On Tue, Jan 16, 2018 at 03:22:18PM +0000, Don Brace wrote: > > -----Original Message----- > > From: Laurence Oberman [mailto:loberman@xxxxxxxxxx] > > Sent: Tuesday, January 16, 2018 7:29 AM > > To: Thomas Gleixner <tglx@xxxxxxxxxxxxx>; Ming Lei <ming.lei@xxxxxxxxxx> > > Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx>; Jens Axboe <axboe@xxxxxx>; > > linux-block@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Mike Snitzer > > <snitzer@xxxxxxxxxx>; Don Brace <don.brace@xxxxxxxxxxxxx> > > 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
