During earlier discussions of zswap there was a plan to make it work with zsmalloc as an option instead of zbud. Does zbud work for compression factors better than 2:1? I have the impression (maybe wrong) that it does not. In our use of zram (Chrome OS) typical overall compression ratios are between 2.5:1 and 3:1. We would hate to waste that memory if we switch to zswap. Thanks! On Tue, Aug 13, 2013 at 10:55 PM, Minchan Kim <minchan@xxxxxxxxxx> wrote: > It's 6th trial of zram/zsmalloc promotion. > [patch 5, zram: promote zram from staging] explains why we need zram. > > Main reason to block promotion is there was no review of zsmalloc part > while Jens already acked zram part. > > At that time, zsmalloc was used for zram, zcache and zswap so everybody > wanted to make it general and at last, Mel reviewed it. > Most of review was related to zswap dumping mechanism which can pageout > compressed page into swap in runtime and zswap gives up using zsmalloc > and invented a new wheel, zbud. Other reviews were not major. > http://lkml.indiana.edu/hypermail/linux/kernel/1304.1/04334.html > > Zcache don't use zsmalloc either so only zsmalloc user is zram now. > So I think there is no concern any more. > > Patch 1 adds new Kconfig for zram to use page table method instead > of copy. Andrew suggested it. > > Patch 2 adds lots of commnt for zsmalloc. > > Patch 3 moves zsmalloc under driver/staging/zram because zram is only > user for zram now. > > Patch 4 makes unmap_kernel_range exportable function because zsmalloc > have used map_vm_area which is already exported function but zsmalloc > need to use unmap_kernel_range and it should be built with module. > > Patch 5 moves zram from driver/staging to driver/blocks, finally. > > It touches mm, staging, blocks so I am not sure who is right position > maintainer so I will Cc Andrw, Jens and Greg. > > This patch is based on next-20130813. > > Thanks. > > Minchan Kim (4): > zsmalloc: add Kconfig for enabling page table method > zsmalloc: move it under zram > mm: export unmap_kernel_range > zram: promote zram from staging > > Nitin Cupta (1): > zsmalloc: add more comment > > drivers/block/Kconfig | 2 + > drivers/block/Makefile | 1 + > drivers/block/zram/Kconfig | 37 + > drivers/block/zram/Makefile | 3 + > drivers/block/zram/zram.txt | 71 ++ > drivers/block/zram/zram_drv.c | 987 +++++++++++++++++++++++++++ > drivers/block/zram/zsmalloc.c | 1084 ++++++++++++++++++++++++++++++ > drivers/staging/Kconfig | 4 - > drivers/staging/Makefile | 2 - > drivers/staging/zram/Kconfig | 25 - > drivers/staging/zram/Makefile | 3 - > drivers/staging/zram/zram.txt | 77 --- > drivers/staging/zram/zram_drv.c | 984 --------------------------- > drivers/staging/zram/zram_drv.h | 125 ---- > drivers/staging/zsmalloc/Kconfig | 10 - > drivers/staging/zsmalloc/Makefile | 3 - > drivers/staging/zsmalloc/zsmalloc-main.c | 1063 ----------------------------- > drivers/staging/zsmalloc/zsmalloc.h | 43 -- > include/linux/zram.h | 123 ++++ > include/linux/zsmalloc.h | 52 ++ > mm/vmalloc.c | 1 + > 21 files changed, 2361 insertions(+), 2339 deletions(-) > create mode 100644 drivers/block/zram/Kconfig > create mode 100644 drivers/block/zram/Makefile > create mode 100644 drivers/block/zram/zram.txt > create mode 100644 drivers/block/zram/zram_drv.c > create mode 100644 drivers/block/zram/zsmalloc.c > delete mode 100644 drivers/staging/zram/Kconfig > delete mode 100644 drivers/staging/zram/Makefile > delete mode 100644 drivers/staging/zram/zram.txt > delete mode 100644 drivers/staging/zram/zram_drv.c > delete mode 100644 drivers/staging/zram/zram_drv.h > delete mode 100644 drivers/staging/zsmalloc/Kconfig > delete mode 100644 drivers/staging/zsmalloc/Makefile > delete mode 100644 drivers/staging/zsmalloc/zsmalloc-main.c > delete mode 100644 drivers/staging/zsmalloc/zsmalloc.h > create mode 100644 include/linux/zram.h > create mode 100644 include/linux/zsmalloc.h > > -- > 1.7.9.5 > -- 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>