diff mbox series

[net-next,resend,2/2] sfc: set affinity hints in local NUMA node only

Message ID 20220216094139.15989-3-ihuguet@redhat.com (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series sfc: optimize RXQs count and affinities | expand

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Context Check Description
netdev/tree_selection success Clearly marked for net-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/cc_maintainers warning 5 maintainers not CCed: hawk@kernel.org daniel@iogearbox.net john.fastabend@gmail.com bpf@vger.kernel.org ast@kernel.org
netdev/build_clang success Errors and warnings before: 0 this patch: 0
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 20 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Íñigo Huguet Feb. 16, 2022, 9:41 a.m. UTC 
Affinity hints were being set to CPUs in local NUMA node first, and then
in other CPUs. This was creating 2 unintended issues:
1. Channels created to be assigned each to a different physical core
   were assigned to hyperthreading siblings because of being in same
   NUMA node.
   Since the patch previous to this one, this did not longer happen
   with default rss_cpus modparam because less channels are created.
2. XDP channels could be assigned to CPUs in different NUMA nodes,
   decreasing performance too much (to less than half in some of my
   tests).

This patch sets the affinity hints spreading the channels only in local
NUMA node's CPUs. A fallback for the case that no CPU in local NUMA node
is online has been added too.

Example of CPUs being assigned in a non optimal way before this and the
previous patch (note: in this system, xdp-8 to xdp-15 are created
because num_possible_cpus == 64, but num_present_cpus == 32 so they're
never used):

$ lscpu | grep -i numa
NUMA node(s):                    2
NUMA node0 CPU(s):               0-7,16-23
NUMA node1 CPU(s):               8-15,24-31

$ grep -H . /proc/irq/*/0000:07:00.0*/../smp_affinity_list
/proc/irq/141/0000:07:00.0-0/../smp_affinity_list:0
/proc/irq/142/0000:07:00.0-1/../smp_affinity_list:1
/proc/irq/143/0000:07:00.0-2/../smp_affinity_list:2
/proc/irq/144/0000:07:00.0-3/../smp_affinity_list:3
/proc/irq/145/0000:07:00.0-4/../smp_affinity_list:4
/proc/irq/146/0000:07:00.0-5/../smp_affinity_list:5
/proc/irq/147/0000:07:00.0-6/../smp_affinity_list:6
/proc/irq/148/0000:07:00.0-7/../smp_affinity_list:7
/proc/irq/149/0000:07:00.0-8/../smp_affinity_list:16
/proc/irq/150/0000:07:00.0-9/../smp_affinity_list:17
/proc/irq/151/0000:07:00.0-10/../smp_affinity_list:18
/proc/irq/152/0000:07:00.0-11/../smp_affinity_list:19
/proc/irq/153/0000:07:00.0-12/../smp_affinity_list:20
/proc/irq/154/0000:07:00.0-13/../smp_affinity_list:21
/proc/irq/155/0000:07:00.0-14/../smp_affinity_list:22
/proc/irq/156/0000:07:00.0-15/../smp_affinity_list:23
/proc/irq/157/0000:07:00.0-xdp-0/../smp_affinity_list:8
/proc/irq/158/0000:07:00.0-xdp-1/../smp_affinity_list:9
/proc/irq/159/0000:07:00.0-xdp-2/../smp_affinity_list:10
/proc/irq/160/0000:07:00.0-xdp-3/../smp_affinity_list:11
/proc/irq/161/0000:07:00.0-xdp-4/../smp_affinity_list:12
/proc/irq/162/0000:07:00.0-xdp-5/../smp_affinity_list:13
/proc/irq/163/0000:07:00.0-xdp-6/../smp_affinity_list:14
/proc/irq/164/0000:07:00.0-xdp-7/../smp_affinity_list:15
/proc/irq/165/0000:07:00.0-xdp-8/../smp_affinity_list:24
/proc/irq/166/0000:07:00.0-xdp-9/../smp_affinity_list:25
/proc/irq/167/0000:07:00.0-xdp-10/../smp_affinity_list:26
/proc/irq/168/0000:07:00.0-xdp-11/../smp_affinity_list:27
/proc/irq/169/0000:07:00.0-xdp-12/../smp_affinity_list:28
/proc/irq/170/0000:07:00.0-xdp-13/../smp_affinity_list:29
/proc/irq/171/0000:07:00.0-xdp-14/../smp_affinity_list:30
/proc/irq/172/0000:07:00.0-xdp-15/../smp_affinity_list:31

CPUs assignments after this and previous patch, so normal channels
created only one per core in NUMA node and affinities set only to local
NUMA node:

$ grep -H . /proc/irq/*/0000:07:00.0*/../smp_affinity_list
/proc/irq/116/0000:07:00.0-0/../smp_affinity_list:0
/proc/irq/117/0000:07:00.0-1/../smp_affinity_list:1
/proc/irq/118/0000:07:00.0-2/../smp_affinity_list:2
/proc/irq/119/0000:07:00.0-3/../smp_affinity_list:3
/proc/irq/120/0000:07:00.0-4/../smp_affinity_list:4
/proc/irq/121/0000:07:00.0-5/../smp_affinity_list:5
/proc/irq/122/0000:07:00.0-6/../smp_affinity_list:6
/proc/irq/123/0000:07:00.0-7/../smp_affinity_list:7
/proc/irq/124/0000:07:00.0-xdp-0/../smp_affinity_list:16
/proc/irq/125/0000:07:00.0-xdp-1/../smp_affinity_list:17
/proc/irq/126/0000:07:00.0-xdp-2/../smp_affinity_list:18
/proc/irq/127/0000:07:00.0-xdp-3/../smp_affinity_list:19
/proc/irq/128/0000:07:00.0-xdp-4/../smp_affinity_list:20
/proc/irq/129/0000:07:00.0-xdp-5/../smp_affinity_list:21
/proc/irq/130/0000:07:00.0-xdp-6/../smp_affinity_list:22
/proc/irq/131/0000:07:00.0-xdp-7/../smp_affinity_list:23
/proc/irq/132/0000:07:00.0-xdp-8/../smp_affinity_list:0
/proc/irq/133/0000:07:00.0-xdp-9/../smp_affinity_list:1
/proc/irq/134/0000:07:00.0-xdp-10/../smp_affinity_list:2
/proc/irq/135/0000:07:00.0-xdp-11/../smp_affinity_list:3
/proc/irq/136/0000:07:00.0-xdp-12/../smp_affinity_list:4
/proc/irq/137/0000:07:00.0-xdp-13/../smp_affinity_list:5
/proc/irq/138/0000:07:00.0-xdp-14/../smp_affinity_list:6
/proc/irq/139/0000:07:00.0-xdp-15/../smp_affinity_list:7

Signed-off-by: Íñigo Huguet <ihuguet@redhat.com>
---
 drivers/net/ethernet/sfc/efx_channels.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

Comments

Martin Habets Feb. 19, 2022, 1:51 p.m. UTC | #1 
On Wed, Feb 16, 2022 at 10:41:39AM +0100, Íñigo Huguet wrote:
> Affinity hints were being set to CPUs in local NUMA node first, and then
> in other CPUs. This was creating 2 unintended issues:
> 1. Channels created to be assigned each to a different physical core
>    were assigned to hyperthreading siblings because of being in same
>    NUMA node.
>    Since the patch previous to this one, this did not longer happen
>    with default rss_cpus modparam because less channels are created.
> 2. XDP channels could be assigned to CPUs in different NUMA nodes,
>    decreasing performance too much (to less than half in some of my
>    tests).
> 
> This patch sets the affinity hints spreading the channels only in local
> NUMA node's CPUs. A fallback for the case that no CPU in local NUMA node
> is online has been added too.
> 
> Example of CPUs being assigned in a non optimal way before this and the
> previous patch (note: in this system, xdp-8 to xdp-15 are created
> because num_possible_cpus == 64, but num_present_cpus == 32 so they're
> never used):
> 
> $ lscpu | grep -i numa
> NUMA node(s):                    2
> NUMA node0 CPU(s):               0-7,16-23
> NUMA node1 CPU(s):               8-15,24-31
> 
> $ grep -H . /proc/irq/*/0000:07:00.0*/../smp_affinity_list
> /proc/irq/141/0000:07:00.0-0/../smp_affinity_list:0
> /proc/irq/142/0000:07:00.0-1/../smp_affinity_list:1
> /proc/irq/143/0000:07:00.0-2/../smp_affinity_list:2
> /proc/irq/144/0000:07:00.0-3/../smp_affinity_list:3
> /proc/irq/145/0000:07:00.0-4/../smp_affinity_list:4
> /proc/irq/146/0000:07:00.0-5/../smp_affinity_list:5
> /proc/irq/147/0000:07:00.0-6/../smp_affinity_list:6
> /proc/irq/148/0000:07:00.0-7/../smp_affinity_list:7
> /proc/irq/149/0000:07:00.0-8/../smp_affinity_list:16
> /proc/irq/150/0000:07:00.0-9/../smp_affinity_list:17
> /proc/irq/151/0000:07:00.0-10/../smp_affinity_list:18
> /proc/irq/152/0000:07:00.0-11/../smp_affinity_list:19
> /proc/irq/153/0000:07:00.0-12/../smp_affinity_list:20
> /proc/irq/154/0000:07:00.0-13/../smp_affinity_list:21
> /proc/irq/155/0000:07:00.0-14/../smp_affinity_list:22
> /proc/irq/156/0000:07:00.0-15/../smp_affinity_list:23
> /proc/irq/157/0000:07:00.0-xdp-0/../smp_affinity_list:8
> /proc/irq/158/0000:07:00.0-xdp-1/../smp_affinity_list:9
> /proc/irq/159/0000:07:00.0-xdp-2/../smp_affinity_list:10
> /proc/irq/160/0000:07:00.0-xdp-3/../smp_affinity_list:11
> /proc/irq/161/0000:07:00.0-xdp-4/../smp_affinity_list:12
> /proc/irq/162/0000:07:00.0-xdp-5/../smp_affinity_list:13
> /proc/irq/163/0000:07:00.0-xdp-6/../smp_affinity_list:14
> /proc/irq/164/0000:07:00.0-xdp-7/../smp_affinity_list:15
> /proc/irq/165/0000:07:00.0-xdp-8/../smp_affinity_list:24
> /proc/irq/166/0000:07:00.0-xdp-9/../smp_affinity_list:25
> /proc/irq/167/0000:07:00.0-xdp-10/../smp_affinity_list:26
> /proc/irq/168/0000:07:00.0-xdp-11/../smp_affinity_list:27
> /proc/irq/169/0000:07:00.0-xdp-12/../smp_affinity_list:28
> /proc/irq/170/0000:07:00.0-xdp-13/../smp_affinity_list:29
> /proc/irq/171/0000:07:00.0-xdp-14/../smp_affinity_list:30
> /proc/irq/172/0000:07:00.0-xdp-15/../smp_affinity_list:31
> 
> CPUs assignments after this and previous patch, so normal channels
> created only one per core in NUMA node and affinities set only to local
> NUMA node:
> 
> $ grep -H . /proc/irq/*/0000:07:00.0*/../smp_affinity_list
> /proc/irq/116/0000:07:00.0-0/../smp_affinity_list:0
> /proc/irq/117/0000:07:00.0-1/../smp_affinity_list:1
> /proc/irq/118/0000:07:00.0-2/../smp_affinity_list:2
> /proc/irq/119/0000:07:00.0-3/../smp_affinity_list:3
> /proc/irq/120/0000:07:00.0-4/../smp_affinity_list:4
> /proc/irq/121/0000:07:00.0-5/../smp_affinity_list:5
> /proc/irq/122/0000:07:00.0-6/../smp_affinity_list:6
> /proc/irq/123/0000:07:00.0-7/../smp_affinity_list:7
> /proc/irq/124/0000:07:00.0-xdp-0/../smp_affinity_list:16
> /proc/irq/125/0000:07:00.0-xdp-1/../smp_affinity_list:17
> /proc/irq/126/0000:07:00.0-xdp-2/../smp_affinity_list:18
> /proc/irq/127/0000:07:00.0-xdp-3/../smp_affinity_list:19
> /proc/irq/128/0000:07:00.0-xdp-4/../smp_affinity_list:20
> /proc/irq/129/0000:07:00.0-xdp-5/../smp_affinity_list:21
> /proc/irq/130/0000:07:00.0-xdp-6/../smp_affinity_list:22
> /proc/irq/131/0000:07:00.0-xdp-7/../smp_affinity_list:23
> /proc/irq/132/0000:07:00.0-xdp-8/../smp_affinity_list:0
> /proc/irq/133/0000:07:00.0-xdp-9/../smp_affinity_list:1
> /proc/irq/134/0000:07:00.0-xdp-10/../smp_affinity_list:2
> /proc/irq/135/0000:07:00.0-xdp-11/../smp_affinity_list:3
> /proc/irq/136/0000:07:00.0-xdp-12/../smp_affinity_list:4
> /proc/irq/137/0000:07:00.0-xdp-13/../smp_affinity_list:5
> /proc/irq/138/0000:07:00.0-xdp-14/../smp_affinity_list:6
> /proc/irq/139/0000:07:00.0-xdp-15/../smp_affinity_list:7
> 
> Signed-off-by: Íñigo Huguet <ihuguet@redhat.com>
> ---
>  drivers/net/ethernet/sfc/efx_channels.c | 12 ++++++++++--
>  1 file changed, 10 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/ethernet/sfc/efx_channels.c b/drivers/net/ethernet/sfc/efx_channels.c
> index ec6c2f231e73..ef3168fbb5a6 100644
> --- a/drivers/net/ethernet/sfc/efx_channels.c
> +++ b/drivers/net/ethernet/sfc/efx_channels.c
> @@ -387,10 +387,18 @@ void efx_set_interrupt_affinity(struct efx_nic *efx)
>  {
>  	struct efx_channel *channel;
>  	unsigned int cpu;
> +	int numa_node = pcibus_to_node(efx->pci_dev->bus);
> +	const struct cpumask *numa_mask = cpumask_of_node(numa_node);

This violates the reverse Xmas convention.
Other than that it looks good to me.

Martin

> +	/* If no online CPUs in local node, fallback to any online CPU */
> +	if (cpumask_first_and(cpu_online_mask, numa_mask) >= nr_cpu_ids)
> +		numa_mask = cpu_online_mask;
> +
> +	cpu = -1;
>  	efx_for_each_channel(channel, efx) {
> -		cpu = cpumask_local_spread(channel->channel,
> -					   pcibus_to_node(efx->pci_dev->bus));
> +		cpu = cpumask_next_and(cpu, cpu_online_mask, numa_mask);
> +		if (cpu >= nr_cpu_ids)
> +			cpu = cpumask_first_and(cpu_online_mask, numa_mask);
>  		irq_set_affinity_hint(channel->irq, cpumask_of(cpu));
>  	}
>  }
> -- 
> 2.31.1
diff mbox series

Patch

diff --git a/drivers/net/ethernet/sfc/efx_channels.c b/drivers/net/ethernet/sfc/efx_channels.c
index ec6c2f231e73..ef3168fbb5a6 100644
--- a/drivers/net/ethernet/sfc/efx_channels.c
+++ b/drivers/net/ethernet/sfc/efx_channels.c
@@ -387,10 +387,18 @@  void efx_set_interrupt_affinity(struct efx_nic *efx)
 {
 	struct efx_channel *channel;
 	unsigned int cpu;
+	int numa_node = pcibus_to_node(efx->pci_dev->bus);
+	const struct cpumask *numa_mask = cpumask_of_node(numa_node);
 
+	/* If no online CPUs in local node, fallback to any online CPU */
+	if (cpumask_first_and(cpu_online_mask, numa_mask) >= nr_cpu_ids)
+		numa_mask = cpu_online_mask;
+
+	cpu = -1;
 	efx_for_each_channel(channel, efx) {
-		cpu = cpumask_local_spread(channel->channel,
-					   pcibus_to_node(efx->pci_dev->bus));
+		cpu = cpumask_next_and(cpu, cpu_online_mask, numa_mask);
+		if (cpu >= nr_cpu_ids)
+			cpu = cpumask_first_and(cpu_online_mask, numa_mask);
 		irq_set_affinity_hint(channel->irq, cpumask_of(cpu));
 	}
 }