) diff --git a/configure b/configure index 234a4c5..ef8d7ae 100755 --- a/configure +++ b/configure @@ -165,7 +165,6 @@ darwin_user="no" bsd_user="no" guest_base="" uname_release="" -io_thread="no" mixemu="no" aix="no" blobs="yes" @@ -722,8 +721,6 @@ for opt do ;; --enable-attr) attr="yes" ;; - --enable-io-thread) io_thread="yes" - ;; --disable-blobs) blobs="no" ;; --with-pkgversion=*) pkgversion=" ($optarg)" @@ -2159,12 +2156,6 @@ EOF if compile_prog "" "" ; then signalfd=yes -elif test "$kvm" = "yes" -a "$io_thread" != "yes"; then - echo - echo "ERROR: Host kernel lacks signalfd() support," - echo "but KVM depends on it when the IO thread is disabled." - echo - exit 1 fi # check if eventfd is supported @@ -2711,7 +2702,6 @@ echo "NPTL support $nptl" echo "GUEST_BASE $guest_base" echo "PIE user targets $user_pie" echo "vde support $vde" -echo "IO thread $io_thread" echo "Linux AIO support $linux_aio" echo "ATTR/XATTR support $attr" echo "Install blobs $blobs" @@ -2969,9 +2959,6 @@ if test "$xen" = "yes" ; then echo "CONFIG_XEN_BACKEND=y" >> $config_host_mak echo "CONFIG_XEN_CTRL_INTERFACE_VERSION=$xen_ctrl_version" >> $config_host_mak fi -if test "$io_thread" = "yes" ; then - echo "CONFIG_IOTHREAD=y" >> $config_host_mak -fi if test "$linux_aio" = "yes" ; then echo "CONFIG_LINUX_AIO=y" >> $config_host_mak fi diff --git a/cpus.c b/cpus.c index c996ac5..fe18a60 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; @@ -1036,8 +900,6 @@ void vm_stop(int reason) do_vm_stop(reason); } -#endif - static int tcg_cpu_exec(CPUState *env) { int ret; @@ -1092,11 +954,6 @@ 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); diff --git a/hw/qxl.c b/hw/qxl.c index bab60a5..c3a3e97 100644 --- a/hw/qxl.c +++ b/hw/qxl.c @@ -1388,11 +1388,7 @@ static void init_pipe_signaling(PCIQXLDevice *d) dprint(d, 1, "%s: pipe creation failed\n", __FUNCTION__); return; } -#ifdef CONFIG_IOTHREAD fcntl(d->pipe[0], F_SETFL, O_NONBLOCK); -#else - fcntl(d->pipe[0], F_SETFL, O_NONBLOCK /* | O_ASYNC */); -#endif fcntl(d->pipe[1], F_SETFL, O_NONBLOCK); fcntl(d->pipe[0], F_SETOWN, getpid()); diff --git a/kvm-all.c b/kvm-all.c index 0ae2e26..fbb9ff3 100644 --- a/kvm-all.c +++ b/kvm-all.c @@ -479,7 +479,7 @@ static int kvm_check_many_ioeventfds(void) * Older kernels have a 6 device limit on the KVM io bus. Find out so we * can avoid creating too many ioeventfds. */ -#if defined(CONFIG_EVENTFD) && defined(CONFIG_IOTHREAD) +#if defined(CONFIG_EVENTFD) int ioeventfds[7]; int i, ret = 0; for (i = 0; i < ARRAY_SIZE(ioeventfds); i++) { diff --git a/qemu-timer.c b/qemu-timer.c index 19313d3..46dd483 100644 --- a/qemu-timer.c +++ b/qemu-timer.c @@ -101,22 +101,6 @@ static int64_t cpu_get_clock(void) } } -#ifndef CONFIG_IOTHREAD -static int64_t qemu_icount_delta(void) -{ - if (!use_icount) { - return 5000 * (int64_t) 1000000; - } else if (use_icount == 1) { - /* When not using an adaptive execution frequency - we tend to get badly out of sync with real time, - so just delay for a reasonable amount of time. */ - return 0; - } else { - return cpu_get_icount() - cpu_get_clock(); - } -} -#endif - /* enable cpu_get_ticks() */ void cpu_enable_ticks(void) { @@ -688,9 +672,7 @@ void configure_icount(const char *option) if (!option) return; -#ifdef CONFIG_IOTHREAD vm_clock->warp_timer = qemu_new_timer_ns(rt_clock, icount_warp_rt, NULL); -#endif if (strcmp(option, "auto") != 0) { icount_time_shift = strtol(option, NULL, 0); @@ -1178,41 +1160,6 @@ void quit_timers(void) int qemu_calculate_timeout(void) { -#ifndef CONFIG_IOTHREAD - int timeout; - - if (!vm_running) - timeout = 5000; - else { - /* XXX: use timeout computed from timers */ - int64_t add; - int64_t delta; - /* Advance virtual time to the next event. */ - delta = qemu_icount_delta(); - if (delta > 0) { - /* If virtual time is ahead of real time then just - wait for IO. */ - timeout = (delta + 999999) / 1000000; - } else { - /* Wait for either IO to occur or the next - timer event. */ - add = qemu_next_icount_deadline(); - /* We advance the timer before checking for IO. - Limit the amount we advance so that early IO - activity won't get the guest too far ahead. */ - if (add > 10000000) - add = 10000000; - delta += add; - qemu_icount += qemu_icount_round (add); - timeout = delta / 1000000; - if (timeout < 0) - timeout = 0; - } - } - - return timeout; -#else /* CONFIG_IOTHREAD */ return 1000; -#endif } diff --git a/vl.c b/vl.c index d661e8e..11f5669 100644 --- a/vl.c +++ b/vl.c @@ -1438,17 +1438,6 @@ void main_loop_wait(int nonblocking) } -#ifndef CONFIG_IOTHREAD -static int vm_request_pending(void) -{ - return powerdown_requested || - reset_requested || - shutdown_requested || - debug_requested || - vmstop_requested; -} -#endif - qemu_irq qemu_system_powerdown; static void main_loop(void) @@ -1462,12 +1451,6 @@ static void main_loop(void) qemu_main_loop_start(); for (;;) { -#ifndef CONFIG_IOTHREAD - nonblocking = cpu_exec_all(); - if (vm_request_pending()) { - nonblocking = true; - } -#endif #ifdef CONFIG_PROFILER ti = profile_getclock(); #endif