From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2EE921FF7C3 for ; Wed, 27 Nov 2024 15:20:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732720849; cv=none; b=ctQOmTxZ3nXIT6SfB/2H295z3/5HHcjtzGWmMzG1LarwargBxnjO0GDRHcPKx+MpRpytFyDTHuqYIMWawCh8Hk7fSqGYMPxQye5ws9SYVrH01XThUjcuQk2Z7cSK/q9Z3Hd8959C8egZpmZ/Hm8OUn3FBUAnyVoWco7vRNXyZ8E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732720849; c=relaxed/simple; bh=/3Wsd0r1atmN8QgendSG2mAiHmuXScUakR9O7v+XZZE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=HJN45DrIBVzBoRQI9+3dqS4U114FpuubS3ECJUT1Gig21oVxolNUHmLLZIw+T/KupTr7AO2e5rcuV1RzG80p2o4nim0HaaRKBc7AEfw6mi8wItC9QXeXLiBI9CnQK3/QpBirKFIcveNR4DxqZ05q1K6ITskV1dPJQeqEmEIo5oE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=Fgjqd4DN; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Fgjqd4DN" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1732720847; 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: in-reply-to:in-reply-to:references:references; bh=2m3sM+geAVqtO9zJQ0mLUooy55Xp73Cx8PifdCc8B0s=; b=Fgjqd4DN2aKOuctsRJhwLxq1ItF7Pg5AgJMOXrojlJaE7oiSSlW1rFiqrFOMPFqd2siPAv 2rkOQpJrpwdxFEeqTjotnA/e+u1QdMO2wLH7l/4x0MqWyEhS2r8I6P+s+HS3yzLTxULOrl dGNLSa2U0vl11ZE97QM1m0BvJc0Sz30= Received: from mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-74-vbvfy8jRNE639mBPqSDwow-1; Wed, 27 Nov 2024 10:20:41 -0500 X-MC-Unique: vbvfy8jRNE639mBPqSDwow-1 X-Mimecast-MFC-AGG-ID: vbvfy8jRNE639mBPqSDwow Received: from mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id EFD3D1936133; Wed, 27 Nov 2024 15:20:39 +0000 (UTC) Received: from fedora (unknown [10.72.116.17]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 14770300019E; Wed, 27 Nov 2024 15:20:33 +0000 (UTC) Date: Wed, 27 Nov 2024 23:20:28 +0800 From: Ming Lei To: Qiang Ma Cc: James.Bottomley@hansenpartnership.com, martin.petersen@oracle.com, axboe@kernel.dk, dwagner@suse.de, hare@suse.de, linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] scsi: Don't wait for completion of in-flight requests Message-ID: References: <20241126115008.31272-1-maqianga@uniontech.com> <2100C70C0D4CA64E+20241127220437.65ae99dd@john-PC> Precedence: bulk X-Mailing-List: linux-scsi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <2100C70C0D4CA64E+20241127220437.65ae99dd@john-PC> X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 On Wed, Nov 27, 2024 at 10:04:37PM +0800, Qiang Ma wrote: > On Tue, 26 Nov 2024 22:15:02 +0800 > Ming Lei wrote: > > > On Tue, Nov 26, 2024 at 07:50:08PM +0800, Qiang Ma wrote: > > > Problem: > > > When the system disk uses the scsi disk bus, The main > > > qemu command line includes: > > > ... > > > -device virtio-scsi-pci,id=scsi0 \ > > > -device scsi-hd,scsi-id=1,drive=drive-virtio-disk > > > -drive id=drive-virtio-disk,if=none,file=/home/kvm/test.qcow2 > > > ... > > > > > > The dmesg log is as follows:: > > > > > > [ 50.304591][ T4382] sd 0:0:0:0: [sda] Synchronizing SCSI cache > > > [ 50.377002][ T4382] kexec_core: Starting new kernel Why is one new kernel started? what event triggers kernel_kexec()? machine_shutdown() follows, probably the scsi controller is dead. > > > [ 50.669775][ T194] psci: CPU1 killed (polled 0 ms) > > > [ 50.849665][ T194] psci: CPU2 killed (polled 0 ms) > > > [ 51.109625][ T194] psci: CPU3 killed (polled 0 ms) > > > [ 51.319594][ T194] psci: CPU4 killed (polled 0 ms) > > > [ 51.489667][ T194] psci: CPU5 killed (polled 0 ms) > > > [ 51.709582][ T194] psci: CPU6 killed (polled 0 ms) > > > [ 51.949508][ T10] psci: CPU7 killed (polled 0 ms) > > > [ 52.139499][ T10] psci: CPU8 killed (polled 0 ms) > > > [ 52.289426][ T10] psci: CPU9 killed (polled 0 ms) > > > [ 52.439552][ T10] psci: CPU10 killed (polled 0 ms) > > > [ 52.579525][ T10] psci: CPU11 killed (polled 0 ms) > > > [ 52.709501][ T10] psci: CPU12 killed (polled 0 ms) > > > [ 52.819509][ T194] psci: CPU13 killed (polled 0 ms) > > > [ 52.919509][ T194] psci: CPU14 killed (polled 0 ms) > > > [ 243.214009][ T115] INFO: task kworker/0:1:10 blocked for more > > > than 122 seconds. [ 243.214810][ T115] Not tainted 6.6.0+ #1 > > > [ 243.215517][ T115] "echo 0 > > > > /proc/sys/kernel/hung_task_timeout_secs" disables this message. > > > > [ 243.216390][ T115] task:kworker/0:1 state:D stack:0 > > > > pid:10 ppid:2 flags:0x00000008 > > > [ 243.217299][ T115] Workqueue: events vmstat_shepherd > > > [ 243.217816][ T115] Call trace: > > > [ 243.218133][ T115] __switch_to+0x130/0x1e8 > > > [ 243.218568][ T115] __schedule+0x660/0xcf8 > > > [ 243.219013][ T115] schedule+0x58/0xf0 > > > [ 243.219402][ T115] percpu_rwsem_wait+0xb0/0x1d0 > > > [ 243.219880][ T115] __percpu_down_read+0x40/0xe0 > > > [ 243.220353][ T115] cpus_read_lock+0x5c/0x70 > > > [ 243.220795][ T115] vmstat_shepherd+0x40/0x140 > > > [ 243.221250][ T115] process_one_work+0x170/0x3c0 > > > [ 243.221726][ T115] worker_thread+0x234/0x3b8 > > > [ 243.222176][ T115] kthread+0xf0/0x108 > > > [ 243.222564][ T115] ret_from_fork+0x10/0x20 > > > ... > > > [ 243.254080][ T115] INFO: task kworker/0:2:194 blocked for more > > > than 122 seconds. [ 243.254834][ T115] Not tainted 6.6.0+ #1 > > > [ 243.255529][ T115] "echo 0 > > > > /proc/sys/kernel/hung_task_timeout_secs" disables this message. > > > > [ 243.256378][ T115] task:kworker/0:2 state:D stack:0 > > > > pid:194 ppid:2 flags:0x00000008 > > > [ 243.257284][ T115] Workqueue: events work_for_cpu_fn > > > [ 243.257793][ T115] Call trace: > > > [ 243.258111][ T115] __switch_to+0x130/0x1e8 > > > [ 243.258541][ T115] __schedule+0x660/0xcf8 > > > [ 243.258971][ T115] schedule+0x58/0xf0 > > > [ 243.259360][ T115] schedule_timeout+0x280/0x2f0 > > > [ 243.259832][ T115] wait_for_common+0xcc/0x2d8 > > > [ 243.260287][ T115] wait_for_completion+0x20/0x38 > > > [ 243.260767][ T115] cpuhp_kick_ap+0xe8/0x278 > > > [ 243.261207][ T115] cpuhp_kick_ap_work+0x5c/0x188 > > > [ 243.261688][ T115] _cpu_down+0x120/0x378 > > > [ 243.262103][ T115] __cpu_down_maps_locked+0x20/0x38 > > > [ 243.262609][ T115] work_for_cpu_fn+0x24/0x40 > > > [ 243.263059][ T115] process_one_work+0x170/0x3c0 > > > [ 243.263533][ T115] worker_thread+0x234/0x3b8 > > > [ 243.263981][ T115] kthread+0xf0/0x108 > > > [ 243.264405][ T115] ret_from_fork+0x10/0x20 > > > [ 243.264846][ T115] INFO: task kworker/15:2:639 blocked for more > > > than 122 seconds. [ 243.265602][ T115] Not tainted 6.6.0+ #1 > > > [ 243.266296][ T115] "echo 0 > > > > /proc/sys/kernel/hung_task_timeout_secs" disables this message. > > > > [ 243.267143][ T115] task:kworker/15:2 state:D stack:0 > > > > pid:639 ppid:2 flags:0x00000008 > > > [ 243.268044][ T115] Workqueue: events_freezable_power_ > > > disk_events_workfn [ 243.268727][ T115] Call trace: > > > [ 243.269051][ T115] __switch_to+0x130/0x1e8 > > > [ 243.269481][ T115] __schedule+0x660/0xcf8 > > > [ 243.269903][ T115] schedule+0x58/0xf0 > > > [ 243.270293][ T115] schedule_timeout+0x280/0x2f0 > > > [ 243.270763][ T115] io_schedule_timeout+0x50/0x70 > > > [ 243.271245][ T115] wait_for_common_io.constprop.0+0xb0/0x298 > > > [ 243.271830][ T115] wait_for_completion_io+0x1c/0x30 > > > [ 243.272335][ T115] blk_execute_rq+0x1d8/0x278 > > > [ 243.272793][ T115] scsi_execute_cmd+0x114/0x238 > > > [ 243.273267][ T115] sr_check_events+0xc8/0x310 [sr_mod] > > > [ 243.273808][ T115] cdrom_check_events+0x2c/0x50 [cdrom] > > > [ 243.274408][ T115] sr_block_check_events+0x34/0x48 [sr_mod] > > > [ 243.274994][ T115] disk_check_events+0x44/0x1b0 > > > [ 243.275468][ T115] disk_events_workfn+0x20/0x38 > > > [ 243.275939][ T115] process_one_work+0x170/0x3c0 > > > [ 243.276410][ T115] worker_thread+0x234/0x3b8 > > > [ 243.276855][ T115] kthread+0xf0/0x108 > > > [ 243.277241][ T115] ret_from_fork+0x10/0x20 > > > > Question is why this scsi command can't be completed? > > > > When blk_mq_hctx_notify_offline() is called, the CPU isn't shutdown > > yet, and it still can handle interrupt of this SCSI command. > > > > > > Thanks, > > Ming > > > > > Sorry, at the moment I don't know why it can't be finished, > just provides a solution like loop and dm-rq. > > Currently see the call stack: > => blk_mq_run_hw_queue > =>__blk_mq_sched_restart > => blk_mq_run_hw_queue > => __blk_mq_sched_restart > => __blk_mq_free_request > => blk_mq_free_request > => blk_mq_end_request > => blk_flush_complete_seq > => flush_end_io > => __blk_mq_end_request > => scsi_end_request > => scsi_io_completion > => scsi_finish_command > => scsi_complete > => blk_mq_complete_request > => scsi_done_internal > => scsi_done > => virtscsi_complete_cmd > => virtscsi_req_done > => vring_interrupt > > In finction blk_mq_run_hw_queue(): > __blk_mq_run_dispatch_ops(hctx->queue, false, > need_run = !blk_queue_quiesced(hctx->queue) && > blk_mq_hctx_has_pending(hctx)); > > if (!need_run) > return; > > Come here and return directly. Does blk_queue_quiesced() return true? Thanks, Ming