On Mon, Jan 18, 2016 at 6:56 AM, Geert Uytterhoeven <ge...@linux-m68k.org> wrote: > Hi Kirill, > > On Mon, Jan 18, 2016 at 12:40 PM, Kirill A. Shutemov > <kir...@shutemov.name> wrote: >> On Mon, Jan 18, 2016 at 11:09:00AM +0100, Geert Uytterhoeven wrote: >>> fs/built-in.o: In function `smaps_account': >>> task_mmu.c:(.text+0x4f8fa): undefined reference to >>> `__compiletime_assert_471' >>> >>> Seen with m68k/allmodconfig or allyesconfig and gcc version 4.1.2 20061115 >>> (prerelease) (Ubuntu 4.1.1-21). >>> Not seen when compiling the affected file with gcc 4.6.3 or 4.9.0, or with >>> the >>> m68k defconfigs. >> >> Ughh. >> >> Please, test this: >> >> From 5ac27019f886eef033e84c9579e09099469ccbf9 Mon Sep 17 00:00:00 2001 >> From: "Kirill A. Shutemov" <kirill.shute...@linux.intel.com> >> Date: Mon, 18 Jan 2016 14:32:49 +0300 >> Subject: [PATCH] mm, proc: add workaround for old compilers >> >> For THP=n, HPAGE_PMD_NR in smaps_account() expands to BUILD_BUG(). >> That's fine since this codepath is eliminated by modern compilers. >> >> But older compilers have not that efficient dead code elimination. >> It causes problem at least with gcc 4.1.2 on m68k. >> >> Let's replace HPAGE_PMD_NR with 1 << compound_order(page). >> >> Signed-off-by: Kirill A. Shutemov <kirill.shute...@linux.intel.com> >> Reported-by: Geert Uytterhoeven <ge...@linux-m68k.org> > > Thanks, that fixes it! > > Tested-by: Geert Uytterhoeven <ge...@linux-m68k.org>
Same breakage on ia64 (with gcc 4.3.4). Same fix works for me. Tested-by: Tony Luck <tony.l...@intel.com>