From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932371AbeCEQav (ORCPT ); Mon, 5 Mar 2018 11:30:51 -0500 Received: from mga07.intel.com ([134.134.136.100]:9033 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752368AbeCEQ01 (ORCPT ); Mon, 5 Mar 2018 11:26:27 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.47,427,1515484800"; d="scan'208";a="39349290" From: "Kirill A. Shutemov" To: Ingo Molnar , x86@kernel.org, Thomas Gleixner , "H. Peter Anvin" , Tom Lendacky Cc: Dave Hansen , Kai Huang , linux-kernel@vger.kernel.org, linux-mm@kvack.org, "Kirill A. Shutemov" Subject: [RFC, PATCH 14/22] mm, khugepaged: Do not collapse pages in encrypted VMAs Date: Mon, 5 Mar 2018 19:26:02 +0300 Message-Id: <20180305162610.37510-15-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.16.1 In-Reply-To: <20180305162610.37510-1-kirill.shutemov@linux.intel.com> References: <20180305162610.37510-1-kirill.shutemov@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Pages for encrypted VMAs have to be allocated in a special way: we would need to propagate down not only desired NUMA node but also whether the page is encrypted. It complicates not-so-trivial routine of huge page allocation in khugepaged even more. I also puts more pressure on page allocator: we cannot re-use pages allocated for encrypted VMA to collapse page in unencrypted one or vice versa. I think for now it worth skipping encrypted VMAs. We can return to this topic later. Signed-off-by: Kirill A. Shutemov --- mm/khugepaged.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/mm/khugepaged.c b/mm/khugepaged.c index b7e2268dfc9a..601151678414 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -830,6 +830,8 @@ static bool hugepage_vma_check(struct vm_area_struct *vma) return false; if (is_vma_temporary_stack(vma)) return false; + if (vma_is_encrypted(vma)) + return false; return !(vma->vm_flags & VM_NO_KHUGEPAGED); } -- 2.16.1