From patchwork Wed Oct 11 09:22:03 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Juan Quintela X-Patchwork-Id: 13417018 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 AEC02CD6E56 for ; Wed, 11 Oct 2023 09:38:01 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qqVSH-0005lA-FI; Wed, 11 Oct 2023 05:24:37 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qqVSE-0005Wl-3L for qemu-devel@nongnu.org; Wed, 11 Oct 2023 05:24:35 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qqVSC-0005GQ-E9 for qemu-devel@nongnu.org; Wed, 11 Oct 2023 05:24:33 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1697016271; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=k93ppU9takGNXa65Qf4sjjQAREAzL8cPGsOKxV8iTAU=; b=Du1I9vnZKNcrMHrwJjb/dH+/IC6y9jCjhuicJXpXPwunVWL3d/6Bq21lDlpUKmyHZ6zS3F HJF2bqhXMMjaHe8wjQc+T68JpguYm11cx7ZM1FPliQYvZD57Z08XdBgknmG6QKGLi2UDmY bhCwpcg284DQpGNaUjWV4w5F6dvFzFA= Received: from mimecast-mx02.redhat.com (mx-ext.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-144-jYufwREGOBes5dZ7FBgVcw-1; Wed, 11 Oct 2023 05:24:19 -0400 X-MC-Unique: jYufwREGOBes5dZ7FBgVcw-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.rdu2.redhat.com [10.11.54.7]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 41BC93814597; Wed, 11 Oct 2023 09:24:18 +0000 (UTC) Received: from secure.mitica (unknown [10.39.195.75]) by smtp.corp.redhat.com (Postfix) with ESMTP id 820FE1C060AE; Wed, 11 Oct 2023 09:24:16 +0000 (UTC) From: Juan Quintela To: qemu-devel@nongnu.org Cc: Laurent Vivier , Peter Xu , Paolo Bonzini , Markus Armbruster , Juan Quintela , Thomas Huth , Li Zhijian , Leonardo Bras , Eric Blake , Fabiano Rosas Subject: [PULL 65/65] migration: Add migration_rp_wait|kick() Date: Wed, 11 Oct 2023 11:22:03 +0200 Message-ID: <20231011092203.1266-66-quintela@redhat.com> In-Reply-To: <20231011092203.1266-1-quintela@redhat.com> References: <20231011092203.1266-1-quintela@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.7 Received-SPF: pass client-ip=170.10.133.124; envelope-from=quintela@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 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: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org From: Peter Xu It's just a simple wrapper for rp_sem on either wait() or kick(), make it even clearer on how it is used. Prepared to be used even for other things. Reviewed-by: Fabiano Rosas Signed-off-by: Peter Xu Message-ID: <20231004220240.167175-8-peterx@redhat.com> Signed-off-by: Juan Quintela --- migration/migration.h | 15 +++++++++++++++ migration/migration.c | 14 ++++++++++++-- migration/ram.c | 16 +++++++--------- 3 files changed, 34 insertions(+), 11 deletions(-) diff --git a/migration/migration.h b/migration/migration.h index 4106a1dc54..cd5534337c 100644 --- a/migration/migration.h +++ b/migration/migration.h @@ -316,6 +316,12 @@ struct MigrationState { * be cleared in the rp_thread! */ bool rp_thread_created; + /* + * Used to synchronize between migration main thread and return + * path thread. The migration thread can wait() on this sem, while + * other threads (e.g., return path thread) can kick it using a + * post(). + */ QemuSemaphore rp_sem; /* * We post to this when we got one PONG from dest. So far it's an @@ -527,4 +533,13 @@ void migration_populate_vfio_info(MigrationInfo *info); void migration_reset_vfio_bytes_transferred(void); void postcopy_temp_page_reset(PostcopyTmpPage *tmp_page); +/* Migration thread waiting for return path thread. */ +void migration_rp_wait(MigrationState *s); +/* + * Kick the migration thread waiting for return path messages. NOTE: the + * name can be slightly confusing (when read as "kick the rp thread"), just + * to remember the target is always the migration thread. + */ +void migration_rp_kick(MigrationState *s); + #endif diff --git a/migration/migration.c b/migration/migration.c index 409eb3e916..1c6c81ad49 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -1763,6 +1763,16 @@ static void mark_source_rp_bad(MigrationState *s) s->rp_state.error = true; } +void migration_rp_wait(MigrationState *s) +{ + qemu_sem_wait(&s->rp_state.rp_sem); +} + +void migration_rp_kick(MigrationState *s) +{ + qemu_sem_post(&s->rp_state.rp_sem); +} + static struct rp_cmd_args { ssize_t len; /* -1 = variable */ const char *name; @@ -1835,7 +1845,7 @@ static int migrate_handle_rp_resume_ack(MigrationState *s, uint32_t value) MIGRATION_STATUS_POSTCOPY_ACTIVE); /* Notify send thread that time to continue send pages */ - qemu_sem_post(&s->rp_state.rp_sem); + migration_rp_kick(s); return 0; } @@ -2464,7 +2474,7 @@ static int postcopy_resume_handshake(MigrationState *s) qemu_savevm_send_postcopy_resume(s->to_dst_file); while (s->state == MIGRATION_STATUS_POSTCOPY_RECOVER) { - qemu_sem_wait(&s->rp_state.rp_sem); + migration_rp_wait(s); } if (s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE) { diff --git a/migration/ram.c b/migration/ram.c index 6c40d9af0c..2f5ce4d60b 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -4141,7 +4141,7 @@ static int ram_dirty_bitmap_sync_all(MigrationState *s, RAMState *rs) /* Wait until all the ramblocks' dirty bitmap synced */ while (qatomic_read(&rs->postcopy_bmap_sync_requested)) { - qemu_sem_wait(&s->rp_state.rp_sem); + migration_rp_wait(s); } trace_ram_dirty_bitmap_sync_complete(); @@ -4149,11 +4149,6 @@ static int ram_dirty_bitmap_sync_all(MigrationState *s, RAMState *rs) return 0; } -static void ram_dirty_bitmap_reload_notify(MigrationState *s) -{ - qemu_sem_post(&s->rp_state.rp_sem); -} - /* * Read the received bitmap, revert it as the initial dirty bitmap. * This is only used when the postcopy migration is paused but wants @@ -4237,10 +4232,13 @@ int ram_dirty_bitmap_reload(MigrationState *s, RAMBlock *block) qatomic_dec(&rs->postcopy_bmap_sync_requested); /* - * We succeeded to sync bitmap for current ramblock. If this is - * the last one to sync, we need to notify the main send thread. + * We succeeded to sync bitmap for current ramblock. Always kick the + * migration thread to check whether all requested bitmaps are + * reloaded. NOTE: it's racy to only kick when requested==0, because + * we don't know whether the migration thread may still be increasing + * it. */ - ram_dirty_bitmap_reload_notify(s); + migration_rp_kick(s); ret = 0; out: