如何覆蓋 NVME 設備的 IRQ 關聯
我正在嘗試將所有中斷移至核心 0-3,以保持其餘核心空閒,以實現高速、低延遲的虛擬化。
我寫了一個快速腳本來將 IRQ 親和性設置為 0-3:
#!/bin/bash while IFS= read -r LINE; do echo "0-3 -> \"$LINE\"" sudo bash -c "echo 0-3 > \"$LINE\"" done <<< "$(find /proc/irq/ -name smp_affinity_list)"
這似乎適用於 USB 設備和網路設備,但不適用於 NVME 設備。他們都產生這個錯誤:
bash: line 1: echo: write error: Input/output error
他們頑固地繼續在我幾乎所有的核心上均勻地產生中斷。
如果我檢查這些設備的目前親和力:
$ cat /proc/irq/81/smp_affinity_list 0-1,16-17 $ cat /proc/irq/82/smp_affinity_list 2-3,18-19 $ cat /proc/irq/83/smp_affinity_list 4-5,20-21 $ cat /proc/irq/84/smp_affinity_list 6-7,22-23 ...
似乎“某事”正在完全控制跨核心傳播 IRQ,而不是讓我改變它。
將這些移動到其他核心是完全關鍵的,因為我在這些核心上的虛擬機中執行大量 IO,並且 NVME 驅動器正在產生大量中斷。這不是 Windows,我應該能夠決定我的機器做什麼。
什麼是控制這些設備的 IRQ 親和性以及如何覆蓋它?
我在 Gigabyte Auros X570 Master 主機板上使用 Ryzen 3950X CPU,3 個 NVME 驅動器連接到主機板上的 M.2 埠。
(更新:我現在使用的是 5950X,仍然有完全相同的問題)
核心:5.12.2-arch1-1
lspci -v
與 NVME 相關的輸出:01:00.0 Non-Volatile memory controller: Phison Electronics Corporation E12 NVMe Controller (rev 01) (prog-if 02 [NVM Express]) Subsystem: Phison Electronics Corporation E12 NVMe Controller Flags: bus master, fast devsel, latency 0, IRQ 45, NUMA node 0, IOMMU group 14 Memory at fc100000 (64-bit, non-prefetchable) [size=16K] Capabilities: [80] Express Endpoint, MSI 00 Capabilities: [d0] MSI-X: Enable+ Count=9 Masked- Capabilities: [e0] MSI: Enable- Count=1/8 Maskable- 64bit+ Capabilities: [f8] Power Management version 3 Capabilities: [100] Latency Tolerance Reporting Capabilities: [110] L1 PM Substates Capabilities: [128] Alternative Routing-ID Interpretation (ARI) Capabilities: [200] Advanced Error Reporting Capabilities: [300] Secondary PCI Express Kernel driver in use: nvme 04:00.0 Non-Volatile memory controller: Phison Electronics Corporation E12 NVMe Controller (rev 01) (prog-if 02 [NVM Express]) Subsystem: Phison Electronics Corporation E12 NVMe Controller Flags: bus master, fast devsel, latency 0, IRQ 24, NUMA node 0, IOMMU group 25 Memory at fbd00000 (64-bit, non-prefetchable) [size=16K] Capabilities: [80] Express Endpoint, MSI 00 Capabilities: [d0] MSI-X: Enable+ Count=9 Masked- Capabilities: [e0] MSI: Enable- Count=1/8 Maskable- 64bit+ Capabilities: [f8] Power Management version 3 Capabilities: [100] Latency Tolerance Reporting Capabilities: [110] L1 PM Substates Capabilities: [128] Alternative Routing-ID Interpretation (ARI) Capabilities: [200] Advanced Error Reporting Capabilities: [300] Secondary PCI Express Kernel driver in use: nvme 05:00.0 Non-Volatile memory controller: Phison Electronics Corporation E12 NVMe Controller (rev 01) (prog-if 02 [NVM Express]) Subsystem: Phison Electronics Corporation E12 NVMe Controller Flags: bus master, fast devsel, latency 0, IRQ 40, NUMA node 0, IOMMU group 26 Memory at fbc00000 (64-bit, non-prefetchable) [size=16K] Capabilities: [80] Express Endpoint, MSI 00 Capabilities: [d0] MSI-X: Enable+ Count=9 Masked- Capabilities: [e0] MSI: Enable- Count=1/8 Maskable- 64bit+ Capabilities: [f8] Power Management version 3 Capabilities: [100] Latency Tolerance Reporting Capabilities: [110] L1 PM Substates Capabilities: [128] Alternative Routing-ID Interpretation (ARI) Capabilities: [200] Advanced Error Reporting Capabilities: [300] Secondary PCI Express Kernel driver in use: nvme
$ dmesg | grep -i nvme [ 2.042888] nvme nvme0: pci function 0000:01:00.0 [ 2.042912] nvme nvme1: pci function 0000:04:00.0 [ 2.042941] nvme nvme2: pci function 0000:05:00.0 [ 2.048103] nvme nvme0: missing or invalid SUBNQN field. [ 2.048109] nvme nvme2: missing or invalid SUBNQN field. [ 2.048109] nvme nvme1: missing or invalid SUBNQN field. [ 2.048112] nvme nvme0: Shutdown timeout set to 10 seconds [ 2.048120] nvme nvme1: Shutdown timeout set to 10 seconds [ 2.048127] nvme nvme2: Shutdown timeout set to 10 seconds [ 2.049578] nvme nvme0: 8/0/0 default/read/poll queues [ 2.049668] nvme nvme1: 8/0/0 default/read/poll queues [ 2.049716] nvme nvme2: 8/0/0 default/read/poll queues [ 2.051211] nvme1n1: p1 [ 2.051260] nvme2n1: p1 [ 2.051577] nvme0n1: p1 p2
什麼是控制這些設備的 IRQ 親和性?
自v4.8以來的Linux 核心在 NVMe 驅動程序中自動使用MSI/MSI-X中斷屏蔽;和
IRQD_AFFINITY_MANAGED
, 自動管理核心中的 MSI/MSI-X 中斷。查看這些送出:
90c9712fbb388077b5e53069cae43f1acbb0102a
- NVMe:始終使用 MSI/MSI-X 中斷9c2555835bb3d34dfac52a0be943dcc4bedd650f
- genirq:引入IRQD_AFFINITY_MANAGED
標誌通過輸出查看您的核心版本和設備功能
lspci -v
,顯然是這樣。以及如何覆蓋它?
除了禁用標誌和重新編譯核心之外,還可能禁用 MSI/MSI-X 到您的 PCI 橋接器(而不是設備):
echo 1 > /sys/bus/pci/devices/$bridge/msi_bus
請注意,禁用 MSI/MSI-X 會對性能產生影響。有關更多詳細資訊,請參閱此核心文件。
除了禁用 MSI/MSI-X,更好的方法是保留 MSI-X,同時在 NVMe 驅動程序中啟用輪詢模式。請參閱Andrew H 的回答。