On Thu, 18 Oct 2012 14:33:23 +0800 Dave Young <dyo...@redhat.com> wrote: [...] > Just see Yinghai's coments, later init_memory_mapping cleanup > will also address the 4k pages in first 2/4M, so revert them should be better. > https://lkml.org/lkml/2012/9/4/533 > > Here is a patch for the reverting: > --- > x86 mm: Revert find_early_table_space fix > > 722bc6b16771ed80871e1fd81c86d3627dda2ac8 Try to address the issue that the > first 2/4M should use 4k pages if PSE enabled. but extra counts should only > valid for x86_32. This commit cause kdump regression, kdump kernel hangs > happens > with it. > > As Yinghai Lu said they should be reverted. see below post: > https://lkml.org/lkml/2012/9/4/533 > > As there's a later fix to above fix which is > bd2753b2dda7bb43c7468826de75f49c6a7e8965 > So we need revert both of these two commits. > > Tested kdump on physical and virutual machines. > > Reverted commits: > commit 722bc6b16771ed80871e1fd81c86d3627dda2ac8 > Author: WANG Cong <xiyou.wangc...@gmail.com> > Date: Mon Mar 5 15:05:13 2012 -0800 > > x86/mm: Fix the size calculation of mapping tables > > For machines that enable PSE, the first 2/4M memory region still uses > 4K pages, so needs more PTEs in this case, but > find_early_table_space() doesn't count this. > > This patch fixes it. > > The bug was found via code review, no misbehavior of the kernel > was observed. > > Signed-off-by: WANG Cong <xiyou.wangc...@gmail.com> > Cc: Yinghai Lu <ying...@kernel.org> > Cc: Tejun Heo <t...@kernel.org> > Cc: <ianfang...@gmail.com> > Signed-off-by: Andrew Morton <a...@linux-foundation.org> > Link: http://lkml.kernel.org/n/tip-kq6a00qe33h7c7ais2xsy...@git.kernel.org > Signed-off-by: Ingo Molnar <mi...@elte.hu> > > commit bd2753b2dda7bb43c7468826de75f49c6a7e8965 > Author: Yinghai Lu <ying...@kernel.org> > Date: Wed Jun 6 10:55:40 2012 -0700 > > x86/mm: Only add extra pages count for the first memory range during > pre-allocatio > > Robin found this regression: > > | I just tried to boot an 8TB system. It fails very early in boot with: > | Kernel panic - not syncing: Cannot find space for the kernel page tables > > git bisect commit 722bc6b16771ed80871e1fd81c86d3627dda2ac8. > > A git revert of that commit does boot past that point on the 8TB > configuration. > > That commit will add up extra pages for all memory range even > above 4g. > > Try to limit that extra page count adding to first entry only. > > Bisected-by: Robin Holt <h...@sgi.com> > Tested-by: Robin Holt <h...@sgi.com> > Signed-off-by: Yinghai Lu <ying...@kernel.org> > Cc: WANG Cong <xiyou.wangc...@gmail.com> > Cc: Linus Torvalds <torva...@linux-foundation.org> > Cc: Andrew Morton <a...@linux-foundation.org> > Cc: Peter Zijlstra <a.p.zijls...@chello.nl> > Link: > http://lkml.kernel.org/r/CAE9FiQUj3wyzQxtq9yzBNc9u220p8JZ1FYHG7t%3DMOzJ%3D9B > Signed-off-by: Ingo Molnar <mi...@kernel.org> > > > Signed-off-by: Dave Young <dyo...@redhat.com> > --- > arch/x86/mm/init.c | 22 +++++++++------------- > 1 file changed, 9 insertions(+), 13 deletions(-)
The patch looks good. I reproduced the issue with last upstream commit 43c422eda99b894f18d1cca17bcd2401efaf7bd0 and confirmed that it does work with the patch applied. thanks a lot! Acked-by: Flavio Leitner <f...@redhat.com> Tested-by: Flavio Leitner <f...@redhat.com> fbl -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
