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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 A7F83C43382 for ; Thu, 27 Sep 2018 07:11:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6035B204EC for ; Thu, 27 Sep 2018 07:11:13 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6035B204EC Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.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 S1727111AbeI0N16 (ORCPT ); Thu, 27 Sep 2018 09:27:58 -0400 Received: from mx2.suse.de ([195.135.220.15]:41410 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726669AbeI0N16 (ORCPT ); Thu, 27 Sep 2018 09:27:58 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay1.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id BCFA0ADBC; Thu, 27 Sep 2018 07:11:08 +0000 (UTC) Subject: Re: [PATCH v3] memory_hotplug: Free pages as higher order To: Arun KS , kys@microsoft.com, haiyangz@microsoft.com, sthemmin@microsoft.com, boris.ostrovsky@oracle.com, akpm@linux-foundation.org, dan.j.williams@intel.com, mhocko@suse.com, vbabka@suse.cz, iamjoonsoo.kim@lge.com, gregkh@linuxfoundation.org, osalvador@suse.de, malat@debian.org, kirill.shutemov@linux.intel.com, jrdr.linux@gmail.com, yasu.isimatu@gmail.com, mgorman@techsingularity.net, aaron.lu@intel.com, devel@linuxdriverproject.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, xen-devel@lists.xenproject.org Cc: vatsa@codeaurora.org, vinmenon@codeaurora.org, getarunks@gmail.com References: <1538031530-25489-1-git-send-email-arunks@codeaurora.org> From: Juergen Gross Openpgp: preference=signencrypt Autocrypt: addr=jgross@suse.com; prefer-encrypt=mutual; keydata= xsBNBFOMcBYBCACgGjqjoGvbEouQZw/ToiBg9W98AlM2QHV+iNHsEs7kxWhKMjrioyspZKOB ycWxw3ie3j9uvg9EOB3aN4xiTv4qbnGiTr3oJhkB1gsb6ToJQZ8uxGq2kaV2KL9650I1SJve dYm8Of8Zd621lSmoKOwlNClALZNew72NjJLEzTalU1OdT7/i1TXkH09XSSI8mEQ/ouNcMvIJ NwQpd369y9bfIhWUiVXEK7MlRgUG6MvIj6Y3Am/BBLUVbDa4+gmzDC9ezlZkTZG2t14zWPvx XP3FAp2pkW0xqG7/377qptDmrk42GlSKN4z76ELnLxussxc7I2hx18NUcbP8+uty4bMxABEB AAHNHkp1ZXJnZW4gR3Jvc3MgPGpncm9zc0BzdXNlLmRlPsLAeQQTAQIAIwUCU4xw6wIbAwcL CQgHAwIBBhUIAgkKCwQWAgMBAh4BAheAAAoJELDendYovxMvi4UH/Ri+OXlObzqMANruTd4N zmVBAZgx1VW6jLc8JZjQuJPSsd/a+bNr3BZeLV6lu4Pf1Yl2Log129EX1KWYiFFvPbIiq5M5 kOXTO8Eas4CaScCvAZ9jCMQCgK3pFqYgirwTgfwnPtxFxO/F3ZcS8jovza5khkSKL9JGq8Nk czDTruQ/oy0WUHdUr9uwEfiD9yPFOGqp4S6cISuzBMvaAiC5YGdUGXuPZKXLpnGSjkZswUzY d9BVSitRL5ldsQCg6GhDoEAeIhUC4SQnT9SOWkoDOSFRXZ+7+WIBGLiWMd+yKDdRG5RyP/8f 3tgGiB6cyuYfPDRGsELGjUaTUq3H2xZgIPfOwE0EU4xwFgEIAMsx+gDjgzAY4H1hPVXgoLK8 B93sTQFN9oC6tsb46VpxyLPfJ3T1A6Z6MVkLoCejKTJ3K9MUsBZhxIJ0hIyvzwI6aYJsnOew cCiCN7FeKJ/oA1RSUemPGUcIJwQuZlTOiY0OcQ5PFkV5YxMUX1F/aTYXROXgTmSaw0aC1Jpo w7Ss1mg4SIP/tR88/d1+HwkJDVW1RSxC1PWzGizwRv8eauImGdpNnseneO2BNWRXTJumAWDD pYxpGSsGHXuZXTPZqOOZpsHtInFyi5KRHSFyk2Xigzvh3b9WqhbgHHHE4PUVw0I5sIQt8hJq 5nH5dPqz4ITtCL9zjiJsExHuHKN3NZsAEQEAAcLAXwQYAQIACQUCU4xwFgIbDAAKCRCw3p3W KL8TL0P4B/9YWver5uD/y/m0KScK2f3Z3mXJhME23vGBbMNlfwbr+meDMrJZ950CuWWnQ+d+ Ahe0w1X7e3wuLVODzjcReQ/v7b4JD3wwHxe+88tgB9byc0NXzlPJWBaWV01yB2/uefVKryAf AHYEd0gCRhx7eESgNBe3+YqWAQawunMlycsqKa09dBDL1PFRosF708ic9346GLHRc6Vj5SRA UTHnQqLetIOXZm3a2eQ1gpQK9MmruO86Vo93p39bS1mqnLLspVrL4rhoyhsOyh0Hd28QCzpJ wKeHTd0MAWAirmewHXWPco8p1Wg+V+5xfZzuQY0f4tQxvOpXpt4gQ1817GQ5/Ed/wsDtBBgB CAAgFiEEhRJncuj2BJSl0Jf3sN6d1ii/Ey8FAlrd8NACGwIAgQkQsN6d1ii/Ey92IAQZFggA HRYhBFMtsHpB9jjzHji4HoBcYbtP2GO+BQJa3fDQAAoJEIBcYbtP2GO+TYsA/30H/0V6cr/W V+J/FCayg6uNtm3MJLo4rE+o4sdpjjsGAQCooqffpgA+luTT13YZNV62hAnCLKXH9n3+ZAgJ RtAyDWk1B/0SMDVs1wxufMkKC3Q/1D3BYIvBlrTVKdBYXPxngcRoqV2J77lscEvkLNUGsu/z W2pf7+P3mWWlrPMJdlbax00vevyBeqtqNKjHstHatgMZ2W0CFC4hJ3YEetuRBURYPiGzuJXU pAd7a7BdsqWC4o+GTm5tnGrCyD+4gfDSpkOT53S/GNO07YkPkm/8J4OBoFfgSaCnQ1izwgJQ jIpcG2fPCI2/hxf2oqXPYbKr1v4Z1wthmoyUgGN0LPTIm+B5vdY82wI5qe9uN6UOGyTH2B3p hRQUWqCwu2sqkI3LLbTdrnyDZaixT2T0f4tyF5Lfs+Ha8xVMhIyzNb1byDI5FKCb Message-ID: <36488c0e-6bae-e277-2cdb-32d0dcc40065@suse.com> Date: Thu, 27 Sep 2018 09:11:06 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <1538031530-25489-1-git-send-email-arunks@codeaurora.org> Content-Type: text/plain; charset=utf-8 Content-Language: de-DE Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 27/09/18 08:58, Arun KS wrote: > When free pages are done with higher order, time spend on > coalescing pages by buddy allocator can be reduced. With > section size of 256MB, hot add latency of a single section > shows improvement from 50-60 ms to less than 1 ms, hence > improving the hot add latency by 60%. > > Modify external providers of online callback to align with > the change. > > Signed-off-by: Arun KS > --- > Changes since v2: > reuse code from __free_pages_boot_core() > > Changes since v1: > - Removed prefetch() > > Changes since RFC: > - Rebase. > - As suggested by Michal Hocko remove pages_per_block. > - Modifed external providers of online_page_callback. > > v2: https://lore.kernel.org/patchwork/patch/991363/ > v1: https://lore.kernel.org/patchwork/patch/989445/ > RFC: https://lore.kernel.org/patchwork/patch/984754/ > > --- > drivers/hv/hv_balloon.c | 6 ++++-- > drivers/xen/balloon.c | 18 ++++++++++++++--- > include/linux/memory_hotplug.h | 2 +- > mm/internal.h | 1 + > mm/memory_hotplug.c | 44 ++++++++++++++++++++++++++++++------------ > mm/page_alloc.c | 2 +- > 6 files changed, 54 insertions(+), 19 deletions(-) > ... > diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c > index e12bb25..010cf4d 100644 > --- a/drivers/xen/balloon.c > +++ b/drivers/xen/balloon.c > @@ -390,8 +390,8 @@ static enum bp_state reserve_additional_memory(void) > > /* > * add_memory_resource() will call online_pages() which in its turn > - * will call xen_online_page() callback causing deadlock if we don't > - * release balloon_mutex here. Unlocking here is safe because the > + * will call xen_bring_pgs_online() callback causing deadlock if we > + * don't release balloon_mutex here. Unlocking here is safe because the > * callers drop the mutex before trying again. > */ > mutex_unlock(&balloon_mutex); > @@ -422,6 +422,18 @@ static void xen_online_page(struct page *page) > mutex_unlock(&balloon_mutex); > } > > +static int xen_bring_pgs_online(struct page *pg, unsigned int order) > +{ > + unsigned long i, size = (1 << order); > + unsigned long start_pfn = page_to_pfn(pg); > + > + pr_debug("Online %lu pages starting at pfn 0x%lx\n", size, start_pfn); > + for (i = 0; i < size; i++) > + xen_online_page(pfn_to_page(start_pfn + i)); xen_online_page() isn't very complex and this is the only user. Why don't you move its body in here and drop the extra function? And now you can execute the loop with balloon_mutex held instead of taking and releasing it in each iteration of the loop. Juergen