From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 92709C6778A for ; Wed, 4 Jul 2018 03:00:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 43C402470F for ; Wed, 4 Jul 2018 03:00:03 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 43C402470F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753548AbeGDC77 (ORCPT ); Tue, 3 Jul 2018 22:59:59 -0400 Received: from mga09.intel.com ([134.134.136.24]:57263 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752916AbeGDC75 (ORCPT ); Tue, 3 Jul 2018 22:59:57 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga102.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 03 Jul 2018 19:59:57 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.51,306,1526367600"; d="scan'208";a="72071482" Received: from yhuang-dev.sh.intel.com (HELO yhuang-dev) ([10.239.13.118]) by orsmga002.jf.intel.com with ESMTP; 03 Jul 2018 19:59:55 -0700 From: "Huang\, Ying" To: Sergey Senozhatsky Cc: Andrew Morton , , , Hugh Dickins , "Kirill A. Shutemov" , Daniel Jordan Subject: Re: [PATCH -mm -v4 00/21] mm, THP, swap: Swapout/swapin THP in one piece References: <20180622035151.6676-1-ying.huang@intel.com> <20180627215144.73e98b01099191da59bff28c@linux-foundation.org> <20180704021153.GA3346@jagdpanzerIV> <878t6rvj12.fsf@yhuang-dev.intel.com> <20180704022734.GB3346@jagdpanzerIV> Date: Wed, 04 Jul 2018 10:59:55 +0800 In-Reply-To: <20180704022734.GB3346@jagdpanzerIV> (Sergey Senozhatsky's message of "Wed, 4 Jul 2018 11:27:34 +0900") Message-ID: <87zhz7u2ms.fsf@yhuang-dev.intel.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=ascii Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Sergey Senozhatsky writes: > On (07/04/18 10:20), Huang, Ying wrote: >> > On (06/27/18 21:51), Andrew Morton wrote: >> >> On Fri, 22 Jun 2018 11:51:30 +0800 "Huang, Ying" wrote: >> >> >> >> > This is the final step of THP (Transparent Huge Page) swap >> >> > optimization. After the first and second step, the splitting huge >> >> > page is delayed from almost the first step of swapout to after swapout >> >> > has been finished. In this step, we avoid splitting THP for swapout >> >> > and swapout/swapin the THP in one piece. >> >> >> >> It's a tremendously good performance improvement. It's also a >> >> tremendously large patchset :( >> > >> > Will zswap gain a THP swap out/in support at some point? >> > >> > >> > mm/zswap.c: static int zswap_frontswap_store(...) >> > ... >> > /* THP isn't supported */ >> > if (PageTransHuge(page)) { >> > ret = -EINVAL; >> > goto reject; >> > } >> >> That's not on my TODO list. Do you have interest to work on this? > > I'd say I'm interested. Can't promise that I'll have enough spare time > any time soon, tho. Thanks! > The numbers you posted do look fantastic indeed, embedded devices > [which normally use zswap/zram quite heavily] _probably_ should see > some performance improvement as well once zswap [and may be zram] can > handle THP. Yes. I think so too. Best Regards, Huang, Ying