Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752507AbbDBVxJ (ORCPT ); Thu, 2 Apr 2015 17:53:09 -0400 Received: from mail-pa0-f54.google.com ([209.85.220.54]:36774 "EHLO mail-pa0-f54.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751289AbbDBVxG (ORCPT ); Thu, 2 Apr 2015 17:53:06 -0400 Date: Thu, 2 Apr 2015 15:53:01 -0600 From: Lina Iyer To: Kevin Hilman Cc: Andrew Morton , Nishanth Menon , Magnus Damm , Russell King - ARM Linux , Arnd Bergmann , Ard Biesheuvel , Marc Zyngier , Tyler Baker , "linux-sh@vger.kernel.org" , Will Deacon , Linux Kernel Development , "linux-mm@kvack.org" , Simon Horman , Geert Uytterhoeven , Catalin Marinas , "grygorii.strashko@linaro.org" , "linux-omap@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" Subject: Re: [PATCH] mm/migrate: Mark unmap_and_move() "noinline" to avoid ICE in gcc 4.7.3 Message-ID: <20150402215301.GA24500@linaro.org> References: <20150327100612.GB1562@arm.com> <7hbnj99epe.fsf@deeprootsystems.com> <7h8uec95t2.fsf@deeprootsystems.com> <551BBEC5.7070801@arm.com> <20150401124007.20c440cc43a482f698f461b8@linux-foundation.org> <7hwq1v4iq4.fsf@deeprootsystems.com> <20150402191230.GA24219@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2414 Lines: 66 On Thu, Apr 02 2015 at 15:12 -0600, Kevin Hilman wrote: >On Thu, Apr 2, 2015 at 12:12 PM, Lina Iyer wrote: >> On Wed, Apr 01 2015 at 15:57 -0600, Kevin Hilman wrote: >>> >>> Andrew Morton writes: >>> >>>> 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... >>> >>> >>> Your patch on top of Geert's still compiles fine for me with gcc-4.7.3. >>> However, I'm not sure how specific we can be on the versions. >>> >>> /me goes to test a few more compilers... OK... >>> >>> ICE: 4.7.1, 4.7.3, 4.8.3 >>> OK: 4.6.3, 4.9.2, 4.9.3 >>> >>> The diff below[2] on top of yours compiles fine here and at least covers >>> the compilers I *know* to trigger the ICE. >> >> >> I see ICE on arm-linux-gnueabi-gcc (Ubuntu/Linaro 4.7.4-2ubuntu1) 4.7.4 >> > >Thanks for checking. I'm assuming my patch fixes it for your since >that should catch any 4.7.x compiler. Yes, thank you. This fixes it on 4.7.4 > >Kevin -- 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/