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2015-09-09mm: zbud: constify the zbud_opsKrzysztof Kozlowski1-3/+3
The structure zbud_ops is not modified so make the pointer to it a pointer to const. Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> Acked-by: Dan Streetman <ddstreet@ieee.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-09mm: zpool: constify the zpool_opsKrzysztof Kozlowski1-2/+2
The structure zpool_ops is not modified so make the pointer to it a pointer to const. Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> Acked-by: Dan Streetman <ddstreet@ieee.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-26zpool: remove zpool_evict()Dan Streetman1-4/+19
Remove zpool_evict() helper function. As zbud is currently the only zpool implementation that supports eviction, add zpool and zpool_ops references to struct zbud_pool and directly call zpool_ops->evict(zpool, handle) on eviction. Currently zpool provides the zpool_evict helper which locks the zpool list lock and searches through all pools to find the specific one matching the caller, and call the corresponding zpool_ops->evict function. However, this is unnecessary, as the zbud pool can simply keep a reference to the zpool that created it, as well as the zpool_ops, and directly call the zpool_ops->evict function, when it needs to evict a page. This avoids a spinlock and list search in zpool for each eviction. Signed-off-by: Dan Streetman <ddstreet@ieee.org> Cc: Seth Jennings <sjennings@variantweb.net> Cc: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-13mm/zpool: add name argument to create zpoolGanesh Mahendran1-1/+2
Currently the underlay of zpool: zsmalloc/zbud, do not know who creates them. There is not a method to let zsmalloc/zbud find which caller they belong to. Now we want to add statistics collection in zsmalloc. We need to name the debugfs dir for each pool created. The way suggested by Minchan Kim is to use a name passed by caller(such as zram) to create the zsmalloc pool. /sys/kernel/debug/zsmalloc/zram0 This patch adds an argument `name' to zs_create_pool() and other related functions. Signed-off-by: Ganesh Mahendran <opensource.ganesh@gmail.com> Acked-by: Minchan Kim <minchan@kernel.org> Cc: Seth Jennings <sjennings@variantweb.net> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Dan Streetman <ddstreet@ieee.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13mm/zbud: init user ops only when it is neededHeesub Shin1-1/+1
When zbud is initialized through the zpool wrapper, pool->ops which points to user-defined operations is always set regardless of whether it is specified from the upper layer. This causes zbud_reclaim_page() to iterate its loop for evicting pool pages out without any gain. This patch sets the user-defined ops only when it is needed, so that zbud_reclaim_page() can bail out the reclamation loop earlier if there is no user-defined operations specified. Signed-off-by: Heesub Shin <heesub.shin@samsung.com> Acked-by: Dan Streetman <ddstreet@ieee.org> Cc: Seth Jennings <sjennings@variantweb.net> Cc: Sunae Seo <sunae.seo@samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-11-20Merge Linus' tree to be be to apply submitted patches to newer code thanJiri Kosina1-8/+104
current trivial.git base
2014-11-13zbud, zswap: change module author emailSeth Jennings1-1/+1
Old email no longer viable. Signed-off-by: Seth Jennings <sjennings@variantweb.net> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2014-10-10zbud: avoid accessing last unused freelistChao Yu1-6/+7
For now, there are NCHUNKS of 64 freelists in zbud_pool, the last unbuddied[63] freelist linked with all zbud pages which have free chunks of 63. Calculating according to context of num_free_chunks(), our max chunk number of unbuddied zbud page is 62, so none of zbud pages will be added/removed in last freelist, but still we will try to find an unbuddied zbud page in the last unused freelist, it is unneeded. This patch redefines NCHUNKS to 63 as free chunk number in one zbud page, hence we can decrease size of zpool and avoid accessing the last unused freelist whenever failing to allocate zbud from freelist in zbud_alloc. Signed-off-by: Chao Yu <chao2.yu@samsung.com> Cc: Seth Jennings <sjennings@variantweb.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-30mm/zpool: use prefixed module loadingKees Cook1-0/+1
To avoid potential format string expansion via module parameters, do not use the zpool type directly in request_module() without a format string. Additionally, to avoid arbitrary modules being loaded via zpool API (e.g. via the zswap_zpool_type module parameter) add a "zpool-" prefix to the requested module, as well as module aliases for the existing zpool types (zbud and zsmalloc). Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Seth Jennings <sjennings@variantweb.net> Cc: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Acked-by: Dan Streetman <ddstreet@ieee.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-07mm/zpool: zbud/zsmalloc implement zpoolDan Streetman1-0/+94
Update zbud and zsmalloc to implement the zpool api. [fengguang.wu@intel.com: make functions static] Signed-off-by: Dan Streetman <ddstreet@ieee.org> Tested-by: Seth Jennings <sjennings@variantweb.net> Cc: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Weijie Yang <weijie.yang@samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-07mm/zbud: change zbud_alloc size type to size_tDan Streetman1-2/+2
Change the type of the zbud_alloc() size param from unsigned int to size_t. Technically, this should not make any difference, as the zbud implementation already restricts the size to well within either type's limits; but as zsmalloc (and kmalloc) use size_t, and zpool will use size_t, this brings the size parameter type in line with zsmalloc/zpool. Signed-off-by: Dan Streetman <ddstreet@ieee.org> Acked-by: Seth Jennings <sjennings@variantweb.net> Tested-by: Seth Jennings <sjennings@variantweb.net> Cc: Weijie Yang <weijie.yang@samsung.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-05mm/zbud.c: make size unsigned like unique callsiteFabian Frederick1-2/+2
zbud_alloc is only called by zswap_frontswap_store with unsigned int len. Change function parameter + update >= 0 check. Signed-off-by: Fabian Frederick <fabf@skynet.be> Acked-by: Seth Jennings <sjennings@variantweb.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12mm/zbud: fix some trivial typos in commentsJianguo Wu1-2/+2
Signed-off-by: Jianguo Wu <wujianguo@huawei.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>
2013-08-01mm: zbud: fix condition check on allocation sizeHeesub Shin1-1/+1
zbud_alloc() incorrectly verifies the size of allocation limit. It should deny the allocation request greater than (PAGE_SIZE - ZHDR_SIZE_ALIGNED - CHUNK_SIZE), not (PAGE_SIZE - ZHDR_SIZE_ALIGNED) which has no remaining spaces for its buddy. There is no point in spending the entire zbud page storing only a single page, since we don't have any benefits. Signed-off-by: Heesub Shin <heesub.shin@samsung.com> Acked-by: Seth Jennings <sjenning@linux.vnet.ibm.com> Cc: Bob Liu <bob.liu@oracle.com> Cc: Dongjun Shin <d.j.shin@samsung.com> Cc: Sunae Seo <sunae.seo@samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-11zbud: add to mm/Seth Jennings1-0/+527
zbud is an special purpose allocator for storing compressed pages. It is designed to store up to two compressed pages per physical page. While this design limits storage density, it has simple and deterministic reclaim properties that make it preferable to a higher density approach when reclaim will be used. zbud works by storing compressed pages, or "zpages", together in pairs in a single memory page called a "zbud page". The first buddy is "left justifed" at the beginning of the zbud page, and the last buddy is "right justified" at the end of the zbud page. The benefit is that if either buddy is freed, the freed buddy space, coalesced with whatever slack space that existed between the buddies, results in the largest possible free region within the zbud page. zbud also provides an attractive lower bound on density. The ratio of zpages to zbud pages can not be less than 1. This ensures that zbud can never "do harm" by using more pages to store zpages than the uncompressed zpages would have used on their own. This implementation is a rewrite of the zbud allocator internally used by zcache in the driver/staging tree. The rewrite was necessary to remove some of the zcache specific elements that were ingrained throughout and provide a generic allocation interface that can later be used by zsmalloc and others. This patch adds zbud to mm/ for later use by zswap. Signed-off-by: Seth Jennings <sjenning@linux.vnet.ibm.com> Acked-by: Rik van Riel <riel@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Dan Magenheimer <dan.magenheimer@oracle.com> Cc: Robert Jennings <rcj@linux.vnet.ibm.com> Cc: Jenifer Hopper <jhopper@us.ibm.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Johannes Weiner <jweiner@redhat.com> Cc: Larry Woodman <lwoodman@redhat.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Dave Hansen <dave@sr71.net> Cc: Joe Perches <joe@perches.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Cody P Schafer <cody@linux.vnet.ibm.com> Cc: Hugh Dickens <hughd@google.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Bob Liu <bob.liu@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>