Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752628AbbDBVMi (ORCPT ); Thu, 2 Apr 2015 17:12:38 -0400 Received: from mail.kernel.org ([198.145.29.136]:59189 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751892AbbDBVMf (ORCPT ); Thu, 2 Apr 2015 17:12:35 -0400 MIME-Version: 1.0 In-Reply-To: <20150402191230.GA24219@linaro.org> References: <20150327002554.GA5527@verge.net.au> <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> Date: Thu, 2 Apr 2015 14:12:28 -0700 Message-ID: Subject: Re: [PATCH] mm/migrate: Mark unmap_and_move() "noinline" to avoid ICE in gcc 4.7.3 From: Kevin Hilman To: Lina Iyer Cc: Kevin Hilman , 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" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2260 Lines: 63 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. 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/