From mboxrd@z Thu Jan 1 00:00:00 1970 From: lina.iyer@linaro.org (Lina Iyer) Date: Thu, 2 Apr 2015 15:53:01 -0600 Subject: [PATCH] mm/migrate: Mark unmap_and_move() "noinline" to avoid ICE in gcc 4.7.3 In-Reply-To: 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> Message-ID: <20150402215301.GA24500@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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