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Date:   Wed, 26 Jan 2022 17:20:03 -0800
From:   "Paul E. McKenney" <paulmck@kernel.org>
To:     Zhouyi Zhou <zhouzhouyi@gmail.com>
Cc:     Paul Menzel <pmenzel@molgen.mpg.de>,
        Josh Triplett <josh@joshtriplett.org>,
        rcu <rcu@vger.kernel.org>, linux-kselftest@vger.kernel.org,
        LKML <linux-kernel@vger.kernel.org>
Subject: Re: Problems with rcutorture on ppc64le: allmodconfig(2) and other
 failures
Message-ID: <20220127012003.GB4285@paulmck-ThinkPad-P17-Gen-1>
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On Thu, Jan 27, 2022 at 08:57:02AM +0800, Zhouyi Zhou wrote:
> Hi Paul
> 
> Thank you for your perfect patch!
> 
> After apply your patch, I invoke
> "tools/testing/selftests/rcutorture/bin/torture.sh --duration 10" on
> next-20220125. we succeed in allmodconfig!

Very good!

> Following are the test logs (154.223.142.244 is my own internet cloud
> server maintained by myself, I believe it is safe to access the text
> content via web, but not so sure)
> 
> 1. torture log
> http://154.223.142.244/logs/20220127/2022.01.26-19.43.04.log (there
> are many Chinese words "Thursday" in it because I forget to set
> terminal locale to English, I am sorry), I excerpt some content here:

Not a problem, Google Translate decided that this was the corresponding
English:

	Thursday January 27th, 2022

I really do need to get my browser to do the Chinese characters.  My
vim displays them just fine.  :-/

> SUCCESSES:
> allmodconfig(0)
> tools/testing/selftests/rcutorture/res/2022.01.26-19.43.04-torture/allmodconfig
> FAILURES:
> rcutorture(2) /home/zzy/Program/linux-next/linux-next/tools/testing/selftests/rcutorture/res/2022.01.26-19.43.04-torture/results-rcutorture
>   Summary: Warnings: 1 Call Traces: 1
>   Summary: Warnings: 1 Call Traces: 1
>   Summary: Warnings: 1 Call Traces: 1
>   Summary: Warnings: 1 Call Traces: 1
>   Summary: Warnings: 1 Call Traces: 1
> 
> 2. Make.exitcode for allmodeconfig
> http://154.223.142.244/logs/20220127/allmodconfig/Make.exitcode

Zero, which is good.  ;-)

> 3. Make.out for allmodeconfig
> http://154.223.142.244/logs/20220127/allmodconfig/Make.out
> 
> 4. result of invoking: find 2022.01.26-19.43.04-torture -name
> console.log.diags|xargs -I{} echo "echo {}; cat {}"|xargs -I{} bash -c
> "{}":
> http://154.223.142.244/logs/20220127/consoles.logs.diags
> All of the console.log.diags complain about one thing:
> 2022.01.26-19.43.04-torture/results-refscale-clock/NOPREEMPT/console.log.diags
> [    0.017721] WARNING: CPU: 0 PID: 0 at
> kernel/trace/trace_events.c:417 trace_event_raw_init+0xea/0x580
> [    0.017754] Call Trace:
> 2022.01.26-19.43.04-torture/results-rcuscale-kvfree-kasan/TREE/console.log.diags
> [    0.102911] WARNING: CPU: 0 PID: 0 at
> kernel/trace/trace_events.c:417 trace_event_raw_init+0x113/0x6e0
> [    0.102992] Call Trace:
> 2022.01.26-19.43.04-torture/results-rcuscale-tasks-tracing-kasan/TREE/console.log.diags
> [    0.060924] WARNING: CPU: 0 PID: 0 at
> kernel/trace/trace_events.c:417 trace_event_raw_init+0x113/0x6e0
> [    0.061006] Call Trace:
> I am glad to study these warnings further but they don't seem to be
> related to this patch.

There was at least one RCU bug in this -next, fixed by this commit:

da123016ca8c ("rcu-tasks: Fix computation of CPU-to-list shift counts")

But this warning looks like something else.  For one thing, you would
have had to be running on a system with exactly three CPUs to trigger
the RCU bug given the usual rcutorture scenarios.

May I add your Tested-by to this commit?

						Thanx, Paul

> Thanks again
> Sincerely
> Zhouyi
> 
> On Wed, Jan 26, 2022 at 1:14 PM Paul E. McKenney <paulmck@kernel.org> wrote:
> >
> > On Tue, Jan 25, 2022 at 08:50:22PM -0800, Paul E. McKenney wrote:
> > > On Wed, Jan 26, 2022 at 12:09:12PM +0800, Zhouyi Zhou wrote:
> > > > Great Discovery !!
> > > > Hi Paul,
> > > > I track the log
> > > > make[2]: *** No rule to make target
> > > > 'arch/x86/kvm//home/zzy/Program/linux-next/linux-next/tools/testing/selftests/rcutorture/kvm_main.o',
> > >
> > > That does look like a very odd pathname, now that you mention it.
> > >
> > > > needed by 'arch/x86/kvm/kvm.o
> > > > into the file virt/kvm/Makefile.kvm:
> > > > 1# SPDX-License-Identifier: GPL-2.0
> > > >  2#
> > > >  3# Makefile for Kernel-based Virtual Machine module
> > > >  4#
> > > >  5
> > > >  6KVM ?= ../../../virt/kvm
> > > >  7
> > > >  8kvm-y := $(KVM)/kvm_main.o $(KVM)/eventfd.o $(KVM)/binary_stats.o
> > > >  9kvm-$(CONFIG_KVM_VFIO) += $(KVM)/vfio.o
> > > > 10kvm-$(CONFIG_KVM_MMIO) += $(KVM)/coalesced_mmio.o
> > > > 11kvm-$(CONFIG_KVM_ASYNC_PF) += $(KVM)/async_pf.o
> > > > 12kvm-$(CONFIG_HAVE_KVM_IRQ_ROUTING) += $(KVM)/irqchip.o
> > > > 13kvm-$(CONFIG_HAVE_KVM_DIRTY_RING) += $(KVM)/dirty_ring.o
> > > > 14kvm-$(CONFIG_HAVE_KVM_PFNCACHE) += $(KVM)/pfncache.o
> > > > line 6's ?= indicates to set the KDIR variable only if it's not
> > > > set/doesn't have a value.
> > > >
> > > > I guess we have set the variable KVM somewhere before make, I will
> > > > continue tracking it.
> > >
> > > But if you build an allmodconfig kernel by hand afterwards, it works?
> > >
> > > I wonder if I need to use a different environment variable in my scripts.
> > > For example, from tools/testing/selftests/rcutorture/bin/kvm.sh:
> > >
> > > KVM="`pwd`/tools/testing/selftests/rcutorture"; export KVM
> > > PATH=${KVM}/bin:$PATH; export PATH
> > >
> > > Maybe like the (untested) patch shown below.
> >
> > A somewhat more official version below.  Thank you for following up
> > on this!
> >
> >                                                         Thanx, Paul
> >
> > ------------------------------------------------------------------------
> >
> > commit 6b5cdbe80b01ce604fdf0f3ef6717a6466aca041
> > Author: Paul E. McKenney <paulmck@kernel.org>
> > Date:   Tue Jan 25 21:08:55 2022 -0800
> >
> >     torture: Change KVM environment variable to RCUTORTURE
> >
> >     The torture-test scripting's long-standing use of KVM as the environment
> >     variable tracking the pathname of the rcutorture directory now conflicts
> >     with allmodconfig builds due to the virt/kvm/Makefile.kvm file's use
> >     of this as a makefile variable.  This commit therefore changes the
> >     torture-test scripting from KVM to RCUTORTURE, avoiding the name conflict.
> >
> >     Reported-by: Zhouyi Zhou <zhouzhouyi@gmail.com>
> >     Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
> >
> > diff --git a/tools/testing/selftests/rcutorture/bin/kvm-again.sh b/tools/testing/selftests/rcutorture/bin/kvm-again.sh
> > index 5a0023d183dac..0941f1ddab658 100755
> > --- a/tools/testing/selftests/rcutorture/bin/kvm-again.sh
> > +++ b/tools/testing/selftests/rcutorture/bin/kvm-again.sh
> > @@ -47,8 +47,8 @@ else
> >         exit 1
> >  fi
> >
> > -KVM="`pwd`/tools/testing/selftests/rcutorture"; export KVM
> > -PATH=${KVM}/bin:$PATH; export PATH
> > +RCUTORTURE="`pwd`/tools/testing/selftests/rcutorture"; export RCUTORTURE
> > +PATH=${RCUTORTURE}/bin:$PATH; export PATH
> >  . functions.sh
> >
> >  dryrun=
> > diff --git a/tools/testing/selftests/rcutorture/bin/kvm-check-branches.sh b/tools/testing/selftests/rcutorture/bin/kvm-check-branches.sh
> > index 370406bbfeedc..f17000a2ccf1f 100755
> > --- a/tools/testing/selftests/rcutorture/bin/kvm-check-branches.sh
> > +++ b/tools/testing/selftests/rcutorture/bin/kvm-check-branches.sh
> > @@ -49,8 +49,8 @@ fi
> >  mkdir $resdir/$ds
> >  echo Results directory: $resdir/$ds
> >
> > -KVM="`pwd`/tools/testing/selftests/rcutorture"; export KVM
> > -PATH=${KVM}/bin:$PATH; export PATH
> > +RCUTORTURE="`pwd`/tools/testing/selftests/rcutorture"; export RCUTORTURE
> > +PATH=${RCUTORTURE}/bin:$PATH; export PATH
> >  . functions.sh
> >  echo Using all `identify_qemu_vcpus` CPUs.
> >
> > diff --git a/tools/testing/selftests/rcutorture/bin/kvm-end-run-stats.sh b/tools/testing/selftests/rcutorture/bin/kvm-end-run-stats.sh
> > index e4a00779b8c69..ee886b40a5d2c 100755
> > --- a/tools/testing/selftests/rcutorture/bin/kvm-end-run-stats.sh
> > +++ b/tools/testing/selftests/rcutorture/bin/kvm-end-run-stats.sh
> > @@ -22,8 +22,8 @@ T=${TMPDIR-/tmp}/kvm-end-run-stats.sh.$$
> >  trap 'rm -rf $T' 0
> >  mkdir $T
> >
> > -KVM="`pwd`/tools/testing/selftests/rcutorture"; export KVM
> > -PATH=${KVM}/bin:$PATH; export PATH
> > +RCUTORTURE="`pwd`/tools/testing/selftests/rcutorture"; export RCUTORTURE
> > +PATH=${RCUTORTURE}/bin:$PATH; export PATH
> >  . functions.sh
> >  default_starttime="`get_starttime`"
> >  starttime="${2-default_starttime}"
> > diff --git a/tools/testing/selftests/rcutorture/bin/kvm-remote.sh b/tools/testing/selftests/rcutorture/bin/kvm-remote.sh
> > index 29b068a55b466..8c4c1e4792d02 100755
> > --- a/tools/testing/selftests/rcutorture/bin/kvm-remote.sh
> > +++ b/tools/testing/selftests/rcutorture/bin/kvm-remote.sh
> > @@ -19,8 +19,8 @@ then
> >         exit 1
> >  fi
> >
> > -KVM="`pwd`/tools/testing/selftests/rcutorture"; export KVM
> > -PATH=${KVM}/bin:$PATH; export PATH
> > +RCUTORTURE="`pwd`/tools/testing/selftests/rcutorture"; export RCUTORTURE
> > +PATH=${RCUTORTURE}/bin:$PATH; export PATH
> >  . functions.sh
> >
> >  starttime="`get_starttime`"
> > @@ -108,8 +108,8 @@ else
> >                 cat $T/kvm-again.sh.out | tee -a "$oldrun/remote-log"
> >                 exit 2
> >         fi
> > -       cp -a "$rundir" "$KVM/res/"
> > -       oldrun="$KVM/res/$ds"
> > +       cp -a "$rundir" "$RCUTORTURE/res/"
> > +       oldrun="$RCUTORTURE/res/$ds"
> >  fi
> >  echo | tee -a "$oldrun/remote-log"
> >  echo " ----" kvm-again.sh output: "(`date`)" | tee -a "$oldrun/remote-log"
> > diff --git a/tools/testing/selftests/rcutorture/bin/kvm.sh b/tools/testing/selftests/rcutorture/bin/kvm.sh
> > index 348ad177a5acc..55b2c15332827 100755
> > --- a/tools/testing/selftests/rcutorture/bin/kvm.sh
> > +++ b/tools/testing/selftests/rcutorture/bin/kvm.sh
> > @@ -25,15 +25,15 @@ LANG=en_US.UTF-8; export LANG
> >
> >  dur=$((30*60))
> >  dryrun=""
> > -KVM="`pwd`/tools/testing/selftests/rcutorture"; export KVM
> > -PATH=${KVM}/bin:$PATH; export PATH
> > +RCUTORTURE="`pwd`/tools/testing/selftests/rcutorture"; export RCUTORTURE
> > +PATH=${RCUTORTURE}/bin:$PATH; export PATH
> >  . functions.sh
> >
> >  TORTURE_ALLOTED_CPUS="`identify_qemu_vcpus`"
> >  TORTURE_DEFCONFIG=defconfig
> >  TORTURE_BOOT_IMAGE=""
> >  TORTURE_BUILDONLY=
> > -TORTURE_INITRD="$KVM/initrd"; export TORTURE_INITRD
> > +TORTURE_INITRD="$RCUTORTURE/initrd"; export TORTURE_INITRD
> >  TORTURE_KCONFIG_ARG=""
> >  TORTURE_KCONFIG_GDB_ARG=""
> >  TORTURE_BOOT_GDB_ARG=""
> > @@ -262,7 +262,7 @@ else
> >         exit 1
> >  fi
> >
> > -CONFIGFRAG=${KVM}/configs/${TORTURE_SUITE}; export CONFIGFRAG
> > +CONFIGFRAG=${RCUTORTURE}/configs/${TORTURE_SUITE}; export CONFIGFRAG
> >
> >  defaultconfigs="`tr '\012' ' ' < $CONFIGFRAG/CFLIST`"
> >  if test -z "$configs"
> > @@ -272,7 +272,7 @@ fi
> >
> >  if test -z "$resdir"
> >  then
> > -       resdir=$KVM/res
> > +       resdir=$RCUTORTURE/res
> >  fi
> >
> >  # Create a file of test-name/#cpus pairs, sorted by decreasing #cpus.
> > @@ -386,7 +386,7 @@ END {
> >  # Generate a script to execute the tests in appropriate batches.
> >  cat << ___EOF___ > $T/script
> >  CONFIGFRAG="$CONFIGFRAG"; export CONFIGFRAG
> > -KVM="$KVM"; export KVM
> > +RCUTORTURE="$RCUTORTURE"; export RCUTORTURE
> >  PATH="$PATH"; export PATH
> >  TORTURE_ALLOTED_CPUS="$TORTURE_ALLOTED_CPUS"; export TORTURE_ALLOTED_CPUS
> >  TORTURE_BOOT_IMAGE="$TORTURE_BOOT_IMAGE"; export TORTURE_BOOT_IMAGE
> > @@ -569,7 +569,7 @@ ___EOF___
> >  awk < $T/cfgcpu.pack \
> >         -v TORTURE_BUILDONLY="$TORTURE_BUILDONLY" \
> >         -v CONFIGDIR="$CONFIGFRAG/" \
> > -       -v KVM="$KVM" \
> > +       -v RCUTORTURE="$RCUTORTURE" \
> >         -v ncpus=$cpus \
> >         -v jitter="$jitter" \
> >         -v rd=$resdir/$ds/ \
> > diff --git a/tools/testing/selftests/rcutorture/bin/torture.sh b/tools/testing/selftests/rcutorture/bin/torture.sh
> > index d1cb60085d8f2..e00e60efb2310 100755
> > --- a/tools/testing/selftests/rcutorture/bin/torture.sh
> > +++ b/tools/testing/selftests/rcutorture/bin/torture.sh
> > @@ -13,8 +13,8 @@
> >  scriptname=$0
> >  args="$*"
> >
> > -KVM="`pwd`/tools/testing/selftests/rcutorture"; export KVM
> > -PATH=${KVM}/bin:$PATH; export PATH
> > +RCUTORTURE="`pwd`/tools/testing/selftests/rcutorture"; export RCUTORTURE
> > +PATH=${RCUTORTURE}/bin:$PATH; export PATH
> >  . functions.sh
> >
> >  TORTURE_ALLOTED_CPUS="`identify_qemu_vcpus`"