1#!/bin/bash 2# SPDX-License-Identifier: GPL-2.0 3 4. "$(cd "$(dirname "$0")" && pwd)"/test_common.sh 5 6TID="generic_12" 7ERR_CODE=0 8 9if ! _have_program bpftrace; then 10 exit "$UBLK_SKIP_CODE" 11fi 12 13_prep_test "null" "do imbalanced load, it should be balanced over I/O threads" 14 15NTHREADS=6 16dev_id=$(_add_ublk_dev -t null -q 4 -d 16 --nthreads $NTHREADS --per_io_tasks) 17_check_add_dev $TID $? 18 19dev_t=$(_get_disk_dev_t "$dev_id") 20bpftrace trace/count_ios_per_tid.bt "$dev_t" > "$UBLK_TMP" 2>&1 & 21btrace_pid=$! 22sleep 2 23 24if ! kill -0 "$btrace_pid" > /dev/null 2>&1; then 25 _cleanup_test "null" 26 exit "$UBLK_SKIP_CODE" 27fi 28 29# do imbalanced I/O on the ublk device 30# pin to cpu 0 to prevent migration/only target one queue 31fio --name=write_seq \ 32 --filename=/dev/ublkb"${dev_id}" \ 33 --ioengine=libaio --iodepth=16 \ 34 --rw=write \ 35 --size=512M \ 36 --direct=1 \ 37 --bs=4k \ 38 --cpus_allowed=0 > /dev/null 2>&1 39ERR_CODE=$? 40kill "$btrace_pid" 41wait 42 43# check that every task handles some I/O, even though all I/O was issued 44# from a single CPU. when ublk gets support for round-robin tag 45# allocation, this check can be strengthened to assert that every thread 46# handles the same number of I/Os 47NR_THREADS_THAT_HANDLED_IO=$(grep -c '@' ${UBLK_TMP}) 48if [[ $NR_THREADS_THAT_HANDLED_IO -ne $NTHREADS ]]; then 49 echo "only $NR_THREADS_THAT_HANDLED_IO handled I/O! expected $NTHREADS" 50 cat "$UBLK_TMP" 51 ERR_CODE=255 52fi 53 54_cleanup_test "null" 55_show_result $TID $ERR_CODE 56