1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
|
#!/bin/bash
# Copyright 2016 Google Inc. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# For a single-queue / no MSI-X virtionet device, sets the IRQ affinities to
# processor 0. For this virtionet configuration, distributing IRQs to all
# processors results in comparatively high cpu utilization and comparatively
# low network bandwidth.
#
# For a multi-queue / MSI-X virtionet device, sets the IRQ affinities to the
# per-IRQ affinity hint. The virtionet driver maps each virtionet TX (RX) queue
# MSI-X interrupt to a unique single CPU if the number of TX (RX) queues equals
# the number of online CPUs. The mapping of network MSI-X interrupt vector to
# CPUs is stored in the virtionet MSI-X interrupt vector affinity hint. This
# configuration allows network traffic to be spread across the CPUs, giving
# each CPU a dedicated TX and RX network queue, while ensuring that all packets
# from a single flow are delivered to the same CPU.
function is_decimal_int() {
[ "${1}" -eq "${1}" ] > /dev/null 2>&1
}
function set_channels() {
ethtool -L "${1}" combined "${2}" > /dev/null 2>&1
}
echo "Running $(basename "$0")."
NET_DEVS=/sys/bus/virtio/drivers/virtio_net/virtio*
# Loop through all the virtionet devices and enable multi-queue
if [ -x /sbin/ethtool ]; then
for dev in $NET_DEVS; do
ETH_DEVS=${dev}/net/*
for eth_dev in $ETH_DEVS; do
eth_dev=$(basename "$eth_dev")
if ! errormsg=$(ethtool -l "$eth_dev" 2>&1); then
echo "/sbin/ethtool says that $eth_dev does not support virtionet multiqueue: $errormsg."
continue
fi
num_max_channels=$(ethtool -l "$eth_dev" | grep -m 1 Combined | cut -f2)
[ "${num_max_channels}" -eq "1" ] && continue
if is_decimal_int "$num_max_channels" && \
set_channels "$eth_dev" "$num_max_channels"; then
echo "Set channels for $eth_dev to $num_max_channels."
else
echo "Could not set channels for $eth_dev to $num_max_channels."
fi
done
done
else
echo "/sbin/ethtool not found: cannot configure virtionet multiqueue."
fi
for dev in $NET_DEVS
do
dev=$(basename "$dev")
irq_dir=/proc/irq/*
for irq in $irq_dir
do
smp_affinity="${irq}/smp_affinity"
[ ! -f "${smp_affinity}" ] && continue
# Classify this IRQ as virtionet intx, virtionet MSI-X, or non-virtionet
# If the IRQ type is virtionet intx, a subdirectory with the same name as
# the device will be present. If the IRQ type is virtionet MSI-X, then
# a subdirectory of the form <device name>-<input|output>.N will exist.
# In this case, N is the input (output) queue number, and is specified as
# a decimal integer ranging from 0 to K - 1 where K is the number of
# input (output) queues in the virtionet device.
virtionet_intx_dir="${irq}/${dev}"
virtionet_msix_dir_regex=".*/${dev}-(input|output)\.[0-9]+$"
if [ -d "${virtionet_intx_dir}" ]; then
# All virtionet intx IRQs are delivered to CPU 0
echo "Setting ${smp_affinity} to 01 for device ${dev}."
echo "01" > "${smp_affinity}"
continue
fi
# Not virtionet intx, probe for MSI-X
virtionet_msix_found=0
for entry in ${irq}/${dev}*; do
if [[ "$entry" =~ ${virtionet_msix_dir_regex} ]]; then
virtionet_msix_found=1
fi
done
affinity_hint="${irq}/affinity_hint"
[ "$virtionet_msix_found" -eq 0 -o ! -f "${affinity_hint}" ] && continue
# The affinity hint file contains a CPU mask, consisting of
# groups of up to 8 hexadecimal digits, separated by a comma. Each bit
# position in the CPU mask hex value specifies whether this interrupt
# should be delivered to the corresponding CPU. For example, if bits 0
# and 3 are set in the affinity hint CPU mask hex value, then the
# interrupt should be delivered to CPUs 0 and 3. The virtionet device
# driver should set only a single bit in the affinity hint per MSI-X
# interrupt, ensuring each TX (RX) queue is used only by a single CPU.
# The virtionet driver will only specify an affinity hint if the number of
# TX (RX) queues equals the number of online CPUs. If no affinity hint is
# specified for an IRQ, the affinity hint file will contain all zeros.
affinity_cpumask=$(cat "${affinity_hint}")
affinity_hint_enabled=0
# Parse the affinity hint, skip if mask is invalid or is empty (all-zeros)
OIFS=${IFS}
IFS=","
for cpu_bitmap in ${affinity_cpumask}; do
bitmap_val=$(printf "%d" "0x${cpu_bitmap}" 2>/dev/null)
if [ "$?" -ne 0 ]; then
echo "Invalid affinity hint ${affinity_hint}: ${affinity_cpumask}."
affinity_hint_enabled=0
break
elif [ "${bitmap_val}" -ne 0 ]; then
affinity_hint_enabled=1
fi
done
IFS=${OIFS}
if [ "${affinity_hint_enabled}" -eq 0 ]; then
echo "Cannot set IRQ affinity ${smp_affinity}, affinity hint disabled."
else
# Set the IRQ CPU affinity to the virtionet-initialized affinity hint
echo "Setting ${smp_affinity} to ${affinity_cpumask} for device ${dev}."
echo "${affinity_cpumask}" > "${smp_affinity}"
fi
done
done
|
