From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx135.postini.com [74.125.245.135]) by kanga.kvack.org (Postfix) with SMTP id 6DB4F6B005C for ; Tue, 5 Feb 2013 21:50:31 -0500 (EST) Date: Wed, 6 Feb 2013 11:50:28 +0900 From: Minchan Kim Subject: Re: [PATCH v2] zsmalloc: Add Kconfig for enabling PTE method Message-ID: <20130206025028.GH11197@blaptop> References: <1360117028-5625-1-git-send-email-minchan@kernel.org> <20130206022854.GA1681@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130206022854.GA1681@kroah.com> Sender: owner-linux-mm@kvack.org List-ID: To: Greg Kroah-Hartman Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrew Morton , Seth Jennings , Nitin Gupta , Dan Magenheimer , Konrad Rzeszutek Wilk On Tue, Feb 05, 2013 at 06:28:54PM -0800, Greg Kroah-Hartman wrote: > On Wed, Feb 06, 2013 at 11:17:08AM +0900, Minchan Kim wrote: > > diff --git a/drivers/staging/zsmalloc/Kconfig b/drivers/staging/zsmalloc/Kconfig > > index 9084565..232b3b6 100644 > > --- a/drivers/staging/zsmalloc/Kconfig > > +++ b/drivers/staging/zsmalloc/Kconfig > > @@ -8,3 +8,15 @@ config ZSMALLOC > > non-standard allocator interface where a handle, not a pointer, is > > returned by an alloc(). This handle must be mapped in order to > > access the allocated space. > > + > > +config PGTABLE_MAPPING > > + bool "Use page table mapping to access allocations that span two pages" > > No tabs? > > Please also put "ZSmalloc somewhere in the text here, otherwise it > really doesn't make much sense when seeing it in a menu. > > > + depends on ZSMALLOC > > + default n > > That's the default, so it can be dropped. > > > + help > > + By default, zsmalloc uses a copy-based object mapping method to access > > + allocations that span two pages. However, if a particular architecture > > + performs VM mapping faster than copying, then you should select this. > > + This causes zsmalloc to use page table mapping rather than copying > > + for object mapping. You can check speed with zsmalloc benchmark[1]. > > + [1] https://github.com/spartacus06/zsmalloc > > Care to specify exactly _what_ architectures this should be set for or > not? That will help the distros out a lot in determining if this should > be enabled or not. > > > diff --git a/drivers/staging/zsmalloc/zsmalloc-main.c b/drivers/staging/zsmalloc/zsmalloc-main.c > > index 06f73a9..2c1805c 100644 > > --- a/drivers/staging/zsmalloc/zsmalloc-main.c > > +++ b/drivers/staging/zsmalloc/zsmalloc-main.c > > @@ -207,6 +207,7 @@ struct zs_pool { > > struct size_class size_class[ZS_SIZE_CLASSES]; > > > > gfp_t flags; /* allocation flags used when growing pool */ > > + > > }; > > > > /* > > Why add this extra line? > > thanks, > > greg k-h Sorry for bothering you. I fixed all you pointed out. Thanks for the review, Greg! Here it goes. ------------------- 8< -------------------