From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Rothwell Subject: Re: linux-next: build failure after merge of the akpm-current tree Date: Thu, 7 Sep 2017 15:23:55 +1000 Message-ID: <20170907152355.16f4490a@canb.auug.org.au> References: <20170801163904.7d49881a@canb.auug.org.au> <20170801205054.17c8579f@canb.auug.org.au> <00BCCF64-C319-44F0-992B-7F78D4676B5E@cs.rutgers.edu> <20170802154554.2fe6515b@canb.auug.org.au> <20170802163137.064ba4bf@canb.auug.org.au> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: Received: from ozlabs.org ([103.22.144.67]:38433 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752525AbdIGFX6 (ORCPT ); Thu, 7 Sep 2017 01:23:58 -0400 In-Reply-To: <20170802163137.064ba4bf@canb.auug.org.au> Sender: linux-next-owner@vger.kernel.org List-ID: To: Zi Yan Cc: Andrew Morton , Linux-Next Mailing List , Linux Kernel Mailing List Hi all, On Wed, 2 Aug 2017 16:31:45 +1000 Stephen Rothwell wrote: > > On Wed, 2 Aug 2017 15:45:54 +1000 Stephen Rothwell wrote: > > > > On Tue, 01 Aug 2017 09:08:01 -0400 "Zi Yan" wrote: > > > > > > I found two possible fixes. > > > > > > 1. This uses C++ zero initializer, GCC is OK with it. > > > I tested with GCC 4.9.3 (has the initialization bug) and GCC 6.4.0. > > > > > > --- a/include/linux/swapops.h~a > > > +++ a/include/linux/swapops.h > > > @@ -217,7 +217,7 @@ static inline swp_entry_t pmd_to_swp_ent > > > > > > static inline pmd_t swp_entry_to_pmd(swp_entry_t entry) > > > { > > > - return (pmd_t){ 0 }; > > > + return (pmd_t){}; > > > } > > > > I have done that for today ... please decide which is best (or find > > something better - maybe every platform really needs to have a __pmd() > > definition) and submit a real fix patch to Andrew. > > OK, that failed for my compiler (gcc 5.2.0) like this: > > In file included from mm/vmscan.c:55:0: > include/linux/swapops.h: In function 'swp_entry_to_pmd': > include/linux/swapops.h:226:16: error: empty scalar initializer > return (pmd_t){}; > ^ > include/linux/swapops.h:226:16: note: (near initialization for '(anonymous)') This has reappeared today :-( (for the arm multi_v7_defconfig build at least) > So I used the other idea (on top of Andrew's current tree): The fix patch now looks like this: From: Stephen Rothwell Date: Wed, 2 Aug 2017 15:55:02 +1000 Subject: [PATCH] mm-thp-enable-thp-migration-in-generic-path-fix-fix Signed-off-by: Stephen Rothwell --- include/linux/swapops.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/include/linux/swapops.h b/include/linux/swapops.h index 45b092aa6419..61cffa148a79 100644 --- a/include/linux/swapops.h +++ b/include/linux/swapops.h @@ -223,7 +223,9 @@ static inline swp_entry_t pmd_to_swp_entry(pmd_t pmd) static inline pmd_t swp_entry_to_pmd(swp_entry_t entry) { - return (pmd_t){}; + pmd_t e; + memset(&e, 0, sizeof(pmd_t)); + return e; } static inline int is_pmd_migration_entry(pmd_t pmd) -- Cheers, Stephen Rothwell