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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 27AF9C46467 for ; Sat, 14 Jan 2023 05:27:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229543AbjANF1U (ORCPT ); Sat, 14 Jan 2023 00:27:20 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57788 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229475AbjANF1S (ORCPT ); Sat, 14 Jan 2023 00:27:18 -0500 Received: from mail-pl1-x62c.google.com (mail-pl1-x62c.google.com [IPv6:2607:f8b0:4864:20::62c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 754F526B6 for ; Fri, 13 Jan 2023 21:27:17 -0800 (PST) Received: by mail-pl1-x62c.google.com with SMTP id k12so3345640plk.0 for ; Fri, 13 Jan 2023 21:27:17 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=Hi6SpGutrYkialV9PtuSHrkLtH3EwVjUiZj+JV18HOU=; b=AOvLMulYqiLdTSzTT+e9jUZEthaYWtfhs46a1EKVU3Uwb+06h44K25V+0mKVO4YmLl FQKlYMuEAAWCCX4CiPEKKIds9fom3gxOui+g2KjkLgh6vctl+W4rwYUWnJh1usm9WW5k ZhyT1p0EnD5LOTuKbmhmo3qrZvSGfAYnpAxl0= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=Hi6SpGutrYkialV9PtuSHrkLtH3EwVjUiZj+JV18HOU=; b=VVmEacC7PS3zxqHZx0p4TVCol0EImM+2Y3Q0bhc4XIqCM5txZ6JTsiCfhbIaxl5+w9 L357fwS6X+/fmjYhoccPuZbEcHUtTXJ1HCk3MszUGqLBn1aRC4leSKKebN275uj8KRe9 wp7UUnONVXa8Wq4VajVXSnTcBzVSHsXCimmDzsEtrXSiLjhS/e6HTlnHds/TeGHdP66W owGhXrZD47Ao3apOWnK+oBYmae38BH4qIcHLmLS0c9dxOkdnUFGKFIbdegqDG2U/3Ivf OTgdyVC5Id7dQIO7PoSZ8tTrjxQS4IrinhTyV9MA/Unat3ai9vk6oKgBOxsoQEe88RAT aQUg== X-Gm-Message-State: AFqh2kqWo0GBKyuhJMbuf0CuMxvmTsqUaJ1jrI9Z1jLnngsQX3nDskc3 tt/QNXx7oB8n4dHDBfyvIM05zw== X-Google-Smtp-Source: AMrXdXtN10GPHVzK1LFg3aIeZT7yW6CksfZNv/xVmMqQdGuu0DR9yrvzw5WgzYj2vtLRtsISoIc6nQ== X-Received: by 2002:a17:902:b613:b0:18f:98bb:c08e with SMTP id b19-20020a170902b61300b0018f98bbc08emr80267513pls.36.1673674036887; Fri, 13 Jan 2023 21:27:16 -0800 (PST) Received: from google.com (KD124209188001.ppp-bb.dion.ne.jp. [124.209.188.1]) by smtp.gmail.com with ESMTPSA id j3-20020a170902da8300b0018725c2fc46sm14910927plx.303.2023.01.13.21.27.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 13 Jan 2023 21:27:16 -0800 (PST) Date: Sat, 14 Jan 2023 14:27:12 +0900 From: Sergey Senozhatsky To: Mike Kravetz Cc: Sergey Senozhatsky , Minchan Kim , Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCHv2 0/4] zsmalloc: make zspage chain size configurable Message-ID: References: <20230109033838.2779902-1-senozhatsky@chromium.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On (23/01/13 11:57), Mike Kravetz wrote: > > This turns hard coded limit on maximum number of physical > > pages per-zspage into a config option. It also increases the default > > limit from 4 to 8. > > > > Sergey Senozhatsky (4): > > zsmalloc: rework zspage chain size selection > > zsmalloc: skip chain size calculation for pow_of_2 classes > > zsmalloc: make zspage chain size configurable > > zsmalloc: set default zspage chain size to 8 > > > > Documentation/mm/zsmalloc.rst | 168 ++++++++++++++++++++++++++++++++++ > > mm/Kconfig | 19 ++++ > > mm/zsmalloc.c | 72 +++++---------- > > 3 files changed, 212 insertions(+), 47 deletions(-) > > Hi Sergey, Hi Mike, > The following BUG shows up after this series in linux-next. I can easily > recreate by doing the following: > > # echo large_value > /sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages > where 'large_value' is a so big that there could never possibly be that > many 2MB huge pages in the system. Hmm... Are we sure this is related? I really cannot see how chain-size can have an effect on zspage ->isolate counter. What chain-size value do you use? You don't see problems with chain size of 4?