diff mbox

[rfc,5/6] block: Add rdma affinity based queue mapping helper

Message ID 1491140492-25703-6-git-send-email-sagi@grimberg.me (mailing list archive)
State RFC
Headers show

Commit Message

Sagi Grimberg April 2, 2017, 1:41 p.m. UTC
Like pci and virtio, we add a rdma helper for affinity
spreading. This achieves optimal mq affinity assignments
according to the underlying rdma device affinity maps.

Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
---
 block/Kconfig               |  5 ++++
 block/Makefile              |  1 +
 block/blk-mq-rdma.c         | 56 +++++++++++++++++++++++++++++++++++++++++++++
 include/linux/blk-mq-rdma.h | 10 ++++++++
 4 files changed, 72 insertions(+)
 create mode 100644 block/blk-mq-rdma.c
 create mode 100644 include/linux/blk-mq-rdma.h

Comments

Christoph Hellwig April 4, 2017, 6:33 a.m. UTC | #1
On Sun, Apr 02, 2017 at 04:41:31PM +0300, Sagi Grimberg wrote:
> Like pci and virtio, we add a rdma helper for affinity
> spreading. This achieves optimal mq affinity assignments
> according to the underlying rdma device affinity maps.
> 
> Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
> ---
>  block/Kconfig               |  5 ++++
>  block/Makefile              |  1 +
>  block/blk-mq-rdma.c         | 56 +++++++++++++++++++++++++++++++++++++++++++++
>  include/linux/blk-mq-rdma.h | 10 ++++++++
>  4 files changed, 72 insertions(+)
>  create mode 100644 block/blk-mq-rdma.c
>  create mode 100644 include/linux/blk-mq-rdma.h
> 
> diff --git a/block/Kconfig b/block/Kconfig
> index 89cd28f8d051..3ab42bbb06d5 100644
> --- a/block/Kconfig
> +++ b/block/Kconfig
> @@ -206,4 +206,9 @@ config BLK_MQ_VIRTIO
>  	depends on BLOCK && VIRTIO
>  	default y
>  
> +config BLK_MQ_RDMA
> +	bool
> +	depends on BLOCK && INFINIBAND
> +	default y
> +
>  source block/Kconfig.iosched
> diff --git a/block/Makefile b/block/Makefile
> index 081bb680789b..4498603dbc83 100644
> --- a/block/Makefile
> +++ b/block/Makefile
> @@ -26,6 +26,7 @@ obj-$(CONFIG_BLK_CMDLINE_PARSER)	+= cmdline-parser.o
>  obj-$(CONFIG_BLK_DEV_INTEGRITY) += bio-integrity.o blk-integrity.o t10-pi.o
>  obj-$(CONFIG_BLK_MQ_PCI)	+= blk-mq-pci.o
>  obj-$(CONFIG_BLK_MQ_VIRTIO)	+= blk-mq-virtio.o
> +obj-$(CONFIG_BLK_MQ_RDMA)	+= blk-mq-rdma.o
>  obj-$(CONFIG_BLK_DEV_ZONED)	+= blk-zoned.o
>  obj-$(CONFIG_BLK_WBT)		+= blk-wbt.o
>  obj-$(CONFIG_BLK_DEBUG_FS)	+= blk-mq-debugfs.o
> diff --git a/block/blk-mq-rdma.c b/block/blk-mq-rdma.c
> new file mode 100644
> index 000000000000..d402f7c93528
> --- /dev/null
> +++ b/block/blk-mq-rdma.c
> @@ -0,0 +1,56 @@
> +/*
> + * Copyright (c) 2017 Sagi Grimberg.
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms and conditions of the GNU General Public License,
> + * version 2, as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope it will be useful, but WITHOUT
> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
> + * more details.
> + */
> +#include <linux/blk-mq.h>
> +#include <linux/blk-mq-rdma.h>
> +#include <rdma/ib_verbs.h>
> +#include <linux/module.h>
> +#include "blk-mq.h"
> +
> +/**
> + * blk_mq_rdma_map_queues - provide a default queue mapping for rdma device
> + * @set:	tagset to provide the mapping for
> + * @dev:	rdma device associated with @set.
> + * @first_vec:	first interrupt vectors to use for queues (usually 0)
> + *
> + * This function assumes the rdma device @dev has at least as many available
> + * interrupt vetors as @set has queues.  It will then query it's affinity mask
> + * and built queue mapping that maps a queue to the CPUs that have irq affinity
> + * for the corresponding vector.
> + *
> + * In case either the driver passed a @dev with less vectors than
> + * @set->nr_hw_queues, or @dev does not provide an affinity mask for a
> + * vector, we fallback to the naive mapping.
> + */
> +int blk_mq_rdma_map_queues(struct blk_mq_tag_set *set,
> +		struct ib_device *dev, int first_vec)
> +{
> +	const struct cpumask *mask;
> +	unsigned int queue, cpu;
> +
> +	if (set->nr_hw_queues > dev->num_comp_vectors)
> +		goto fallback;

maybe print a warning here?

Otherwise looks fine:

Reviewed-by: Christoph Hellwig <hch@lst.de>
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Max Gurtovoy April 4, 2017, 7:46 a.m. UTC | #2
> diff --git a/block/blk-mq-rdma.c b/block/blk-mq-rdma.c
> new file mode 100644
> index 000000000000..d402f7c93528
> --- /dev/null
> +++ b/block/blk-mq-rdma.c
> @@ -0,0 +1,56 @@
> +/*
> + * Copyright (c) 2017 Sagi Grimberg.
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms and conditions of the GNU General Public License,
> + * version 2, as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope it will be useful, but WITHOUT
> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
> + * more details.
> + */

shouldn't you include  <linux/kobject.h> and <linux/blkdev.h> like in 
commit 8ec2ef2b66ea2f that fixes blk-mq-pci.c ?

> +#include <linux/blk-mq.h>
> +#include <linux/blk-mq-rdma.h>
> +#include <rdma/ib_verbs.h>
> +#include <linux/module.h>
> +#include "blk-mq.h"

Is this include needed ?


> +
> +/**
> + * blk_mq_rdma_map_queues - provide a default queue mapping for rdma device
> + * @set:	tagset to provide the mapping for
> + * @dev:	rdma device associated with @set.
> + * @first_vec:	first interrupt vectors to use for queues (usually 0)
> + *
> + * This function assumes the rdma device @dev has at least as many available
> + * interrupt vetors as @set has queues.  It will then query it's affinity mask
> + * and built queue mapping that maps a queue to the CPUs that have irq affinity
> + * for the corresponding vector.
> + *
> + * In case either the driver passed a @dev with less vectors than
> + * @set->nr_hw_queues, or @dev does not provide an affinity mask for a
> + * vector, we fallback to the naive mapping.
> + */
> +int blk_mq_rdma_map_queues(struct blk_mq_tag_set *set,
> +		struct ib_device *dev, int first_vec)
> +{
> +	const struct cpumask *mask;
> +	unsigned int queue, cpu;
> +
> +	if (set->nr_hw_queues > dev->num_comp_vectors)
> +		goto fallback;
> +
> +	for (queue = 0; queue < set->nr_hw_queues; queue++) {
> +		mask = ib_get_vector_affinity(dev, first_vec + queue);
> +		if (!mask)
> +			goto fallback;

Christoph,
we can use fallback also in the blk-mq-pci.c in case 
pci_irq_get_affinity fails, right ?

> +
> +		for_each_cpu(cpu, mask)
> +			set->mq_map[cpu] = queue;
> +	}
> +
> +	return 0;
> +fallback:
> +	return blk_mq_map_queues(set);
> +}
> +EXPORT_SYMBOL_GPL(blk_mq_rdma_map_queues);

Otherwise, Looks good.

Reviewed-by: Max Gurtovoy <maxg@mellanox.com>

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Christoph Hellwig April 4, 2017, 1:09 p.m. UTC | #3
On Tue, Apr 04, 2017 at 10:46:54AM +0300, Max Gurtovoy wrote:
>> +	if (set->nr_hw_queues > dev->num_comp_vectors)
>> +		goto fallback;
>> +
>> +	for (queue = 0; queue < set->nr_hw_queues; queue++) {
>> +		mask = ib_get_vector_affinity(dev, first_vec + queue);
>> +		if (!mask)
>> +			goto fallback;
>
> Christoph,
> we can use fallback also in the blk-mq-pci.c in case pci_irq_get_affinity 
> fails, right ?

For PCI it shouldn't fail as the driver calling pci_irq_get_affinity
knows how it set up the interrupts.  So I don't think it's necessary there.
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Jens Axboe April 5, 2017, 2:17 p.m. UTC | #4
On 04/02/2017 07:41 AM, Sagi Grimberg wrote:
> Like pci and virtio, we add a rdma helper for affinity
> spreading. This achieves optimal mq affinity assignments
> according to the underlying rdma device affinity maps.

Reviewed-by: Jens Axboe <axboe@fb.com>
Sagi Grimberg April 6, 2017, 9:23 a.m. UTC | #5
> shouldn't you include  <linux/kobject.h> and <linux/blkdev.h> like in
> commit 8ec2ef2b66ea2f that fixes blk-mq-pci.c ?

Not really. We can lose these from blk-mq-pci.c as well.

>> +#include <linux/blk-mq.h>
>> +#include <linux/blk-mq-rdma.h>
>> +#include <rdma/ib_verbs.h>
>> +#include <linux/module.h>
>> +#include "blk-mq.h"
>
> Is this include needed ?

You're right, I can just keep:

+#include <linux/blk-mq.h>
+#include <linux/blk-mq-rdma.h>
+#include <rdma/ib_verbs.h>
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diff mbox

Patch

diff --git a/block/Kconfig b/block/Kconfig
index 89cd28f8d051..3ab42bbb06d5 100644
--- a/block/Kconfig
+++ b/block/Kconfig
@@ -206,4 +206,9 @@  config BLK_MQ_VIRTIO
 	depends on BLOCK && VIRTIO
 	default y
 
+config BLK_MQ_RDMA
+	bool
+	depends on BLOCK && INFINIBAND
+	default y
+
 source block/Kconfig.iosched
diff --git a/block/Makefile b/block/Makefile
index 081bb680789b..4498603dbc83 100644
--- a/block/Makefile
+++ b/block/Makefile
@@ -26,6 +26,7 @@  obj-$(CONFIG_BLK_CMDLINE_PARSER)	+= cmdline-parser.o
 obj-$(CONFIG_BLK_DEV_INTEGRITY) += bio-integrity.o blk-integrity.o t10-pi.o
 obj-$(CONFIG_BLK_MQ_PCI)	+= blk-mq-pci.o
 obj-$(CONFIG_BLK_MQ_VIRTIO)	+= blk-mq-virtio.o
+obj-$(CONFIG_BLK_MQ_RDMA)	+= blk-mq-rdma.o
 obj-$(CONFIG_BLK_DEV_ZONED)	+= blk-zoned.o
 obj-$(CONFIG_BLK_WBT)		+= blk-wbt.o
 obj-$(CONFIG_BLK_DEBUG_FS)	+= blk-mq-debugfs.o
diff --git a/block/blk-mq-rdma.c b/block/blk-mq-rdma.c
new file mode 100644
index 000000000000..d402f7c93528
--- /dev/null
+++ b/block/blk-mq-rdma.c
@@ -0,0 +1,56 @@ 
+/*
+ * Copyright (c) 2017 Sagi Grimberg.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ */
+#include <linux/blk-mq.h>
+#include <linux/blk-mq-rdma.h>
+#include <rdma/ib_verbs.h>
+#include <linux/module.h>
+#include "blk-mq.h"
+
+/**
+ * blk_mq_rdma_map_queues - provide a default queue mapping for rdma device
+ * @set:	tagset to provide the mapping for
+ * @dev:	rdma device associated with @set.
+ * @first_vec:	first interrupt vectors to use for queues (usually 0)
+ *
+ * This function assumes the rdma device @dev has at least as many available
+ * interrupt vetors as @set has queues.  It will then query it's affinity mask
+ * and built queue mapping that maps a queue to the CPUs that have irq affinity
+ * for the corresponding vector.
+ *
+ * In case either the driver passed a @dev with less vectors than
+ * @set->nr_hw_queues, or @dev does not provide an affinity mask for a
+ * vector, we fallback to the naive mapping.
+ */
+int blk_mq_rdma_map_queues(struct blk_mq_tag_set *set,
+		struct ib_device *dev, int first_vec)
+{
+	const struct cpumask *mask;
+	unsigned int queue, cpu;
+
+	if (set->nr_hw_queues > dev->num_comp_vectors)
+		goto fallback;
+
+	for (queue = 0; queue < set->nr_hw_queues; queue++) {
+		mask = ib_get_vector_affinity(dev, first_vec + queue);
+		if (!mask)
+			goto fallback;
+
+		for_each_cpu(cpu, mask)
+			set->mq_map[cpu] = queue;
+	}
+
+	return 0;
+fallback:
+	return blk_mq_map_queues(set);
+}
+EXPORT_SYMBOL_GPL(blk_mq_rdma_map_queues);
diff --git a/include/linux/blk-mq-rdma.h b/include/linux/blk-mq-rdma.h
new file mode 100644
index 000000000000..b4ade198007d
--- /dev/null
+++ b/include/linux/blk-mq-rdma.h
@@ -0,0 +1,10 @@ 
+#ifndef _LINUX_BLK_MQ_RDMA_H
+#define _LINUX_BLK_MQ_RDMA_H
+
+struct blk_mq_tag_set;
+struct ib_device;
+
+int blk_mq_rdma_map_queues(struct blk_mq_tag_set *set,
+		struct ib_device *dev, int first_vec);
+
+#endif /* _LINUX_BLK_MQ_RDMA_H */