Re: [PATCH 0/3 -perfbook] Makefile fix and RCU test bar chart update

[Akira Yokosawa <akiyks@gmail.com>]

On Tue, 19 Jan 2021 10:22:19 -0800, Paul E. McKenney wrote:
> On Mon, Jan 18, 2021 at 12:02:53AM +0900, Akira Yokosawa wrote:
>> Hi Paul,
>>
>> This patch set is last minute updates for the Second Edition.
>>
>> Patch 1/3 fixes a regression resulting in the "(m)" flag in the
>> watermark of footnote area.  It can happen only in parallel make
>> of first build. See the commit log of the root cause of the false
>> flag.
> 
> I don't see a patch 1/3, but I did apply and push the others, thank
> you!

I'll resend 1/3 soon.

> 
> See below for a delta on top of patch 2/3.
> 
>> Patches 2/3 and 3/3 are my attempt to update Figure 12.4 to extend
>> the bar chart up to Linux v5.10.
>>
>> I thought all I need to do would be to append data of v5.x releases.
>> However, when I ran the rcutorture.sh (for the first time), I noticed
>> the differences in line counts of RCU code of previous releases.
>>
>> My guess is that when you collected the data, your Linux git
>> repository had some untracked file(s) which unfortunately matched
>> the wildcard pattern in the script.
>>
>> Can you check the data on your own?
> 
> I do see some differences.  For one thing, your formal/data/rcu-test.dat
> file has "" in the version field for every three of four versions.
> (I don't see how the script does that.  Was this something that you
> hand-edited?)

Ah, I should have mentioned the hand-edit.

>               The numbers were different, but to your point about
> untracked files, I cloned a fresh repo to avoid untracked files.
> 
> After that, the numbers match yours except for v5.8 onwards, which
> have refscale.sh instead of refperf.sh.

You mean refperf.c -> refscale.c.  I missed that rename.

> 
>> Also, the discussion of the evolution of use of validation needs
>> some expansion to mention the trend of v5.x era.
>> Especially, v5.0 had a spike in test ratio.
>> A new trend of RCU code increase can be seen since v5.8.
>> Can you add some explanation regarding them?
> 
> Done!  Please see the second diff below.
> 
> 							Thanx, Paul
> 
> ------------------------------------------------------------------------
> 
> diff --git a/CodeSamples/formal/rcutorture.sh b/CodeSamples/formal/rcutorture.sh
> index 0782b39..bc9a285 100644
> --- a/CodeSamples/formal/rcutorture.sh
> +++ b/CodeSamples/formal/rcutorture.sh
> @@ -1,6 +1,6 @@
>  #!/bin/bash
>  #
> -# rcutorture.sh: Output LaTeX table entries showing the fraction of
> +# rcutorture.sh: Output gnuplot .dat entries showing the fraction of
>  #	Linux-kernel RCU that is test code.  Run in a git clone of
>  #	the Linux-kernel source tree.
>  #
> @@ -25,9 +25,9 @@ tags="`git tag -l | grep '^v' | grep -v -e - | grep -v '\..*\..*\.' | grep -v '2
>  for t in $tags
>  do
>  	git reset --hard $t > /dev/null 2>&1
> -	nontorture="`ls kernel/*rcu*.* kernel/rcu/* include/linux/*rcu* 2> /dev/null | grep -v torture | grep -v rcuperf | grep -v refperf | grep -v rcuscale`"
> +	nontorture="`ls kernel/*rcu*.* kernel/rcu/* include/linux/*rcu* 2> /dev/null | grep -v torture | grep -v rcuperf | grep -v refperf | grep -v rcuscale | grep -v refscale`"
>  	ntn="`wc -l $nontorture 2> /dev/null | tail -1 | awk '{ print $1 }'`"
> -	tn="`wc -l tools/testing/selftests/rcutorture/configs/*/*.sh kernel/rcutorture.c kernel/rcu/torture.c kernel/rcu/rcutorture.c kernel/rcu/rcuperf.c kernel/rcu/refperf.c kernel/rcu/rcuscale.c kernel/torture.c tools/testing/selftests/rcutorture/bin/* 2> /dev/null | tail -1 | awk '{ print $1 }'`"
> +	tn="`wc -l tools/testing/selftests/rcutorture/configs/*/*.sh kernel/rcutorture.c kernel/rcu/torture.c kernel/rcu/rcutorture.c kernel/rcu/rcuperf.c kernel/rcu/refperf.c kernel/rcu/rcuscale.c kernel/rcu/refscale.c kernel/torture.c tools/testing/selftests/rcutorture/bin/* 2> /dev/null | tail -1 | awk '{ print $1 }'`"
>  	frac="`awk -v ntn=$ntn -v tn=$tn 'END { printf "%.1f", 100 * tn / (tn + ntn) "%"; }' < /dev/null`"
>  	echo $t  $ntn $tn $((ntn + tn)) $frac
>  done
> 
> ------------------------------------------------------------------------
> 
> commit 3c8c4764725cccdf9f25dc1b87b9080d8b4f5199
> Author: Paul E. McKenney <paulmck@kernel.org>
> Date:   Tue Jan 19 10:18:12 2021 -0800
> 
>     formal: Add commentary on changes in Linux-kernel RCU
>     
>     This commit adds explanations for the larger changes shown in the Figure
>     12.4 bar graph.
>     
>     Reported-by: Akira Yokosawa <akiyks@gmail.com>
>     Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
> 
> diff --git a/formal/formal.tex b/formal/formal.tex
> index 2428942..99d13aa 100644
> --- a/formal/formal.tex
> +++ b/formal/formal.tex
> @@ -343,6 +343,14 @@ Linux kernel v3.14 added scripting that automated testing and also
>  analysis of test results, moving RCU towards continuous integration.
>  Linux kernel v4.7 added a performance validation suite for RCU's update-side
>  primitives.
> +Linux kernel v4.12 added Tree SRCU, featuring improved update-side
> +scalability, and v4.13 removed the old less-scalable SRCU implementation.
> +Linux kernel v5.0 briefly hosted the \path{nolibc} library within
> +the rcutorture scripting directory before it moved to its long-term
> +home in \path{tools/include/nolibc}.
> +Linux kernel v5.8 added the Tasks Trace and Rude flavors of RCU.
> +Linux kernel v5.9 added the \path{refscale.c} suite of read-side performance
> +tests.
>  Numerous other changes may be found in the Linux kernel's \co{git} archives.
>  % rcutorture
>  % v2.6.15: First torture test
> @@ -355,7 +363,11 @@ Numerous other changes may be found in the Linux kernel's \co{git} archives.
>  % v3.15: Add support for multiple torture-tests suites for locktorture.
>  % v3.16: Add support for conditional grace-period primitives.
>  % v4.7: Add update-side performance validation suite. *
> +% v4.12: Added Tree SRCU.
> +% v4.13: Removed non-Tree SRCU.
>  % v5.0: nolibc was briefly in the rcutorture scripting directory.
> +% v5.8: Added Tasks Trace RCU and Rude RCU.
> +% v5.9: Added refscale.c.
>  
>  We have established that the validation budget varies from one project
>  to the next, and also over the lifetime of any given project.
> 

Looks good to me.

I'm submitting the patch of Figure 12.4 based on the updated
rcutorture.sh.

        Thanks, Akira