From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pb0-f41.google.com (mail-pb0-f41.google.com [209.85.160.41]) by kanga.kvack.org (Postfix) with ESMTP id 31C396B0031 for ; Mon, 14 Oct 2013 17:25:26 -0400 (EDT) Received: by mail-pb0-f41.google.com with SMTP id rp2so7861189pbb.14 for ; Mon, 14 Oct 2013 14:25:25 -0700 (PDT) From: "Kirill A. Shutemov" In-Reply-To: <00000141b85a90a0-7cf6bab0-4c17-4fc0-8224-74bbb1fc85ee-000000@email.amazonses.com> References: <1381428359-14843-1-git-send-email-kirill.shutemov@linux.intel.com> <1381428359-14843-35-git-send-email-kirill.shutemov@linux.intel.com> <00000141a3f48ada-37ee9c14-2f2b-40a2-93f4-70258363351b-000000@email.amazonses.com> <20131010200921.91D84E0090@blue.fi.intel.com> <00000141a7d2aa7b-e59f292a-746c-4f55-aa51-9fa060a7fbeb-000000@email.amazonses.com> <20131014090437.F22CBE0090@blue.fi.intel.com> <00000141b85a90a0-7cf6bab0-4c17-4fc0-8224-74bbb1fc85ee-000000@email.amazonses.com> Subject: Re: [PATCH 34/34] mm: dynamically allocate page->ptl if it cannot be embedded to struct page Content-Transfer-Encoding: 7bit Message-Id: <20131014212514.C7C19E0090@blue.fi.intel.com> Date: Tue, 15 Oct 2013 00:25:14 +0300 (EEST) Sender: owner-linux-mm@kvack.org List-ID: To: Christoph Lameter Cc: "Kirill A. Shutemov" , Andrew Morton , Peter Zijlstra , Ingo Molnar , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org Christoph Lameter wrote: > On Mon, 14 Oct 2013, Kirill A. Shutemov wrote: > > > > > > Could you make the check a CONFIG option? CONFIG_PTLOCK_DOES_NOT_FIT_IN_PAGE_STRUCT or > > > > > so? > > > > > > > > No. We will have to track what affects sizeof(spinlock_t) manually. > > > > Not a fun and error prune. > > > > > > You can generate a config option depending on the size of the object via > > > Kbuild. Kbuild will determine the setting before building the kernel as a > > > whole by runing some small C program. > > > > I don't think it's any better than what we have there now. > > Well with the CONFIG options we can then create macros etc that handle > things differently depending on the ptl being in the page or not. Feel free to propose a patch. I don't see much point. -- Kirill A. Shutemov -- 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