From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756187AbbLDLuK (ORCPT ); Fri, 4 Dec 2015 06:50:10 -0500 Received: from terminus.zytor.com ([198.137.202.10]:59876 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756135AbbLDLuE (ORCPT ); Fri, 4 Dec 2015 06:50:04 -0500 Date: Fri, 4 Dec 2015 03:49:01 -0800 From: tip-bot for Rasmus Villemoes Message-ID: Cc: hpa@zytor.com, toshi.kani@hp.com, linux@rasmusvillemoes.dk, linux-kernel@vger.kernel.org, torvalds@linux-foundation.org, peterz@infradead.org, tglx@linutronix.de, mingo@kernel.org Reply-To: toshi.kani@hp.com, hpa@zytor.com, torvalds@linux-foundation.org, peterz@infradead.org, mingo@kernel.org, tglx@linutronix.de, linux-kernel@vger.kernel.org, linux@rasmusvillemoes.dk In-Reply-To: <1449002691-20783-1-git-send-email-linux@rasmusvillemoes.dk> References: <1449002691-20783-1-git-send-email-linux@rasmusvillemoes.dk> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/mm] x86/mm/mtrr: Mark the 'range_new' static variable in mtrr_calc_range_state() as __initdata Git-Commit-ID: c332813b51cbe807d539bb059b81235abf1e3fdd X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: c332813b51cbe807d539bb059b81235abf1e3fdd Gitweb: http://git.kernel.org/tip/c332813b51cbe807d539bb059b81235abf1e3fdd Author: Rasmus Villemoes AuthorDate: Tue, 1 Dec 2015 21:44:50 +0100 Committer: Ingo Molnar CommitDate: Fri, 4 Dec 2015 09:11:28 +0100 x86/mm/mtrr: Mark the 'range_new' static variable in mtrr_calc_range_state() as __initdata 'range_new' doesn't seem to be used after init. It is only passed to memset(), sum_ranges(), memcmp() and x86_get_mtrr_mem_range(), the latter of which also only passes it on to various *range* library functions. So mark it __initdata to free up an extra page after init. Its contents are wiped at every call to mtrr_calc_range_state(), so it being static is not about preserving state between calls, but simply to avoid a 4k+ stack frame. While there, add a comment explaining this and why it's safe. We could also mark nr_range_new as __initdata, but since it's just a single int and also doesn't carry state between calls (it is unconditionally assigned to before it is read), we might as well make it an ordinary automatic variable. Signed-off-by: Rasmus Villemoes Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Toshi Kani Link: http://lkml.kernel.org/r/1449002691-20783-1-git-send-email-linux@rasmusvillemoes.dk Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/mtrr/cleanup.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/cpu/mtrr/cleanup.c b/arch/x86/kernel/cpu/mtrr/cleanup.c index 70d7c93..0d98503 100644 --- a/arch/x86/kernel/cpu/mtrr/cleanup.c +++ b/arch/x86/kernel/cpu/mtrr/cleanup.c @@ -593,9 +593,16 @@ mtrr_calc_range_state(u64 chunk_size, u64 gran_size, unsigned long x_remove_base, unsigned long x_remove_size, int i) { - static struct range range_new[RANGE_NUM]; + /* + * range_new should really be an automatic variable, but + * putting 4096 bytes on the stack is frowned upon, to put it + * mildly. It is safe to make it a static __initdata variable, + * since mtrr_calc_range_state is only called during init and + * there's no way it will call itself recursively. + */ + static struct range range_new[RANGE_NUM] __initdata; unsigned long range_sums_new; - static int nr_range_new; + int nr_range_new; int num_reg; /* Convert ranges to var ranges state: */