Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752779AbbBWVDZ (ORCPT ); Mon, 23 Feb 2015 16:03:25 -0500 Received: from mga01.intel.com ([192.55.52.88]:56017 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751601AbbBWVDY (ORCPT ); Mon, 23 Feb 2015 16:03:24 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.09,633,1418112000"; d="scan'208";a="689641017" From: Andi Kleen To: Vlastimil Babka Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrew Morton , Hugh Dickins , Andrea Arcangeli , "Kirill A. Shutemov" , Rik van Riel , Mel Gorman , Michal Hocko , Ebru Akagunduz , Alex Thorlton , David Rientjes , Peter Zijlstra , Ingo Molnar Subject: Re: [RFC 0/6] the big khugepaged redesign References: <1424696322-21952-1-git-send-email-vbabka@suse.cz> Date: Mon, 23 Feb 2015 13:03:22 -0800 In-Reply-To: <1424696322-21952-1-git-send-email-vbabka@suse.cz> (Vlastimil Babka's message of "Mon, 23 Feb 2015 13:58:36 +0100") Message-ID: <87lhjouyqt.fsf@tassilo.jf.intel.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1024 Lines: 27 Vlastimil Babka writes: > This has been already discussed as a good > idea and a RFC has been posted by Alex Thorlton last October [5]. In my opinion it's a very bad idea. It heavily penalizes the single threaded application case, which is quite important. And it would likely lead to even larger latencies on the application base, even for the multithreaded case, as there is no good way anymore to hide blocking latencies in the process. The current single thead khugepaged has various issues, but this would just make it much worse. IMHO it's useless to do much here without a lot of data first to identify the actual problems. Doing things first without analysis first seems totally backwards. -Andi -- ak@linux.intel.com -- Speaking for myself only -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/