From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53687) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cdcl0-00029r-RP for qemu-devel@nongnu.org; Tue, 14 Feb 2017 08:03:00 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cdckx-00053e-NH for qemu-devel@nongnu.org; Tue, 14 Feb 2017 08:02:58 -0500 Received: from mail-wr0-x242.google.com ([2a00:1450:400c:c0c::242]:36678) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1cdckx-00052j-DT for qemu-devel@nongnu.org; Tue, 14 Feb 2017 08:02:55 -0500 Received: by mail-wr0-x242.google.com with SMTP id k90so27438951wrc.3 for ; Tue, 14 Feb 2017 05:02:55 -0800 (PST) Sender: Paolo Bonzini References: <1487006388-7966-1-git-send-email-quintela@redhat.com> <1487006388-7966-7-git-send-email-quintela@redhat.com> From: Paolo Bonzini Message-ID: Date: Tue, 14 Feb 2017 14:02:56 +0100 MIME-Version: 1.0 In-Reply-To: <1487006388-7966-7-git-send-email-quintela@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Subject: Re: [Qemu-devel] [PULL 06/12] migration: Create multifd migration threads List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Juan Quintela , qemu-devel@nongnu.org Cc: amit.shah@redhat.com, dgilbert@redhat.com On 13/02/2017 18:19, Juan Quintela wrote: > Creation of the threads, nothing inside yet. > > Signed-off-by: Juan Quintela > Reviewed-by: Dr. David Alan Gilbert > > -- > > Use pointers instead of long array names > Move to use semaphores instead of conditions as paolo suggestion > --- > include/migration/migration.h | 4 + > migration/migration.c | 6 ++ > migration/ram.c | 168 ++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 178 insertions(+) > > diff --git a/include/migration/migration.h b/include/migration/migration.h > index 3c7f165..13fac75 100644 > --- a/include/migration/migration.h > +++ b/include/migration/migration.h > @@ -256,6 +256,10 @@ MigrationState *migrate_get_current(void); > > int migrate_multifd_threads(void); > int migrate_multifd_group(void); > +void migrate_multifd_send_threads_create(void); > +void migrate_multifd_send_threads_join(void); > +void migrate_multifd_recv_threads_create(void); > +void migrate_multifd_recv_threads_join(void); > > void migrate_compress_threads_create(void); > void migrate_compress_threads_join(void); > diff --git a/migration/migration.c b/migration/migration.c > index 2b2d0a8..d2705d7 100644 > --- a/migration/migration.c > +++ b/migration/migration.c > @@ -344,6 +344,7 @@ static void process_incoming_migration_bh(void *opaque) > MIGRATION_STATUS_FAILED); > error_report_err(local_err); > migrate_decompress_threads_join(); > + migrate_multifd_recv_threads_join(); > exit(EXIT_FAILURE); > } > > @@ -368,6 +369,7 @@ static void process_incoming_migration_bh(void *opaque) > runstate_set(global_state_get_runstate()); > } > migrate_decompress_threads_join(); > + migrate_multifd_recv_threads_join(); > /* > * This must happen after any state changes since as soon as an external > * observer sees this event they might start to prod at the VM assuming > @@ -433,6 +435,7 @@ static void process_incoming_migration_co(void *opaque) > MIGRATION_STATUS_FAILED); > error_report("load of migration failed: %s", strerror(-ret)); > migrate_decompress_threads_join(); > + migrate_multifd_recv_threads_join(); > exit(EXIT_FAILURE); > } > > @@ -445,6 +448,7 @@ void migration_fd_process_incoming(QEMUFile *f) > Coroutine *co = qemu_coroutine_create(process_incoming_migration_co, f); > > migrate_decompress_threads_create(); > + migrate_multifd_recv_threads_create(); > qemu_file_set_blocking(f, false); > qemu_coroutine_enter(co); > } > @@ -974,6 +978,7 @@ static void migrate_fd_cleanup(void *opaque) > qemu_mutex_lock_iothread(); > > migrate_compress_threads_join(); > + migrate_multifd_send_threads_join(); > qemu_fclose(s->to_dst_file); > s->to_dst_file = NULL; > } > @@ -2100,6 +2105,7 @@ void migrate_fd_connect(MigrationState *s) > } > > migrate_compress_threads_create(); > + migrate_multifd_send_threads_create(); > qemu_thread_create(&s->thread, "live_migration", migration_thread, s, > QEMU_THREAD_JOINABLE); > s->migration_thread_running = true; > diff --git a/migration/ram.c b/migration/ram.c > index 4422ee8..0cb19cf 100644 > --- a/migration/ram.c > +++ b/migration/ram.c > @@ -382,6 +382,174 @@ void migrate_compress_threads_create(void) > } > } > > +/* Multiple fd's */ > + > +struct MultiFDSendParams { > + QemuThread thread; > + QemuSemaphore sem; > + QemuMutex mutex; > + bool quit; > +}; > +typedef struct MultiFDSendParams MultiFDSendParams; > + > +static MultiFDSendParams *multifd_send; > + > +static void *multifd_send_thread(void *opaque) > +{ > + MultiFDSendParams *params = opaque; > + > + while (true) { > + qemu_mutex_lock(¶ms->mutex); > + if (params->quit) { > + qemu_mutex_unlock(¶ms->mutex); > + break; > + } > + qemu_mutex_unlock(¶ms->mutex); > + qemu_sem_wait(¶ms->sem); > + } You can use while (true) { qemu_sem_wait(¶ms->sem); if (atomic_read(¶ms->quit)) { break; } if (atomic_read(¶ms->address)) { params->address = 0; params->done = true; qemu_set_post(&multifd_send_sem); } } ... atomic_set(&p->quit, true); qemu_sem_post(&p->sem); This avoid params->mutex, and it works because wait and post are respectively acquire and release operations: the read certainly happens after wait, the write certainly happens before the post. Likewise for ->done in patch 9; ->address and later ->pages.num don't even need atomic_read/atomic_set because there are two semaphores involved and they act as the synchronization point. Paolo > + > + return NULL; > +} > + > +static void terminate_multifd_send_threads(void) > +{ > + int i, thread_count; > + > + thread_count = migrate_multifd_threads(); > + for (i = 0; i < thread_count; i++) { > + MultiFDSendParams *p = &multifd_send[i]; > + > + qemu_mutex_lock(&p->mutex); > + p->quit = true; > + qemu_sem_post(&p->sem); > + qemu_mutex_unlock(&p->mutex); > + } > +} > + > +void migrate_multifd_send_threads_join(void) > +{ > + int i, thread_count; > + > + if (!migrate_use_multifd()) { > + return; > + } > + terminate_multifd_send_threads(); > + thread_count = migrate_multifd_threads(); > + for (i = 0; i < thread_count; i++) { > + MultiFDSendParams *p = &multifd_send[i]; > + > + qemu_thread_join(&p->thread); > + qemu_mutex_destroy(&p->mutex); > + qemu_sem_destroy(&p->sem); > + } > + g_free(multifd_send); > + multifd_send = NULL; > +} > + > +void migrate_multifd_send_threads_create(void) > +{ > + int i, thread_count; > + > + if (!migrate_use_multifd()) { > + return; > + } > + thread_count = migrate_multifd_threads(); > + multifd_send = g_new0(MultiFDSendParams, thread_count); > + for (i = 0; i < thread_count; i++) { > + char thread_name[15]; > + MultiFDSendParams *p = &multifd_send[i]; > + > + qemu_mutex_init(&p->mutex); > + qemu_sem_init(&p->sem, 0); > + p->quit = false; > + snprintf(thread_name, 15, "multifd_send_%d", i); > + qemu_thread_create(&p->thread, thread_name, multifd_send_thread, p, > + QEMU_THREAD_JOINABLE); > + } > +} > + > +struct MultiFDRecvParams { > + QemuThread thread; > + QemuSemaphore sem; > + QemuMutex mutex; > + bool quit; > +}; > +typedef struct MultiFDRecvParams MultiFDRecvParams; > + > +static MultiFDRecvParams *multifd_recv; > + > +static void *multifd_recv_thread(void *opaque) > +{ > + MultiFDRecvParams *params = opaque; > + > + while (true) { > + qemu_mutex_lock(¶ms->mutex); > + if (params->quit) { > + qemu_mutex_unlock(¶ms->mutex); > + break; > + } > + qemu_mutex_unlock(¶ms->mutex); > + qemu_sem_wait(¶ms->sem); > + } > + > + return NULL; > +} > + > +static void terminate_multifd_recv_threads(void) > +{ > + int i, thread_count; > + > + thread_count = migrate_multifd_threads(); > + for (i = 0; i < thread_count; i++) { > + MultiFDRecvParams *p = &multifd_recv[i]; > + > + qemu_mutex_lock(&p->mutex); > + p->quit = true; > + qemu_sem_post(&p->sem); > + qemu_mutex_unlock(&p->mutex); > + } > +} > + > +void migrate_multifd_recv_threads_join(void) > +{ > + int i, thread_count; > + > + if (!migrate_use_multifd()) { > + return; > + } > + terminate_multifd_recv_threads(); > + thread_count = migrate_multifd_threads(); > + for (i = 0; i < thread_count; i++) { > + MultiFDRecvParams *p = &multifd_recv[i]; > + > + qemu_thread_join(&p->thread); > + qemu_mutex_destroy(&p->mutex); > + qemu_sem_destroy(&p->sem); > + } > + g_free(multifd_recv); > + multifd_recv = NULL; > +} > + > +void migrate_multifd_recv_threads_create(void) > +{ > + int i, thread_count; > + > + if (!migrate_use_multifd()) { > + return; > + } > + thread_count = migrate_multifd_threads(); > + multifd_recv = g_new0(MultiFDRecvParams, thread_count); > + for (i = 0; i < thread_count; i++) { > + MultiFDRecvParams *p = &multifd_recv[i]; > + > + qemu_mutex_init(&p->mutex); > + qemu_sem_init(&p->sem, 0); > + p->quit = false; > + qemu_thread_create(&p->thread, "multifd_recv", multifd_recv_thread, p, > + QEMU_THREAD_JOINABLE); > + } > +} > + > /** > * save_page_header: Write page header to wire > * >