Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753551AbbDATkL (ORCPT ); Wed, 1 Apr 2015 15:40:11 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:33781 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753197AbbDATkI (ORCPT ); Wed, 1 Apr 2015 15:40:08 -0400 Date: Wed, 1 Apr 2015 12:40:07 -0700 From: Andrew Morton To: Marc Zyngier Cc: Geert Uytterhoeven , Kevin Hilman , Ard Biesheuvel , Will Deacon , Simon Horman , Tyler Baker , Nishanth Menon , Russell King - ARM Linux , Arnd Bergmann , "linux-sh@vger.kernel.org" , Catalin Marinas , Magnus Damm , "grygorii.strashko@linaro.org" , "linux-omap@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , Linux Kernel Development , "linux-mm@kvack.org" Subject: Re: [PATCH] mm/migrate: Mark unmap_and_move() "noinline" to avoid ICE in gcc 4.7.3 Message-Id: <20150401124007.20c440cc43a482f698f461b8@linux-foundation.org> In-Reply-To: <551BBEC5.7070801@arm.com> References: <20150324004537.GA24816@verge.net.au> <20150324161358.GA694@kahuna> <20150326003939.GA25368@verge.net.au> <20150326133631.GB2805@arm.com> <20150327002554.GA5527@verge.net.au> <20150327100612.GB1562@arm.com> <7hbnj99epe.fsf@deeprootsystems.com> <7h8uec95t2.fsf@deeprootsystems.com> <551BBEC5.7070801@arm.com> X-Mailer: Sylpheed 3.4.1 (GTK+ 2.24.23; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1989 Lines: 59 On Wed, 01 Apr 2015 10:47:49 +0100 Marc Zyngier wrote: > > -static int unmap_and_move(new_page_t get_new_page, free_page_t put_new_page, > > - unsigned long private, struct page *page, int force, > > - enum migrate_mode mode) > > +static noinline int unmap_and_move(new_page_t get_new_page, > > + free_page_t put_new_page, > > + unsigned long private, struct page *page, > > + int force, enum migrate_mode mode) > > { > > int rc = 0; > > int *result = NULL; > > > > Ouch. That's really ugly. And on 32bit ARM, we end-up spilling half of > the parameters on the stack, which is not going to help performance > either (not that this would be useful on 32bit ARM anyway...). > > Any chance you could make this dependent on some compiler detection > mechanism? With my arm compiler (gcc-4.4.4) the patch makes no difference - unmap_and_move() isn't being inlined anyway. How does this look? Kevin, could you please retest? I might have fat-fingered something... --- a/mm/migrate.c~mm-migrate-mark-unmap_and_move-noinline-to-avoid-ice-in-gcc-473-fix +++ a/mm/migrate.c @@ -901,10 +901,20 @@ out: } /* + * gcc-4.7.3 on arm gets an ICE when inlining unmap_and_move(). Work around + * it. + */ +#if GCC_VERSION == 40703 && defined(CONFIG_ARM) +#define ICE_noinline noinline +#else +#define ICE_noinline +#endif + +/* * Obtain the lock on page, remove all ptes and migrate the page * to the newly allocated page in newpage. */ -static noinline int unmap_and_move(new_page_t get_new_page, +static ICE_noinline int unmap_and_move(new_page_t get_new_page, free_page_t put_new_page, unsigned long private, struct page *page, int force, enum migrate_mode mode) _ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/