On Mon, Feb 04, 2013 at 09:23:41AM +0900, Minchan Kim wrote: > Zsmalloc has two methods 1) copy-based and 2) pte based to access > allocations that span two pages. > You can see history why we supported two approach from [1]. > > But it was bad choice that adding hard coding to select architecture > which want to use pte based method. This patch removed it and adds > new Kconfig to select the approach. > > This patch is based on next-20130202. > > [1] https://lkml.org/lkml/2012/7/11/58 > > Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > Cc: Seth Jennings <sjenning@xxxxxxxxxxxxxxxxxx> > Cc: Nitin Gupta <ngupta@xxxxxxxxxx> > Cc: Dan Magenheimer <dan.magenheimer@xxxxxxxxxx> > Cc: Konrad Rzeszutek Wilk <konrad@xxxxxxxxxx> > Signed-off-by: Minchan Kim <minchan@xxxxxxxxxx> > --- > drivers/staging/zsmalloc/Kconfig | 12 ++++++++++++ > drivers/staging/zsmalloc/zsmalloc-main.c | 11 ----------- > 2 files changed, 12 insertions(+), 11 deletions(-) > > diff --git a/drivers/staging/zsmalloc/Kconfig b/drivers/staging/zsmalloc/Kconfig > index 9084565..2359123 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 ZSMALLOC_PGTABLE_MAPPING > + bool "Use page table mapping to access allocations that span two pages" > + depends on ZSMALLOC > + default n > + 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 > diff --git a/drivers/staging/zsmalloc/zsmalloc-main.c b/drivers/staging/zsmalloc/zsmalloc-main.c > index 06f73a9..b161ca1 100644 > --- a/drivers/staging/zsmalloc/zsmalloc-main.c > +++ b/drivers/staging/zsmalloc/zsmalloc-main.c > @@ -218,17 +218,6 @@ struct zs_pool { > #define CLASS_IDX_MASK ((1 << CLASS_IDX_BITS) - 1) > #define FULLNESS_MASK ((1 << FULLNESS_BITS) - 1) > > -/* > - * 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 it should be added here > - * so that USE_PGTABLE_MAPPING is defined. This causes zsmalloc to use > - * page table mapping rather than copying for object mapping. > -*/ > -#if defined(CONFIG_ARM) > -#define USE_PGTABLE_MAPPING > -#endif Did you test this? I don't see the new config value you added actually do anything in this code. Also, if I select it incorrectly on ARM, or or other platforms, what is keeping this from doing bad things? thanks, greg k-h -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>