multitorture1.ksh - torture system with many many parallel processes
Posted by Anonymous on Wed 26th Jul 2023 14:37
raw | new post

#!/bin/ksh93

#
# multitorture1.ksh - torture system with many many parallel processes
#
# Used to trigger MCE errors on specific hardware
#

function dmesg_count_mces
{
        nameref c=$1

        c.msgs="${ dmesg | fgrep 'mce:' ; }"

        c.count=${ wc -l <<<"${c.msgs}" ; }
        return 0
}

#
# compound variable to store filtered dmesg(1) output and
# statistics/counts
#
compound dmsg_mces=(
        compound before=(
                typeset msgs
                integer count
        )
        compound after=(
                typeset msgs
                integer count
        )
)

#
# main
#
export PATH='/bin:/usr/bin'

builtin cat
builtin wc

typeset x
integer i j


set -o bgnice # background jobs will be nice'ed

printf $"# Start.\n"

#
# get a horribly large string
#
x="$( for ((i=0 ; i < 60000 ; i++)) ; do printf "%d\n" i; done )"

dmesg_count_mces dmsg_mces.before

for ((j=0 ; j < 50 ; j++)) ; do
        printf $"\n# Starting child processes (cycle %d) ...\n" j
        for ((i=0 ; i < 100 ; i++)) ; do
                {
                        printf '.'
                        # sleep, so parent process has enough time
                        # to |fork()| the other children
                        sleep 5

                        #
                        # torture!!
                        #
                        sort <<<"$x" | \
                                sort -r | \
                                sort | \
                                sort -r -n | \
                                sort -n | \
                                sort -u | openssl sha512
                } &
        done
        sleep 3
        printf '\n'

        # wait until all children are done
        wait

        dmesg_count_mces dmsg_mces.after

        if (( dmsg_mces.after.count > dmsg_mces.before.count )) ; then
                printf $"# Congratulations: You have new mce entries in dmesg (\u[2620]) after %d cycles\n" j
                diff -u <( cat <<<"${dmsg_mces.before.msgs}" ) <( cat <<<"${dmsg_mces.after.msgs}" )
                break
        fi
done

printf $"# Done.\n"
exit 0
# EOF.