1#!/bin/bash 2# SPDX-License-Identifier: GPL-2.0 3 4. "$(cd "$(dirname "$0")" && pwd)"/test_common.sh 5 6ERR_CODE=0 7 8if ! _have_program bpftrace; then 9 exit "$UBLK_SKIP_CODE" 10fi 11 12if ! _have_program fio; then 13 exit "$UBLK_SKIP_CODE" 14fi 15 16_prep_test "null" "do imbalanced load, it should be balanced over I/O threads" 17 18NTHREADS=6 19dev_id=$(_add_ublk_dev -t null -q 4 -d 16 --nthreads $NTHREADS --per_io_tasks) 20_check_add_dev $TID $? 21 22dev_t=$(_get_disk_dev_t "$dev_id") 23bpftrace trace/count_ios_per_tid.bt "$dev_t" > "$UBLK_TMP" 2>&1 & 24btrace_pid=$! 25sleep 2 26 27if ! kill -0 "$btrace_pid" > /dev/null 2>&1; then 28 _cleanup_test "null" 29 exit "$UBLK_SKIP_CODE" 30fi 31 32# do imbalanced I/O on the ublk device 33# pin to cpu 0 to prevent migration/only target one queue 34fio --name=write_seq \ 35 --filename=/dev/ublkb"${dev_id}" \ 36 --ioengine=libaio --iodepth=16 \ 37 --rw=write \ 38 --size=512M \ 39 --direct=1 \ 40 --bs=4k \ 41 --cpus_allowed=0 > /dev/null 2>&1 42ERR_CODE=$? 43kill "$btrace_pid" 44wait 45 46# check that every task handles some I/O, even though all I/O was issued 47# from a single CPU. when ublk gets support for round-robin tag 48# allocation, this check can be strengthened to assert that every thread 49# handles the same number of I/Os 50NR_THREADS_THAT_HANDLED_IO=$(grep -c '@' ${UBLK_TMP}) 51if [[ $NR_THREADS_THAT_HANDLED_IO -ne $NTHREADS ]]; then 52 echo "only $NR_THREADS_THAT_HANDLED_IO handled I/O! expected $NTHREADS" 53 cat "$UBLK_TMP" 54 ERR_CODE=255 55fi 56 57_cleanup_test "null" 58_show_result $TID $ERR_CODE 59