From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58012) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZHuqX-0005MO-2q for qemu-devel@nongnu.org; Wed, 22 Jul 2015 10:18:15 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZHuqT-0001As-Bh for qemu-devel@nongnu.org; Wed, 22 Jul 2015 10:18:09 -0400 Received: from mx1.redhat.com ([209.132.183.28]:43391) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZHuqT-0001Ah-41 for qemu-devel@nongnu.org; Wed, 22 Jul 2015 10:18:05 -0400 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (Postfix) with ESMTPS id CFE67A2C08 for ; Wed, 22 Jul 2015 14:18:04 +0000 (UTC) Received: from donizetti.redhat.com (ovpn-112-49.ams2.redhat.com [10.36.112.49]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id t6MEI1Uj018944 for ; Wed, 22 Jul 2015 10:18:03 -0400 From: Paolo Bonzini Date: Wed, 22 Jul 2015 16:18:01 +0200 Message-Id: <1437574681-18362-2-git-send-email-pbonzini@redhat.com> Subject: [Qemu-devel] [PATCH] rcu: actually register threads that have RCU read-side critical sections List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Otherwise, grace periods are detected too early! Signed-off-by: Paolo Bonzini --- cpus.c | 6 ++++++ iothread.c | 5 +++++ migration/migration.c | 4 ++++ tests/test-rcu-list.c | 4 ++++ util/rcu.c | 2 ++ 5 files changed, 21 insertions(+) diff --git a/cpus.c b/cpus.c index b00a423..a822ce3 100644 --- a/cpus.c +++ b/cpus.c @@ -954,6 +954,8 @@ static void *qemu_kvm_cpu_thread_fn(void *arg) CPUState *cpu = arg; int r; + rcu_register_thread(); + qemu_mutex_lock_iothread(); qemu_thread_get_self(cpu->thread); cpu->thread_id = qemu_get_thread_id(); @@ -995,6 +997,8 @@ static void *qemu_dummy_cpu_thread_fn(void *arg) sigset_t waitset; int r; + rcu_register_thread(); + qemu_mutex_lock_iothread(); qemu_thread_get_self(cpu->thread); cpu->thread_id = qemu_get_thread_id(); @@ -1034,6 +1038,8 @@ static void *qemu_tcg_cpu_thread_fn(void *arg) { CPUState *cpu = arg; + rcu_register_thread(); + qemu_mutex_lock_iothread(); qemu_tcg_init_cpu_signals(); qemu_thread_get_self(cpu->thread); diff --git a/iothread.c b/iothread.c index 6d2a33f..da6ce7b 100644 --- a/iothread.c +++ b/iothread.c @@ -18,6 +18,7 @@ #include "sysemu/iothread.h" #include "qmp-commands.h" #include "qemu/error-report.h" +#include "qemu/rcu.h" typedef ObjectClass IOThreadClass; @@ -31,6 +32,8 @@ static void *iothread_run(void *opaque) IOThread *iothread = opaque; bool blocking; + rcu_register_thread(); + qemu_mutex_lock(&iothread->init_done_lock); iothread->thread_id = qemu_get_thread_id(); qemu_cond_signal(&iothread->init_done_cond); @@ -45,6 +48,8 @@ static void *iothread_run(void *opaque) } aio_context_release(iothread->ctx); } + + rcu_unregister_thread(); return NULL; } diff --git a/migration/migration.c b/migration/migration.c index 86ca099..fd4f99b 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -22,6 +22,7 @@ #include "block/block.h" #include "qapi/qmp/qerror.h" #include "qemu/sockets.h" +#include "qemu/rcu.h" #include "migration/block.h" #include "qemu/thread.h" #include "qmp-commands.h" @@ -917,6 +918,8 @@ static void *migration_thread(void *opaque) int64_t start_time = initial_time; bool old_vm_running = false; + rcu_register_thread(); + qemu_savevm_state_header(s->file); qemu_savevm_state_begin(s->file, &s->params); @@ -1016,6 +1019,7 @@ static void *migration_thread(void *opaque) qemu_bh_schedule(s->cleanup_bh); qemu_mutex_unlock_iothread(); + rcu_unregister_thread(); return NULL; } diff --git a/tests/test-rcu-list.c b/tests/test-rcu-list.c index 4c5f62e..daa8bf4 100644 --- a/tests/test-rcu-list.c +++ b/tests/test-rcu-list.c @@ -108,6 +108,8 @@ static void *rcu_q_reader(void *arg) long long n_reads_local = 0; struct list_element *el; + rcu_register_thread(); + *(struct rcu_reader_data **)arg = &rcu_reader; atomic_inc(&nthreadsrunning); while (goflag == GOFLAG_INIT) { @@ -129,6 +131,8 @@ static void *rcu_q_reader(void *arg) qemu_mutex_lock(&counts_mutex); n_reads += n_reads_local; qemu_mutex_unlock(&counts_mutex); + + rcu_unregister_thread(); return NULL; } diff --git a/util/rcu.c b/util/rcu.c index 7270151..cdcad67 100644 --- a/util/rcu.c +++ b/util/rcu.c @@ -216,6 +216,8 @@ static void *call_rcu_thread(void *opaque) { struct rcu_head *node; + rcu_register_thread(); + for (;;) { int tries = 0; int n = atomic_read(&rcu_call_count); -- 2.4.3