Received: by 2002:a25:6193:0:0:0:0:0 with SMTP id v141csp793820ybb; Wed, 8 Apr 2020 10:00:30 -0700 (PDT) X-Google-Smtp-Source: APiQypLKAWSfLTqBakyNsmFJ+tFnPo9g8KMLbw6Yr1CWiP6VJpcO7er8wOpT6d497/NFOiPpzS9a X-Received: by 2002:a05:6830:146:: with SMTP id j6mr6363300otp.352.1586365229863; Wed, 08 Apr 2020 10:00:29 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1586365229; cv=none; d=google.com; s=arc-20160816; b=W+ZxtZ+HTsQnYTDp0KnDu7V59bPPUYRqZhVwJO8whQg9fEh1M8JJUagBrO0FBRC0wY ySMI6q/Oqqwv4db4P3X2GXNWdSe+3zt/yAbaG03VGm7yrLR2EfWTTFLID0W+O8lCT9re aUhaYpFrxMPAeLwWfyD9SJjnpFSz3wwRb2vojEF3epqPg2BScTwLvPLmUlIXmLLZTpRy sLTpjQl3hisadPgI47DWm06ty0VhXjBVvX5CiHKhkidCh2a7WhHR1E3V7N77YAipt3mI IT5VugKDvWNOB8pLqQPywarfLYN5EwDmrwHeJXHoU/XvxYSoJlrHO5EEwiZhaj7f9Jkw 2akw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:in-reply-to:content-disposition :mime-version:references:message-id:subject:cc:to:from:date :dkim-signature; bh=5Zyr+e9ojNxPf0UJbZ9u+v/X52sgt1i2sd8hmR6F47U=; b=d5cd2t+OfD8nLZuFVIpvsMeHZ5fjAdskJ756VKlUhMvTmWq+gdpFW2cHl9oL+wu5rK AvQdterIemTFQ6/FRWV2XI3YpvlCvK1XxYhPk7ERhU0PnRFGBTsyaZCCRVHmp2d40XeQ Z5kTKQGUpFzfijO8neEoOZiNcBhvAPD7u0Towic6dMo3izh4REGp2xwoX1SSWESsahkT Zm5BFwPjv4DhKkRwrLp23p6G4faUaBXxdCk3YUnM4Io9uFJ2lG7Dmd2Iebt2GMFvncU/ MiyofomkAOqrpQR2ayyqx85DES2tilSERd94jwuu1KNkr22K2KWYZ1cK36DVlh+/pDrg m0yg== ARC-Authentication-Results: i=1; mx.google.com; dkim=fail header.i=@infradead.org header.s=bombadil.20170209 header.b=L32SowMk; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id u133si2429086oib.138.2020.04.08.10.00.11; Wed, 08 Apr 2020 10:00:29 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=fail header.i=@infradead.org header.s=bombadil.20170209 header.b=L32SowMk; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728048AbgDHPPf (ORCPT + 99 others); Wed, 8 Apr 2020 11:15:35 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:59280 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727028AbgDHPPf (ORCPT ); Wed, 8 Apr 2020 11:15:35 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=5Zyr+e9ojNxPf0UJbZ9u+v/X52sgt1i2sd8hmR6F47U=; b=L32SowMkDY1Nvkk1P+JH95Mz1a GuD4zRqv2dPCcJVwSn1QwymJ24KIDAK1RGhAyV/QQ+p2QbBtRHvi/a1FYE3qfogJFrnBZkDlThFzK IqCB93D/bsMtpUeC4hD3PyzdzrsUqcglZldNwu/V0g0eR8ChVF9oZFNzWsry73hFTny3aFVqoOety mJ0SNj2FV0h0akd26thCyTTJlDnP3cVMyV9RDiMHzwxr89F3pcghAW072S9K43a3CAhduPy/Qqxhj 9VZc0gmBwmCxm9pi6xN0ggQWrzvceGDE2Tt7CjnyWIReAaTLibi/4WD/2QFbaSK0YWgfUD4jZuoHs 1qhQI+Mw==; Received: from willy by bombadil.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1jMCQB-0000vd-W6; Wed, 08 Apr 2020 15:15:19 +0000 Date: Wed, 8 Apr 2020 08:15:19 -0700 From: Matthew Wilcox To: Peter Zijlstra Cc: Randy Dunlap , Christoph Hellwig , Andrew Morton , "K. Y. Srinivasan" , Haiyang Zhang , Stephen Hemminger , Wei Liu , x86@kernel.org, David Airlie , Daniel Vetter , Laura Abbott , Sumit Semwal , Sakari Ailus , Minchan Kim , Nitin Gupta , Robin Murphy , Christophe Leroy , linuxppc-dev@lists.ozlabs.org, linux-hyperv@vger.kernel.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, iommu@lists.linux-foundation.org, linux-arm-kernel@lists.infradead.org, linux-s390@vger.kernel.org, bpf@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 10/28] mm: only allow page table mappings for built-in zsmalloc Message-ID: <20200408151519.GQ21484@bombadil.infradead.org> References: <20200408115926.1467567-1-hch@lst.de> <20200408115926.1467567-11-hch@lst.de> <20200408151203.GN20730@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200408151203.GN20730@hirez.programming.kicks-ass.net> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Apr 08, 2020 at 05:12:03PM +0200, Peter Zijlstra wrote: > On Wed, Apr 08, 2020 at 08:01:00AM -0700, Randy Dunlap wrote: > > Hi, > > > > On 4/8/20 4:59 AM, Christoph Hellwig wrote: > > > diff --git a/mm/Kconfig b/mm/Kconfig > > > index 36949a9425b8..614cc786b519 100644 > > > --- a/mm/Kconfig > > > +++ b/mm/Kconfig > > > @@ -702,7 +702,7 @@ config ZSMALLOC > > > > > > config ZSMALLOC_PGTABLE_MAPPING > > > bool "Use page table mapping to access object in zsmalloc" > > > - depends on ZSMALLOC > > > + depends on ZSMALLOC=y > > > > It's a bool so this shouldn't matter... not needed. > > My mm/Kconfig has: > > config ZSMALLOC > tristate "Memory allocator for compressed pages" > depends on MMU > > which I think means it can be modular, no? Randy means that ZSMALLOC_PGTABLE_MAPPING is a bool, so I think hch's patch is wrong ... if ZSMALLOC is 'm' then ZSMALLOC_PGTABLE_MAPPING would become 'n' instead of 'y'.