set_irq_affinity

#!/bin/bash
# SPDX-License-Identifier: BSD-3-Clause
# Copyright (C) 2015 - 2023 Intel Corporation
#
# Affinitize interrupts to cores
#
# typical usage is (as root):
# set_irq_affinity -x local eth1 <eth2> <eth3>
# set_irq_affinity -s eth1
#
# to get help:
# set_irq_affinity

usage()
{
	echo
	echo "Usage: option -s <interface> to show current settings only"
	echo "Usage: $0 [-x|-X] [all|local|remote [<node>]|one <core>|custom|<cores>] <interface> ..."
	echo "	Options: "
	echo "	  -s		Shows current affinity settings"
	echo "	  -x		Configure XPS as well as smp_affinity"
	echo "	  -X		Disable XPS but set smp_affinity"
	echo "	  [all] is the default value"
	echo "	  [remote [<node>]] can be followed by a specific node number"
	echo "	Examples:"
	echo "	  $0 -s eth1            # Show settings on eth1"

	echo "	  $0 all eth1 eth2      # eth1 and eth2 to all cores"
	echo "	  $0 one 2 eth1         # eth1 to core 2 only"
	echo "	  $0 local eth1         # eth1 to local cores only"
	echo "	  $0 remote eth1        # eth1 to remote cores only"
	echo "	  $0 custom eth1        # prompt for eth1 interface"
	echo "	  $0 0-7,16-23 eth0     # eth1 to cores 0-7 and 16-23"
	echo
	exit 1
}

usageX()
{
	echo "options -x and -X cannot both be specified, pick one"
	exit 1
}

if [ "$1" == "-x" ]; then
	XPS_ENA=1
	shift
fi

if [ "$1" == "-s" ]; then
	SHOW=1
	echo Show affinity settings
	shift
fi

if [ "$1" == "-X" ]; then
	if [ -n "$XPS_ENA" ]; then
		usageX
	fi
	XPS_DIS=2
	shift
fi

if [ "$1" == -x ]; then
	usageX
fi

if [ -n "$XPS_ENA" ] && [ -n "$XPS_DIS" ]; then
	usageX
fi

if [ -z "$XPS_ENA" ]; then
	XPS_ENA=$XPS_DIS
fi

SED=`which sed`
if [[ ! -x $SED ]]; then
	echo " $0: ERROR: sed not found in path, this script requires sed"
	exit 1
fi

num='^[0-9]+$'

# search helpers
NOZEROCOMMA="s/^[0,]*//"
# Vars
AFF=$1
shift

case "$AFF" in
    remote)	[[ $1 =~ $num ]] && rnode=$1 && shift ;;
    one)	[[ $1 =~ $num ]] && cnt=$1 && shift ;;
    all)	;;
    local)	;;
    custom)	;;
    [0-9]*)	;;
    -h|--help)	usage ;;
    "")		usage ;;
    *)		IFACES=$AFF && AFF=all ;;	# Backwards compat mode
esac

# append the interfaces listed to the string with spaces
while [ "$#" -ne "0" ] ; do
	IFACES+=" $1"
	shift
done

# for now the user must specify interfaces
if [ -z "$IFACES" ]; then
	usage
	exit 2
fi

notfound()
{
	echo $MYIFACE: not found
	exit 15
}

# check the interfaces exist
for MYIFACE in $IFACES; do
	grep -q $MYIFACE /proc/net/dev || notfound
done

# support functions

build_mask()
{
	VEC=$core
	if [ $VEC -ge 32 ]
	then
		MASK_FILL=""
		MASK_ZERO="00000000"
		let "IDX = $VEC / 32"
		for ((i=1; i<=$IDX;i++))
		do
			MASK_FILL="${MASK_FILL},${MASK_ZERO}"
		done

		let "VEC -= 32 * $IDX"
		MASK_TMP=$((1<<$VEC))
		MASK=$(printf "%X%s" $MASK_TMP $MASK_FILL)
	else
		MASK_TMP=$((1<<$VEC))
		MASK=$(printf "%X" $MASK_TMP)
	fi
}

show_affinity()
{
	# returns the MASK variable
	build_mask

	SMP_I=`sed -E "${NOZEROCOMMA}" /proc/irq/$IRQ/smp_affinity`
	HINT=`sed -E "${NOZEROCOMMA}" /proc/irq/$IRQ/affinity_hint`
	printf "ACTUAL	%s %d %s <- /proc/irq/$IRQ/smp_affinity\n" $IFACE $core $SMP_I
	printf "HINT 	%s %d %s <- /proc/irq/$IRQ/affinity_hint\n" $IFACE $core $HINT
	IRQ_CHECK=`grep '[-,]' /proc/irq/$IRQ/smp_affinity_list`
	if [ ! -z $IRQ_CHECK ]; then
		printf " WARNING -- SMP_AFFINITY is assigned to multiple cores $IRQ_CHECK\n"
	fi
	if [ "$SMP_I" != "$HINT" ]; then
		printf " WARNING -- SMP_AFFINITY VALUE does not match AFFINITY_HINT \n"
	fi
	printf "NODE 	%s %d %s <- /proc/irq/$IRQ/node\n" $IFACE $core `cat /proc/irq/$IRQ/node`
	printf "LIST	%s %d [%s] <- /proc/irq/$IRQ/smp_affinity_list\n" $IFACE $core `cat /proc/irq/$IRQ/smp_affinity_list`
	printf "XPS	%s %d %s <- /sys/class/net/%s/queues/tx-%d/xps_cpus\n" $IFACE $core `cat /sys/class/net/$IFACE/queues/tx-$((n-1))/xps_cpus` $IFACE $((n-1))
	if [ -z `ls /sys/class/net/$IFACE/queues/tx-$((n-1))/xps_rxqs` ]; then
		echo "WARNING: xps rxqs not supported on $IFACE"
	else
		printf "XPSRXQs	%s %d %s <- /sys/class/net/%s/queues/tx-%d/xps_rxqs\n" $IFACE $core `cat /sys/class/net/$IFACE/queues/tx-$((n-1))/xps_rxqs` $IFACE $((n-1))
	fi
	printf "TX_MAX	%s %d %s <- /sys/class/net/%s/queues/tx-%d/tx_maxrate\n" $IFACE $core `cat /sys/class/net/$IFACE/queues/tx-$((n-1))/tx_maxrate` $IFACE $((n-1))
	printf "BQLIMIT	%s %d %s <- /sys/class/net/%s/queues/tx-%d/byte_queue_limits/limit\n" $IFACE $core `cat /sys/class/net/$IFACE/queues/tx-$((n-1))/byte_queue_limits/limit` $IFACE $((n-1))
	printf "BQL_MAX	%s %d %s <- /sys/class/net/%s/queues/tx-%d/byte_queue_limits/limit_max\n" $IFACE $core `cat /sys/class/net/$IFACE/queues/tx-$((n-1))/byte_queue_limits/limit_max` $IFACE $((n-1))
	printf "BQL_MIN	%s %d %s <- /sys/class/net/%s/queues/tx-%d/byte_queue_limits/limit_min\n" $IFACE $core `cat /sys/class/net/$IFACE/queues/tx-$((n-1))/byte_queue_limits/limit_min` $IFACE $((n-1))
	if [ -z `ls /sys/class/net/$IFACE/queues/rx-$((n-1))/rps_flow_cnt` ]; then
		echo "WARNING: aRFS is not supported on $IFACE"
	else
		printf "RPSFCNT	%s %d %s <- /sys/class/net/%s/queues/rx-%d/rps_flow_cnt\n" $IFACE $core `cat /sys/class/net/$IFACE/queues/rx-$((n-1))/rps_flow_cnt` $IFACE $((n-1))
	fi
	if [ -z `ls /sys/class/net/$IFACE/queues/rx-$((n-1))/rps_cpus` ]; then
		echo "WARNING: rps_cpus is not available on $IFACE"
	else
		printf "RPSCPU	%s %d %s <- /sys/class/net/%s/queues/rx-%d/rps_cpus\n" $IFACE $core `cat /sys/class/net/$IFACE/queues/rx-$((n-1))/rps_cpus` $IFACE $((n-1))
	fi
	echo
}

set_affinity()
{
	# returns the MASK variable
	build_mask

	printf "%s" $MASK > /proc/irq/$IRQ/smp_affinity
	printf "%s %d %s -> /proc/irq/$IRQ/smp_affinity\n" $IFACE $core $MASK
	SMP_I=`sed -E "${NOZEROCOMMA}" /proc/irq/$IRQ/smp_affinity`
	if [ "$SMP_I" != "$MASK" ]; then
		printf " ACTUAL\t%s %d %s <- /proc/irq/$IRQ/smp_affinity\n" $IFACE $core $SMP_I
		printf " WARNING -- SMP_AFFINITY setting failed\n"
	fi
	case "$XPS_ENA" in
	1)
		printf "%s %d %s -> /sys/class/net/%s/queues/tx-%d/xps_cpus\n" $IFACE $core $MASK $IFACE $((n-1))
		printf "%s" $MASK > /sys/class/net/$IFACE/queues/tx-$((n-1))/xps_cpus
	;;
	2)
		MASK=0
		printf "%s %d %s -> /sys/class/net/%s/queues/tx-%d/xps_cpus\n" $IFACE $core $MASK $IFACE $((n-1))
		printf "%s" $MASK > /sys/class/net/$IFACE/queues/tx-$((n-1))/xps_cpus
	;;
	*)
	esac
}

# Allow usage of , or -
#
parse_range () {
        RANGE=${@//,/ }
        RANGE=${RANGE//-/..}
        LIST=""
        for r in $RANGE; do
		# eval lets us use vars in {#..#} range
                [[ $r =~ '..' ]] && r="$(eval echo {$r})"
		LIST+=" $r"
        done
	echo $LIST
}

# Affinitize interrupts
#
doaff()
{
	CORES=$(parse_range $CORES)
	ncores=$(echo $CORES | wc -w)
	n=1

	# this script only supports interrupt vectors in pairs,
	# modification would be required to support a single Tx or Rx queue
	# per interrupt vector

	queues="${IFACE}-.*TxRx"

	irqs=$(grep "$queues" /proc/interrupts | cut -f1 -d:)
	[ -z "$irqs" ] && irqs=$(grep $IFACE /proc/interrupts | cut -f1 -d:)
	[ -z "$irqs" ] && irqs=$(for i in `ls -1 /sys/class/net/${IFACE}/device/msi_irqs | sort -n` ;do grep -w $i: /proc/interrupts | egrep -v 'fdir|async|misc|ctrl' | cut -f 1 -d :; done)
	[ -z "$irqs" ] && echo "Error: Could not find interrupts for $IFACE"

	if [ "$SHOW" == "1" ] ; then
		echo "TYPE IFACE CORE MASK -> FILE"
		echo "============================"
	else
		echo "IFACE CORE MASK -> FILE"
		echo "======================="
	fi

	for IRQ in $irqs; do
		[ "$n" -gt "$ncores" ] && n=1
		j=1
		# much faster than calling cut for each
		for i in $CORES; do
			[ $((j++)) -ge $n ] && break
		done
		core=$i
		if [ "$SHOW" == "1" ] ; then
			show_affinity
		else
			set_affinity
		fi
		((n++))
	done
}

# these next 2 lines would allow script to auto-determine interfaces
#[ -z "$IFACES" ] && IFACES=$(ls /sys/class/net)
#[ -z "$IFACES" ] && echo "Error: No interfaces up" && exit 1

# echo IFACES is $IFACES

CORES=$(</sys/devices/system/cpu/online)
[ "$CORES" ] || CORES=$(grep ^proc /proc/cpuinfo | cut -f2 -d:)

# Core list for each node from sysfs
node_dir=/sys/devices/system/node
for i in $(ls -d $node_dir/node*); do
	i=${i/*node/}
	corelist[$i]=$(<$node_dir/node${i}/cpulist)
done

for IFACE in $IFACES; do
	# echo $IFACE being modified

	dev_dir=/sys/class/net/$IFACE/device
	[ -e $dev_dir/numa_node ] && node=$(<$dev_dir/numa_node)
	[ "$node" ] && [ "$node" -gt 0 ] || node=0

	case "$AFF" in
	local)
		CORES=${corelist[$node]}
	;;
	remote)
		[ "$rnode" ] || { [ $node -eq 0 ] && rnode=1 || rnode=0; }
		CORES=${corelist[$rnode]}
	;;
	one)
		[ -n "$cnt" ] || cnt=0
		CORES=$cnt
	;;
	all)
		CORES=$CORES
	;;
	custom)
		echo -n "Input cores for $IFACE (ex. 0-7,15-23): "
		read CORES
	;;
	[0-9]*)
		CORES=$AFF
	;;
	*)
		usage
		exit 1
	;;
	esac

	# call the worker function
	doaff
done

# check for irqbalance running
IRQBALANCE_ON=`ps ax | grep -v grep | grep -q irqbalance; echo $?`
if [ "$IRQBALANCE_ON" == "0" ] ; then
	echo " WARNING: irqbalance is running and will"
	echo "          likely override this script's affinitization."
	echo "          Please stop the irqbalance service and/or execute"
	echo "          'killall irqbalance'"
	exit 2
fi