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From:   Thomas Gleixner <tglx@linutronix.de>
To:     Mark Rutland <mark.rutland@arm.com>, linux-kernel@vger.kernel.org
Cc:     benh@kernel.crashing.org, boqun.feng@gmail.com, bp@alien8.de,
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Subject: Re: [RFC PATCH 01/10] thread_info: add helpers to snapshot thread flags
In-Reply-To: <20210609122001.18277-2-mark.rutland@arm.com>
References: <20210609122001.18277-1-mark.rutland@arm.com> <20210609122001.18277-2-mark.rutland@arm.com>
Date:   Sun, 20 Jun 2021 00:28:04 +0200
Message-ID: <87h7hth4ln.ffs@nanos.tec.linutronix.de>
MIME-Version: 1.0
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On Wed, Jun 09 2021 at 13:19, Mark Rutland wrote:
> We have common helpers to manipulate individual thread flags, but where
> code wants to check several flags at once, it must open code reading
> current_thread_info()->flags and operating on a snapshot.

Who's we?

> As some flags can be set remotely it's necessary to use READ_ONCE() to
> get a consistent snapshot even when IRQs are disabled, but some code
> forgets to do this. Generally this is unlike to cause a problem in
> practice, but it is somewhat unsound, and KCSAN will legitimately warn
> that there is a data race.
>
> To make it easier to do the right thing, and to highlight that
> concurrent modification is possible, let's add a new helpers to
> snapshot

let's add? Why not simply "add"?

> +static inline unsigned long read_ti_thread_flags(struct thread_info *ti)

__always_inline() as Marco pointed out already

Other than those nitpicks:

 Reviewed-by: Thomas Gleixner <tglx@linutronix.de>