From mboxrd@z Thu Jan 1 00:00:00 1970 From: Randy Dunlap Subject: Re: [PATCH 10/28] mm: only allow page table mappings for built-in zsmalloc Date: Wed, 8 Apr 2020 08:37:59 -0700 Message-ID: References: <20200408115926.1467567-1-hch@lst.de> <20200408115926.1467567-11-hch@lst.de> <20200408151203.GN20730@hirez.programming.kicks-ass.net> <20200408151519.GQ21484@bombadil.infradead.org> <20200408153602.GA28081@lst.de> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: Received: from bombadil.infradead.org ([198.137.202.133]:42844 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728895AbgDHPiI (ORCPT ); Wed, 8 Apr 2020 11:38:08 -0400 In-Reply-To: <20200408153602.GA28081@lst.de> Content-Language: en-US Sender: linux-arch-owner@vger.kernel.org List-ID: To: Christoph Hellwig , Matthew Wilcox Cc: Peter Zijlstra , 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 On 4/8/20 8:36 AM, Christoph Hellwig wrote: > On Wed, Apr 08, 2020 at 08:15:19AM -0700, Matthew Wilcox wrote: >>>>> 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'. > > In Linus' tree you can select PGTABLE_MAPPING=y with ZSMALLOC=m, > and that fits my understanding of the kbuild language. With this > patch I can't anymore. > Makes sense. thanks. -- ~Randy From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from bombadil.infradead.org ([198.137.202.133]:42844 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728895AbgDHPiI (ORCPT ); Wed, 8 Apr 2020 11:38:08 -0400 Subject: Re: [PATCH 10/28] mm: only allow page table mappings for built-in zsmalloc References: <20200408115926.1467567-1-hch@lst.de> <20200408115926.1467567-11-hch@lst.de> <20200408151203.GN20730@hirez.programming.kicks-ass.net> <20200408151519.GQ21484@bombadil.infradead.org> <20200408153602.GA28081@lst.de> From: Randy Dunlap Message-ID: Date: Wed, 8 Apr 2020 08:37:59 -0700 MIME-Version: 1.0 In-Reply-To: <20200408153602.GA28081@lst.de> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-arch-owner@vger.kernel.org List-ID: To: Christoph Hellwig , Matthew Wilcox Cc: Peter Zijlstra , 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 Message-ID: <20200408153759.z7IhoEk0ao2dNq9aN5aVFDSj8lxnTGmu1IUJ9fhbqE0@z> On 4/8/20 8:36 AM, Christoph Hellwig wrote: > On Wed, Apr 08, 2020 at 08:15:19AM -0700, Matthew Wilcox wrote: >>>>> 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'. > > In Linus' tree you can select PGTABLE_MAPPING=y with ZSMALLOC=m, > and that fits my understanding of the kbuild language. With this > patch I can't anymore. > Makes sense. thanks. -- ~Randy