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Date:   Thu, 12 Apr 2018 10:13:23 +0200
From:   Peter Zijlstra <peterz@infradead.org>
To:     Joe Perches <joe@perches.com>
Cc:     Julia Lawall <julia.lawall@lip6.fr>,
        Andrew Morton <akpm@linux-foundation.org>,
        "Rafael J. Wysocki" <rafael@kernel.org>,
        Andy Whitcroft <apw@canonical.com>, yuankuiz@codeaurora.org,
        Linux PM <linux-pm@vger.kernel.org>,
        "Rafael J. Wysocki" <rjw@rjwysocki.net>,
        Frederic Weisbecker <fweisbec@gmail.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        paulmck@linux.vnet.ibm.com, Ingo Molnar <mingo@kernel.org>,
        Len Brown <len.brown@intel.com>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] checkpatch: Add a --strict test for structs with bool
 member definitions
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On Wed, Apr 11, 2018 at 11:42:20PM -0700, Joe Perches wrote:
> I personally do not find a significant issue with
> uncontrolled sizes of bool in kernel structs as
> all of the kernel structs are transitory and not
> written out to storage.

People that care about cache locality, false sharing and other such
things really care about structure layout.

Growing a structure into another cacheline can be a significant
performance hit -- cache misses hurt.