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From:   Nick Desaulniers <ndesaulniers@google.com>
Date:   Mon, 9 Jan 2023 16:02:48 -0800
Message-ID: <CAKwvOdmt7mnP_dfCMO_YUV792Zgtirk=NFqe8XH0z88-b0e23A@mail.gmail.com>
Subject: Re: [PATCH rcu 22/27] init: Remove "select SRCU"
To:     "Paul E. McKenney" <paulmck@kernel.org>
Cc:     rcu@vger.kernel.org, linux-kernel@vger.kernel.org,
        kernel-team@meta.com, rostedt@goodmis.org,
        Andrew Morton <akpm@linux-foundation.org>,
        Masahiro Yamada <masahiroy@kernel.org>,
        Johannes Weiner <hannes@cmpxchg.org>,
        Vlastimil Babka <vbabka@suse.cz>,
        Nathan Chancellor <nathan@kernel.org>,
        Arnd Bergmann <arnd@arndb.de>, Miguel Ojeda <ojeda@kernel.org>,
        Masami Hiramatsu <mhiramat@kernel.org>,
        Dmitry Torokhov <dmitry.torokhov@gmail.com>,
        Aaron Tomlin <atomlin@redhat.com>, Tejun Heo <tj@kernel.org>,
        Christophe Leroy <christophe.leroy@csgroup.eu>
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On Wed, Jan 4, 2023 at 4:38 PM Paul E. McKenney <paulmck@kernel.org> wrote:
>
> Now that the SRCU Kconfig option is unconditionally selected, there is
> no longer any point in selecting it.  Therefore, remove the "select SRCU"
> Kconfig statements.

Looks like that's the case as of
commit 0cd7e350abc4 ("rcu: Make SRCU mandatory")
in v6.2-rc1.

>
> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Nick Desaulniers <ndesaulniers@google.com>
> Cc: Masahiro Yamada <masahiroy@kernel.org>
> Cc: Johannes Weiner <hannes@cmpxchg.org>
> Cc: Vlastimil Babka <vbabka@suse.cz>
> Cc: Nathan Chancellor <nathan@kernel.org>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Miguel Ojeda <ojeda@kernel.org>
> Cc: Masami Hiramatsu <mhiramat@kernel.org>
> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
> Cc: Aaron Tomlin <atomlin@redhat.com>
> Cc: Tejun Heo <tj@kernel.org>
> Cc: Christophe Leroy <christophe.leroy@csgroup.eu>

Patch LGTM
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>

Note that there's quite a few more of these though. Perhaps best to
remove them all together? Or perhaps you already have individual
patches out already for all of these?

$ grep -rn 'select SRCU'
mm/Kconfig:670: select SRCU
kernel/power/Kconfig:121: select SRCU
arch/mips/kvm/Kconfig:29: select SRCU
arch/riscv/kvm/Kconfig:30: select SRCU
arch/s390/kvm/Kconfig:34: select SRCU
arch/powerpc/kvm/Kconfig:25: select SRCU
arch/x86/kvm/Kconfig:49: select SRCU
arch/x86/Kconfig:286: select SRCU
arch/x86/Kconfig:1941: select SRCU
arch/arm64/kvm/Kconfig:31: select SRCU
init/Kconfig:1868: select SRCU
security/tomoyo/Kconfig:9: select SRCU
fs/btrfs/Kconfig:20: select SRCU
fs/dlm/Kconfig:7: select SRCU
fs/quota/Kconfig:9: select SRCU
fs/notify/Kconfig:4: select SRCU
drivers/md/Kconfig:9: select SRCU
drivers/clk/Kconfig:26: select SRCU
drivers/dax/Kconfig:4: select SRCU
drivers/devfreq/Kconfig:4: select SRCU
drivers/net/Kconfig:337: select SRCU
drivers/hwtracing/stm/Kconfig:5: select SRCU
drivers/cpufreq/Kconfig:6: select SRCU
drivers/opp/Kconfig:4: select SRCU

> ---
>  init/Kconfig | 1 -
>  1 file changed, 1 deletion(-)
>
> diff --git a/init/Kconfig b/init/Kconfig
> index 7e5c3ddc341de..af511c726d695 100644
> --- a/init/Kconfig
> +++ b/init/Kconfig
> @@ -1865,7 +1865,6 @@ config PERF_EVENTS
>         default y if PROFILING
>         depends on HAVE_PERF_EVENTS
>         select IRQ_WORK
> -       select SRCU
>         help
>           Enable kernel support for various performance events provided
>           by software and hardware.
> --
> 2.31.1.189.g2e36527f23
>


-- 
Thanks,
~Nick Desaulniers