From patchwork Wed Mar 2 18:29:30 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Dr. David Alan Gilbert" X-Patchwork-Id: 1599996 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: bilbo.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=MyRp3XQq; dkim-atps=neutral Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by bilbo.ozlabs.org (Postfix) with ESMTPS id 4K836Q4nWQz9sG1 for ; Thu, 3 Mar 2022 05:48:30 +1100 (AEDT) Received: from localhost ([::1]:42864 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nPU1U-0007JJ-00 for incoming@patchwork.ozlabs.org; Wed, 02 Mar 2022 13:48:28 -0500 Received: from eggs.gnu.org ([209.51.188.92]:36768) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nPTkd-0001UR-Ku for qemu-devel@nongnu.org; Wed, 02 Mar 2022 13:31:03 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]:35273) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nPTkb-0000KA-GN for qemu-devel@nongnu.org; Wed, 02 Mar 2022 13:31:03 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1646245860; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=0PbF8YIadBK+ZkjWWRQZ0TnFmDA+2sgn4LnHgGUaaEg=; b=MyRp3XQq7XmKAXW2ebFI//aG36CIdX14wxPr67WAey+u3+CUhsLYOb6JpwETbuRd+l8a3j J9X3XhtikWsrn6FLX2Uv8rkMZeCm4eITuPL8mbQZusBwzKQpU7nrMKMQyBnxp+KsrwnDEL wSsFO2FrAlG+cJ6WJoOBi55eaI6PEQs= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-577-lO5QZGZEO6yRlioD319XxQ-1; Wed, 02 Mar 2022 13:30:54 -0500 X-MC-Unique: lO5QZGZEO6yRlioD319XxQ-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id B6BBC19251C0; Wed, 2 Mar 2022 18:30:52 +0000 (UTC) Received: from dgilbert-t580.localhost (unknown [10.33.36.30]) by smtp.corp.redhat.com (Postfix) with ESMTP id 2157A1059170; Wed, 2 Mar 2022 18:30:50 +0000 (UTC) From: "Dr. David Alan Gilbert (git)" To: qemu-devel@nongnu.org, f.ebner@proxmox.com, hreitz@redhat.com, jinpu.wang@ionos.com, peter.maydell@linaro.org, peterx@redhat.com, s.reiter@proxmox.com Subject: [PULL 12/18] migration: Add postcopy_thread_create() Date: Wed, 2 Mar 2022 18:29:30 +0000 Message-Id: <20220302182936.227719-13-dgilbert@redhat.com> In-Reply-To: <20220302182936.227719-1-dgilbert@redhat.com> References: <20220302182936.227719-1-dgilbert@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=dgilbert@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=170.10.129.124; envelope-from=dgilbert@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -28 X-Spam_score: -2.9 X-Spam_bar: -- X-Spam_report: (-2.9 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.082, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: quintela@redhat.com Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" From: Peter Xu Postcopy create threads. A common manner is we init a sem and use it to sync with the thread. Namely, we have fault_thread_sem and listen_thread_sem and they're only used for this. Make it a shared infrastructure so it's easier to create yet another thread. Reviewed-by: Dr. David Alan Gilbert Signed-off-by: Peter Xu Message-Id: <20220301083925.33483-7-peterx@redhat.com> Signed-off-by: Dr. David Alan Gilbert --- migration/migration.h | 8 +++++--- migration/postcopy-ram.c | 23 +++++++++++++++++------ migration/postcopy-ram.h | 4 ++++ migration/savevm.c | 12 +++--------- 4 files changed, 29 insertions(+), 18 deletions(-) diff --git a/migration/migration.h b/migration/migration.h index 42c7395094..8445e1d14a 100644 --- a/migration/migration.h +++ b/migration/migration.h @@ -70,7 +70,11 @@ struct MigrationIncomingState { /* A hook to allow cleanup at the end of incoming migration */ void *transport_data; void (*transport_cleanup)(void *data); - + /* + * Used to sync thread creations. Note that we can't create threads in + * parallel with this sem. + */ + QemuSemaphore thread_sync_sem; /* * Free at the start of the main state load, set as the main thread finishes * loading state. @@ -83,13 +87,11 @@ struct MigrationIncomingState { size_t largest_page_size; bool have_fault_thread; QemuThread fault_thread; - QemuSemaphore fault_thread_sem; /* Set this when we want the fault thread to quit */ bool fault_thread_quit; bool have_listen_thread; QemuThread listen_thread; - QemuSemaphore listen_thread_sem; /* For the kernel to send us notifications */ int userfault_fd; diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c index 30c3508f44..d08d396c63 100644 --- a/migration/postcopy-ram.c +++ b/migration/postcopy-ram.c @@ -78,6 +78,20 @@ int postcopy_notify(enum PostcopyNotifyReason reason, Error **errp) &pnd); } +/* + * NOTE: this routine is not thread safe, we can't call it concurrently. But it + * should be good enough for migration's purposes. + */ +void postcopy_thread_create(MigrationIncomingState *mis, + QemuThread *thread, const char *name, + void *(*fn)(void *), int joinable) +{ + qemu_sem_init(&mis->thread_sync_sem, 0); + qemu_thread_create(thread, name, fn, mis, joinable); + qemu_sem_wait(&mis->thread_sync_sem); + qemu_sem_destroy(&mis->thread_sync_sem); +} + /* Postcopy needs to detect accesses to pages that haven't yet been copied * across, and efficiently map new pages in, the techniques for doing this * are target OS specific. @@ -902,7 +916,7 @@ static void *postcopy_ram_fault_thread(void *opaque) trace_postcopy_ram_fault_thread_entry(); rcu_register_thread(); mis->last_rb = NULL; /* last RAMBlock we sent part of */ - qemu_sem_post(&mis->fault_thread_sem); + qemu_sem_post(&mis->thread_sync_sem); struct pollfd *pfd; size_t pfd_len = 2 + mis->postcopy_remote_fds->len; @@ -1173,11 +1187,8 @@ int postcopy_ram_incoming_setup(MigrationIncomingState *mis) return -1; } - qemu_sem_init(&mis->fault_thread_sem, 0); - qemu_thread_create(&mis->fault_thread, "postcopy/fault", - postcopy_ram_fault_thread, mis, QEMU_THREAD_JOINABLE); - qemu_sem_wait(&mis->fault_thread_sem); - qemu_sem_destroy(&mis->fault_thread_sem); + postcopy_thread_create(mis, &mis->fault_thread, "postcopy/fault", + postcopy_ram_fault_thread, QEMU_THREAD_JOINABLE); mis->have_fault_thread = true; /* Mark so that we get notified of accesses to unwritten areas */ diff --git a/migration/postcopy-ram.h b/migration/postcopy-ram.h index 6d2b3cf124..07684c0e1d 100644 --- a/migration/postcopy-ram.h +++ b/migration/postcopy-ram.h @@ -135,6 +135,10 @@ void postcopy_remove_notifier(NotifierWithReturn *n); /* Call the notifier list set by postcopy_add_start_notifier */ int postcopy_notify(enum PostcopyNotifyReason reason, Error **errp); +void postcopy_thread_create(MigrationIncomingState *mis, + QemuThread *thread, const char *name, + void *(*fn)(void *), int joinable); + struct PostCopyFD; /* ufd is a pointer to the struct uffd_msg *TODO: more Portable! */ diff --git a/migration/savevm.c b/migration/savevm.c index 0ccd7e5e3f..967ff80547 100644 --- a/migration/savevm.c +++ b/migration/savevm.c @@ -1863,7 +1863,7 @@ static void *postcopy_ram_listen_thread(void *opaque) migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE, MIGRATION_STATUS_POSTCOPY_ACTIVE); - qemu_sem_post(&mis->listen_thread_sem); + qemu_sem_post(&mis->thread_sync_sem); trace_postcopy_ram_listen_thread_start(); rcu_register_thread(); @@ -1988,14 +1988,8 @@ static int loadvm_postcopy_handle_listen(MigrationIncomingState *mis) } mis->have_listen_thread = true; - /* Start up the listening thread and wait for it to signal ready */ - qemu_sem_init(&mis->listen_thread_sem, 0); - qemu_thread_create(&mis->listen_thread, "postcopy/listen", - postcopy_ram_listen_thread, NULL, - QEMU_THREAD_DETACHED); - qemu_sem_wait(&mis->listen_thread_sem); - qemu_sem_destroy(&mis->listen_thread_sem); - + postcopy_thread_create(mis, &mis->listen_thread, "postcopy/listen", + postcopy_ram_listen_thread, QEMU_THREAD_DETACHED); trace_loadvm_postcopy_handle_listen("return"); return 0;