[PATCH rcu 12/21] torture: Make kvm.sh select per-scenario affinity masks

Paul E. McKenney
2021-07-21T21:02:09Z

This commit causes kvm.sh to use the new kvm-assign-cpus.sh and
kvm-get-cpus-script.sh scripts to create a TORTURE_AFFINITY environment
variable containing either an empty string (for no affinity) or a list
of CPUs to pin the scenario's vCPUs to. A later commit will make
use of this information to actually pin the vCPUs.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
.../rcutorture/bin/kvm-assign-cpus.sh | 105 ++++++++++++++++++
.../rcutorture/bin/kvm-get-cpus-script.sh | 87 +++++++++++++++
.../rcutorture/bin/kvm-test-1-run-batch.sh | 1 +
tools/testing/selftests/rcutorture/bin/kvm.sh | 14 ++-
4 files changed, 205 insertions(+), 2 deletions(-)
create mode 100755 tools/testing/selftests/rcutorture/bin/kvm-assign-cpus.sh
create mode 100755 tools/testing/selftests/rcutorture/bin/kvm-get-cpus-script.sh

diff --git a/tools/testing/selftests/rcutorture/bin/kvm-assign-cpus.sh b/tools/testing/selftests/rcutorture/bin/kvm-assign-cpus.sh
new file mode 100755
index 0000000000000..494ae91cc1f0e
--- /dev/null
+++ b/tools/testing/selftests/rcutorture/bin/kvm-assign-cpus.sh
@@ -0,0 +1,105 @@
+#!/bin/sh
+#
+# Produce awk statements roughly depicting the system's CPU and cache
+# layout. If the required information is not available, produce
+# error messages as awk comments. Successful exit regardless.
+#
+# Usage: kvm-assign-cpus.sh /path/to/sysfs
+
+T=/tmp/kvm-assign-cpus.sh.$$
+trap 'rm -rf $T' 0 2
+mkdir $T
+
+sysfsdir=${1-/sys/devices/system/node}
+if ! cd "$sysfsdir" > $T/msg 2>&1
+then
+ sed -e 's/^/# /' < $T/msg
+ exit 0
+fi
+nodelist="`ls -d node*`"
+for i in node*
+do
+ if ! test -d $i/
+ then
+ echo "# Not a directory: $sysfsdir/node*"
+ exit 0
+ fi
+ for j in $i/cpu*/cache/index*
+ do
+ if ! test -d $j/
+ then
+ echo "# Not a directory: $sysfsdir/$j"
+ exit 0
+ else
+ break
+ fi
+ done
+ indexlist="`ls -d $i/cpu* | grep 'cpu[0-9][0-9]*' | head -1 | sed -e 's,^.*$,ls -d &/cache/index*,' | sh | sed -e 's,^.*/,,'`"
+ break
+done
+for i in node*/cpu*/cache/index*/shared_cpu_list
+do
+ if ! test -f $i
+ then
+ echo "# Not a file: $sysfsdir/$i"
+ exit 0
+ else
+ break
+ fi
+done
+firstshared=
+for i in $indexlist
+do
+ rm -f $T/cpulist
+ for n in node*
+ do
+ f="$n/cpu*/cache/$i/shared_cpu_list"
+ if ! cat $f > $T/msg 2>&1
+ then
+ sed -e 's/^/# /' < $T/msg
+ exit 0
+ fi
+ cat $f >> $T/cpulist
+ done
+ if grep -q '[-,]' $T/cpulist
+ then
+ if test -z "$firstshared"
+ then
+ firstshared="$i"
+ fi
+ fi
+done
+if test -z "$firstshared"
+then
+ splitindex="`echo $indexlist | sed -e 's/ .*$//'`"
+else
+ splitindex="$firstshared"
+fi
+nodenum=0
+for n in node*
+do
+ cat $n/cpu*/cache/$splitindex/shared_cpu_list | sort -u -k1n |
+ awk -v nodenum="$nodenum" '
+ BEGIN {
+ idx = 0;
+ }
+
+ {
+ nlists = split($0, cpulists, ",");
+ for (i = 1; i <= nlists; i++) {
+ listsize = split(cpulists[i], cpus, "-");
+ if (listsize == 1)
+ cpus[2] = cpus[1];
+ for (j = cpus[1]; j <= cpus[2]; j++) {
+ print "cpu[" nodenum "][" idx "] = " j ";";
+ idx++;
+ }
+ }
+ }
+
+ END {
+ print "nodecpus[" nodenum "] = " idx ";";
+ }'
+ nodenum=`expr $nodenum + 1`
+done
+echo "numnodes = $nodenum;"
diff --git a/tools/testing/selftests/rcutorture/bin/kvm-get-cpus-script.sh b/tools/testing/selftests/rcutorture/bin/kvm-get-cpus-script.sh
new file mode 100755
index 0000000000000..0ab7fca5bec12
--- /dev/null
+++ b/tools/testing/selftests/rcutorture/bin/kvm-get-cpus-script.sh
@@ -0,0 +1,87 @@
+#!/bin/sh
+#
+# Create an awk script that takes as input numbers of CPUs and outputs
+# lists of CPUs, one per line in both cases.
+#
+# Usage: kvm-get-cpus-script.sh /path/to/cpu/arrays /path/to/put/script [ /path/to/state ]
+#
+# The CPU arrays are output by kvm-assign-cpus.sh, and are valid awk
+# statements initializing the variables describing the system's topology.
+#
+# The optional state is input by this script (if the file exists and is
+# non-empty), and can also be output by this script.
+
+cpuarrays="${1-/sys/devices/system/node}"
+scriptfile="${2}"
+statefile="${3}"
+
+if ! test -f "$cpuarrays"
+then
+ echo "File not found: $cpuarrays" 1>&2
+ exit 1
+fi
+scriptdir="`dirname "$scriptfile"`"
+if ! test -d "$scriptdir" || ! test -x "$scriptdir" || ! test -w "$scriptdir"
+then
+ echo "Directory not usable for script output: $scriptdir"
+ exit 1
+fi
+
+cat << '___EOF___' > "$scriptfile"
+BEGIN {
+___EOF___
+cat "$cpuarrays" >> "$scriptfile"
+if test -r "$statefile"
+then
+ cat "$statefile" >> "$scriptfile"
+fi
+cat << '___EOF___' >> "$scriptfile"
+}
+
+# Do we have the system architecture to guide CPU affinity?
+function gotcpus()
+{
+ return numnodes != "";
+}
+
+# Return a comma-separated list of the next n CPUs.
+function nextcpus(n, i, s)
+{
+ for (i = 0; i < n; i++) {
+ if (nodecpus[curnode] == "")
+ curnode = 0;
+ if (cpu[curnode][curcpu[curnode]] == "")
+ curcpu[curnode] = 0;
+ if (s != "")
+ s = s ",";
+ s = s cpu[curnode][curcpu[curnode]];
+ curcpu[curnode]++;
+ curnode++
+ }
+ return s;
+}
+
+# Dump out the current node/CPU state so that a later invocation of this
+# script can continue where this one left off. Of course, this only works
+# when a state file was specified and where there was valid sysfs state.
+# Returns 1 if the state was dumped, 0 otherwise.
+#
+# Dumping the state for one system configuration and loading it into
+# another isn't likely to do what you want, whatever that might be.
+function dumpcpustate( i, fn)
+{
+___EOF___
+echo ' fn = "'"$statefile"'";' >> $scriptfile
+cat << '___EOF___' >> "$scriptfile"
+ if (fn != "" && gotcpus()) {
+ print "curnode = " curnode ";" > fn;
+ for (i = 0; i < numnodes; i++)
+ if (curcpu[i] != "")
+ print "curcpu[" i "] = " curcpu[i] ";" >> fn;
+ return 1;
+ }
+ if (fn != "")
+ print "# No CPU state to dump." > fn;
+ return 0;
+}
+___EOF___
diff --git a/tools/testing/selftests/rcutorture/bin/kvm-test-1-run-batch.sh b/tools/testing/selftests/rcutorture/bin/kvm-test-1-run-batch.sh
index 7ea0809e229e9..005a048c55aa0 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm-test-1-run-batch.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm-test-1-run-batch.sh
@@ -54,6 +54,7 @@ for i in "$@"
do
echo ---- System running test: `uname -a` > $i/kvm-test-1-run-qemu.sh.out
echo > $i/kvm-test-1-run-qemu.sh.out
+ export TORTURE_AFFINITY=
kvm-test-1-run-qemu.sh $i >> $i/kvm-test-1-run-qemu.sh.out 2>&1 &
done
for i in $runfiles
diff --git a/tools/testing/selftests/rcutorture/bin/kvm.sh b/tools/testing/selftests/rcutorture/bin/kvm.sh
index 0f26a81599f5c..f442d84fb2a3e 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm.sh
@@ -430,7 +430,9 @@ then
git diff HEAD >> $resdir/$ds/testid.txt
fi
___EOF___
-cat << '___EOF___' > $T/dumpbatches.awk
+kvm-assign-cpus.sh /sys/devices/system/node > $T/cpuarray.awk
+kvm-get-cpus-script.sh $T/cpuarray.awk $T/dumpbatches.awk
+cat << '___EOF___' >> $T/dumpbatches.awk
BEGIN {
i = 0;
}
@@ -442,7 +444,7 @@ BEGIN {
}

# Dump out the scripting required to run one test batch.
-function dump(first, pastlast, batchnum)
+function dump(first, pastlast, batchnum, affinitylist)
{
print "echo ----Start batch " batchnum ": `date` | tee -a " rd "log";
print "needqemurun="
@@ -474,6 +476,14 @@ function dump(first, pastlast, batchnum)
print "echo ", cfr[jn], cpusr[jn] ovf ": Starting build. `date` | tee -a " rd "log";
print "mkdir " rd cfr[jn] " || :";
print "touch " builddir ".wait";
+ affinitylist = "";
+ if (gotcpus()) {
+ affinitylist = nextcpus(cpusr[jn]);
+ }
+ if (affinitylist ~ /^[0-9,-][0-9,-]*$/)
+ print "export TORTURE_AFFINITY=" affinitylist;
+ else
+ print "export TORTURE_AFFINITY=";
print "kvm-test-1-run.sh " CONFIGDIR cf[j], rd cfr[jn], dur " \"" TORTURE_QEMU_ARG "\" \"" TORTURE_BOOTARGS "\" > " rd cfr[jn] "/kvm-test-1-run.sh.out 2>&1 &"
print "echo ", cfr[jn], cpusr[jn] ovf ": Waiting for build to complete. `date` | tee -a " rd "log";
print "while test -f " builddir ".wait"
--
2.31.1.189.g2e36527f23