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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id D48E1C00140 for ; Tue, 9 Aug 2022 03:14:20 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 507318E0001; Mon, 8 Aug 2022 23:14:20 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 4B62D6B0072; Mon, 8 Aug 2022 23:14:20 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 37DCF8E0001; Mon, 8 Aug 2022 23:14:20 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id 264006B0071 for ; Mon, 8 Aug 2022 23:14:20 -0400 (EDT) Received: from smtpin07.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id EB85F80161 for ; Tue, 9 Aug 2022 03:14:19 +0000 (UTC) X-FDA: 79778585838.07.ADA2003 Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by imf01.hostedemail.com (Postfix) with ESMTP id 434D340179 for ; Tue, 9 Aug 2022 03:14:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1660014859; x=1691550859; h=from:to:cc:subject:references:date:in-reply-to: message-id:mime-version; bh=rapC+xk33EA/lz7q1a+W/DDjjYOU9PGdfL3uB3RSTtk=; b=LXbpQhtKU2vtlcM+/xhmDr0ZO5M0DvL0phnTRmYOXLYXga0z7U9jhXpP knnHnA7u6F828tPNiQqrZkMeVqJHIxnD3O2FWYopg+edEkzANkAjEV/Rs s02EZfjTLwroWmFst9zppbJWnCQ8PoZ5qmaM2s1uybHWucd4Tqbk0HML5 PLFY0vi9z5fpATpQKOGjCXqGa/5fticD7bgDOzS8KNcuy4S5IrZP3KTwp 7UCRst9DQQZnIvkncewR7aq/ZiPK8b09CUW7y+huWieXPCkx0Hg1fvf1L avbXdT9rQ7dlbeZ7SEO2I4JZCQJhrnJgvV7X8WeTPtokQwyBrjx23cvbs Q==; X-IronPort-AV: E=McAfee;i="6400,9594,10433"; a="288307192" X-IronPort-AV: E=Sophos;i="5.93,223,1654585200"; d="scan'208";a="288307192" Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Aug 2022 20:14:01 -0700 X-IronPort-AV: E=Sophos;i="5.93,223,1654585200"; d="scan'208";a="932318884" Received: from yhuang6-desk2.sh.intel.com (HELO yhuang6-desk2.ccr.corp.intel.com) ([10.238.208.55]) by fmsmga005-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Aug 2022 20:13:57 -0700 From: "Huang, Ying" To: "Aneesh Kumar K.V" Cc: linux-mm@kvack.org, akpm@linux-foundation.org, Wei Xu , Yang Shi , Davidlohr Bueso , Tim C Chen , Michal Hocko , Linux Kernel Mailing List , Hesham Almatary , Dave Hansen , Jonathan Cameron , Alistair Popple , Dan Williams , Johannes Weiner , jvgediya.oss@gmail.com Subject: Re: [PATCH v13 9/9] lib/nodemask: Optimize node_random for nodemask with single NUMA node References: <20220808062601.836025-1-aneesh.kumar@linux.ibm.com> <20220808062601.836025-10-aneesh.kumar@linux.ibm.com> Date: Tue, 09 Aug 2022 11:13:54 +0800 In-Reply-To: <20220808062601.836025-10-aneesh.kumar@linux.ibm.com> (Aneesh Kumar K. V.'s message of "Mon, 8 Aug 2022 11:56:01 +0530") Message-ID: <87fsi6glcd.fsf@yhuang6-desk2.ccr.corp.intel.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=ascii ARC-Authentication-Results: i=1; imf01.hostedemail.com; dkim=none ("invalid DKIM record") header.d=intel.com header.s=Intel header.b=LXbpQhtK; spf=pass (imf01.hostedemail.com: domain of ying.huang@intel.com designates 192.55.52.93 as permitted sender) smtp.mailfrom=ying.huang@intel.com; dmarc=pass (policy=none) header.from=intel.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1660014859; a=rsa-sha256; cv=none; b=tNVF5ygA0K3CzqtvOo60YeY45f0XSzO0mWHkRYJe+Zppg7xXQqQ7W+8wrkXMJx5mu5ESGU VdnX5Bps/Rkk4DUZcgB0+ED/XYey5++DNV6xPpHYjY+I5IdX9yya19JZ2sIQQ36gEHMGwN XdpIrv0vJG+mvKPAZoHcqtRvQ8rufJQ= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1660014859; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=RhPcngva/d2S8d0lxvBdl5Q2n2kMTrgumdgfj+OUaDw=; b=5cWEyuxn+MbUCtWGdlNB7DWqj+b8RTY4kt8sAAbqtaczrXvqiF2EhAEXPmwyZo2f6h+hBw wXlHVlSETviWK/y0rxSmpO5eS9kxCROZW3Gwa26O5t8izLFPsWi/IINVLoN0vqTvxNdLya bMJYxjAncGfj+w9CIjzA5F/LwIMTaY8= X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 434D340179 X-Rspam-User: Authentication-Results: imf01.hostedemail.com; dkim=none ("invalid DKIM record") header.d=intel.com header.s=Intel header.b=LXbpQhtK; spf=pass (imf01.hostedemail.com: domain of ying.huang@intel.com designates 192.55.52.93 as permitted sender) smtp.mailfrom=ying.huang@intel.com; dmarc=pass (policy=none) header.from=intel.com X-Stat-Signature: 1cd7iinj1jccmmst73rdi6bp53opq1fu X-HE-Tag: 1660014859-293361 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: "Aneesh Kumar K.V" writes: > The most common case for certain node_random usage (demotion nodemask) is with > nodemask weight 1. We can avoid calling get_random_init() in that case and > always return the only node set in the nodemask. I think that this patch can sit between [5/9] and [6/9], just after it is used. > Signed-off-by: Aneesh Kumar K.V > --- > lib/nodemask.c | 15 ++++++++++++--- > 1 file changed, 12 insertions(+), 3 deletions(-) > > diff --git a/lib/nodemask.c b/lib/nodemask.c > index e22647f5181b..c91a6b0404a5 100644 > --- a/lib/nodemask.c > +++ b/lib/nodemask.c > @@ -20,12 +20,21 @@ EXPORT_SYMBOL(__next_node_in); > */ > int node_random(const nodemask_t *maskp) > { > - int w, bit = NUMA_NO_NODE; > + int w, bit; > > w = nodes_weight(*maskp); > - if (w) > + switch (w) { > + case 0: > + bit = NUMA_NO_NODE; > + break; > + case 1: > + bit = __first_node(maskp); Per my understanding, first_node() is the formal API and we should use that? Just like we use nodes_weight() instead of __nodes_weight(). Best Regards, Huang, Ying > + break; > + default: > bit = bitmap_ord_to_pos(maskp->bits, > - get_random_int() % w, MAX_NUMNODES); > + get_random_int() % w, MAX_NUMNODES); > + break; > + } > return bit; > } > #endif