linux-dev/drivers/staging/zram/Makefile, branch master

zram: promote zram from staging

2014-01-31T00:56:55Z

Zram has lived in staging for a LONG LONG time and have been fixed/improved by many contributors so code is clean and stable now. Of course, there are lots of product using zram in real practice. The major TV companys have used zram as swap since two years ago and recently our production team released android smart phone with zram which is used as swap, too and recently Android Kitkat start to use zram for small memory smart phone. And there was a report Google released their ChromeOS with zram, too and cyanogenmod have been used zram long time ago. And I heard some disto have used zram block device for tmpfs. In addition, I saw many report from many other peoples. For example, Lubuntu start to use it. The benefit of zram is very clear. With my experience, one of the benefit was to remove jitter of video application with backgroud memory pressure. It would be effect of efficient memory usage by compression but more issue is whether swap is there or not in the system. Recent mobile platforms have used JAVA so there are many anonymous pages. But embedded system normally are reluctant to use eMMC or SDCard as swap because there is wear-leveling and latency issues so if we do not use swap, it means we can't reclaim anoymous pages and at last, we could encounter OOM kill. :( Although we have real storage as swap, it was a problem, too. Because it sometime ends up making system very unresponsible caused by slow swap storage performance. Quote from Luigi on Google "Since Chrome OS was mentioned: the main reason why we don't use swap to a disk (rotating or SSD) is because it doesn't degrade gracefully and leads to a bad interactive experience. Generally we prefer to manage RAM at a higher level, by transparently killing and restarting processes. But we noticed that zram is fast enough to be competitive with the latter, and it lets us make more efficient use of the available RAM. " and he announced. http://www.spinics.net/lists/linux-mm/msg57717.html Other uses case is to use zram for block device. Zram is block device so anyone can format the block device and mount on it so some guys on the internet start zram as /var/tmp. http://forums.gentoo.org/viewtopic-t-838198-start-0.html Let's promote zram and enhance/maintain it instead of removing. Signed-off-by: Minchan Kim Reviewed-by: Konrad Rzeszutek Wilk Acked-by: Nitin Gupta Acked-by: Pekka Enberg Cc: Bob Liu Cc: Greg Kroah-Hartman Cc: Hugh Dickins Cc: Jens Axboe Cc: Luigi Semenzato Cc: Mel Gorman Cc: Rik van Riel Cc: Seth Jennings Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

zram: remove zram_sysfs file (v2)

2013-06-24T22:59:03Z

Move zram sysfs code to zram drv and remove zram_sysfs.c file. This gives ability to make static a number of previously exported zram functions, used from zram sysfs, e.g. internal zram zram_meta_alloc/free(). We also can drop zram_drv wrapper functions, used from zram sysfs: e.g. zram_reset_device()/__zram_reset_device() pair. v2: as suggested by Greg K-H, move MODULE description to the bottom of the file. Signed-off-by: Sergey Senozhatsky Signed-off-by: Greg Kroah-Hartman

staging: zram: replace xvmalloc with zsmalloc

2012-02-09T01:13:00Z

Replaces xvmalloc with zsmalloc as the compressed page allocator for zram Signed-off-by: Nitin Gupta Acked-by: Seth Jennings Signed-off-by: Greg Kroah-Hartman

staging: Allow sharing xvmalloc for zram and zcache

2011-02-23T22:02:56Z

Both zram and zcache use xvmalloc allocator. If xvmalloc is compiled separately for both of them, we will get linker error if they are both selected as "built-in". We can also get linker error regarding missing xvmalloc symbols if zram is not built. So, we now compile xvmalloc separately and export its symbols which are then used by both of zram and zcache. Signed-off-by: Nitin Gupta Acked-by: Randy Dunlap Signed-off-by: Greg Kroah-Hartman

Staging: zram: Makefile: replace the use of -objs with -y

2010-10-08T14:23:41Z

Changed -objs to -y in Makefile. Signed-off-by: Tracey Dent Signed-off-by: Greg Kroah-Hartman

Staging: zram: Replace ioctls with sysfs interface

2010-08-31T22:33:54Z

Creates per-device sysfs nodes in /sys/block/zram/ Currently following stats are exported: - disksize - num_reads - num_writes - invalid_io - zero_pages - orig_data_size - compr_data_size - mem_used_total By default, disksize is set to 0. So, to start using a zram device, fist write a disksize value and then initialize device by writing any positive value to initstate. For example: # initialize /dev/zram0 with 50MB disksize echo 50*1024*1024 | bc > /sys/block/zram0/disksize echo 1 > /sys/block/zram0/initstate When done using a disk, issue reset to free its memory by writing any positive value to reset node: echo 1 > /sys/block/zram0/reset This change also obviates the need for 'rzscontrol' utility. Signed-off-by: Nitin Gupta Acked-by: Pekka Enberg Signed-off-by: Greg Kroah-Hartman

Staging: Rename ramzswap files to zram

2010-06-18T19:46:42Z

Related changes: - Modify revelant Kconfig and Makefile accordingly. - Change include filenames in code. - Remove dependency on CONFIG_SWAP in Kconfig as zram usage is no longer limited to swap disks. Signed-off-by: Nitin Gupta Acked-by: Pekka Enberg Signed-off-by: Greg Kroah-Hartman