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Date:   Mon, 25 Jul 2022 12:39:48 -0700
From:   Andrew Morton <akpm@linux-foundation.org>
To:     Ben Dooks <ben-linux@fluff.org>
Cc:     linux-kernel@vger.kernel.org, sparclinux@vger.kernel.org,
        linux-riscv@lists.infradead.org, linuxppc-dev@lists.ozlabs.org,
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        linux-csky@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-snps-arc@lists.infradead.org, linux-alpha@vger.kernel.org
Subject: Re: [PATCH] profile: setup_profiling_timer() is moslty not
 implemented
Message-Id: <20220725123948.f16674b10022404814161d4a@linux-foundation.org>
In-Reply-To: <20220721195509.418205-1-ben-linux@fluff.org>
References: <20220721195509.418205-1-ben-linux@fluff.org>
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On Thu, 21 Jul 2022 20:55:09 +0100 Ben Dooks <ben-linux@fluff.org> wrote:

> The setup_profiling_timer() is mostly un-implemented by many
> architectures. In many places it isn't guarded by CONFIG_PROFILE
> which is needed for it to be used. Make it a weak symbol in
> kernel/profile.c and remove the 'return -EINVAL' implementations
> from the kenrel.
> 
> There are a couple of architectures which do return 0 from
> the setup_profiling_timer() function but they don't seem to
> do anything else with it. To keep the /proc compatibility for
> now, leave these for a future update or removal.
> 
> On ARM, this fixes the following sparse warning:
> arch/arm/kernel/smp.c:793:5: warning: symbol 'setup_profiling_timer' was not declared. Should it be static?

I'll grab this.

We have had some problems with weak functions lately.  See

https://lore.kernel.org/all/87ee0q7b92.fsf@email.froward.int.ebiederm.org/T/#u

Hopefully that was a rare corner case.