Re: [PATCH] nvme: utilize two queue maps, one for reads and one for writes

Re: [PATCH] nvme: utilize two queue maps, one for reads and one for writes

[Guenter Roeck]

Hi,

On Wed, Oct 31, 2018 at 08:36:31AM -0600, Jens Axboe wrote:
> NVMe does round-robin between queues by default, which means that
> sharing a queue map for both reads and writes can be problematic
> in terms of read servicing. It's much easier to flood the queue
> with writes and reduce the read servicing.
> 
> Implement two queue maps, one for reads and one for writes. The
> write queue count is configurable through the 'write_queues'
> parameter.
> 
> By default, we retain the previous behavior of having a single
> queue set, shared between reads and writes. Setting 'write_queues'
> to a non-zero value will create two queue sets, one for reads and
> one for writes, the latter using the configurable number of
> queues (hardware queue counts permitting).
> 
> Reviewed-by: Hannes Reinecke <hare@suse.com>
> Reviewed-by: Keith Busch <keith.busch@intel.com>
> Signed-off-by: Jens Axboe <axboe@kernel.dk>

This patch causes hangs when running recent versions of
-next with several architectures; see the -next column at
kerneltests.org/builders for details.  Bisect log below; this
was run with qemu on alpha. Reverting this patch as well as
"nvme: add separate poll queue map" fixes the problem.

Guenter

---
# bad: [220dcf1c6fc97f8873b6d9fe121b80decd4b71a8] Add linux-next specific files for 20181113
# good: [ccda4af0f4b92f7b4c308d3acc262f4a7e3affad] Linux 4.20-rc2
git bisect start 'HEAD' 'v4.20-rc2'
# good: [b5ae1d7e1bd7cf5dfdef977774da5cb69c60c911] Merge remote-tracking branch 'crypto/master'
git bisect good b5ae1d7e1bd7cf5dfdef977774da5cb69c60c911
# bad: [be877b847ffe96fb18e4925f05d5c2eb12b6b9f1] Merge remote-tracking branch 'block/for-next'
git bisect bad be877b847ffe96fb18e4925f05d5c2eb12b6b9f1
# good: [088122c5028636643d566c89cfdc621beed79974] Merge remote-tracking branch 'drm-intel/for-linux-next'
git bisect good 088122c5028636643d566c89cfdc621beed79974
# good: [3577f74d5ae898c34252c5cdc096a681910a919f] Merge remote-tracking branch 'drm-misc/for-linux-next'
git bisect good 3577f74d5ae898c34252c5cdc096a681910a919f
# good: [72008e28c7bf500a03f09929176bd025de94861b] Merge remote-tracking branch 'sound-asoc/for-next'
git bisect good 72008e28c7bf500a03f09929176bd025de94861b
# bad: [d1e36282b0bbd5de6a9c4d5275e94ef3b3438f48] block: add REQ_HIPRI and inherit it from IOCB_HIPRI
git bisect bad d1e36282b0bbd5de6a9c4d5275e94ef3b3438f48
# good: [4316b79e4321d4140164e42f228778e5bc66c84f] block: kill legacy parts of timeout handling
git bisect good 4316b79e4321d4140164e42f228778e5bc66c84f
# good: [a0fedc857dff457e123aeaa2039d28ac90e543df] Merge branch 'irq/for-block' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into for-4.21/block
git bisect good a0fedc857dff457e123aeaa2039d28ac90e543df
# good: [b3c661b15d5ab11d982e58bee23e05c1780528a1] blk-mq: support multiple hctx maps
git bisect good b3c661b15d5ab11d982e58bee23e05c1780528a1
# good: [67cae4c948a5311121905a2a8740c50daf7f6478] blk-mq: cleanup and improve list insertion
git bisect good 67cae4c948a5311121905a2a8740c50daf7f6478
# good: [843477d4cc5c4bb4e346c561ecd3b9d0bd67e8c8] blk-mq: initial support for multiple queue maps
git bisect good 843477d4cc5c4bb4e346c561ecd3b9d0bd67e8c8
# bad: [3b6592f70ad7b4c24dd3eb2ac9bbe3353d02c992] nvme: utilize two queue maps, one for reads and one for writes
git bisect bad 3b6592f70ad7b4c24dd3eb2ac9bbe3353d02c992
# first bad commit: [3b6592f70ad7b4c24dd3eb2ac9bbe3353d02c992] nvme: utilize two queue maps, one for reads and one for writes

> ---
>  drivers/nvme/host/pci.c | 200 +++++++++++++++++++++++++++++++++++++++++++-----
>  1 file changed, 181 insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
> index 49ad854d1b91..1987df13b73e 100644
> --- a/drivers/nvme/host/pci.c
> +++ b/drivers/nvme/host/pci.c
> @@ -74,11 +74,29 @@ static int io_queue_depth = 1024;
>  module_param_cb(io_queue_depth, &io_queue_depth_ops, &io_queue_depth, 0644);
>  MODULE_PARM_DESC(io_queue_depth, "set io queue depth, should >= 2");
>  
> +static int queue_count_set(const char *val, const struct kernel_param *kp);
> +static const struct kernel_param_ops queue_count_ops = {
> +	.set = queue_count_set,
> +	.get = param_get_int,
> +};
> +
> +static int write_queues;
> +module_param_cb(write_queues, &queue_count_ops, &write_queues, 0644);
> +MODULE_PARM_DESC(write_queues,
> +	"Number of queues to use for writes. If not set, reads and writes "
> +	"will share a queue set.");
> +
>  struct nvme_dev;
>  struct nvme_queue;
>  
>  static void nvme_dev_disable(struct nvme_dev *dev, bool shutdown);
>  
> +enum {
> +	NVMEQ_TYPE_READ,
> +	NVMEQ_TYPE_WRITE,
> +	NVMEQ_TYPE_NR,
> +};
> +
>  /*
>   * Represents an NVM Express device.  Each nvme_dev is a PCI function.
>   */
> @@ -92,6 +110,7 @@ struct nvme_dev {
>  	struct dma_pool *prp_small_pool;
>  	unsigned online_queues;
>  	unsigned max_qid;
> +	unsigned io_queues[NVMEQ_TYPE_NR];
>  	unsigned int num_vecs;
>  	int q_depth;
>  	u32 db_stride;
> @@ -134,6 +153,17 @@ static int io_queue_depth_set(const char *val, const struct kernel_param *kp)
>  	return param_set_int(val, kp);
>  }
>  
> +static int queue_count_set(const char *val, const struct kernel_param *kp)
> +{
> +	int n = 0, ret;
> +
> +	ret = kstrtoint(val, 10, &n);
> +	if (n > num_possible_cpus())
> +		n = num_possible_cpus();
> +
> +	return param_set_int(val, kp);
> +}
> +
>  static inline unsigned int sq_idx(unsigned int qid, u32 stride)
>  {
>  	return qid * 2 * stride;
> @@ -218,9 +248,20 @@ static inline void _nvme_check_size(void)
>  	BUILD_BUG_ON(sizeof(struct nvme_dbbuf) != 64);
>  }
>  
> +static unsigned int max_io_queues(void)
> +{
> +	return num_possible_cpus() + write_queues;
> +}
> +
> +static unsigned int max_queue_count(void)
> +{
> +	/* IO queues + admin queue */
> +	return 1 + max_io_queues();
> +}
> +
>  static inline unsigned int nvme_dbbuf_size(u32 stride)
>  {
> -	return ((num_possible_cpus() + 1) * 8 * stride);
> +	return (max_queue_count() * 8 * stride);
>  }
>  
>  static int nvme_dbbuf_dma_alloc(struct nvme_dev *dev)
> @@ -431,12 +472,41 @@ static int nvme_init_request(struct blk_mq_tag_set *set, struct request *req,
>  	return 0;
>  }
>  
> +static int queue_irq_offset(struct nvme_dev *dev)
> +{
> +	/* if we have more than 1 vec, admin queue offsets us by 1 */
> +	if (dev->num_vecs > 1)
> +		return 1;
> +
> +	return 0;
> +}
> +
>  static int nvme_pci_map_queues(struct blk_mq_tag_set *set)
>  {
>  	struct nvme_dev *dev = set->driver_data;
> +	int i, qoff, offset;
> +
> +	offset = queue_irq_offset(dev);
> +	for (i = 0, qoff = 0; i < set->nr_maps; i++) {
> +		struct blk_mq_queue_map *map = &set->map[i];
> +
> +		map->nr_queues = dev->io_queues[i];
> +		if (!map->nr_queues) {
> +			BUG_ON(i == NVMEQ_TYPE_READ);
>  
> -	return blk_mq_pci_map_queues(&set->map[0], to_pci_dev(dev->dev),
> -			dev->num_vecs > 1 ? 1 /* admin queue */ : 0);
> +			/* shared set, resuse read set parameters */
> +			map->nr_queues = dev->io_queues[NVMEQ_TYPE_READ];
> +			qoff = 0;
> +			offset = queue_irq_offset(dev);
> +		}
> +
> +		map->queue_offset = qoff;
> +		blk_mq_pci_map_queues(map, to_pci_dev(dev->dev), offset);
> +		qoff += map->nr_queues;
> +		offset += map->nr_queues;
> +	}
> +
> +	return 0;
>  }
>  
>  /**
> @@ -849,6 +919,14 @@ static blk_status_t nvme_queue_rq(struct blk_mq_hw_ctx *hctx,
>  	return ret;
>  }
>  
> +static int nvme_rq_flags_to_type(struct request_queue *q, unsigned int flags)
> +{
> +	if ((flags & REQ_OP_MASK) == REQ_OP_READ)
> +		return NVMEQ_TYPE_READ;
> +
> +	return NVMEQ_TYPE_WRITE;
> +}
> +
>  static void nvme_pci_complete_rq(struct request *req)
>  {
>  	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
> @@ -1475,13 +1553,14 @@ static const struct blk_mq_ops nvme_mq_admin_ops = {
>  };
>  
>  static const struct blk_mq_ops nvme_mq_ops = {
> -	.queue_rq	= nvme_queue_rq,
> -	.complete	= nvme_pci_complete_rq,
> -	.init_hctx	= nvme_init_hctx,
> -	.init_request	= nvme_init_request,
> -	.map_queues	= nvme_pci_map_queues,
> -	.timeout	= nvme_timeout,
> -	.poll		= nvme_poll,
> +	.queue_rq		= nvme_queue_rq,
> +	.rq_flags_to_type	= nvme_rq_flags_to_type,
> +	.complete		= nvme_pci_complete_rq,
> +	.init_hctx		= nvme_init_hctx,
> +	.init_request		= nvme_init_request,
> +	.map_queues		= nvme_pci_map_queues,
> +	.timeout		= nvme_timeout,
> +	.poll			= nvme_poll,
>  };
>  
>  static void nvme_dev_remove_admin(struct nvme_dev *dev)
> @@ -1891,6 +1970,87 @@ static int nvme_setup_host_mem(struct nvme_dev *dev)
>  	return ret;
>  }
>  
> +static void nvme_calc_io_queues(struct nvme_dev *dev, unsigned int nr_io_queues)
> +{
> +	unsigned int this_w_queues = write_queues;
> +
> +	/*
> +	 * Setup read/write queue split
> +	 */
> +	if (nr_io_queues == 1) {
> +		dev->io_queues[NVMEQ_TYPE_READ] = 1;
> +		dev->io_queues[NVMEQ_TYPE_WRITE] = 0;
> +		return;
> +	}
> +
> +	/*
> +	 * If 'write_queues' is set, ensure it leaves room for at least
> +	 * one read queue
> +	 */
> +	if (this_w_queues >= nr_io_queues)
> +		this_w_queues = nr_io_queues - 1;
> +
> +	/*
> +	 * If 'write_queues' is set to zero, reads and writes will share
> +	 * a queue set.
> +	 */
> +	if (!this_w_queues) {
> +		dev->io_queues[NVMEQ_TYPE_WRITE] = 0;
> +		dev->io_queues[NVMEQ_TYPE_READ] = nr_io_queues;
> +	} else {
> +		dev->io_queues[NVMEQ_TYPE_WRITE] = this_w_queues;
> +		dev->io_queues[NVMEQ_TYPE_READ] = nr_io_queues - this_w_queues;
> +	}
> +}
> +
> +static int nvme_setup_irqs(struct nvme_dev *dev, int nr_io_queues)
> +{
> +	struct pci_dev *pdev = to_pci_dev(dev->dev);
> +	int irq_sets[2];
> +	struct irq_affinity affd = {
> +		.pre_vectors = 1,
> +		.nr_sets = ARRAY_SIZE(irq_sets),
> +		.sets = irq_sets,
> +	};
> +	int result;
> +
> +	/*
> +	 * For irq sets, we have to ask for minvec == maxvec. This passes
> +	 * any reduction back to us, so we can adjust our queue counts and
> +	 * IRQ vector needs.
> +	 */
> +	do {
> +		nvme_calc_io_queues(dev, nr_io_queues);
> +		irq_sets[0] = dev->io_queues[NVMEQ_TYPE_READ];
> +		irq_sets[1] = dev->io_queues[NVMEQ_TYPE_WRITE];
> +		if (!irq_sets[1])
> +			affd.nr_sets = 1;
> +
> +		/*
> +		 * Need IRQs for read+write queues, and one for the admin queue
> +		 */
> +		nr_io_queues = irq_sets[0] + irq_sets[1] + 1;
> +
> +		result = pci_alloc_irq_vectors_affinity(pdev, nr_io_queues,
> +				nr_io_queues,
> +				PCI_IRQ_ALL_TYPES | PCI_IRQ_AFFINITY, &affd);
> +
> +		/*
> +		 * Need to reduce our vec counts
> +		 */
> +		if (result == -ENOSPC) {
> +			nr_io_queues--;
> +			if (!nr_io_queues)
> +				return result;
> +			continue;
> +		} else if (result <= 0)
> +			return -EIO;
> +		break;
> +	} while (1);
> +
> +	return result;
> +}
> +
>  static int nvme_setup_io_queues(struct nvme_dev *dev)
>  {
>  	struct nvme_queue *adminq = &dev->queues[0];
> @@ -1898,11 +2058,7 @@ static int nvme_setup_io_queues(struct nvme_dev *dev)
>  	int result, nr_io_queues;
>  	unsigned long size;
>  
> -	struct irq_affinity affd = {
> -		.pre_vectors = 1
> -	};
> -
> -	nr_io_queues = num_possible_cpus();
> +	nr_io_queues = max_io_queues();
>  	result = nvme_set_queue_count(&dev->ctrl, &nr_io_queues);
>  	if (result < 0)
>  		return result;
> @@ -1937,13 +2093,18 @@ static int nvme_setup_io_queues(struct nvme_dev *dev)
>  	 * setting up the full range we need.
>  	 */
>  	pci_free_irq_vectors(pdev);
> -	result = pci_alloc_irq_vectors_affinity(pdev, 1, nr_io_queues + 1,
> -			PCI_IRQ_ALL_TYPES | PCI_IRQ_AFFINITY, &affd);
> +
> +	result = nvme_setup_irqs(dev, nr_io_queues);
>  	if (result <= 0)
>  		return -EIO;
> +
>  	dev->num_vecs = result;
>  	dev->max_qid = max(result - 1, 1);
>  
> +	dev_info(dev->ctrl.device, "%d/%d read/write queues\n",
> +					dev->io_queues[NVMEQ_TYPE_READ],
> +					dev->io_queues[NVMEQ_TYPE_WRITE]);
> +
>  	/*
>  	 * Should investigate if there's a performance win from allocating
>  	 * more queues than interrupt vectors; it might allow the submission
> @@ -2045,6 +2206,7 @@ static int nvme_dev_add(struct nvme_dev *dev)
>  	if (!dev->ctrl.tagset) {
>  		dev->tagset.ops = &nvme_mq_ops;
>  		dev->tagset.nr_hw_queues = dev->online_queues - 1;
> +		dev->tagset.nr_maps = NVMEQ_TYPE_NR;
>  		dev->tagset.timeout = NVME_IO_TIMEOUT;
>  		dev->tagset.numa_node = dev_to_node(dev->dev);
>  		dev->tagset.queue_depth =
> @@ -2491,8 +2653,8 @@ static int nvme_probe(struct pci_dev *pdev, const struct pci_device_id *id)
>  	if (!dev)
>  		return -ENOMEM;
>  
> -	dev->queues = kcalloc_node(num_possible_cpus() + 1,
> -			sizeof(struct nvme_queue), GFP_KERNEL, node);
> +	dev->queues = kcalloc_node(max_queue_count(), sizeof(struct nvme_queue),
> +					GFP_KERNEL, node);
>  	if (!dev->queues)
>  		goto free;
>  
> -- 
> 2.7.4

Re: [PATCH] nvme: utilize two queue maps, one for reads and one for writes

[Jens Axboe]

On 11/13/18 5:41 PM, Guenter Roeck wrote:
> Hi,
> 
> On Wed, Oct 31, 2018 at 08:36:31AM -0600, Jens Axboe wrote:
>> NVMe does round-robin between queues by default, which means that
>> sharing a queue map for both reads and writes can be problematic
>> in terms of read servicing. It's much easier to flood the queue
>> with writes and reduce the read servicing.
>>
>> Implement two queue maps, one for reads and one for writes. The
>> write queue count is configurable through the 'write_queues'
>> parameter.
>>
>> By default, we retain the previous behavior of having a single
>> queue set, shared between reads and writes. Setting 'write_queues'
>> to a non-zero value will create two queue sets, one for reads and
>> one for writes, the latter using the configurable number of
>> queues (hardware queue counts permitting).
>>
>> Reviewed-by: Hannes Reinecke <hare@suse.com>
>> Reviewed-by: Keith Busch <keith.busch@intel.com>
>> Signed-off-by: Jens Axboe <axboe@kernel.dk>
> 
> This patch causes hangs when running recent versions of
> -next with several architectures; see the -next column at
> kerneltests.org/builders for details.  Bisect log below; this
> was run with qemu on alpha. Reverting this patch as well as
> "nvme: add separate poll queue map" fixes the problem.

I don't see anything related to what hung, the trace, and so on.
Can you clue me in? Where are the test results with dmesg?

How to reproduce?

-- 
Jens Axboe

Re: nvme: utilize two queue maps, one for reads and one for writes

[Mike Snitzer]

On Tue, Nov 13 2018 at  7:51pm -0500,
Jens Axboe <axboe@kernel.dk> wrote:

> On 11/13/18 5:41 PM, Guenter Roeck wrote:
> > Hi,
> > 
> > On Wed, Oct 31, 2018 at 08:36:31AM -0600, Jens Axboe wrote:
> >> NVMe does round-robin between queues by default, which means that
> >> sharing a queue map for both reads and writes can be problematic
> >> in terms of read servicing. It's much easier to flood the queue
> >> with writes and reduce the read servicing.
> >>
> >> Implement two queue maps, one for reads and one for writes. The
> >> write queue count is configurable through the 'write_queues'
> >> parameter.
> >>
> >> By default, we retain the previous behavior of having a single
> >> queue set, shared between reads and writes. Setting 'write_queues'
> >> to a non-zero value will create two queue sets, one for reads and
> >> one for writes, the latter using the configurable number of
> >> queues (hardware queue counts permitting).
> >>
> >> Reviewed-by: Hannes Reinecke <hare@suse.com>
> >> Reviewed-by: Keith Busch <keith.busch@intel.com>
> >> Signed-off-by: Jens Axboe <axboe@kernel.dk>
> > 
> > This patch causes hangs when running recent versions of
> > -next with several architectures; see the -next column at
> > kerneltests.org/builders for details.  Bisect log below; this
> > was run with qemu on alpha. Reverting this patch as well as
> > "nvme: add separate poll queue map" fixes the problem.
> 
> I don't see anything related to what hung, the trace, and so on.
> Can you clue me in? Where are the test results with dmesg?
> 
> How to reproduce?

Think Guenter should've provided a full kerneltests.org url, but I had a
look and found this for powerpc with -next:
https://kerneltests.org/builders/next-powerpc-next/builds/998/steps/buildcommand/logs/stdio

Has useful logs of the build failure due to block.

(not seeing any -next failure for alpha but Guenter said he was using
qemu so the build failure could've been any arch qemu supports)

Mike

Re: nvme: utilize two queue maps, one for reads and one for writes

[Mike Snitzer]

On Tue, Nov 13 2018 at  8:28pm -0500,
Mike Snitzer <snitzer@redhat.com> wrote:

> On Tue, Nov 13 2018 at  7:51pm -0500,
> Jens Axboe <axboe@kernel.dk> wrote:
> 
> > On 11/13/18 5:41 PM, Guenter Roeck wrote:
> > > Hi,
> > > 
> > > On Wed, Oct 31, 2018 at 08:36:31AM -0600, Jens Axboe wrote:
> > >> NVMe does round-robin between queues by default, which means that
> > >> sharing a queue map for both reads and writes can be problematic
> > >> in terms of read servicing. It's much easier to flood the queue
> > >> with writes and reduce the read servicing.
> > >>
> > >> Implement two queue maps, one for reads and one for writes. The
> > >> write queue count is configurable through the 'write_queues'
> > >> parameter.
> > >>
> > >> By default, we retain the previous behavior of having a single
> > >> queue set, shared between reads and writes. Setting 'write_queues'
> > >> to a non-zero value will create two queue sets, one for reads and
> > >> one for writes, the latter using the configurable number of
> > >> queues (hardware queue counts permitting).
> > >>
> > >> Reviewed-by: Hannes Reinecke <hare@suse.com>
> > >> Reviewed-by: Keith Busch <keith.busch@intel.com>
> > >> Signed-off-by: Jens Axboe <axboe@kernel.dk>
> > > 
> > > This patch causes hangs when running recent versions of
> > > -next with several architectures; see the -next column at
> > > kerneltests.org/builders for details.  Bisect log below; this
> > > was run with qemu on alpha. Reverting this patch as well as
> > > "nvme: add separate poll queue map" fixes the problem.
> > 
> > I don't see anything related to what hung, the trace, and so on.
> > Can you clue me in? Where are the test results with dmesg?
> > 
> > How to reproduce?
> 
> Think Guenter should've provided a full kerneltests.org url, but I had a
> look and found this for powerpc with -next:
> https://kerneltests.org/builders/next-powerpc-next/builds/998/steps/buildcommand/logs/stdio
> 
> Has useful logs of the build failure due to block.

Take that back, of course I only had a quick look and first scrolled to
this fragment and thought "yeap shows block build failure" (not
_really_):

opt/buildbot/slave/next-next/build/kernel/sched/psi.c: In function 'cgroup_move_task':
/opt/buildbot/slave/next-next/build/include/linux/spinlock.h:273:32: warning: 'rq' may be used uninitialized in this function [-Wmaybe-uninitialized]
 #define raw_spin_unlock(lock)  _raw_spin_unlock(lock)
                                ^~~~~~~~~~~~~~~~
/opt/buildbot/slave/next-next/build/kernel/sched/psi.c:639:13: note: 'rq' was declared here
  struct rq *rq;
             ^~

Re: [PATCH] nvme: utilize two queue maps, one for reads and one for writes

[Guenter Roeck]

On Tue, Nov 13, 2018 at 05:51:08PM -0700, Jens Axboe wrote:
> On 11/13/18 5:41 PM, Guenter Roeck wrote:
> > Hi,
> > 
> > On Wed, Oct 31, 2018 at 08:36:31AM -0600, Jens Axboe wrote:
> >> NVMe does round-robin between queues by default, which means that
> >> sharing a queue map for both reads and writes can be problematic
> >> in terms of read servicing. It's much easier to flood the queue
> >> with writes and reduce the read servicing.
> >>
> >> Implement two queue maps, one for reads and one for writes. The
> >> write queue count is configurable through the 'write_queues'
> >> parameter.
> >>
> >> By default, we retain the previous behavior of having a single
> >> queue set, shared between reads and writes. Setting 'write_queues'
> >> to a non-zero value will create two queue sets, one for reads and
> >> one for writes, the latter using the configurable number of
> >> queues (hardware queue counts permitting).
> >>
> >> Reviewed-by: Hannes Reinecke <hare@suse.com>
> >> Reviewed-by: Keith Busch <keith.busch@intel.com>
> >> Signed-off-by: Jens Axboe <axboe@kernel.dk>
> > 
> > This patch causes hangs when running recent versions of
> > -next with several architectures; see the -next column at
> > kerneltests.org/builders for details.  Bisect log below; this
> > was run with qemu on alpha. Reverting this patch as well as
> > "nvme: add separate poll queue map" fixes the problem.
> 
> I don't see anything related to what hung, the trace, and so on.
> Can you clue me in? Where are the test results with dmesg?
> 
alpha just stalls during boot. parisc reports a hung task
in nvme_reset_work. sparc64 reports EIO when instantiating
the nvme driver, called from nvme_reset_work, and then stalls.
In all three cases, reverting the two mentioned patches fixes
the problem.

https://kerneltests.org/builders/qemu-parisc-next/builds/173/steps/qemubuildcommand_1/logs/stdio

is an example log for parisc.

I didn't check if the other boot failures (ppc looks bad)
have the same root cause.

> How to reproduce?
> 
parisc:

qemu-system-hppa -kernel vmlinux -no-reboot \
	-snapshot -device nvme,serial=foo,drive=d0 \
	-drive file=rootfs.ext2,if=none,format=raw,id=d0 \
	-append 'root=/dev/nvme0n1 rw rootwait panic=-1 console=ttyS0,115200 ' \
	-nographic -monitor null

alpha:

qemu-system-alpha -M clipper -kernel arch/alpha/boot/vmlinux -no-reboot \
	-snapshot -device nvme,serial=foo,drive=d0 \
	-drive file=rootfs.ext2,if=none,format=raw,id=d0 \
	-append 'root=/dev/nvme0n1 rw rootwait panic=-1 console=ttyS0' \
	-m 128M -nographic -monitor null -serial stdio

sparc64:

qemu-system-sparc64 -M sun4u -cpu 'TI UltraSparc IIi' -m 512 \
	-snapshot -device nvme,serial=foo,drive=d0,bus=pciB \
	-drive file=rootfs.ext2,if=none,format=raw,id=d0 \
	-kernel arch/sparc/boot/image -no-reboot \
	-append 'root=/dev/nvme0n1 rw rootwait panic=-1 console=ttyS0' \
	-nographic -monitor none

The root file systems are available from the respective subdirectories
of:

https://github.com/groeck/linux-build-test/tree/master/rootfs

Guenter

Re: [PATCH] nvme: utilize two queue maps, one for reads and one for writes

[Jens Axboe]

On 11/13/18 9:52 PM, Guenter Roeck wrote:
> On Tue, Nov 13, 2018 at 05:51:08PM -0700, Jens Axboe wrote:
>> On 11/13/18 5:41 PM, Guenter Roeck wrote:
>>> Hi,
>>>
>>> On Wed, Oct 31, 2018 at 08:36:31AM -0600, Jens Axboe wrote:
>>>> NVMe does round-robin between queues by default, which means that
>>>> sharing a queue map for both reads and writes can be problematic
>>>> in terms of read servicing. It's much easier to flood the queue
>>>> with writes and reduce the read servicing.
>>>>
>>>> Implement two queue maps, one for reads and one for writes. The
>>>> write queue count is configurable through the 'write_queues'
>>>> parameter.
>>>>
>>>> By default, we retain the previous behavior of having a single
>>>> queue set, shared between reads and writes. Setting 'write_queues'
>>>> to a non-zero value will create two queue sets, one for reads and
>>>> one for writes, the latter using the configurable number of
>>>> queues (hardware queue counts permitting).
>>>>
>>>> Reviewed-by: Hannes Reinecke <hare@suse.com>
>>>> Reviewed-by: Keith Busch <keith.busch@intel.com>
>>>> Signed-off-by: Jens Axboe <axboe@kernel.dk>
>>>
>>> This patch causes hangs when running recent versions of
>>> -next with several architectures; see the -next column at
>>> kerneltests.org/builders for details.  Bisect log below; this
>>> was run with qemu on alpha. Reverting this patch as well as
>>> "nvme: add separate poll queue map" fixes the problem.
>>
>> I don't see anything related to what hung, the trace, and so on.
>> Can you clue me in? Where are the test results with dmesg?
>>
> alpha just stalls during boot. parisc reports a hung task
> in nvme_reset_work. sparc64 reports EIO when instantiating
> the nvme driver, called from nvme_reset_work, and then stalls.
> In all three cases, reverting the two mentioned patches fixes
> the problem.

I think the below patch should fix it.

> https://kerneltests.org/builders/qemu-parisc-next/builds/173/steps/qemubuildcommand_1/logs/stdio
> 
> is an example log for parisc.
> 
> I didn't check if the other boot failures (ppc looks bad)
> have the same root cause.
> 
>> How to reproduce?
>>
> parisc:
> 
> qemu-system-hppa -kernel vmlinux -no-reboot \
> 	-snapshot -device nvme,serial=foo,drive=d0 \
> 	-drive file=rootfs.ext2,if=none,format=raw,id=d0 \
> 	-append 'root=/dev/nvme0n1 rw rootwait panic=-1 console=ttyS0,115200 ' \
> 	-nographic -monitor null
> 
> alpha:
> 
> qemu-system-alpha -M clipper -kernel arch/alpha/boot/vmlinux -no-reboot \
> 	-snapshot -device nvme,serial=foo,drive=d0 \
> 	-drive file=rootfs.ext2,if=none,format=raw,id=d0 \
> 	-append 'root=/dev/nvme0n1 rw rootwait panic=-1 console=ttyS0' \
> 	-m 128M -nographic -monitor null -serial stdio
> 
> sparc64:
> 
> qemu-system-sparc64 -M sun4u -cpu 'TI UltraSparc IIi' -m 512 \
> 	-snapshot -device nvme,serial=foo,drive=d0,bus=pciB \
> 	-drive file=rootfs.ext2,if=none,format=raw,id=d0 \
> 	-kernel arch/sparc/boot/image -no-reboot \
> 	-append 'root=/dev/nvme0n1 rw rootwait panic=-1 console=ttyS0' \
> 	-nographic -monitor none
> 
> The root file systems are available from the respective subdirectories
> of:
> 
> https://github.com/groeck/linux-build-test/tree/master/rootfs

This is useful, thanks! I haven't tried it yet, but I was able to
reproduce on x86 with MSI turned off.


diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 8df868afa363..6c03461ad988 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -2098,7 +2098,7 @@ static int nvme_setup_irqs(struct nvme_dev *dev, int nr_io_queues)
 		.nr_sets = ARRAY_SIZE(irq_sets),
 		.sets = irq_sets,
 	};
-	int result;
+	int result = 0;
 
 	/*
 	 * For irq sets, we have to ask for minvec == maxvec. This passes
@@ -2113,9 +2113,16 @@ static int nvme_setup_irqs(struct nvme_dev *dev, int nr_io_queues)
 			affd.nr_sets = 1;
 
 		/*
-		 * Need IRQs for read+write queues, and one for the admin queue
+		 * Need IRQs for read+write queues, and one for the admin queue.
+		 * If we can't get more than one vector, we have to share the
+		 * admin queue and IO queue vector. For that case, don't add
+		 * an extra vector for the admin queue, or we'll continue
+		 * asking for 2 and get -ENOSPC in return.
 		 */
-		nr_io_queues = irq_sets[0] + irq_sets[1] + 1;
+		if (result == -ENOSPC && nr_io_queues == 1)
+			nr_io_queues = 1;
+		else
+			nr_io_queues = irq_sets[0] + irq_sets[1] + 1;
 
 		result = pci_alloc_irq_vectors_affinity(pdev, nr_io_queues,
 				nr_io_queues,

-- 
Jens Axboe

Re: [PATCH] nvme: utilize two queue maps, one for reads and one for writes

[Guenter Roeck]

Hi Jens,

On Wed, Nov 14, 2018 at 10:12:44AM -0700, Jens Axboe wrote:
> On 11/13/18 9:52 PM, Guenter Roeck wrote:
> > On Tue, Nov 13, 2018 at 05:51:08PM -0700, Jens Axboe wrote:
> >> On 11/13/18 5:41 PM, Guenter Roeck wrote:
> >>> Hi,
> >>>
> >>> On Wed, Oct 31, 2018 at 08:36:31AM -0600, Jens Axboe wrote:
> >>>> NVMe does round-robin between queues by default, which means that
> >>>> sharing a queue map for both reads and writes can be problematic
> >>>> in terms of read servicing. It's much easier to flood the queue
> >>>> with writes and reduce the read servicing.
> >>>>
> >>>> Implement two queue maps, one for reads and one for writes. The
> >>>> write queue count is configurable through the 'write_queues'
> >>>> parameter.
> >>>>
> >>>> By default, we retain the previous behavior of having a single
> >>>> queue set, shared between reads and writes. Setting 'write_queues'
> >>>> to a non-zero value will create two queue sets, one for reads and
> >>>> one for writes, the latter using the configurable number of
> >>>> queues (hardware queue counts permitting).
> >>>>
> >>>> Reviewed-by: Hannes Reinecke <hare@suse.com>
> >>>> Reviewed-by: Keith Busch <keith.busch@intel.com>
> >>>> Signed-off-by: Jens Axboe <axboe@kernel.dk>
> >>>
> >>> This patch causes hangs when running recent versions of
> >>> -next with several architectures; see the -next column at
> >>> kerneltests.org/builders for details.  Bisect log below; this
> >>> was run with qemu on alpha. Reverting this patch as well as
> >>> "nvme: add separate poll queue map" fixes the problem.
> >>
> >> I don't see anything related to what hung, the trace, and so on.
> >> Can you clue me in? Where are the test results with dmesg?
> >>
> > alpha just stalls during boot. parisc reports a hung task
> > in nvme_reset_work. sparc64 reports EIO when instantiating
> > the nvme driver, called from nvme_reset_work, and then stalls.
> > In all three cases, reverting the two mentioned patches fixes
> > the problem.
> 
> I think the below patch should fix it.
> 
Sorry I wasn't able to test this earlier. Looks like it does
fix the problem; the problem is no longer seen in next-20181115.
Minor comment below.

Guenter

> > https://kerneltests.org/builders/qemu-parisc-next/builds/173/steps/qemubuildcommand_1/logs/stdio
> > 
> > is an example log for parisc.
> > 
> > I didn't check if the other boot failures (ppc looks bad)
> > have the same root cause.
> > 
> >> How to reproduce?
> >>
> > parisc:
> > 
> > qemu-system-hppa -kernel vmlinux -no-reboot \
> > 	-snapshot -device nvme,serial=foo,drive=d0 \
> > 	-drive file=rootfs.ext2,if=none,format=raw,id=d0 \
> > 	-append 'root=/dev/nvme0n1 rw rootwait panic=-1 console=ttyS0,115200 ' \
> > 	-nographic -monitor null
> > 
> > alpha:
> > 
> > qemu-system-alpha -M clipper -kernel arch/alpha/boot/vmlinux -no-reboot \
> > 	-snapshot -device nvme,serial=foo,drive=d0 \
> > 	-drive file=rootfs.ext2,if=none,format=raw,id=d0 \
> > 	-append 'root=/dev/nvme0n1 rw rootwait panic=-1 console=ttyS0' \
> > 	-m 128M -nographic -monitor null -serial stdio
> > 
> > sparc64:
> > 
> > qemu-system-sparc64 -M sun4u -cpu 'TI UltraSparc IIi' -m 512 \
> > 	-snapshot -device nvme,serial=foo,drive=d0,bus=pciB \
> > 	-drive file=rootfs.ext2,if=none,format=raw,id=d0 \
> > 	-kernel arch/sparc/boot/image -no-reboot \
> > 	-append 'root=/dev/nvme0n1 rw rootwait panic=-1 console=ttyS0' \
> > 	-nographic -monitor none
> > 
> > The root file systems are available from the respective subdirectories
> > of:
> > 
> > https://github.com/groeck/linux-build-test/tree/master/rootfs
> 
> This is useful, thanks! I haven't tried it yet, but I was able to
> reproduce on x86 with MSI turned off.
> 
> 
> diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
> index 8df868afa363..6c03461ad988 100644
> --- a/drivers/nvme/host/pci.c
> +++ b/drivers/nvme/host/pci.c
> @@ -2098,7 +2098,7 @@ static int nvme_setup_irqs(struct nvme_dev *dev, int nr_io_queues)
>  		.nr_sets = ARRAY_SIZE(irq_sets),
>  		.sets = irq_sets,
>  	};
> -	int result;
> +	int result = 0;
>  
>  	/*
>  	 * For irq sets, we have to ask for minvec == maxvec. This passes
> @@ -2113,9 +2113,16 @@ static int nvme_setup_irqs(struct nvme_dev *dev, int nr_io_queues)
>  			affd.nr_sets = 1;
>  
>  		/*
> -		 * Need IRQs for read+write queues, and one for the admin queue
> +		 * Need IRQs for read+write queues, and one for the admin queue.
> +		 * If we can't get more than one vector, we have to share the
> +		 * admin queue and IO queue vector. For that case, don't add
> +		 * an extra vector for the admin queue, or we'll continue
> +		 * asking for 2 and get -ENOSPC in return.
>  		 */
> -		nr_io_queues = irq_sets[0] + irq_sets[1] + 1;
> +		if (result == -ENOSPC && nr_io_queues == 1)
> +			nr_io_queues = 1;

Setting nr_io_queues to 1 when it already is set to 1 doesn't really do
anything. Is this for clarification ?

> +		else
> +			nr_io_queues = irq_sets[0] + irq_sets[1] + 1;
>  
>  		result = pci_alloc_irq_vectors_affinity(pdev, nr_io_queues,
>  				nr_io_queues,
> 
> -- 
> Jens Axboe
> 

Re: [PATCH] nvme: utilize two queue maps, one for reads and one for writes

[Jens Axboe]

On 11/15/18 11:28 AM, Guenter Roeck wrote:
> Hi Jens,
> 
>> I think the below patch should fix it.
>>
> Sorry I wasn't able to test this earlier. Looks like it does
> fix the problem; the problem is no longer seen in next-20181115.
> Minor comment below.

That's fine, thanks for testing!

>>  		/*
>> -		 * Need IRQs for read+write queues, and one for the admin queue
>> +		 * Need IRQs for read+write queues, and one for the admin queue.
>> +		 * If we can't get more than one vector, we have to share the
>> +		 * admin queue and IO queue vector. For that case, don't add
>> +		 * an extra vector for the admin queue, or we'll continue
>> +		 * asking for 2 and get -ENOSPC in return.
>>  		 */
>> -		nr_io_queues = irq_sets[0] + irq_sets[1] + 1;
>> +		if (result == -ENOSPC && nr_io_queues == 1)
>> +			nr_io_queues = 1;
> 
> Setting nr_io_queues to 1 when it already is set to 1 doesn't really do
> anything. Is this for clarification ?

Guess that does look a bit odd, alternative would be to flip the
condition, but I think this one is easier to read.

-- 
Jens Axboe

Re: [PATCH] nvme: utilize two queue maps, one for reads and one for writes

[Guenter Roeck]

On Wed, Nov 14, 2018 at 10:12:44AM -0700, Jens Axboe wrote:
> 
> I think the below patch should fix it.
> 

I spoke too early. sparc64, next-20181115:

[   14.204370] nvme nvme0: pci function 0000:02:00.0
[   14.249956] nvme nvme0: Removing after probe failure status: -5
[   14.263496] ------------[ cut here ]------------
[   14.263913] WARNING: CPU: 0 PID: 15 at kernel/irq/manage.c:1597 __free_irq+0xa4/0x320
[   14.264265] Trying to free already-free IRQ 9
[   14.264519] Modules linked in:
[   14.264961] CPU: 0 PID: 15 Comm: kworker/u2:1 Not tainted 4.20.0-rc2-next-20181115 #1
[   14.265555] Workqueue: nvme-reset-wq nvme_reset_work
[   14.265899] Call Trace:
[   14.266118]  [000000000046944c] __warn+0xcc/0x100
[   14.266375]  [00000000004694b0] warn_slowpath_fmt+0x30/0x40
[   14.266635]  [00000000004d4ce4] __free_irq+0xa4/0x320
[   14.266867]  [00000000004d4ff8] free_irq+0x38/0x80
[   14.267092]  [00000000007b1874] pci_free_irq+0x14/0x40
[   14.267327]  [00000000008a5444] nvme_dev_disable+0xe4/0x520
[   14.267576]  [00000000008a69b8] nvme_reset_work+0x138/0x1c60
[   14.267827]  [0000000000488dd0] process_one_work+0x230/0x6e0
[   14.268079]  [00000000004894f4] worker_thread+0x274/0x520
[   14.268321]  [0000000000490624] kthread+0xe4/0x120
[   14.268544]  [00000000004060c4] ret_from_fork+0x1c/0x2c
[   14.268825]  [0000000000000000]           (null)
[   14.269089] irq event stamp: 32796
[   14.269350] hardirqs last  enabled at (32795): [<0000000000b624a4>] _raw_spin_unlock_irqrestore+0x24/0x80
[   14.269757] hardirqs last disabled at (32796): [<0000000000b622f4>] _raw_spin_lock_irqsave+0x14/0x60
[   14.270566] softirqs last  enabled at (32780): [<0000000000b64c18>] __do_softirq+0x238/0x520
[   14.271206] softirqs last disabled at (32729): [<000000000042ceec>] do_softirq_own_stack+0x2c/0x40
[   14.272288] ---[ end trace cb79ccd2a0a03f3c ]---

Looks like an error during probe followed by an error cleanup problem.

Guenter

Re: [PATCH] nvme: utilize two queue maps, one for reads and one for writes

[Jens Axboe]

On 11/15/18 12:11 PM, Guenter Roeck wrote:
> On Wed, Nov 14, 2018 at 10:12:44AM -0700, Jens Axboe wrote:
>>
>> I think the below patch should fix it.
>>
> 
> I spoke too early. sparc64, next-20181115:
> 
> [   14.204370] nvme nvme0: pci function 0000:02:00.0
> [   14.249956] nvme nvme0: Removing after probe failure status: -5
> [   14.263496] ------------[ cut here ]------------
> [   14.263913] WARNING: CPU: 0 PID: 15 at kernel/irq/manage.c:1597 __free_irq+0xa4/0x320
> [   14.264265] Trying to free already-free IRQ 9
> [   14.264519] Modules linked in:
> [   14.264961] CPU: 0 PID: 15 Comm: kworker/u2:1 Not tainted 4.20.0-rc2-next-20181115 #1
> [   14.265555] Workqueue: nvme-reset-wq nvme_reset_work
> [   14.265899] Call Trace:
> [   14.266118]  [000000000046944c] __warn+0xcc/0x100
> [   14.266375]  [00000000004694b0] warn_slowpath_fmt+0x30/0x40
> [   14.266635]  [00000000004d4ce4] __free_irq+0xa4/0x320
> [   14.266867]  [00000000004d4ff8] free_irq+0x38/0x80
> [   14.267092]  [00000000007b1874] pci_free_irq+0x14/0x40
> [   14.267327]  [00000000008a5444] nvme_dev_disable+0xe4/0x520
> [   14.267576]  [00000000008a69b8] nvme_reset_work+0x138/0x1c60
> [   14.267827]  [0000000000488dd0] process_one_work+0x230/0x6e0
> [   14.268079]  [00000000004894f4] worker_thread+0x274/0x520
> [   14.268321]  [0000000000490624] kthread+0xe4/0x120
> [   14.268544]  [00000000004060c4] ret_from_fork+0x1c/0x2c
> [   14.268825]  [0000000000000000]           (null)
> [   14.269089] irq event stamp: 32796
> [   14.269350] hardirqs last  enabled at (32795): [<0000000000b624a4>] _raw_spin_unlock_irqrestore+0x24/0x80
> [   14.269757] hardirqs last disabled at (32796): [<0000000000b622f4>] _raw_spin_lock_irqsave+0x14/0x60
> [   14.270566] softirqs last  enabled at (32780): [<0000000000b64c18>] __do_softirq+0x238/0x520
> [   14.271206] softirqs last disabled at (32729): [<000000000042ceec>] do_softirq_own_stack+0x2c/0x40
> [   14.272288] ---[ end trace cb79ccd2a0a03f3c ]---
> 
> Looks like an error during probe followed by an error cleanup problem.

Did it previous probe fine? Or is the new thing just the fact that
we spew a warning on trying to free a non-existing vector?

-- 
Jens Axboe

Re: [PATCH] nvme: utilize two queue maps, one for reads and one for writes

[Guenter Roeck]

On Thu, Nov 15, 2018 at 12:29:04PM -0700, Jens Axboe wrote:
> On 11/15/18 12:11 PM, Guenter Roeck wrote:
> > On Wed, Nov 14, 2018 at 10:12:44AM -0700, Jens Axboe wrote:
> >>
> >> I think the below patch should fix it.
> >>
> > 
> > I spoke too early. sparc64, next-20181115:
> > 
> > [   14.204370] nvme nvme0: pci function 0000:02:00.0
> > [   14.249956] nvme nvme0: Removing after probe failure status: -5
> > [   14.263496] ------------[ cut here ]------------
> > [   14.263913] WARNING: CPU: 0 PID: 15 at kernel/irq/manage.c:1597 __free_irq+0xa4/0x320
> > [   14.264265] Trying to free already-free IRQ 9
> > [   14.264519] Modules linked in:
> > [   14.264961] CPU: 0 PID: 15 Comm: kworker/u2:1 Not tainted 4.20.0-rc2-next-20181115 #1
> > [   14.265555] Workqueue: nvme-reset-wq nvme_reset_work
> > [   14.265899] Call Trace:
> > [   14.266118]  [000000000046944c] __warn+0xcc/0x100
> > [   14.266375]  [00000000004694b0] warn_slowpath_fmt+0x30/0x40
> > [   14.266635]  [00000000004d4ce4] __free_irq+0xa4/0x320
> > [   14.266867]  [00000000004d4ff8] free_irq+0x38/0x80
> > [   14.267092]  [00000000007b1874] pci_free_irq+0x14/0x40
> > [   14.267327]  [00000000008a5444] nvme_dev_disable+0xe4/0x520
> > [   14.267576]  [00000000008a69b8] nvme_reset_work+0x138/0x1c60
> > [   14.267827]  [0000000000488dd0] process_one_work+0x230/0x6e0
> > [   14.268079]  [00000000004894f4] worker_thread+0x274/0x520
> > [   14.268321]  [0000000000490624] kthread+0xe4/0x120
> > [   14.268544]  [00000000004060c4] ret_from_fork+0x1c/0x2c
> > [   14.268825]  [0000000000000000]           (null)
> > [   14.269089] irq event stamp: 32796
> > [   14.269350] hardirqs last  enabled at (32795): [<0000000000b624a4>] _raw_spin_unlock_irqrestore+0x24/0x80
> > [   14.269757] hardirqs last disabled at (32796): [<0000000000b622f4>] _raw_spin_lock_irqsave+0x14/0x60
> > [   14.270566] softirqs last  enabled at (32780): [<0000000000b64c18>] __do_softirq+0x238/0x520
> > [   14.271206] softirqs last disabled at (32729): [<000000000042ceec>] do_softirq_own_stack+0x2c/0x40
> > [   14.272288] ---[ end trace cb79ccd2a0a03f3c ]---
> > 
> > Looks like an error during probe followed by an error cleanup problem.
> 
> Did it previous probe fine? Or is the new thing just the fact that
> we spew a warning on trying to free a non-existing vector?
> 
This works fine in mainline, if that is your question.

Guenter

Re: [PATCH] nvme: utilize two queue maps, one for reads and one for writes

[Jens Axboe]

On 11/15/18 12:38 PM, Guenter Roeck wrote:
> On Thu, Nov 15, 2018 at 12:29:04PM -0700, Jens Axboe wrote:
>> On 11/15/18 12:11 PM, Guenter Roeck wrote:
>>> On Wed, Nov 14, 2018 at 10:12:44AM -0700, Jens Axboe wrote:
>>>>
>>>> I think the below patch should fix it.
>>>>
>>>
>>> I spoke too early. sparc64, next-20181115:
>>>
>>> [   14.204370] nvme nvme0: pci function 0000:02:00.0
>>> [   14.249956] nvme nvme0: Removing after probe failure status: -5
>>> [   14.263496] ------------[ cut here ]------------
>>> [   14.263913] WARNING: CPU: 0 PID: 15 at kernel/irq/manage.c:1597 __free_irq+0xa4/0x320
>>> [   14.264265] Trying to free already-free IRQ 9
>>> [   14.264519] Modules linked in:
>>> [   14.264961] CPU: 0 PID: 15 Comm: kworker/u2:1 Not tainted 4.20.0-rc2-next-20181115 #1
>>> [   14.265555] Workqueue: nvme-reset-wq nvme_reset_work
>>> [   14.265899] Call Trace:
>>> [   14.266118]  [000000000046944c] __warn+0xcc/0x100
>>> [   14.266375]  [00000000004694b0] warn_slowpath_fmt+0x30/0x40
>>> [   14.266635]  [00000000004d4ce4] __free_irq+0xa4/0x320
>>> [   14.266867]  [00000000004d4ff8] free_irq+0x38/0x80
>>> [   14.267092]  [00000000007b1874] pci_free_irq+0x14/0x40
>>> [   14.267327]  [00000000008a5444] nvme_dev_disable+0xe4/0x520
>>> [   14.267576]  [00000000008a69b8] nvme_reset_work+0x138/0x1c60
>>> [   14.267827]  [0000000000488dd0] process_one_work+0x230/0x6e0
>>> [   14.268079]  [00000000004894f4] worker_thread+0x274/0x520
>>> [   14.268321]  [0000000000490624] kthread+0xe4/0x120
>>> [   14.268544]  [00000000004060c4] ret_from_fork+0x1c/0x2c
>>> [   14.268825]  [0000000000000000]           (null)
>>> [   14.269089] irq event stamp: 32796
>>> [   14.269350] hardirqs last  enabled at (32795): [<0000000000b624a4>] _raw_spin_unlock_irqrestore+0x24/0x80
>>> [   14.269757] hardirqs last disabled at (32796): [<0000000000b622f4>] _raw_spin_lock_irqsave+0x14/0x60
>>> [   14.270566] softirqs last  enabled at (32780): [<0000000000b64c18>] __do_softirq+0x238/0x520
>>> [   14.271206] softirqs last disabled at (32729): [<000000000042ceec>] do_softirq_own_stack+0x2c/0x40
>>> [   14.272288] ---[ end trace cb79ccd2a0a03f3c ]---
>>>
>>> Looks like an error during probe followed by an error cleanup problem.
>>
>> Did it previous probe fine? Or is the new thing just the fact that
>> we spew a warning on trying to free a non-existing vector?
>>
> This works fine in mainline, if that is your question.

Yeah, as soon as I sent the other email I realized that. Let me send
you a quick patch.

-- 
Jens Axboe

Re: [PATCH] nvme: utilize two queue maps, one for reads and one for writes

[Jens Axboe]

On 11/15/18 12:40 PM, Jens Axboe wrote:
> On 11/15/18 12:38 PM, Guenter Roeck wrote:
>> On Thu, Nov 15, 2018 at 12:29:04PM -0700, Jens Axboe wrote:
>>> On 11/15/18 12:11 PM, Guenter Roeck wrote:
>>>> On Wed, Nov 14, 2018 at 10:12:44AM -0700, Jens Axboe wrote:
>>>>>
>>>>> I think the below patch should fix it.
>>>>>
>>>>
>>>> I spoke too early. sparc64, next-20181115:
>>>>
>>>> [   14.204370] nvme nvme0: pci function 0000:02:00.0
>>>> [   14.249956] nvme nvme0: Removing after probe failure status: -5
>>>> [   14.263496] ------------[ cut here ]------------
>>>> [   14.263913] WARNING: CPU: 0 PID: 15 at kernel/irq/manage.c:1597 __free_irq+0xa4/0x320
>>>> [   14.264265] Trying to free already-free IRQ 9
>>>> [   14.264519] Modules linked in:
>>>> [   14.264961] CPU: 0 PID: 15 Comm: kworker/u2:1 Not tainted 4.20.0-rc2-next-20181115 #1
>>>> [   14.265555] Workqueue: nvme-reset-wq nvme_reset_work
>>>> [   14.265899] Call Trace:
>>>> [   14.266118]  [000000000046944c] __warn+0xcc/0x100
>>>> [   14.266375]  [00000000004694b0] warn_slowpath_fmt+0x30/0x40
>>>> [   14.266635]  [00000000004d4ce4] __free_irq+0xa4/0x320
>>>> [   14.266867]  [00000000004d4ff8] free_irq+0x38/0x80
>>>> [   14.267092]  [00000000007b1874] pci_free_irq+0x14/0x40
>>>> [   14.267327]  [00000000008a5444] nvme_dev_disable+0xe4/0x520
>>>> [   14.267576]  [00000000008a69b8] nvme_reset_work+0x138/0x1c60
>>>> [   14.267827]  [0000000000488dd0] process_one_work+0x230/0x6e0
>>>> [   14.268079]  [00000000004894f4] worker_thread+0x274/0x520
>>>> [   14.268321]  [0000000000490624] kthread+0xe4/0x120
>>>> [   14.268544]  [00000000004060c4] ret_from_fork+0x1c/0x2c
>>>> [   14.268825]  [0000000000000000]           (null)
>>>> [   14.269089] irq event stamp: 32796
>>>> [   14.269350] hardirqs last  enabled at (32795): [<0000000000b624a4>] _raw_spin_unlock_irqrestore+0x24/0x80
>>>> [   14.269757] hardirqs last disabled at (32796): [<0000000000b622f4>] _raw_spin_lock_irqsave+0x14/0x60
>>>> [   14.270566] softirqs last  enabled at (32780): [<0000000000b64c18>] __do_softirq+0x238/0x520
>>>> [   14.271206] softirqs last disabled at (32729): [<000000000042ceec>] do_softirq_own_stack+0x2c/0x40
>>>> [   14.272288] ---[ end trace cb79ccd2a0a03f3c ]---
>>>>
>>>> Looks like an error during probe followed by an error cleanup problem.
>>>
>>> Did it previous probe fine? Or is the new thing just the fact that
>>> we spew a warning on trying to free a non-existing vector?
>>>
>> This works fine in mainline, if that is your question.
> 
> Yeah, as soon as I sent the other email I realized that. Let me send
> you a quick patch.

How's this?


diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index ffbab5b01df4..fd73bfd2d1be 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -2088,15 +2088,11 @@ static int nvme_setup_irqs(struct nvme_dev *dev, int nr_io_queues)
 			affd.nr_sets = 1;
 
 		/*
-		 * Need IRQs for read+write queues, and one for the admin queue.
-		 * If we can't get more than one vector, we have to share the
-		 * admin queue and IO queue vector. For that case, don't add
-		 * an extra vector for the admin queue, or we'll continue
-		 * asking for 2 and get -ENOSPC in return.
+		 * If we got a failure and we're down to asking for just
+		 * 1 + 1 queues, just ask for a single vector. We'll share
+		 * that between the single IO queue and the admin queue.
 		 */
-		if (result == -ENOSPC && nr_io_queues == 1)
-			nr_io_queues = 1;
-		else
+		if (!(result < 0 && nr_io_queues == 1))
 			nr_io_queues = irq_sets[0] + irq_sets[1] + 1;
 
 		result = pci_alloc_irq_vectors_affinity(pdev, nr_io_queues,

-- 
Jens Axboe

Re: [PATCH] nvme: utilize two queue maps, one for reads and one for writes

[Guenter Roeck]

On Thu, Nov 15, 2018 at 12:43:40PM -0700, Jens Axboe wrote:
> On 11/15/18 12:40 PM, Jens Axboe wrote:
> > On 11/15/18 12:38 PM, Guenter Roeck wrote:
> >> On Thu, Nov 15, 2018 at 12:29:04PM -0700, Jens Axboe wrote:
> >>> On 11/15/18 12:11 PM, Guenter Roeck wrote:
> >>>> On Wed, Nov 14, 2018 at 10:12:44AM -0700, Jens Axboe wrote:
> >>>>>
> >>>>> I think the below patch should fix it.
> >>>>>
> >>>>
> >>>> I spoke too early. sparc64, next-20181115:
> >>>>
> >>>> [   14.204370] nvme nvme0: pci function 0000:02:00.0
> >>>> [   14.249956] nvme nvme0: Removing after probe failure status: -5
> >>>> [   14.263496] ------------[ cut here ]------------
> >>>> [   14.263913] WARNING: CPU: 0 PID: 15 at kernel/irq/manage.c:1597 __free_irq+0xa4/0x320
> >>>> [   14.264265] Trying to free already-free IRQ 9
> >>>> [   14.264519] Modules linked in:
> >>>> [   14.264961] CPU: 0 PID: 15 Comm: kworker/u2:1 Not tainted 4.20.0-rc2-next-20181115 #1
> >>>> [   14.265555] Workqueue: nvme-reset-wq nvme_reset_work
> >>>> [   14.265899] Call Trace:
> >>>> [   14.266118]  [000000000046944c] __warn+0xcc/0x100
> >>>> [   14.266375]  [00000000004694b0] warn_slowpath_fmt+0x30/0x40
> >>>> [   14.266635]  [00000000004d4ce4] __free_irq+0xa4/0x320
> >>>> [   14.266867]  [00000000004d4ff8] free_irq+0x38/0x80
> >>>> [   14.267092]  [00000000007b1874] pci_free_irq+0x14/0x40
> >>>> [   14.267327]  [00000000008a5444] nvme_dev_disable+0xe4/0x520
> >>>> [   14.267576]  [00000000008a69b8] nvme_reset_work+0x138/0x1c60
> >>>> [   14.267827]  [0000000000488dd0] process_one_work+0x230/0x6e0
> >>>> [   14.268079]  [00000000004894f4] worker_thread+0x274/0x520
> >>>> [   14.268321]  [0000000000490624] kthread+0xe4/0x120
> >>>> [   14.268544]  [00000000004060c4] ret_from_fork+0x1c/0x2c
> >>>> [   14.268825]  [0000000000000000]           (null)
> >>>> [   14.269089] irq event stamp: 32796
> >>>> [   14.269350] hardirqs last  enabled at (32795): [<0000000000b624a4>] _raw_spin_unlock_irqrestore+0x24/0x80
> >>>> [   14.269757] hardirqs last disabled at (32796): [<0000000000b622f4>] _raw_spin_lock_irqsave+0x14/0x60
> >>>> [   14.270566] softirqs last  enabled at (32780): [<0000000000b64c18>] __do_softirq+0x238/0x520
> >>>> [   14.271206] softirqs last disabled at (32729): [<000000000042ceec>] do_softirq_own_stack+0x2c/0x40
> >>>> [   14.272288] ---[ end trace cb79ccd2a0a03f3c ]---
> >>>>
> >>>> Looks like an error during probe followed by an error cleanup problem.
> >>>
> >>> Did it previous probe fine? Or is the new thing just the fact that
> >>> we spew a warning on trying to free a non-existing vector?
> >>>
> >> This works fine in mainline, if that is your question.
> > 
> > Yeah, as soon as I sent the other email I realized that. Let me send
> > you a quick patch.
> 
> How's this?
> 
> 
> diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
> index ffbab5b01df4..fd73bfd2d1be 100644
> --- a/drivers/nvme/host/pci.c
> +++ b/drivers/nvme/host/pci.c
> @@ -2088,15 +2088,11 @@ static int nvme_setup_irqs(struct nvme_dev *dev, int nr_io_queues)
>  			affd.nr_sets = 1;
>  
>  		/*
> -		 * Need IRQs for read+write queues, and one for the admin queue.
> -		 * If we can't get more than one vector, we have to share the
> -		 * admin queue and IO queue vector. For that case, don't add
> -		 * an extra vector for the admin queue, or we'll continue
> -		 * asking for 2 and get -ENOSPC in return.
> +		 * If we got a failure and we're down to asking for just
> +		 * 1 + 1 queues, just ask for a single vector. We'll share
> +		 * that between the single IO queue and the admin queue.
>  		 */
> -		if (result == -ENOSPC && nr_io_queues == 1)
> -			nr_io_queues = 1;
> -		else
> +		if (!(result < 0 && nr_io_queues == 1))
>  			nr_io_queues = irq_sets[0] + irq_sets[1] + 1;
>  

Unfortunately, the code doesn't even get here because the call of
pci_alloc_irq_vectors_affinity in the first iteration fails with
-EINVAL, which results in an immediate return with -EIO.

Guenter

>  		result = pci_alloc_irq_vectors_affinity(pdev, nr_io_queues,
> 
> -- 
> Jens Axboe
> 

Re: [PATCH] nvme: utilize two queue maps, one for reads and one for writes

[Jens Axboe]

On 11/15/18 3:06 PM, Guenter Roeck wrote:
> On Thu, Nov 15, 2018 at 12:43:40PM -0700, Jens Axboe wrote:
>> On 11/15/18 12:40 PM, Jens Axboe wrote:
>>> On 11/15/18 12:38 PM, Guenter Roeck wrote:
>>>> On Thu, Nov 15, 2018 at 12:29:04PM -0700, Jens Axboe wrote:
>>>>> On 11/15/18 12:11 PM, Guenter Roeck wrote:
>>>>>> On Wed, Nov 14, 2018 at 10:12:44AM -0700, Jens Axboe wrote:
>>>>>>>
>>>>>>> I think the below patch should fix it.
>>>>>>>
>>>>>>
>>>>>> I spoke too early. sparc64, next-20181115:
>>>>>>
>>>>>> [   14.204370] nvme nvme0: pci function 0000:02:00.0
>>>>>> [   14.249956] nvme nvme0: Removing after probe failure status: -5
>>>>>> [   14.263496] ------------[ cut here ]------------
>>>>>> [   14.263913] WARNING: CPU: 0 PID: 15 at kernel/irq/manage.c:1597 __free_irq+0xa4/0x320
>>>>>> [   14.264265] Trying to free already-free IRQ 9
>>>>>> [   14.264519] Modules linked in:
>>>>>> [   14.264961] CPU: 0 PID: 15 Comm: kworker/u2:1 Not tainted 4.20.0-rc2-next-20181115 #1
>>>>>> [   14.265555] Workqueue: nvme-reset-wq nvme_reset_work
>>>>>> [   14.265899] Call Trace:
>>>>>> [   14.266118]  [000000000046944c] __warn+0xcc/0x100
>>>>>> [   14.266375]  [00000000004694b0] warn_slowpath_fmt+0x30/0x40
>>>>>> [   14.266635]  [00000000004d4ce4] __free_irq+0xa4/0x320
>>>>>> [   14.266867]  [00000000004d4ff8] free_irq+0x38/0x80
>>>>>> [   14.267092]  [00000000007b1874] pci_free_irq+0x14/0x40
>>>>>> [   14.267327]  [00000000008a5444] nvme_dev_disable+0xe4/0x520
>>>>>> [   14.267576]  [00000000008a69b8] nvme_reset_work+0x138/0x1c60
>>>>>> [   14.267827]  [0000000000488dd0] process_one_work+0x230/0x6e0
>>>>>> [   14.268079]  [00000000004894f4] worker_thread+0x274/0x520
>>>>>> [   14.268321]  [0000000000490624] kthread+0xe4/0x120
>>>>>> [   14.268544]  [00000000004060c4] ret_from_fork+0x1c/0x2c
>>>>>> [   14.268825]  [0000000000000000]           (null)
>>>>>> [   14.269089] irq event stamp: 32796
>>>>>> [   14.269350] hardirqs last  enabled at (32795): [<0000000000b624a4>] _raw_spin_unlock_irqrestore+0x24/0x80
>>>>>> [   14.269757] hardirqs last disabled at (32796): [<0000000000b622f4>] _raw_spin_lock_irqsave+0x14/0x60
>>>>>> [   14.270566] softirqs last  enabled at (32780): [<0000000000b64c18>] __do_softirq+0x238/0x520
>>>>>> [   14.271206] softirqs last disabled at (32729): [<000000000042ceec>] do_softirq_own_stack+0x2c/0x40
>>>>>> [   14.272288] ---[ end trace cb79ccd2a0a03f3c ]---
>>>>>>
>>>>>> Looks like an error during probe followed by an error cleanup problem.
>>>>>
>>>>> Did it previous probe fine? Or is the new thing just the fact that
>>>>> we spew a warning on trying to free a non-existing vector?
>>>>>
>>>> This works fine in mainline, if that is your question.
>>>
>>> Yeah, as soon as I sent the other email I realized that. Let me send
>>> you a quick patch.
>>
>> How's this?
>>
>>
>> diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
>> index ffbab5b01df4..fd73bfd2d1be 100644
>> --- a/drivers/nvme/host/pci.c
>> +++ b/drivers/nvme/host/pci.c
>> @@ -2088,15 +2088,11 @@ static int nvme_setup_irqs(struct nvme_dev *dev, int nr_io_queues)
>>  			affd.nr_sets = 1;
>>  
>>  		/*
>> -		 * Need IRQs for read+write queues, and one for the admin queue.
>> -		 * If we can't get more than one vector, we have to share the
>> -		 * admin queue and IO queue vector. For that case, don't add
>> -		 * an extra vector for the admin queue, or we'll continue
>> -		 * asking for 2 and get -ENOSPC in return.
>> +		 * If we got a failure and we're down to asking for just
>> +		 * 1 + 1 queues, just ask for a single vector. We'll share
>> +		 * that between the single IO queue and the admin queue.
>>  		 */
>> -		if (result == -ENOSPC && nr_io_queues == 1)
>> -			nr_io_queues = 1;
>> -		else
>> +		if (!(result < 0 && nr_io_queues == 1))
>>  			nr_io_queues = irq_sets[0] + irq_sets[1] + 1;
>>  
> 
> Unfortunately, the code doesn't even get here because the call of
> pci_alloc_irq_vectors_affinity in the first iteration fails with
> -EINVAL, which results in an immediate return with -EIO.

Oh yeah... How about this then?


diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index ffbab5b01df4..4d161daa9c3a 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -2088,15 +2088,11 @@ static int nvme_setup_irqs(struct nvme_dev *dev, int nr_io_queues)
 			affd.nr_sets = 1;
 
 		/*
-		 * Need IRQs for read+write queues, and one for the admin queue.
-		 * If we can't get more than one vector, we have to share the
-		 * admin queue and IO queue vector. For that case, don't add
-		 * an extra vector for the admin queue, or we'll continue
-		 * asking for 2 and get -ENOSPC in return.
+		 * If we got a failure and we're down to asking for just
+		 * 1 + 1 queues, just ask for a single vector. We'll share
+		 * that between the single IO queue and the admin queue.
 		 */
-		if (result == -ENOSPC && nr_io_queues == 1)
-			nr_io_queues = 1;
-		else
+		if (!(result < 0 && nr_io_queues == 1))
 			nr_io_queues = irq_sets[0] + irq_sets[1] + 1;
 
 		result = pci_alloc_irq_vectors_affinity(pdev, nr_io_queues,
@@ -2111,6 +2107,9 @@ static int nvme_setup_irqs(struct nvme_dev *dev, int nr_io_queues)
 			if (!nr_io_queues)
 				return result;
 			continue;
+		} else if (result == -EINVAL) {
+			nr_io_queues = 1;
+			continue;
 		} else if (result <= 0)
 			return -EIO;
 		break;

-- 
Jens Axboe

Re: [PATCH] nvme: utilize two queue maps, one for reads and one for writes

[Guenter Roeck]

On Thu, Nov 15, 2018 at 11:11:26AM -0800, Guenter Roeck wrote:
> On Wed, Nov 14, 2018 at 10:12:44AM -0700, Jens Axboe wrote:
> > 
> > I think the below patch should fix it.
> > 
> 
> I spoke too early. sparc64, next-20181115:
> 
> [   14.204370] nvme nvme0: pci function 0000:02:00.0
> [   14.249956] nvme nvme0: Removing after probe failure status: -5
> [   14.263496] ------------[ cut here ]------------
> [   14.263913] WARNING: CPU: 0 PID: 15 at kernel/irq/manage.c:1597 __free_irq+0xa4/0x320
> [   14.264265] Trying to free already-free IRQ 9
> [   14.264519] Modules linked in:
> [   14.264961] CPU: 0 PID: 15 Comm: kworker/u2:1 Not tainted 4.20.0-rc2-next-20181115 #1
> [   14.265555] Workqueue: nvme-reset-wq nvme_reset_work
> [   14.265899] Call Trace:
> [   14.266118]  [000000000046944c] __warn+0xcc/0x100
> [   14.266375]  [00000000004694b0] warn_slowpath_fmt+0x30/0x40
> [   14.266635]  [00000000004d4ce4] __free_irq+0xa4/0x320
> [   14.266867]  [00000000004d4ff8] free_irq+0x38/0x80
> [   14.267092]  [00000000007b1874] pci_free_irq+0x14/0x40
> [   14.267327]  [00000000008a5444] nvme_dev_disable+0xe4/0x520
> [   14.267576]  [00000000008a69b8] nvme_reset_work+0x138/0x1c60
> [   14.267827]  [0000000000488dd0] process_one_work+0x230/0x6e0
> [   14.268079]  [00000000004894f4] worker_thread+0x274/0x520
> [   14.268321]  [0000000000490624] kthread+0xe4/0x120
> [   14.268544]  [00000000004060c4] ret_from_fork+0x1c/0x2c
> [   14.268825]  [0000000000000000]           (null)
> [   14.269089] irq event stamp: 32796
> [   14.269350] hardirqs last  enabled at (32795): [<0000000000b624a4>] _raw_spin_unlock_irqrestore+0x24/0x80
> [   14.269757] hardirqs last disabled at (32796): [<0000000000b622f4>] _raw_spin_lock_irqsave+0x14/0x60
> [   14.270566] softirqs last  enabled at (32780): [<0000000000b64c18>] __do_softirq+0x238/0x520
> [   14.271206] softirqs last disabled at (32729): [<000000000042ceec>] do_softirq_own_stack+0x2c/0x40
> [   14.272288] ---[ end trace cb79ccd2a0a03f3c ]---
> 
> Looks like an error during probe followed by an error cleanup problem.
> 
On sparc64, pci_alloc_irq_vectors_affinity() returns -EINVAL (possibly
because the controller doesn't support MSI).

[   16.554753] nvme nvme0: pci function 0000:02:00.0
[   16.622894] nvme 0000:02:00.0: pre alloc: nr_io_queues: 2 result: 0
[   16.623814] nvme 0000:02:00.0: post alloc: nr_io_queues: 2 result: -22
[   16.625047] nvme nvme0: Removing after probe failure status: -5

... and, as result, allocating a single (legacy) interrupt isn't even tried.

I didn't try to track down the cleanup failure.

Guenter

Re: [PATCH] nvme: utilize two queue maps, one for reads and one for writes

[Jens Axboe]

On 11/15/18 12:36 PM, Guenter Roeck wrote:
> On Thu, Nov 15, 2018 at 11:11:26AM -0800, Guenter Roeck wrote:
>> On Wed, Nov 14, 2018 at 10:12:44AM -0700, Jens Axboe wrote:
>>>
>>> I think the below patch should fix it.
>>>
>>
>> I spoke too early. sparc64, next-20181115:
>>
>> [   14.204370] nvme nvme0: pci function 0000:02:00.0
>> [   14.249956] nvme nvme0: Removing after probe failure status: -5
>> [   14.263496] ------------[ cut here ]------------
>> [   14.263913] WARNING: CPU: 0 PID: 15 at kernel/irq/manage.c:1597 __free_irq+0xa4/0x320
>> [   14.264265] Trying to free already-free IRQ 9
>> [   14.264519] Modules linked in:
>> [   14.264961] CPU: 0 PID: 15 Comm: kworker/u2:1 Not tainted 4.20.0-rc2-next-20181115 #1
>> [   14.265555] Workqueue: nvme-reset-wq nvme_reset_work
>> [   14.265899] Call Trace:
>> [   14.266118]  [000000000046944c] __warn+0xcc/0x100
>> [   14.266375]  [00000000004694b0] warn_slowpath_fmt+0x30/0x40
>> [   14.266635]  [00000000004d4ce4] __free_irq+0xa4/0x320
>> [   14.266867]  [00000000004d4ff8] free_irq+0x38/0x80
>> [   14.267092]  [00000000007b1874] pci_free_irq+0x14/0x40
>> [   14.267327]  [00000000008a5444] nvme_dev_disable+0xe4/0x520
>> [   14.267576]  [00000000008a69b8] nvme_reset_work+0x138/0x1c60
>> [   14.267827]  [0000000000488dd0] process_one_work+0x230/0x6e0
>> [   14.268079]  [00000000004894f4] worker_thread+0x274/0x520
>> [   14.268321]  [0000000000490624] kthread+0xe4/0x120
>> [   14.268544]  [00000000004060c4] ret_from_fork+0x1c/0x2c
>> [   14.268825]  [0000000000000000]           (null)
>> [   14.269089] irq event stamp: 32796
>> [   14.269350] hardirqs last  enabled at (32795): [<0000000000b624a4>] _raw_spin_unlock_irqrestore+0x24/0x80
>> [   14.269757] hardirqs last disabled at (32796): [<0000000000b622f4>] _raw_spin_lock_irqsave+0x14/0x60
>> [   14.270566] softirqs last  enabled at (32780): [<0000000000b64c18>] __do_softirq+0x238/0x520
>> [   14.271206] softirqs last disabled at (32729): [<000000000042ceec>] do_softirq_own_stack+0x2c/0x40
>> [   14.272288] ---[ end trace cb79ccd2a0a03f3c ]---
>>
>> Looks like an error during probe followed by an error cleanup problem.
>>
> On sparc64, pci_alloc_irq_vectors_affinity() returns -EINVAL (possibly
> because the controller doesn't support MSI).
> 
> [   16.554753] nvme nvme0: pci function 0000:02:00.0
> [   16.622894] nvme 0000:02:00.0: pre alloc: nr_io_queues: 2 result: 0
> [   16.623814] nvme 0000:02:00.0: post alloc: nr_io_queues: 2 result: -22
> [   16.625047] nvme nvme0: Removing after probe failure status: -5
> 
> ... and, as result, allocating a single (legacy) interrupt isn't even tried.
> 
> I didn't try to track down the cleanup failure.

OK, then this isn't a new failure in terms of whether the nvme device will
work, it's just a cleanup issue.

That's less severe than the previous hang :-)

-- 
Jens Axboe

Re: [PATCH] nvme: utilize two queue maps, one for reads and one for writes

[Guenter Roeck]

On Thu, Nov 15, 2018 at 03:12:48PM -0700, Jens Axboe wrote:
> On 11/15/18 3:06 PM, Guenter Roeck wrote:
> > On Thu, Nov 15, 2018 at 12:43:40PM -0700, Jens Axboe wrote:
> >> On 11/15/18 12:40 PM, Jens Axboe wrote:
> >>> On 11/15/18 12:38 PM, Guenter Roeck wrote:
> >>>> On Thu, Nov 15, 2018 at 12:29:04PM -0700, Jens Axboe wrote:
> >>>>> On 11/15/18 12:11 PM, Guenter Roeck wrote:
> >>>>>> On Wed, Nov 14, 2018 at 10:12:44AM -0700, Jens Axboe wrote:
> >>>>>>>
> >>>>>>> I think the below patch should fix it.
> >>>>>>>
> >>>>>>
> >>>>>> I spoke too early. sparc64, next-20181115:
> >>>>>>
> >>>>>> [   14.204370] nvme nvme0: pci function 0000:02:00.0
> >>>>>> [   14.249956] nvme nvme0: Removing after probe failure status: -5
> >>>>>> [   14.263496] ------------[ cut here ]------------
> >>>>>> [   14.263913] WARNING: CPU: 0 PID: 15 at kernel/irq/manage.c:1597 __free_irq+0xa4/0x320
> >>>>>> [   14.264265] Trying to free already-free IRQ 9
> >>>>>> [   14.264519] Modules linked in:
> >>>>>> [   14.264961] CPU: 0 PID: 15 Comm: kworker/u2:1 Not tainted 4.20.0-rc2-next-20181115 #1
> >>>>>> [   14.265555] Workqueue: nvme-reset-wq nvme_reset_work
> >>>>>> [   14.265899] Call Trace:
> >>>>>> [   14.266118]  [000000000046944c] __warn+0xcc/0x100
> >>>>>> [   14.266375]  [00000000004694b0] warn_slowpath_fmt+0x30/0x40
> >>>>>> [   14.266635]  [00000000004d4ce4] __free_irq+0xa4/0x320
> >>>>>> [   14.266867]  [00000000004d4ff8] free_irq+0x38/0x80
> >>>>>> [   14.267092]  [00000000007b1874] pci_free_irq+0x14/0x40
> >>>>>> [   14.267327]  [00000000008a5444] nvme_dev_disable+0xe4/0x520
> >>>>>> [   14.267576]  [00000000008a69b8] nvme_reset_work+0x138/0x1c60
> >>>>>> [   14.267827]  [0000000000488dd0] process_one_work+0x230/0x6e0
> >>>>>> [   14.268079]  [00000000004894f4] worker_thread+0x274/0x520
> >>>>>> [   14.268321]  [0000000000490624] kthread+0xe4/0x120
> >>>>>> [   14.268544]  [00000000004060c4] ret_from_fork+0x1c/0x2c
> >>>>>> [   14.268825]  [0000000000000000]           (null)
> >>>>>> [   14.269089] irq event stamp: 32796
> >>>>>> [   14.269350] hardirqs last  enabled at (32795): [<0000000000b624a4>] _raw_spin_unlock_irqrestore+0x24/0x80
> >>>>>> [   14.269757] hardirqs last disabled at (32796): [<0000000000b622f4>] _raw_spin_lock_irqsave+0x14/0x60
> >>>>>> [   14.270566] softirqs last  enabled at (32780): [<0000000000b64c18>] __do_softirq+0x238/0x520
> >>>>>> [   14.271206] softirqs last disabled at (32729): [<000000000042ceec>] do_softirq_own_stack+0x2c/0x40
> >>>>>> [   14.272288] ---[ end trace cb79ccd2a0a03f3c ]---
> >>>>>>
> >>>>>> Looks like an error during probe followed by an error cleanup problem.
> >>>>>
> >>>>> Did it previous probe fine? Or is the new thing just the fact that
> >>>>> we spew a warning on trying to free a non-existing vector?
> >>>>>
> >>>> This works fine in mainline, if that is your question.
> >>>
> >>> Yeah, as soon as I sent the other email I realized that. Let me send
> >>> you a quick patch.
> >>
> >> How's this?
> >>
> >>
> >> diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
> >> index ffbab5b01df4..fd73bfd2d1be 100644
> >> --- a/drivers/nvme/host/pci.c
> >> +++ b/drivers/nvme/host/pci.c
> >> @@ -2088,15 +2088,11 @@ static int nvme_setup_irqs(struct nvme_dev *dev, int nr_io_queues)
> >>  			affd.nr_sets = 1;
> >>  
> >>  		/*
> >> -		 * Need IRQs for read+write queues, and one for the admin queue.
> >> -		 * If we can't get more than one vector, we have to share the
> >> -		 * admin queue and IO queue vector. For that case, don't add
> >> -		 * an extra vector for the admin queue, or we'll continue
> >> -		 * asking for 2 and get -ENOSPC in return.
> >> +		 * If we got a failure and we're down to asking for just
> >> +		 * 1 + 1 queues, just ask for a single vector. We'll share
> >> +		 * that between the single IO queue and the admin queue.
> >>  		 */
> >> -		if (result == -ENOSPC && nr_io_queues == 1)
> >> -			nr_io_queues = 1;
> >> -		else
> >> +		if (!(result < 0 && nr_io_queues == 1))
> >>  			nr_io_queues = irq_sets[0] + irq_sets[1] + 1;
> >>  
> > 
> > Unfortunately, the code doesn't even get here because the call of
> > pci_alloc_irq_vectors_affinity in the first iteration fails with
> > -EINVAL, which results in an immediate return with -EIO.
> 
> Oh yeah... How about this then?
> 
Yes, this one works (at least on sparc64). Do I need to test
on other architectures as well ?

Thanks,
Guenter

> 
> diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
> index ffbab5b01df4..4d161daa9c3a 100644
> --- a/drivers/nvme/host/pci.c
> +++ b/drivers/nvme/host/pci.c
> @@ -2088,15 +2088,11 @@ static int nvme_setup_irqs(struct nvme_dev *dev, int nr_io_queues)
>  			affd.nr_sets = 1;
>  
>  		/*
> -		 * Need IRQs for read+write queues, and one for the admin queue.
> -		 * If we can't get more than one vector, we have to share the
> -		 * admin queue and IO queue vector. For that case, don't add
> -		 * an extra vector for the admin queue, or we'll continue
> -		 * asking for 2 and get -ENOSPC in return.
> +		 * If we got a failure and we're down to asking for just
> +		 * 1 + 1 queues, just ask for a single vector. We'll share
> +		 * that between the single IO queue and the admin queue.
>  		 */
> -		if (result == -ENOSPC && nr_io_queues == 1)
> -			nr_io_queues = 1;
> -		else
> +		if (!(result < 0 && nr_io_queues == 1))
>  			nr_io_queues = irq_sets[0] + irq_sets[1] + 1;
>  
>  		result = pci_alloc_irq_vectors_affinity(pdev, nr_io_queues,
> @@ -2111,6 +2107,9 @@ static int nvme_setup_irqs(struct nvme_dev *dev, int nr_io_queues)
>  			if (!nr_io_queues)
>  				return result;
>  			continue;
> +		} else if (result == -EINVAL) {

Add an explanation, maybe ?

> +			nr_io_queues = 1;
> +			continue;
>  		} else if (result <= 0)
>  			return -EIO;
>  		break;
> 
> -- 
> Jens Axboe
> 

Re: [PATCH] nvme: utilize two queue maps, one for reads and one for writes

[Jens Axboe]

On 11/15/18 3:46 PM, Guenter Roeck wrote:
> On Thu, Nov 15, 2018 at 03:12:48PM -0700, Jens Axboe wrote:
>> On 11/15/18 3:06 PM, Guenter Roeck wrote:
>>> On Thu, Nov 15, 2018 at 12:43:40PM -0700, Jens Axboe wrote:
>>>> On 11/15/18 12:40 PM, Jens Axboe wrote:
>>>>> On 11/15/18 12:38 PM, Guenter Roeck wrote:
>>>>>> On Thu, Nov 15, 2018 at 12:29:04PM -0700, Jens Axboe wrote:
>>>>>>> On 11/15/18 12:11 PM, Guenter Roeck wrote:
>>>>>>>> On Wed, Nov 14, 2018 at 10:12:44AM -0700, Jens Axboe wrote:
>>>>>>>>>
>>>>>>>>> I think the below patch should fix it.
>>>>>>>>>
>>>>>>>>
>>>>>>>> I spoke too early. sparc64, next-20181115:
>>>>>>>>
>>>>>>>> [   14.204370] nvme nvme0: pci function 0000:02:00.0
>>>>>>>> [   14.249956] nvme nvme0: Removing after probe failure status: -5
>>>>>>>> [   14.263496] ------------[ cut here ]------------
>>>>>>>> [   14.263913] WARNING: CPU: 0 PID: 15 at kernel/irq/manage.c:1597 __free_irq+0xa4/0x320
>>>>>>>> [   14.264265] Trying to free already-free IRQ 9
>>>>>>>> [   14.264519] Modules linked in:
>>>>>>>> [   14.264961] CPU: 0 PID: 15 Comm: kworker/u2:1 Not tainted 4.20.0-rc2-next-20181115 #1
>>>>>>>> [   14.265555] Workqueue: nvme-reset-wq nvme_reset_work
>>>>>>>> [   14.265899] Call Trace:
>>>>>>>> [   14.266118]  [000000000046944c] __warn+0xcc/0x100
>>>>>>>> [   14.266375]  [00000000004694b0] warn_slowpath_fmt+0x30/0x40
>>>>>>>> [   14.266635]  [00000000004d4ce4] __free_irq+0xa4/0x320
>>>>>>>> [   14.266867]  [00000000004d4ff8] free_irq+0x38/0x80
>>>>>>>> [   14.267092]  [00000000007b1874] pci_free_irq+0x14/0x40
>>>>>>>> [   14.267327]  [00000000008a5444] nvme_dev_disable+0xe4/0x520
>>>>>>>> [   14.267576]  [00000000008a69b8] nvme_reset_work+0x138/0x1c60
>>>>>>>> [   14.267827]  [0000000000488dd0] process_one_work+0x230/0x6e0
>>>>>>>> [   14.268079]  [00000000004894f4] worker_thread+0x274/0x520
>>>>>>>> [   14.268321]  [0000000000490624] kthread+0xe4/0x120
>>>>>>>> [   14.268544]  [00000000004060c4] ret_from_fork+0x1c/0x2c
>>>>>>>> [   14.268825]  [0000000000000000]           (null)
>>>>>>>> [   14.269089] irq event stamp: 32796
>>>>>>>> [   14.269350] hardirqs last  enabled at (32795): [<0000000000b624a4>] _raw_spin_unlock_irqrestore+0x24/0x80
>>>>>>>> [   14.269757] hardirqs last disabled at (32796): [<0000000000b622f4>] _raw_spin_lock_irqsave+0x14/0x60
>>>>>>>> [   14.270566] softirqs last  enabled at (32780): [<0000000000b64c18>] __do_softirq+0x238/0x520
>>>>>>>> [   14.271206] softirqs last disabled at (32729): [<000000000042ceec>] do_softirq_own_stack+0x2c/0x40
>>>>>>>> [   14.272288] ---[ end trace cb79ccd2a0a03f3c ]---
>>>>>>>>
>>>>>>>> Looks like an error during probe followed by an error cleanup problem.
>>>>>>>
>>>>>>> Did it previous probe fine? Or is the new thing just the fact that
>>>>>>> we spew a warning on trying to free a non-existing vector?
>>>>>>>
>>>>>> This works fine in mainline, if that is your question.
>>>>>
>>>>> Yeah, as soon as I sent the other email I realized that. Let me send
>>>>> you a quick patch.
>>>>
>>>> How's this?
>>>>
>>>>
>>>> diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
>>>> index ffbab5b01df4..fd73bfd2d1be 100644
>>>> --- a/drivers/nvme/host/pci.c
>>>> +++ b/drivers/nvme/host/pci.c
>>>> @@ -2088,15 +2088,11 @@ static int nvme_setup_irqs(struct nvme_dev *dev, int nr_io_queues)
>>>>  			affd.nr_sets = 1;
>>>>  
>>>>  		/*
>>>> -		 * Need IRQs for read+write queues, and one for the admin queue.
>>>> -		 * If we can't get more than one vector, we have to share the
>>>> -		 * admin queue and IO queue vector. For that case, don't add
>>>> -		 * an extra vector for the admin queue, or we'll continue
>>>> -		 * asking for 2 and get -ENOSPC in return.
>>>> +		 * If we got a failure and we're down to asking for just
>>>> +		 * 1 + 1 queues, just ask for a single vector. We'll share
>>>> +		 * that between the single IO queue and the admin queue.
>>>>  		 */
>>>> -		if (result == -ENOSPC && nr_io_queues == 1)
>>>> -			nr_io_queues = 1;
>>>> -		else
>>>> +		if (!(result < 0 && nr_io_queues == 1))
>>>>  			nr_io_queues = irq_sets[0] + irq_sets[1] + 1;
>>>>  
>>>
>>> Unfortunately, the code doesn't even get here because the call of
>>> pci_alloc_irq_vectors_affinity in the first iteration fails with
>>> -EINVAL, which results in an immediate return with -EIO.
>>
>> Oh yeah... How about this then?
>>
> Yes, this one works (at least on sparc64). Do I need to test
> on other architectures as well ?

Should be fine, hopefully... Thanks for testing!

>> @@ -2111,6 +2107,9 @@ static int nvme_setup_irqs(struct nvme_dev *dev, int nr_io_queues)
>>  			if (!nr_io_queues)
>>  				return result;
>>  			continue;
>> +		} else if (result == -EINVAL) {
> 
> Add an explanation, maybe ?

Yeah, I'll add a proper comment, this was just for testing.

-- 
Jens Axboe