#!/bin/bash # # Alternate sleeping and spinning on randomly selected CPUs. The purpose # of this script is to inflict random OS jitter on a concurrently running # test. # # Usage: jitter.sh me duration [ sleepmax [ spinmax ] ] # # me: Random-number-generator seed salt. # duration: Time to run in seconds. # sleepmax: Maximum microseconds to sleep, defaults to one second. # spinmax: Maximum microseconds to spin, defaults to one millisecond. # # This program is free software; you can redistribute it and/or modify # it under the terms of the GNU General Public License as published by # the Free Software Foundation; either version 2 of the License, or # (at your option) any later version. # # This program is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the # GNU General Public License for more details. # # You should have received a copy of the GNU General Public License # along with this program; if not, you can access it online at # http://www.gnu.org/licenses/gpl-2.0.html. # # Copyright (C) IBM Corporation, 2016 # # Authors: Paul E. McKenney me=$(($1 * 1000)) duration=$2 sleepmax=${3-1000000} spinmax=${4-1000} n=1 starttime=`awk 'BEGIN { print systime(); }' < /dev/null` while : do # Check for done. t=`awk -v s=$starttime 'BEGIN { print systime() - s; }' < /dev/null` if test "$t" -gt "$duration" then exit 0; fi # Set affinity to randomly selected CPU cpus=`ls /sys/devices/system/cpu/*/online | sed -e 's,/[^/]*$,,' -e 's/^[^0-9]*//' | grep -v '^0*$'` cpumask=`awk -v cpus="$cpus" -v me=$me -v n=$n 'BEGIN { srand(n + me + systime()); ncpus = split(cpus, ca); curcpu = ca[int(rand() * ncpus + 1)]; mask = lshift(1, curcpu); if (mask + 0 <= 0) mask = 1; printf("%#x\n", mask); }' < /dev/null` n=$(($n+1)) if ! taskset -p $cpumask $$ > /dev/null 2>&1 then echo taskset failure: '"taskset -p ' $cpumask $$ '"' exit 1 fi # Sleep a random duration sleeptime=`awk -v me=$me -v n=$n -v sleepmax=$sleepmax 'BEGIN { srand(n + me + systime()); printf("%06d", int(rand() * sleepmax)); }' < /dev/null` n=$(($n+1)) sleep .$sleeptime # Spin a random duration limit=`awk -v me=$me -v n=$n -v spinmax=$spinmax 'BEGIN { srand(n + me + systime()); printf("%06d", int(rand() * spinmax)); }' < /dev/null` n=$(($n+1)) for i in {1..$limit} do echo > /dev/null done done exit 1 type='submit' value='search'/>
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authorBjorn Helgaas <bhelgaas@google.com>2017-01-27 15:00:45 -0600
committerBjorn Helgaas <bhelgaas@google.com>2017-01-27 15:00:45 -0600
commit030305d69fc6963c16003f50d7e8d74b02d0a143 (patch)
tree363a4e34d199178769b7e7eeb26ea2620a55847b /sound/pci
parent4d191b1b63c209e37bf27938ef365244d3c41084 (diff)
PCI/ASPM: Handle PCI-to-PCIe bridges as roots of PCIe hierarchies
In a struct pcie_link_state, link->root points to the pcie_link_state of the root of the PCIe hierarchy. For the topmost link, this points to itself (link->root = link). For others, we copy the pointer from the parent (link->root = link->parent->root). Previously we recognized that Root Ports originated PCIe hierarchies, but we treated PCI/PCI-X to PCIe Bridges as being in the middle of the hierarchy, and when we tried to copy the pointer from link->parent->root, there was no parent, and we dereferenced a NULL pointer: BUG: unable to handle kernel NULL pointer dereference at 0000000000000090 IP: [<ffffffff9e424350>] pcie_aspm_init_link_state+0x170/0x820 Recognize that PCI/PCI-X to PCIe Bridges originate PCIe hierarchies just like Root Ports do, so link->root for these devices should also point to itself. Fixes: 51ebfc92b72b ("PCI: Enumerate switches below PCI-to-PCIe bridges") Link: https://bugzilla.kernel.org/show_bug.cgi?id=193411 Link: https://bugzilla.opensuse.org/show_bug.cgi?id=1022181 Tested-by: lists@ssl-mail.com Tested-by: Jayachandran C. <jnair@caviumnetworks.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> CC: stable@vger.kernel.org # v4.2+
Diffstat (limited to 'sound/pci')