From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f54.google.com (mail-pa0-f54.google.com [209.85.220.54]) by kanga.kvack.org (Postfix) with ESMTP id 752506B0032 for ; Wed, 1 Apr 2015 17:55:03 -0400 (EDT) Received: by patj18 with SMTP id j18so64141130pat.2 for ; Wed, 01 Apr 2015 14:55:03 -0700 (PDT) Received: from mail-pa0-f46.google.com (mail-pa0-f46.google.com. [209.85.220.46]) by mx.google.com with ESMTPS id t17si4585605pdl.223.2015.04.01.14.55.02 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 01 Apr 2015 14:55:02 -0700 (PDT) Received: by pacgg7 with SMTP id gg7so64152370pac.0 for ; Wed, 01 Apr 2015 14:55:02 -0700 (PDT) From: Kevin Hilman Subject: Re: [PATCH] mm/migrate: Mark unmap_and_move() "noinline" to avoid ICE in gcc 4.7.3 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> <20150401124007.20c440cc43a482f698f461b8@linux-foundation.org> Date: Wed, 01 Apr 2015 14:54:59 -0700 In-Reply-To: <20150401124007.20c440cc43a482f698f461b8@linux-foundation.org> (Andrew Morton's message of "Wed, 1 Apr 2015 12:40:07 -0700") Message-ID: <7hwq1v4iq4.fsf@deeprootsystems.com> MIME-Version: 1.0 Content-Type: text/plain Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: Marc Zyngier , Geert Uytterhoeven , 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" 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. Kevin [1] diff --git a/mm/migrate.c b/mm/migrate.c index 25fd7f6291de..6e15ae3248e0 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -901,10 +901,10 @@ out: } /* - * gcc-4.7.3 on arm gets an ICE when inlining unmap_and_move(). Work around + * gcc 4.7 and 4.8 on arm gets an ICE when inlining unmap_and_move(). Work around * it. */ -#if GCC_VERSION == 40703 && defined(CONFIG_ARM) +#if (GCC_VERSION >= 40700 && GCC_VERSION < 40900) && defined(CONFIG_ARM) #define ICE_noinline noinline #else #define ICE_noinline -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org