From nobody Thu May 9 23:37:54 2024 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass(p=none dis=none) header.from=suse.de ARC-Seal: i=1; a=rsa-sha256; t=1638532676; cv=none; d=zohomail.com; s=zohoarc; b=hc5vBiom5TvknPFZ0MzZ5fNums/qU57ThPWVt1DzMZKIApwsw/7X1mQNs4F51gut/IL3+r/2x6hdcqyzvRQww8t2293UYK+wWgXSJBsdDPtU5LiQxskOmjYGLdcpzJjR8UKGlfKlFMY+wqdyAG7K1f2XP+Jh3F9xY3+hFCIcllI= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1638532676; h=Content-Transfer-Encoding:Cc:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:To; bh=R7rWtsuUPfBjyZG4Ax61KdJvGnZ6y0nDdjW+4w4ufTQ=; b=jH7bAern9hofq+png2thhAImNpYzC0mDunu3OWGYXjk/cBYy5dwfvHT8nhpm8jTK5KeSXhmmLC7Qzb6X5h89NY3A5j/LJuJGLYxnY26QPFPUfBTNBEkbmHvo4dpU+HoXxepWsv2sCSh4uEDiMCg+IMYGrA+ypOVfiZRiAF82XBU= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass header.from= (p=none dis=none) Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1638532676615502.00071029247965; Fri, 3 Dec 2021 03:57:56 -0800 (PST) Received: from localhost ([::1]:33252 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mt7CN-00047V-Hs for importer@patchew.org; Fri, 03 Dec 2021 06:57:55 -0500 Received: from eggs.gnu.org ([209.51.188.92]:37892) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mt7AI-00022h-UL for qemu-devel@nongnu.org; Fri, 03 Dec 2021 06:55:46 -0500 Received: from smtp-out2.suse.de ([195.135.220.29]:45856) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1mt7AG-0001Rh-B7 for qemu-devel@nongnu.org; Fri, 03 Dec 2021 06:55:46 -0500 Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 1EA071FD40; Fri, 3 Dec 2021 11:55:43 +0000 (UTC) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id E0A7D13DF5; Fri, 3 Dec 2021 11:55:42 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id sBBpNb4FqmHbNgAAMHmgww (envelope-from ); Fri, 03 Dec 2021 11:55:42 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1638532543; h=from:from:reply-to: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=R7rWtsuUPfBjyZG4Ax61KdJvGnZ6y0nDdjW+4w4ufTQ=; b=TN1PdP/4vIzNUVoBV6DAmwzGZm+eMfdczgq3mLGmWVaY1ekqeDzDasS9kOtfPbaLxua3JA JMFZu9cF8f3D8PUMlyTBaSR3u67MCi65qnIquvAdOc7HKuM3q7oqgYpfVFaJL4Bi2HSzD6 Z/hCoueAbuqHmJpM0Yk2PR1TBLNqC6s= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1638532543; h=from:from:reply-to: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=R7rWtsuUPfBjyZG4Ax61KdJvGnZ6y0nDdjW+4w4ufTQ=; b=EbR4+0GmsAeJEvaleTSAoO9oYxi5sB2CMurdW+8wfrEHRjgO5kCieFj74abbf5vdPzVRJv 3mZuOsXczfoJclDg== From: Li Zhang To: dgilbert@redhat.com, quintela@redhat.com, berrange@redhat.com, cfontana@suse.de, qemu-devel@nongnu.org Subject: [PATCH v2 1/1] multifd: Shut down the QIO channels to avoid blocking the send threads when they are terminated. Date: Fri, 3 Dec 2021 12:55:33 +0100 Message-Id: <20211203115533.31534-2-lizhang@suse.de> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20211203115533.31534-1-lizhang@suse.de> References: <20211203115533.31534-1-lizhang@suse.de> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=195.135.220.29; envelope-from=lizhang@suse.de; helo=smtp-out2.suse.de X-Spam_score_int: -43 X-Spam_score: -4.4 X-Spam_bar: ---- X-Spam_report: (-4.4 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_MED=-2.3, 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: , Cc: Li Zhang Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: pass (identity @suse.de) X-ZM-MESSAGEID: 1638532677951100001 Content-Type: text/plain; charset="utf-8" When doing live migration with multifd channels 8, 16 or larger number, the guest hangs in the presence of the network errors such as missing TCP A= CKs. At sender's side: The main thread is blocked on qemu_thread_join, migration_fd_cleanup is called because one thread fails on qio_channel_write_all when the network problem happens and other send threads are blocked on sendmsg. They could not be terminated. So the main thread is blocked on qemu_thread_= join to wait for the threads terminated. (gdb) bt 0 0x00007f30c8dcffc0 in __pthread_clockjoin_ex () at /lib64/libpthread.so.0 1 0x000055cbb716084b in qemu_thread_join (thread=3D0x55cbb881f418) at ../u= til/qemu-thread-posix.c:627 2 0x000055cbb6b54e40 in multifd_save_cleanup () at ../migration/multifd.c:= 542 3 0x000055cbb6b4de06 in migrate_fd_cleanup (s=3D0x55cbb8024000) at ../migr= ation/migration.c:1808 4 0x000055cbb6b4dfb4 in migrate_fd_cleanup_bh (opaque=3D0x55cbb8024000) at= ../migration/migration.c:1850 5 0x000055cbb7173ac1 in aio_bh_call (bh=3D0x55cbb7eb98e0) at ../util/async= .c:141 6 0x000055cbb7173bcb in aio_bh_poll (ctx=3D0x55cbb7ebba80) at ../util/asyn= c.c:169 7 0x000055cbb715ba4b in aio_dispatch (ctx=3D0x55cbb7ebba80) at ../util/aio= -posix.c:381 8 0x000055cbb7173ffe in aio_ctx_dispatch (source=3D0x55cbb7ebba80, callbac= k=3D0x0, user_data=3D0x0) at ../util/async.c:311 9 0x00007f30c9c8cdf4 in g_main_context_dispatch () at /usr/lib64/libglib-2= .0.so.0 10 0x000055cbb71851a2 in glib_pollfds_poll () at ../util/main-loop.c:232 11 0x000055cbb718521c in os_host_main_loop_wait (timeout=3D42251070366) at = ../util/main-loop.c:255 12 0x000055cbb7185321 in main_loop_wait (nonblocking=3D0) at ../util/main-l= oop.c:531 13 0x000055cbb6e6ba27 in qemu_main_loop () at ../softmmu/runstate.c:726 14 0x000055cbb6ad6fd7 in main (argc=3D68, argv=3D0x7ffc0c578888, envp=3D0x7= ffc0c578ab0) at ../softmmu/main.c:50 To make sure that the send threads could be terminated, IO channels should = be shut down to avoid waiting IO. Signed-off-by: Li Zhang Reviewed-by: Daniel P. Berrang=C3=A9 Reviewed-by: Juan Quintela --- migration/multifd.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/migration/multifd.c b/migration/multifd.c index 7c9deb1921..33f8287969 100644 --- a/migration/multifd.c +++ b/migration/multifd.c @@ -523,6 +523,9 @@ static void multifd_send_terminate_threads(Error *err) qemu_mutex_lock(&p->mutex); p->quit =3D true; qemu_sem_post(&p->sem); + if (p->c) { + qio_channel_shutdown(p->c, QIO_CHANNEL_SHUTDOWN_BOTH, NULL); + } qemu_mutex_unlock(&p->mutex); } } --=20 2.31.1