Re: [PATCH] net/mlx5: Add affinity for each irq
From: Shay Drory
Date: Mon Jun 06 2022 - 04:31:30 EST
On 6/6/2022 10:13, Yajun Deng wrote:
The mlx5 would allocate no less than one irq for per cpu, we can bond each
irq to a cpu to improve interrupt performance.
The maximum number of affinity set is hard coded to 4. in case nvec > 4
* (num_CPUs)[1]
we will hit the following WARN[2].
Also, we hit an oops following this WARN...
[1]
mlx5 support up to 2K MSIX (depends on the HW). e.g.: if we max out mlx5
MSIX capability,
we will cross this limit on any machine, at least that I know of.
[2]
This is a machine with 10 CPUs and 350 MSIX
[ 1.633436] ------------[ cut here ]------------
[ 1.633437] WARNING: CPU: 2 PID: 194 at kernel/irq/affinity.c:443 irq_create_affinity_masks+0x175/0x270
[ 1.633467] Modules linked in: mlx5_core(+)
[ 1.633474] CPU: 2 PID: 194 Comm: systemd-modules Not tainted 5.18.0+ #1
[ 1.633480] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
[ 1.633483] RIP: 0010:irq_create_affinity_masks+0x175/0x270
[ 1.633492] Code: 5c 41 5d 41 5e 41 5f c3 48 c7 46 20 90 6d 19 81 48 c7 c0 90 6d 19 81 8b 34 24 4c 89 ef ff d0 41 83 7d 08 04 0f 86 de fe ff ff <0f> 0b 45 31 f6 eb c5 45 8b 5d 00 8b 34 24 43 8d 04 1f 42 8d 0c 1e
[ 1.633497] RSP: 0018:ffff88810716bac0 EFLAGS: 00010202
[ 1.633501] RAX: 000000000000000a RBX: 0000000000000001 RCX: 0000000000000200
[ 1.633504] RDX: ffffffff82605000 RSI: ffffffff82605000 RDI: 0000000000000000
[ 1.633507] RBP: ffff88810716bbd0 R08: 000000000000000a R09: ffffffff82604fc0
[ 1.633510] R10: 0000000000000008 R11: 000ffffffffff000 R12: 0000000000000000
[ 1.633513] R13: ffff88810716bbd0 R14: 0000000000000160 R15: 0000000000000160
[ 1.633516] FS: 00007f8d72994b80(0000) GS:ffff88852c900000(0000) knlGS:0000000000000000
[ 1.633525] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1.633528] CR2: 00007f8d73ba4490 CR3: 0000000103fce001 CR4: 0000000000370ea0
[ 1.633531] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 1.633534] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 1.633536] Call Trace:
[ 1.633549] <TASK>
[ 1.633553] __pci_enable_msix_range+0x2b9/0x4c0
[ 1.633572] pci_alloc_irq_vectors_affinity+0xa5/0x100
[ 1.633579] mlx5_irq_table_create.cold+0x6d/0x22f [mlx5_core]
[ 1.634032] ? probe_one+0x1aa/0x280 [mlx5_core]
[ 1.634193] ? pci_device_probe+0xa4/0x140
[ 1.634201] ? really_probe+0xc9/0x350
[ 1.634205] ? pm_runtime_barrier+0x43/0x80
[ 1.634213] ? __driver_probe_device+0x80/0x170
[ 1.634218] ? driver_probe_device+0x1e/0x90
[ 1.634223] ? __driver_attach+0xcd/0x1b0
[ 1.634226] ? __device_attach_driver+0xf0/0xf0
[ 1.634231] ? __device_attach_driver+0xf0/0xf0
[ 1.634235] ? bus_for_each_dev+0x77/0xc0
[ 1.634243] ? bus_add_driver+0x184/0x1f0
[ 1.634247] ? driver_register+0x8f/0xe0
[ 1.634251] ? 0xffffffffa0180000
[ 1.634256] ? init+0x62/0x1000 [mlx5_core]
[ 1.634413] ? do_one_initcall+0x4a/0x1e0
[ 1.634418] ? kmem_cache_alloc_trace+0x33/0x420
[ 1.634426] ? do_init_module+0x72/0x260
[ 1.634434] ? __do_sys_finit_module+0xbb/0x130
[ 1.634443] ? do_syscall_64+0x3d/0x90
[ 1.634452] ? entry_SYSCALL_64_after_hwframe+0x46/0xb0
[ 1.634461] </TASK>
[ 1.634463] ---[ end trace 0000000000000000 ]---
[[0;32m OK [0m] Finished [0;1;39mudev Coldplug all Devices[0m.
[ 1.713428] Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: mlx5_irq_table_create+0x9c/0xa0 [mlx5_core]
[ 1.715521] CPU: 2 PID: 194 Comm: systemd-modules Tainted: G W 5.18.0+ #1
[ 1.715524] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
[ 1.715525] Call Trace:
[ 1.715532] <TASK>
[ 1.715533] dump_stack_lvl+0x34/0x44
[ 1.715538] panic+0x100/0x255
[ 1.715542] ? mlx5_irq_table_create+0x9c/0xa0 [mlx5_core]
[ 1.715602] __stack_chk_fail+0x10/0x10
[ 1.715607] mlx5_irq_table_create+0x9c/0xa0 [mlx5_core]
[ 1.715662] ? probe_one+0x1aa/0x280 [mlx5_core]
[ 1.715709] ? pci_device_probe+0xa4/0x140
[ 1.715712] ? really_probe+0xc9/0x350
[ 1.715715] ? pm_runtime_barrier+0x43/0x80
[ 1.715718] ? __driver_probe_device+0x80/0x170
[ 1.715719] ? driver_probe_device+0x1e/0x90
[ 1.715721] ? __driver_attach+0xcd/0x1b0
[ 1.715722] ? __device_attach_driver+0xf0/0xf0
[ 1.715723] ? __device_attach_driver+0xf0/0xf0
[ 1.715724] ? bus_for_each_dev+0x77/0xc0
[ 1.715727] ? bus_add_driver+0x184/0x1f0
[ 1.715728] ? driver_register+0x8f/0xe0
[ 1.715730] ? 0xffffffffa0180000
[ 1.715731] ? init+0x62/0x1000 [mlx5_core]
[ 1.715778] ? do_one_initcall+0x4a/0x1e0
[ 1.715781] ? kmem_cache_alloc_trace+0x33/0x420
[ 1.715784] ? do_init_module+0x72/0x260
[ 1.715788] ? __do_sys_finit_module+0xbb/0x130
[ 1.715790] ? do_syscall_64+0x3d/0x90
[ 1.715792] ? entry_SYSCALL_64_after_hwframe+0x46/0xb0
[ 1.715796] </TASK>
[ 1.715938] Kernel Offset: disabled
[ 1.732563] ---[ end Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: mlx5_irq_table_create+0x9c/0xa0 [mlx5_core] ]---
Signed-off-by: Yajun Deng <yajun.deng@xxxxxxxxx>
---
.../net/ethernet/mellanox/mlx5/core/pci_irq.c | 19 ++++++++++++++++++-
1 file changed, 18 insertions(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/pci_irq.c b/drivers/net/ethernet/mellanox/mlx5/core/pci_irq.c
index 662f1d55e30e..d13fc403fe78 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/pci_irq.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/pci_irq.c
@@ -624,11 +624,27 @@ int mlx5_irq_table_get_num_comp(struct mlx5_irq_table *table)
return table->pf_pool->xa_num_irqs.max - table->pf_pool->xa_num_irqs.min;
}
+static void mlx5_calc_sets(struct irq_affinity *affd, unsigned int nvecs)
+{
+ int i;
+
+ affd->nr_sets = (nvecs - 1) / num_possible_cpus() + 1;
+
+ for (i = 0; i < affd->nr_sets; i++) {
+ affd->set_size[i] = min(nvecs, num_possible_cpus());
+ nvecs -= num_possible_cpus();
+ }
+}
+
int mlx5_irq_table_create(struct mlx5_core_dev *dev)
{
int num_eqs = MLX5_CAP_GEN(dev, max_num_eqs) ?
MLX5_CAP_GEN(dev, max_num_eqs) :
1 << MLX5_CAP_GEN(dev, log_max_eq);
+ struct irq_affinity affd = {
+ .pre_vectors = 0,
+ .calc_sets = mlx5_calc_sets,
+ };
int total_vec;
int pf_vec;
int err;
@@ -644,7 +660,8 @@ int mlx5_irq_table_create(struct mlx5_core_dev *dev)
total_vec += MLX5_IRQ_CTRL_SF_MAX +
MLX5_COMP_EQS_PER_SF * mlx5_sf_max_functions(dev);
- total_vec = pci_alloc_irq_vectors(dev->pdev, 1, total_vec, PCI_IRQ_MSIX);
+ total_vec = pci_alloc_irq_vectors_affinity(dev->pdev, 1, total_vec,
+ PCI_IRQ_MSIX | PCI_IRQ_AFFINITY, &affd);
if (total_vec < 0)
return total_vec;
pf_vec = min(pf_vec, total_vec);