From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-f71.google.com (mail-pg0-f71.google.com [74.125.83.71]) by kanga.kvack.org (Postfix) with ESMTP id A5AF96B0012 for ; Mon, 5 Mar 2018 11:26:28 -0500 (EST) Received: by mail-pg0-f71.google.com with SMTP id v8so7534991pgs.9 for ; Mon, 05 Mar 2018 08:26:28 -0800 (PST) Received: from mga14.intel.com (mga14.intel.com. [192.55.52.115]) by mx.google.com with ESMTPS id q24si10299553pff.301.2018.03.05.08.26.27 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 05 Mar 2018 08:26:27 -0800 (PST) From: "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> In-Reply-To: <20180305162610.37510-1-kirill.shutemov@linux.intel.com> References: <20180305162610.37510-1-kirill.shutemov@linux.intel.com> Sender: owner-linux-mm@kvack.org List-ID: 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" 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 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org