Re: [PATCH] realtime-virtual-host profile: remove lapic advancement calculation

Thanks for the patch Marcelo. I believe the tuned.spec file should also be updated now that qemu-kvm-tools-rhev package doesn't seem to be needed? On Tue, Jul 21, 2020 at 7:21 PM Marcelo Tosatti <mtosatti(a)redhat.com&gt; wrote: > > The LAPIC advancement improvement is minimal (3 or 4 us) and its > calculation has shown to be problematic under certain > scenarios (for example if qemu-kvm is not installed). > > Remove it. > > Signed-off-by: Marcelo Tosatti <mtosatti(a)redhat.com&gt; > > diff --git > a/profiles/realtime-virtual-host/find-lapictscdeadline-optimal.sh > b/profiles/realtime-virtual-host/find-lapictscdeadline-optimal.sh > deleted file mode 100755 > index 539c47e..0000000 > --- a/profiles/realtime-virtual-host/find-lapictscdeadline-optimal.sh > +++ /dev/null > @@ -1,30 +0,0 @@ > -#!/bin/bash > - > -: ${1?"Usage: $0 latency-file"} > - > -lines=`wc -l $1 | cut -f 1 -d " "` > -in_range=0 > -prev_value=1 > -for i in `seq 1 $lines`; do > - a=`awk "NR==$i" $1 | cut -f 2 -d ":"` > - value=$(($a*100/$prev_value)) > - if [ $value -ge 98 -a $value -le 102 ]; then > - in_range=$(($in_range + 1)) > - else > - in_range=0 > - fi > - if [ $in_range -ge 2 ]; then > - echo -n "optimal value for lapic_timer_advance_ns is: " > - awk "NR==$(($i - 1))" $1 | cut -f 1 -d ":" > - exit 0 > - fi > - prev_value=$a > -done > -# if still decreasing, then use highest ns value > -if [ $value -le 99 ]; then > - echo -n "optimal value for lapic_timer_advance_ns is: " > - awk "NR==$(($i - 1))" $1 | cut -f 1 -d ":" > - exit 0 > -fi > -echo optimal not found > -exit 1 > diff --git a/profiles/realtime-virtual-host/script.sh > b/profiles/realtime-virtual-host/script.sh > index edae6c5..a11dac7 100755 > --- a/profiles/realtime-virtual-host/script.sh > +++ b/profiles/realtime-virtual-host/script.sh > @@ -2,102 +2,13 @@ > > . /usr/lib/tuned/functions > > -CACHE_VALUE_FILE=./lapic_timer_adv_ns > -CACHE_CPU_FILE=./lapic_timer_adv_ns.cpumodel > -KVM_LAPIC_FILE=/sys/module/kvm/parameters/lapic_timer_advance_ns > KTIMER_LOCKLESS_FILE=/sys/kernel/ktimer_lockless_check > -QEMU=$(type -P qemu-kvm || echo /usr/libexec/qemu-kvm) > -TSCDEADLINE_LATENCY="/usr/share/qemu-kvm/tscdeadline_latency.flat" > -[ -f "$TSCDEADLINE_LATENCY" ] || > TSCDEADLINE_LATENCY="/usr/share/tuned-profiles-nfv-host-bin/tscdeadline_latency.flat" > -[ -f "$TSCDEADLINE_LATENCY" ] || > TSCDEADLINE_LATENCY="/usr/share/tuned/tscdeadline_latency.flat" > - > -run_tsc_deadline_latency() > -{ > - dir=`mktemp -d` > - > - for i in `seq 1000 500 7000`; do > - echo $i > $KVM_LAPIC_FILE > - > - unixpath=`mktemp` > - > - chrt -f 1 $QEMU -S -enable-kvm -device pc-testdev \ > - -device isa-debug-exit,iobase=0xf4,iosize=0x4 \ > - -display none -serial stdio -device pci-testdev \ > - -kernel "$TSCDEADLINE_LATENCY" \ > - -cpu host,tsc-deadline=on \ > - -mon chardev=char0,mode=readline \ > - -chardev socket,id=char0,nowait,path=$unixpath,server | grep > latency | cut -f 2 -d ":" > $dir/out & > - > - sleep 1s > - pidofvcpu=`echo "info cpus" | ncat -U $unixpath | grep thread_id > | cut -f 3 -d "=" | tr -d "\r"` > - taskset -p -c $1 $pidofvcpu >/dev/null > - echo "cont" | ncat -U $unixpath >/dev/null > - wait > - > - if [ ! -f $dir/out ]; then > - die running $TSCDEADLINE_LATENCY failed > - fi > - > - tmp=$(wc -l $dir/out | awk '{ print $1 }') > - if [ $tmp -eq 0 ]; then > - die running $TSCDEADLINE_LATENCY failed > - fi > - > - A=0 > - while read l; do > - A=$(($A+$l)) > - done < $dir/out > - > - lines=`wc -l $dir/out | cut -f 1 -d " "` > - ans=$(($A/$lines)) > - echo $i: $ans > - done > -} > > start() { > setup_kvm_mod_low_latency > > disable_ksm > > - # If CPU model has changed, clean the cache > - if [ -f $CACHE_CPU_FILE ]; then > - curmodel=`cat /proc/cpuinfo | grep "model name" | cut -f 2 -d ":" > | uniq` > - if [ -z "$curmodel" ]; then > - die failed to read CPU model > - fi > - > - genmodel=`cat $CACHE_CPU_FILE` > - > - if [ "$curmodel" != "$genmodel" ]; then > - rm -f $CACHE_VALUE_FILE > - rm -f $CACHE_CPU_FILE > - fi > - fi > - > - # If the cache is empty, find the best lapic_timer_advance_ns value > - # and cache it > - > - if [ ! -f $KVM_LAPIC_FILE ]; then > - die $KVM_LAPIC_FILE not found > - fi > - > - if [ ! -f $CACHE_VALUE_FILE ]; then > - if [ -f "$TSCDEADLINE_LATENCY" ]; then > - tempdir=`mktemp -d` > - isolatedcpu=`echo "$TUNED_isolated_cores_expanded" | cut -f > 1 -d ","` > - run_tsc_deadline_latency $isolatedcpu > $tempdir/lat.out > - if ! ./find-lapictscdeadline-optimal.sh $tempdir/lat.out > > $tempdir/opt.out; then > - die could not find optimal latency > - fi > - echo `cat $tempdir/opt.out | cut -f 2 -d ":"` > > $CACHE_VALUE_FILE > - curmodel=`cat /proc/cpuinfo | grep "model name" | cut -f 2 > -d ":" | uniq` > - echo "$curmodel" > $CACHE_CPU_FILE > - fi > - fi > - > - if [ -f $CACHE_VALUE_FILE ]; then > - echo `cat $CACHE_VALUE_FILE` > $KVM_LAPIC_FILE > - fi > systemctl start rt-entsk > > if [ -f $KTIMER_LOCKLESS_FILE ]; then > >