From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexey Dobriyan Subject: Re: [PATCH] sched: make struct task_struct::state 32-bit Date: Tue, 3 Sep 2019 19:23:03 +0300 Message-ID: <20190903162303.GA2173@avx2> References: <20190902210558.GA23013@avx2> <7b94004e-4a65-462b-cd6b-5cbd23d607bf@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Return-path: Content-Disposition: inline In-Reply-To: <7b94004e-4a65-462b-cd6b-5cbd23d607bf@arm.com> Sender: linux-kernel-owner@vger.kernel.org To: Valentin Schneider Cc: mingo@redhat.com, peterz@infradead.org, linux-kernel@vger.kernel.org, rcu@vger.kernel.org, linux-block@vger.kernel.org, dm-devel@redhat.com, axboe@kernel.dk, aarcange@redhat.com List-Id: dm-devel.ids On Tue, Sep 03, 2019 at 12:02:38AM +0100, Valentin Schneider wrote: > struct task_struct { > struct thread_info thread_info; /* 0 24 */ > volatile int state; /* 24 4 */ > > /* XXX 4 bytes hole, try to pack */ > > void * stack; /* 32 8 */ > > Though seeing as this is also the boundary of the randomized layout we can't > really do much better without changing the boundary itself. So much for > cacheline use :/ Cacheline use of task_struct is pretty hopeless because of all the ifdefs.