From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ee0-f43.google.com (mail-ee0-f43.google.com [74.125.83.43]) by kanga.kvack.org (Postfix) with ESMTP id 8B5756B003A for ; Wed, 14 May 2014 17:18:23 -0400 (EDT) Received: by mail-ee0-f43.google.com with SMTP id d17so94479eek.16 for ; Wed, 14 May 2014 14:18:22 -0700 (PDT) Received: from kirsi1.inet.fi (mta-out1.inet.fi. [62.71.2.198]) by mx.google.com with ESMTP id i49si2552001eem.132.2014.05.14.14.18.21 for ; Wed, 14 May 2014 14:18:22 -0700 (PDT) Date: Thu, 15 May 2014 00:17:48 +0300 From: "Kirill A. Shutemov" Subject: Re: [PATCH 2/2] mm: replace remap_file_pages() syscall with emulation Message-ID: <20140514211748.GA15970@node.dhcp.inet.fi> References: <1399552888-11024-1-git-send-email-kirill.shutemov@linux.intel.com> <1399552888-11024-3-git-send-email-kirill.shutemov@linux.intel.com> <20140508145729.3d82d2c989cfc483c94eb324@linux-foundation.org> <5370E4B4.1060802@oracle.com> <20140512170514.GA28227@node.dhcp.inet.fi> <5373D781.7020109@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5373D781.7020109@oracle.com> Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton , Linus Torvalds Cc: Sasha Levin , "Kirill A. Shutemov" , linux-kernel@vger.kernel.org, linux-mm@kvack.org, peterz@infradead.org, mingo@kernel.org On Wed, May 14, 2014 at 04:52:17PM -0400, Sasha Levin wrote: > On 05/12/2014 01:05 PM, Kirill A. Shutemov wrote: > > Taking into account your employment, is it possible to check how the RDBMS > > (old but it still supported 32-bit versions) would react on -ENOSYS here? > > Alrighty, I got an answer: > > 1. remap_file_pages() only works when the "VLM" feature of the db is enabled, > so those databases can work just fine without it, but be limited to 3-4GB of > memory. This is not needed at all on 64bit machines. Okay. And it seems user need to enable it manually with option USE_INDIRECT_DATA_BUFFERS=TRUE. http://docs.oracle.com/cd/B28359_01/server.111/b32009/appi_vlm.htm > 2. As of OL7 (kernel 3.8), there will not be a 32bit kernel build. I'm still > waiting for an answer whether there will do a 32bit DB build for a 64bit kernel, > but that never happened before and seems unlikely. > > 3. They're basically saying that by the time upstream releases a kernel without > remap_file_pages() no one will need it here. > > To sum it up, they're fine with removing remap_file_pages(). Andrew, Linus, what will we do here: live with emulation or just kill the syscall? Or may be kill the syscall after few releases with emulation? -- 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