From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Wilcox Subject: Re: [PATCH 10/28] mm: only allow page table mappings for built-in zsmalloc Date: Wed, 8 Apr 2020 08:15:19 -0700 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-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <20200408151203.GN20730@hirez.programming.kicks-ass.net> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane-mx.org@lists.infradead.org To: Peter Zijlstra Cc: linux-hyperv@vger.kernel.org, David Airlie , dri-devel@lists.freedesktop.org, linux-mm@kvack.org, "K. Y. Srinivasan" , Sumit Semwal , linux-arch@vger.kernel.org, linux-s390@vger.kernel.org, Wei Liu , Stephen Hemminger , x86@kernel.org, Christoph Hellwig , Laura Abbott , Nitin Gupta , Daniel Vetter , Haiyang Zhang , linaro-mm-sig@lists.linaro.org, bpf@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Christophe Leroy , Robin Murphy , Randy Dunlap , linux-kernel@vger.kernel.org, Minchan Kim , iommu@lists.linux-foundation.org, Sakari Ailus , Andrew List-Id: linux-arch.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'. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: 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 Date: Wed, 8 Apr 2020 08:15:19 -0700 From: Matthew Wilcox 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-arch-owner@vger.kernel.org List-ID: 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 Message-ID: <20200408151519.q3_Mp22xUtLch26sbFyht8TcJNd2Lgj44I63RpDpmYU@z> 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'.