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Message-ID: <ac3d94c2-6ed8-21d1-3ef6-8970bee5262a@alu.unizg.hr>
Date:   Sun, 20 Nov 2022 20:33:50 +0100
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Subject: Re: BUG: BISECTED: in squashfs_xz_uncompress() (Was: RCU stalls in
 squashfs_readahead())
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From:   Mirsad Goran Todorovac <mirsad.todorovac@alu.unizg.hr>
To:     paulmck@kernel.org
Cc:     Phillip Lougher <phillip@squashfs.org.uk>,
        LKML <linux-kernel@vger.kernel.org>, phillip.lougher@gmail.com,
        Thorsten Leemhuis <regressions@leemhuis.info>, elliott@hpe.com
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P.S.

Sorry, Paul, the patches did not apply on the mainline "master" or "v6.1-rc5" nor "v6.0.9".

Here is the session log:

mtodorov@domac:~/linux/kernel/linux_stable_build_b$ git checkout v6.1-rc5
Note: checking out 'v6.1-rc5'.

You are in 'detached HEAD' state. You can look around, make experimental
changes and commit them, and you can discard any commits you make in this
state without impacting any branches by performing another checkout.

If you want to create a new branch to retain commits you create, you may
do so (now or later) by using -b with the checkout command again. Example:

   git checkout -b <new-branch-name>

HEAD is now at 094226ad94f4 Linux 6.1-rc5
mtodorov@domac:~/linux/kernel/linux_stable_build_b$ git apply ../remove-android.patch
error: patch failed: drivers/Makefile:176
error: drivers/Makefile: patch does not apply
error: patch failed: drivers/android/Kconfig:1
error: drivers/android/Kconfig: patch does not apply
error: patch failed: kernel/configs/android-base.config:7
error: kernel/configs/android-base.config: patch does not apply
error: patch failed: kernel/rcu/Kconfig.debug:86
error: kernel/rcu/Kconfig.debug: patch does not apply
error: patch failed: tools/testing/selftests/filesystems/binderfs/config:1
error: tools/testing/selftests/filesystems/binderfs/config: patch does not apply
error: patch failed: tools/testing/selftests/sync/config:1
error: tools/testing/selftests/sync/config: patch does not apply
mtodorov@domac:~/linux/kernel/linux_stable_build_b$ git apply ../introduce-rcu-stall-timeout.patch
error: patch failed: Documentation/admin-guide/kernel-parameters.txt:4893
error: Documentation/admin-guide/kernel-parameters.txt: patch does not apply
error: patch failed: kernel/rcu/Kconfig.debug:91
error: kernel/rcu/Kconfig.debug: patch does not apply
error: patch failed: kernel/rcu/rcu.h:210
error: kernel/rcu/rcu.h: patch does not apply
error: patch failed: kernel/rcu/tree_exp.h:496
error: kernel/rcu/tree_exp.h: patch does not apply
error: patch failed: kernel/rcu/tree_stall.h:25
error: kernel/rcu/tree_stall.h: patch does not apply
error: patch failed: kernel/rcu/update.c:506
error: kernel/rcu/update.c: patch does not apply
mtodorov@domac:~/linux/kernel/linux_stable_build_b$ git checkout v6.0.9
Checking out files: 100% (12048/12048), done.
Previous HEAD position was 094226ad94f4 Linux 6.1-rc5
HEAD is now at be8b93b5cc7d Linux 6.0.9
You have mail in /var/mail/mtodorov
mtodorov@domac:~/linux/kernel/linux_stable_build_b$ git apply ../remove-android.patch
error: patch failed: drivers/Makefile:176
error: drivers/Makefile: patch does not apply
error: patch failed: drivers/android/Kconfig:1
error: drivers/android/Kconfig: patch does not apply
error: patch failed: kernel/configs/android-base.config:7
error: kernel/configs/android-base.config: patch does not apply
error: patch failed: kernel/rcu/Kconfig.debug:86
error: kernel/rcu/Kconfig.debug: patch does not apply
error: patch failed: tools/testing/selftests/filesystems/binderfs/config:1
error: tools/testing/selftests/filesystems/binderfs/config: patch does not apply
error: patch failed: tools/testing/selftests/sync/config:1
error: tools/testing/selftests/sync/config: patch does not apply
mtodorov@domac:~/linux/kernel/linux_stable_build_b$ git apply ../introduce-rcu-stall-timeout.patch
error: patch failed: Documentation/admin-guide/kernel-parameters.txt:4893
error: Documentation/admin-guide/kernel-parameters.txt: patch does not apply
error: patch failed: kernel/rcu/Kconfig.debug:91
error: kernel/rcu/Kconfig.debug: patch does not apply
error: patch failed: kernel/rcu/rcu.h:210
error: kernel/rcu/rcu.h: patch does not apply
error: patch failed: kernel/rcu/tree_exp.h:496
error: kernel/rcu/tree_exp.h: patch does not apply
error: patch failed: kernel/rcu/tree_stall.h:25
error: kernel/rcu/tree_stall.h: patch does not apply
error: patch failed: kernel/rcu/update.c:506
error: kernel/rcu/update.c: patch does not apply
mtodorov@domac:~/linux/kernel/linux_stable_build_b$

Now I really got to try to catch some sleep because I work my day job in the morning.

I must admit that I am not enthusiastic about these patches for I think they only mask
the problem of stalls: removing reports from the logs, but cores will still lock up.

Besides, I also hoped to develop multimedia for Android devices, too, as a part of our
research, to academically justify my work on the Linux kernel bug bisection and learning
about the kernel proper.

I still need to figure out a way to present my results to the academic community, to
have it justified and to have our University more visible and ranked on the world list. ;-)

Thanks,
Mirsad

--
Mirsad Goran Todorovac
Sistem inženjer
Grafički fakultet | Akademija likovnih umjetnosti
Sveučilište u Zagrebu
-- 
System engineer
Faculty of Graphic Arts | Academy of Fine Arts
University of Zagreb, Republic of Croatia
The European Union