Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

4 files changed, 274 insertions, 0 deletions

diff --git a/tools/testing/selftests/rcutorture/doc/TINY_RCU.txt b/tools/testing/selftests/rcutorture/doc/TINY_RCU.txt
new file mode 100644
index 000000000..a75b16991
--- /dev/null
+++ b/tools/testing/selftests/rcutorture/doc/TINY_RCU.txt
@@ -0,0 +1,38 @@
+This document gives a brief rationale for the TINY_RCU test cases.
+
+
+Kconfig Parameters:
+
+CONFIG_DEBUG_LOCK_ALLOC -- Do all three and none of the three.
+CONFIG_PREEMPT_COUNT
+CONFIG_RCU_TRACE
+
+The theory here is that randconfig testing will hit the other six possible
+combinations of these parameters.
+
+
+Kconfig Parameters Ignored:
+
+CONFIG_DEBUG_OBJECTS_RCU_HEAD
+CONFIG_PROVE_RCU
+
+	In common code tested by TREE_RCU test cases.
+
+CONFIG_RCU_NOCB_CPU
+
+	Meaningless for TINY_RCU.
+
+CONFIG_RCU_STALL_COMMON
+CONFIG_RCU_TORTURE_TEST
+
+	Redundant with CONFIG_RCU_TRACE.
+
+CONFIG_HOTPLUG_CPU
+CONFIG_PREEMPT
+CONFIG_PREEMPT_RCU
+CONFIG_SMP
+CONFIG_TINY_RCU
+CONFIG_PREEMPT_RCU
+CONFIG_TREE_RCU
+
+	All forced by CONFIG_TINY_RCU.
diff --git a/tools/testing/selftests/rcutorture/doc/TREE_RCU-kconfig.txt b/tools/testing/selftests/rcutorture/doc/TREE_RCU-kconfig.txt
new file mode 100644
index 000000000..af6fca036
--- /dev/null
+++ b/tools/testing/selftests/rcutorture/doc/TREE_RCU-kconfig.txt
@@ -0,0 +1,81 @@
+This document gives a brief rationale for the TREE_RCU-related test
+cases, a group that includes PREEMPT_RCU.
+
+
+Kconfig Parameters:
+
+CONFIG_DEBUG_LOCK_ALLOC -- Do three, covering CONFIG_PROVE_LOCKING & not.
+CONFIG_DEBUG_OBJECTS_RCU_HEAD -- Do one.
+CONFIG_HOTPLUG_CPU -- Do half.  (Every second.)
+CONFIG_HZ_PERIODIC -- Do one.
+CONFIG_NO_HZ_IDLE -- Do those not otherwise specified. (Groups of two.)
+CONFIG_NO_HZ_FULL -- Do two, one with partial CPU enablement.
+CONFIG_PREEMPT -- Do half.  (First three and #8.)
+CONFIG_PROVE_LOCKING -- Do several, covering CONFIG_DEBUG_LOCK_ALLOC=y and not.
+CONFIG_PROVE_RCU -- Hardwired to CONFIG_PROVE_LOCKING.
+CONFIG_RCU_BOOST -- one of PREEMPT_RCU.
+CONFIG_RCU_FANOUT -- Cover hierarchy, but overlap with others.
+CONFIG_RCU_FANOUT_LEAF -- Do one non-default.
+CONFIG_RCU_FAST_NO_HZ -- Do one, but not with all nohz_full CPUs.
+CONFIG_RCU_NOCB_CPU -- Do three, one with no rcu_nocbs CPUs, one with
+	rcu_nocbs=0, and one with all rcu_nocbs CPUs.
+CONFIG_RCU_TRACE -- Do half.
+CONFIG_SMP -- Need one !SMP for PREEMPT_RCU.
+CONFIG_RCU_EXPERT=n -- Do a few, but these have to be vanilla configurations.
+CONFIG_RCU_EQS_DEBUG -- Do at least one for CONFIG_NO_HZ_FULL and not.
+
+RCU-bh: Do one with PREEMPT and one with !PREEMPT.
+RCU-sched: Do one with PREEMPT but not BOOST.
+
+
+Boot parameters:
+
+nohz_full - do at least one.
+maxcpu -- do at least one.
+rcupdate.rcu_self_test_bh -- Do at least one each, offloaded and not.
+rcupdate.rcu_self_test_sched -- Do at least one each, offloaded and not.
+rcupdate.rcu_self_test -- Do at least one each, offloaded and not.
+rcutree.rcu_fanout_exact -- Do at least one.
+
+
+Kconfig Parameters Ignored:
+
+CONFIG_64BIT
+
+	Used only to check CONFIG_RCU_FANOUT value, inspection suffices.
+
+CONFIG_PREEMPT_COUNT
+CONFIG_PREEMPT_RCU
+
+	Redundant with CONFIG_PREEMPT, ignore.
+
+CONFIG_RCU_BOOST_DELAY
+
+	Inspection suffices, ignore.
+
+CONFIG_RCU_CPU_STALL_TIMEOUT
+
+	Inspection suffices, ignore.
+
+CONFIG_RCU_STALL_COMMON
+
+	Implied by TREE_RCU and PREEMPT_RCU.
+
+CONFIG_RCU_TORTURE_TEST
+CONFIG_RCU_TORTURE_TEST_RUNNABLE
+
+	Always used in KVM testing.
+
+CONFIG_PREEMPT_RCU
+CONFIG_TREE_RCU
+CONFIG_TINY_RCU
+CONFIG_TASKS_RCU
+
+	These are controlled by CONFIG_PREEMPT and/or CONFIG_SMP.
+
+CONFIG_SRCU
+
+	Selected by CONFIG_RCU_TORTURE_TEST, so cannot disable.
+
+
+boot parameters ignored: TBD
diff --git a/tools/testing/selftests/rcutorture/doc/initrd.txt b/tools/testing/selftests/rcutorture/doc/initrd.txt
new file mode 100644
index 000000000..833f826d6
--- /dev/null
+++ b/tools/testing/selftests/rcutorture/doc/initrd.txt
@@ -0,0 +1,113 @@
+This document describes one way to create the initrd directory hierarchy
+in order to allow an initrd to be built into your kernel.  The trick
+here is to steal the initrd file used on your Linux laptop, Ubuntu in
+this case.  There are probably much better ways of doing this.
+
+That said, here are the commands:
+
+------------------------------------------------------------------------
+cd tools/testing/selftests/rcutorture
+zcat /initrd.img > /tmp/initrd.img.zcat
+mkdir initrd
+cd initrd
+cpio -id < /tmp/initrd.img.zcat
+------------------------------------------------------------------------
+
+Another way to create an initramfs image is using "dracut"[1], which is
+available on many distros, however the initramfs dracut generates is a cpio
+archive with another cpio archive in it, so an extra step is needed to create
+the initrd directory hierarchy.
+
+Here are the commands to create a initrd directory for rcutorture using
+dracut:
+
+------------------------------------------------------------------------
+dracut --no-hostonly --no-hostonly-cmdline --module "base bash shutdown" /tmp/initramfs.img
+cd tools/testing/selftests/rcutorture
+mkdir initrd
+cd initrd
+/usr/lib/dracut/skipcpio /tmp/initramfs.img | zcat | cpio -id < /tmp/initramfs.img
+------------------------------------------------------------------------
+
+Interestingly enough, if you are running rcutorture, you don't really
+need userspace in many cases.  Running without userspace has the
+advantage of allowing you to test your kernel independently of the
+distro in place, the root-filesystem layout, and so on.  To make this
+happen, put the following script in the initrd's tree's "/init" file,
+with 0755 mode.
+
+------------------------------------------------------------------------
+#!/bin/sh
+
+[ -d /dev ] || mkdir -m 0755 /dev
+[ -d /root ] || mkdir -m 0700 /root
+[ -d /sys ] || mkdir /sys
+[ -d /proc ] || mkdir /proc
+[ -d /tmp ] || mkdir /tmp
+mkdir -p /var/lock
+mount -t sysfs -o nodev,noexec,nosuid sysfs /sys
+mount -t proc -o nodev,noexec,nosuid proc /proc
+# Some things don't work properly without /etc/mtab.
+ln -sf /proc/mounts /etc/mtab
+
+# Note that this only becomes /dev on the real filesystem if udev's scripts
+# are used; which they will be, but it's worth pointing out
+if ! mount -t devtmpfs -o mode=0755 udev /dev; then
+	echo "W: devtmpfs not available, falling back to tmpfs for /dev"
+	mount -t tmpfs -o mode=0755 udev /dev
+	[ -e /dev/console ] || mknod --mode=600 /dev/console c 5 1
+	[ -e /dev/kmsg ] || mknod --mode=644 /dev/kmsg c 1 11
+	[ -e /dev/null ] || mknod --mode=666 /dev/null c 1 3
+fi
+
+mkdir /dev/pts
+mount -t devpts -o noexec,nosuid,gid=5,mode=0620 devpts /dev/pts || true
+mount -t tmpfs -o "nosuid,size=20%,mode=0755" tmpfs /run
+mkdir /run/initramfs
+# compatibility symlink for the pre-oneiric locations
+ln -s /run/initramfs /dev/.initramfs
+
+# Export relevant variables
+export ROOT=
+export ROOTDELAY=
+export ROOTFLAGS=
+export ROOTFSTYPE=
+export IP=
+export BOOT=
+export BOOTIF=
+export UBIMTD=
+export break=
+export init=/sbin/init
+export quiet=n
+export readonly=y
+export rootmnt=/root
+export debug=
+export panic=
+export blacklist=
+export resume=
+export resume_offset=
+export recovery=
+
+for i in /sys/devices/system/cpu/cpu*/online
+do
+	case $i in
+	'/sys/devices/system/cpu/cpu0/online')
+		;;
+	'/sys/devices/system/cpu/cpu*/online')
+		;;
+	*)
+		echo 1 > $i
+		;;
+	esac
+done
+
+while :
+do
+	sleep 10
+done
+------------------------------------------------------------------------
+
+References:
+[1]: https://dracut.wiki.kernel.org/index.php/Main_Page
+[2]: http://blog.elastocloud.org/2015/06/rapid-linux-kernel-devtest-with-qemu.html
+[3]: https://www.centos.org/forums/viewtopic.php?t=51621
diff --git a/tools/testing/selftests/rcutorture/doc/rcu-test-image.txt b/tools/testing/selftests/rcutorture/doc/rcu-test-image.txt
new file mode 100644
index 000000000..449cf579d
--- /dev/null
+++ b/tools/testing/selftests/rcutorture/doc/rcu-test-image.txt
@@ -0,0 +1,42 @@
+This document describes one way to create the rcu-test-image file
+that contains the filesystem used by the guest-OS kernel.  There are
+probably much better ways of doing this, and this filesystem could no
+doubt be smaller.  It is probably also possible to simply download
+an appropriate image from any number of places.
+
+That said, here are the commands:
+
+------------------------------------------------------------------------
+dd if=/dev/zero of=rcu-test-image bs=400M count=1
+mkfs.ext3 ./rcu-test-image
+sudo mount -o loop ./rcu-test-image /mnt
+
+# Replace "precise" below with your favorite Ubuntu release.
+# Empirical evidence says this image will work for 64-bit, but...
+# Note that debootstrap does take a few minutes to run.  Or longer.
+sudo debootstrap --verbose --arch i386 precise /mnt http://archive.ubuntu.com/ubuntu
+cat << '___EOF___' | sudo dd of=/mnt/etc/fstab
+# UNCONFIGURED FSTAB FOR BASE SYSTEM
+#
+/dev/vda        /               ext3    defaults        1 1
+dev             /dev            tmpfs   rw              0 0
+tmpfs           /dev/shm        tmpfs   defaults        0 0
+devpts          /dev/pts        devpts  gid=5,mode=620  0 0
+sysfs           /sys            sysfs   defaults        0 0
+proc            /proc           proc    defaults        0 0
+___EOF___
+sudo umount /mnt
+------------------------------------------------------------------------
+
+
+References:
+
+	http://sripathikodi.blogspot.com/2010/02/creating-kvm-bootable-fedora-system.html
+	https://help.ubuntu.com/community/KVM/CreateGuests
+	https://help.ubuntu.com/community/JeOSVMBuilder
+	http://wiki.libvirt.org/page/UbuntuKVMWalkthrough
+	http://www.moe.co.uk/2011/01/07/pci_add_option_rom-failed-to-find-romfile-pxe-rtl8139-bin/ -- "apt-get install kvm-pxe"
+	http://www.landley.net/writing/rootfs-howto.html
+	http://en.wikipedia.org/wiki/Initrd
+	http://en.wikipedia.org/wiki/Cpio
+	http://wiki.libvirt.org/page/UbuntuKVMWalkthrough