From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Zijlstra Subject: Re: [PATCH] checkpatch: Add a --strict test for structs with bool member definitions Date: Thu, 12 Apr 2018 10:13:23 +0200 Message-ID: <20180412081323.GV4082@hirez.programming.kicks-ass.net> References: <95477c93db187bab6da8a8ba7c57836868446179.camel@perches.com> <20180410143950.4b8526073b4e3e34689f68cb@linux-foundation.org> <20180410150011.df9e036f57b5bcac7ac19686@linux-foundation.org> <20180411081502.GJ4082@hirez.programming.kicks-ass.net> <20180411092959.e666ec443e4d3bb6f43901d7@linux-foundation.org> <1c9f185f6086e9d89659f93720a27b660ee17c13.camel@perches.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Joe Perches Cc: Julia Lawall , Andrew Morton , "Rafael J. Wysocki" , Andy Whitcroft , yuankuiz@codeaurora.org, Linux PM , "Rafael J. Wysocki" , Frederic Weisbecker , Thomas Gleixner , paulmck@linux.vnet.ibm.com, Ingo Molnar , Len Brown , Linux Kernel Mailing List List-Id: linux-pm@vger.kernel.org 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.