From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ming Lei Subject: Re: [PATCH 0/2] genirq/affinity: try to make sure online CPU is assgined to irq vector Date: Thu, 1 Feb 2018 23:04:48 +0800 Message-ID: <20180201150441.GA32269@ming.t460p> References: <20180115160345.2611-1-ming.lei@redhat.com> <20180115174036.GA20191@infradead.org> <20180116013043.GA3213@ming.t460p> <1516109317.9574.1.camel@redhat.com> <20180201103651.GA29263@ming.t460p> <35e74f9ae47b4b5db8ee4bf3a8989e82@microsemi.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Return-path: Received: from mx1.redhat.com ([209.132.183.28]:60452 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751408AbeBAPFj (ORCPT ); Thu, 1 Feb 2018 10:05:39 -0500 Content-Disposition: inline In-Reply-To: <35e74f9ae47b4b5db8ee4bf3a8989e82@microsemi.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Don Brace Cc: Laurence Oberman , Thomas Gleixner , Christoph Hellwig , Jens Axboe , "linux-block@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Mike Snitzer , linux-scsi@vger.kernel.org On Thu, Feb 01, 2018 at 02:53:35PM +0000, Don Brace wrote: > > -----Original Message----- > > From: Ming Lei [mailto:ming.lei@redhat.com] > > Sent: Thursday, February 01, 2018 4:37 AM > > To: Don Brace > > Cc: Laurence Oberman ; Thomas Gleixner > > ; Christoph Hellwig ; Jens Axboe > > ; linux-block@vger.kernel.org; linux-kernel@vger.kernel.org; > > Mike Snitzer > > Subject: Re: [PATCH 0/2] genirq/affinity: try to make sure online CPU is assgined > > to irq vector > > > > EXTERNAL EMAIL > > > > > > On Tue, Jan 16, 2018 at 03:22:18PM +0000, Don Brace wrote: > > > > -----Original Message----- > > > > From: Laurence Oberman [mailto:loberman@redhat.com] > > > > Sent: Tuesday, January 16, 2018 7:29 AM > > > > To: Thomas Gleixner ; Ming Lei > > > > Cc: Christoph Hellwig ; Jens Axboe ; > > > > linux-block@vger.kernel.org; linux-kernel@vger.kernel.org; Mike Snitzer > > > > ; Don Brace > > > > Subject: Re: [PATCH 0/2] genirq/affinity: try to make sure online CPU is > > assgined > > > > to irq vector > > > > > > > > > > It is because of irq_create_affinity_masks(). > > > > > > > > > > That still does not answer the question. If the interrupt for a queue > > > > > is > > > > > assigned to an offline CPU, then the queue should not be used and > > > > > never > > > > > raise an interrupt. That's how managed interrupts have been designed. > > > > > > > > > > Thanks, > > > > > > > > > > tglx > > > > > > > > > > > > > > > > > > > > > > > > > > > > I captured a full boot log for this issue for Microsemi, I will send it > > > > to Don Brace. > > > > I enabled all the HPSA debug and here is snippet > > > > > > > > > > > > .. > > > > .. > > > > .. > > > > 246.751135] INFO: task systemd-udevd:413 blocked for more than 120 > > > > seconds. > > > > [  246.788008]       Tainted: G I 4.15.0-rc4.noming+ #1 > > > > [  246.822380] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" > > > > disables this message. > > > > [  246.865594] systemd-udevd D 0 413 411 0x80000004 > > > > [  246.895519] Call Trace: > > > > [  246.909713]  ? __schedule+0x340/0xc20 > > > > [  246.930236]  schedule+0x32/0x80 > > > > [  246.947905]  schedule_timeout+0x23d/0x450 > > > > [ 246.970047]  ? find_held_lock+0x2d/0x90 > > > > [  246.991774]  ? wait_for_completion_io+0x108/0x170 > > > > [  247.018172]  io_schedule_timeout+0x19/0x40 > > > > [  247.041208]  wait_for_completion_io+0x110/0x170 > > > > [  247.067326]  ? wake_up_q+0x70/0x70 > > > > [  247.086801]  hpsa_scsi_do_simple_cmd+0xc6/0x100 [hpsa] > > > > [  247.114315]  hpsa_scsi_do_simple_cmd_with_retry+0xb7/0x1c0 [hpsa] > > > > [  247.146629]  hpsa_scsi_do_inquiry+0x73/0xd0 [hpsa] > > > > [  247.174118]  hpsa_init_one+0x12cb/0x1a59 [hpsa] > > > > > > This trace comes from internally generated discovery commands. No SCSI > > devices have > > > been presented to the SML yet. > > > > > > At this point we should be running on only one CPU. These commands are > > meant to use > > > reply queue 0 which are tied to CPU 0. It's interesting that the patch helps. > > > > > > However, I was wondering if you could inspect the iLo IML logs and send the > > > AHS logs for inspection. > > > > Hello Don, > > > > Now the patch has been merged to linus tree as: > > > > 84676c1f21e8ff54b ("genirq/affinity: assign vectors to all possible CPUs") > > > > and it breaks Laurence's machine completely, :-( > > > > I just take a look at HPSA's code, and found that reply queue is chosen > > in the following way in most of code path: > > > > if (likely(reply_queue == DEFAULT_REPLY_QUEUE)) > > cp->ReplyQueue = smp_processor_id() % h->nreply_queues; > > > > h->nreply_queues is the msix vector number which is returned from > > pci_alloc_irq_vectors(), and now some of vectors may be mapped to all > > offline CPUs, for example, one processor isn't plugged to socket. > > > > If I understand correctly, 'cp->ReplyQueue' is aligned to one irq > > vector, and the command is expected by handled via that irq vector, > > is it right? > > > > If yes, now I guess this way can't work any more if number of online > > CPUs is >= h->nreply_queues, and you may need to check the cpu affinity > > of one vector before choosing the reply queue, and block/blk-mq-pci.c > > may be helpful for you. > > > > Thanks, > > Ming > > Thanks Ming, > I start working up a patch. Also the reply queue may be mapped to blk-mq's hw queue directly, then the conversion may be done by blk-mq's MQ framework, but legacy path still need the fix. thanks Ming