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path: root/drivers/staging/zram/Kconfig
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2014-01-30zram: promote zram from stagingMinchan Kim1-25/+0
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 <minchan@kernel.org> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Acked-by: Nitin Gupta <ngupta@vflare.org> Acked-by: Pekka Enberg <penberg@kernel.org> Cc: Bob Liu <bob.liu@oracle.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Hugh Dickins <hughd@google.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Luigi Semenzato <semenzato@google.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Seth Jennings <sjenning@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-01-07staging: Add angle bracket before and after the URLMasanari Iida1-1/+1
Add missing angle bracket before and after the URL. Signed-off-by: Masanari Iida <standby24x7@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-25staging: zram/zcache: swtich Kconfig dependency from X86 to ZSMALLOCSeth Jennings1-4/+1
This patch switches zcache and zram dependency to ZSMALLOC rather than X86. There is no net change since ZSMALLOC depends on X86, however, this prevent further changes to these files as zsmalloc dependencies change. Signed-off-by: Seth Jennings <sjenning@linux.vnet.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-02-13staging: fix powerpc linux-next break on zsmallocSeth Jennings1-1/+3
linux/vmalloc.h added to zsmalloc-main.c to resolve implicit declaration errors. X86 dependency added to zsmalloc and dependent drivers zcache and zram. This X86 only requirement is not ideal. Working to find portable functions for __flush_tlb_one and set_pte. Signed-off-by: Seth Jennings <sjenning@linux.vnet.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-02-08staging: zram: replace xvmalloc with zsmallocNitin Gupta1-5/+1
Replaces xvmalloc with zsmalloc as the compressed page allocator for zram Signed-off-by: Nitin Gupta <ngupta@vflare.org> Acked-by: Seth Jennings <sjenning@linux.vnet.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2011-02-23staging: Allow sharing xvmalloc for zram and zcacheNitin Gupta1-0/+5
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 <ngupta@vflare.org> Acked-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-04zram/xvmalloc: create CONFIG_ZRAM_DEBUG for debug codeRobert Jennings1-0/+8
Add a debug config flag to enable debug printk output and future debug code. Signed-off-by: Robert Jennings <rcj@linux.vnet.ibm.com> Reviewed-by: Pekka Enberg <penberg@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-01-20Staging: zram: make ZRAM depends on SYSFSJerome Marchand1-1/+1
We can not configure zram device without sysfs anyway, so make zram depends on it. Signed-off-by: Jerome Marchand <jmarchan@redhat.com> Acked-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-08-31Staging: zram: Replace ioctls with sysfs interfaceNitin Gupta1-12/+0
Creates per-device sysfs nodes in /sys/block/zram<id>/ 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 <ngupta@vflare.org> Acked-by: Pekka Enberg <penberg@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-06-24Staging: zram: fix build errors, depends on BLOCKRandy Dunlap1-0/+1
Fix 49 zram build errors in one swoop. Examples: drivers/staging/zram/zram_drv.c:225: error: dereferencing pointer to incomplete type drivers/staging/zram/zram_drv.c:226: error: implicit declaration of function 'bio_for_each_segment' drivers/staging/zram/zram_drv.c:226: error: expected ';' before '{' token drivers/staging/zram/zram_drv.c:281: error: implicit declaration of function 'bio_endio' drivers/staging/zram/zram_drv.c:285: error: implicit declaration of function 'bio_io_error' drivers/staging/zram/zram_drv.c:545: error: implicit declaration of function 'set_capacity' drivers/staging/zram/zram_drv.c:548: error: implicit declaration of function 'queue_flag_set_unlocked' drivers/staging/zram/zram_drv.c:548: error: 'QUEUE_FLAG_NONROT' undeclared (first use in this function) drivers/staging/zram/zram_drv.c:548: error: dereferencing pointer to incomplete type Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Cc: Nitin Gupta <ngupta@vflare.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-06-18Staging: Rename ramzswap files to zramNitin Gupta1-0/+28
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 <ngupta@vflare.org> Acked-by: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>