From patchwork Fri Sep 20 10:05:42 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Yuchen X-Patchwork-Id: 13808444 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 3563ECF3974 for ; Fri, 20 Sep 2024 10:07:48 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1sraXD-0003Tq-OD; Fri, 20 Sep 2024 06:06:44 -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 1sraX2-0003Sp-I4 for qemu-devel@nongnu.org; Fri, 20 Sep 2024 06:06:38 -0400 Received: from smtp.h3c.com ([60.191.123.50] helo=h3cspam02-ex.h3c.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1sraWx-0002Is-Kq for qemu-devel@nongnu.org; Fri, 20 Sep 2024 06:06:30 -0400 Received: from mail.maildlp.com ([172.25.15.154]) by h3cspam02-ex.h3c.com with ESMTP id 48KA5dxK089235; Fri, 20 Sep 2024 18:05:39 +0800 (GMT-8) (envelope-from yu.chen@h3c.com) Received: from DAG6EX09-BJD.srv.huawei-3com.com (unknown [10.153.34.11]) by mail.maildlp.com (Postfix) with ESMTP id 863FA2004737; Fri, 20 Sep 2024 18:11:35 +0800 (CST) Received: from DAG6EX10-BJD.srv.huawei-3com.com (10.153.34.12) by DAG6EX09-BJD.srv.huawei-3com.com (10.153.34.11) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1258.27; Fri, 20 Sep 2024 18:05:42 +0800 Received: from DAG6EX10-BJD.srv.huawei-3com.com ([fe80::ade6:b219:16f8:9aa8]) by DAG6EX10-BJD.srv.huawei-3com.com ([fe80::ade6:b219:16f8:9aa8%6]) with mapi id 15.02.1258.027; Fri, 20 Sep 2024 18:05:42 +0800 From: Yuchen To: "peterx@redhat.com" , "farosas@suse.de" CC: "qemu-devel@nongnu.org" Subject: [PATCH] migration/multifd: receive channel socket needs to be set to non-blocking Thread-Topic: [PATCH] migration/multifd: receive channel socket needs to be set to non-blocking Thread-Index: AdsLQcj1g9agKPLCRU2ZlkOXAEmYdw== Date: Fri, 20 Sep 2024 10:05:42 +0000 Message-ID: <37febc26060949f891aedea01de724fc@h3c.com> Accept-Language: zh-CN, en-UM, en-US Content-Language: zh-CN X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.99.196.41] x-sender-location: DAG2 MIME-Version: 1.0 X-DNSRBL: X-MAIL: h3cspam02-ex.h3c.com 48KA5dxK089235 Received-SPF: pass client-ip=60.191.123.50; envelope-from=yu.chen@h3c.com; helo=h3cspam02-ex.h3c.com X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=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 When the migration network is disconnected, the source qemu can exit normally with an error, but the destination qemu is always blocked in recvmsg(), causes the destination qemu main thread to be blocked. The destination qemu block stack: Thread 13 (Thread 0x7f0178bfa640 (LWP 1895906) "multifdrecv_6"): #0 0x00007f041b5af56f in recvmsg () #1 0x000055573ebd0b42 in qio_channel_socket_readv #2 0x000055573ebce83f in qio_channel_readv #3 qio_channel_readv_all_eof #4 0x000055573ebce909 in qio_channel_readv_all #5 0x000055573eaa1b1f in multifd_recv_thread #6 0x000055573ec2f0b9 in qemu_thread_start #7 0x00007f041b52bf7a in start_thread #8 0x00007f041b5ae600 in clone3 Thread 1 (Thread 0x7f0410c62240 (LWP 1895156) "kvm"): #0 0x00007f041b528ae2 in __futex_abstimed_wait_common () #1 0x00007f041b5338b8 in __new_sem_wait_slow64.constprop.0 #2 0x000055573ec2fd34 in qemu_sem_wait (sem=0x555742b5a4e0) #3 0x000055573eaa2f09 in multifd_recv_sync_main () #4 0x000055573e7d590d in ram_load_precopy (f=f@entry=0x555742291c20) #5 0x000055573e7d5cbf in ram_load (opaque=, version_id=, f=0x555742291c20) #6 ram_load_entry (f=0x555742291c20, opaque=, version_id=) #7 0x000055573ea932e7 in qemu_loadvm_section_part_end (mis=0x555741136c00, f=0x555742291c20) #8 qemu_loadvm_state_main (f=f@entry=0x555742291c20, mis=mis@entry=0x555741136c00) #9 0x000055573ea94418 in qemu_loadvm_state (f=0x555742291c20, mode=mode@entry=VMS_MIGRATE) #10 0x000055573ea88be1 in process_incoming_migration_co (opaque=) #11 0x000055573ec43d13 in coroutine_trampoline (i0=, i1=) #12 0x00007f041b4f5d90 in ?? () from target:/usr/lib64/libc.so.6 #13 0x00007ffc11890270 in ?? () #14 0x0000000000000000 in ?? () Setting the receive channel to non-blocking can solve the problem. Signed-off-by: YuChen --- migration/multifd.c | 2 ++ 1 file changed, 2 insertions(+) -- 2.30.2 ------------------------------------------------------------------------------------------------------------------------------------- 本邮件及其附件含有新华三集团的保密信息,仅限于发送给上面地址中列出 的个人或群组。禁止任何其他人以任何形式使用(包括但不限于全部或部分地泄露、复制、 或散发)本邮件中的信息。如果您错收了本邮件,请您立即电话或邮件通知发件人并删除本 邮件! This e-mail and its attachments contain confidential information from New H3C, which is intended only for the person or entity whose address is listed above. Any use of the information contained herein in any way (including, but not limited to, total or partial disclosure, reproduction, or dissemination) by persons other than the intended recipient(s) is prohibited. If you receive this e-mail in error, please notify the sender by phone or email immediately and delete it! diff --git a/migration/multifd.c b/migration/multifd.c index 9b200f4ad9..7b2a768f05 100644 --- a/migration/multifd.c +++ b/migration/multifd.c @@ -1318,6 +1318,8 @@ void multifd_recv_new_channel(QIOChannel *ioc, Error **errp) id = qatomic_read(&multifd_recv_state->count); } + qio_channel_set_blocking(ioc, false, NULL); + p = &multifd_recv_state->params[id]; if (p->c != NULL) { error_setg(&local_err, "multifd: received id '%d' already setup'",