From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 8D54BC433F5 for ; Wed, 16 Feb 2022 06:52:27 +0000 (UTC) Received: from localhost ([::1]:50518 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nKEAr-0002Uv-AJ for qemu-devel@archiver.kernel.org; Wed, 16 Feb 2022 01:52:26 -0500 Received: from eggs.gnu.org ([209.51.188.92]:48040) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nKDoQ-0004A3-HI for qemu-devel@nongnu.org; Wed, 16 Feb 2022 01:29:18 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]:60942) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nKDoO-0006Fc-Pq for qemu-devel@nongnu.org; Wed, 16 Feb 2022 01:29:14 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1644992952; 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=9Dc2Vi2zj/693dIJ2nS//TnSj/P3rpIaVxMb6s1Xx0U=; b=IfjbCz5Q7CHUPy3tczOoWrJYj4ldeXRuuC75joqprDdjHlJaJ22kW5P39P7NgdCng7QU3i mCnky8bZpc97thDLduNQr27iKxX/6GAn13DJr3JYH2v2dGV+L2QQotOKxoGqJUFPz1UVDC 9icUbNSf6tdfIxsiLpy6PxyNy7RM7Gs= Received: from mail-pj1-f72.google.com (mail-pj1-f72.google.com [209.85.216.72]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-53-fu2_qw0COyuFjw1DujZzqA-1; Wed, 16 Feb 2022 01:29:10 -0500 X-MC-Unique: fu2_qw0COyuFjw1DujZzqA-1 Received: by mail-pj1-f72.google.com with SMTP id g19-20020a17090a579300b001b9d80f3714so938922pji.7 for ; Tue, 15 Feb 2022 22:29:10 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=9Dc2Vi2zj/693dIJ2nS//TnSj/P3rpIaVxMb6s1Xx0U=; b=Pf5UI6YOZUufr0p7CNPWvNQeexkNWUAJ24jpEgEPtQQqK1PWplRDpdculiWHNvILz3 UAgSuJ/YNJ/HlkuakcQRoKr6n3ilNq6mJWKQb3QCA7ZXeOmvz6Y6IKDoCwMHFCq5giqn 0bx9A5uzkkMJciADgSNgCqZBpz6yaSic5RCAo33IulV5mxUh4DcblQV8ng/DLnuyWKWh ssFkNblUOYXukbCgY5VGzb9jG7Tv6m5o7Dip/DEYBUMgGnrDAj9zWO3GwKu1nZbDYKIE XxYq9RlPK0jBTkvr50jaYNagbZnFJTgDxgprlWp+NzoYbgfTU8hxfuocK9uUV4vO3G5i cQxw== X-Gm-Message-State: AOAM532KJqKTe2iail47k8KoN9OWjsE+G5Hn/42h7qmPEMcR1+Eyu91U gLBzQqEZJRjN6XUyvNBpgR0AoOdEYZm15svKesGf+cmCqoAB5qpKZUDyBz4eQNx+Uruz7lo+Ywb +yehq2Mg5pShpdiXmLlvxQCRkgdkdbrdkIRLdzYGpb6/6nl5UxdkanVMaZZoRv81d X-Received: by 2002:a17:902:9f96:b0:14f:1b7f:d5 with SMTP id g22-20020a1709029f9600b0014f1b7f00d5mr1439142plq.126.1644992948896; Tue, 15 Feb 2022 22:29:08 -0800 (PST) X-Google-Smtp-Source: ABdhPJzn7fuCz3WIYS+/waBLZ7Yr/451j0PJTgscnUQaZyZjZACXg1XBc1Qu+l8j5mVh4PxsmOLUOQ== X-Received: by 2002:a17:902:9f96:b0:14f:1b7f:d5 with SMTP id g22-20020a1709029f9600b0014f1b7f00d5mr1439114plq.126.1644992948428; Tue, 15 Feb 2022 22:29:08 -0800 (PST) Received: from localhost.localdomain ([64.64.123.81]) by smtp.gmail.com with ESMTPSA id 17sm42104657pfl.175.2022.02.15.22.29.02 (version=TLS1_3 cipher=TLS_CHACHA20_POLY1305_SHA256 bits=256/256); Tue, 15 Feb 2022 22:29:08 -0800 (PST) From: Peter Xu To: qemu-devel@nongnu.org Subject: [PATCH 06/20] migration: Add postcopy_thread_create() Date: Wed, 16 Feb 2022 14:27:55 +0800 Message-Id: <20220216062809.57179-7-peterx@redhat.com> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20220216062809.57179-1-peterx@redhat.com> References: <20220216062809.57179-1-peterx@redhat.com> MIME-Version: 1.0 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=peterx@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset="US-ASCII" Received-SPF: pass client-ip=170.10.129.124; envelope-from=peterx@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=-0.083, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, 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: Leonardo Bras Soares Passos , "Dr . David Alan Gilbert" , peterx@redhat.com, Juan Quintela Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" 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. Signed-off-by: Peter Xu --- 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 315f784965..d3ec22e6de 100644 --- a/migration/postcopy-ram.c +++ b/migration/postcopy-ram.c @@ -77,6 +77,20 @@ 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. @@ -901,7 +915,7 @@ 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; @@ -1172,11 +1186,8 @@ 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; -- 2.32.0