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2022-12-11zpool: clean out dead codeJohannes Weiner
There is a lot of provision for flexibility that isn't actually needed or used. Zswap (the only zpool user) always passes zpool_ops with an .evict method set. The backends who reclaim only do so for zswap, so they can also directly call zpool_ops without indirection or checks. Finally, there is no need to check the retries parameters and bail with -EINVAL in the reclaim function, when that's called just a few lines below with a hard-coded 8. There is no need to duplicate the evictable and sleep_mapped attrs from the driver in zpool_ops. Link: https://lkml.kernel.org/r/20221128191616.1261026-3-nphamcs@gmail.com Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Nhat Pham <nphamcs@gmail.com> Cc: Dan Streetman <ddstreet@ieee.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Seth Jennings <sjenning@redhat.com> Cc: Vitaly Wool <vitaly.wool@konsulko.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2021-07-01mm/zbud: add kerneldoc fields for zbud_poolMel Gorman
make W=1 generates the following warning for zbud_pool mm/zbud.c:105: warning: Function parameter or member 'zpool' not described in 'zbud_pool' mm/zbud.c:105: warning: Function parameter or member 'zpool_ops' not described in 'zbud_pool' Commit 479305fd7172 ("zpool: remove zpool_evict()") removed the zpool_evict helper and added the associated zpool and operations structure in struct zbud_pool but did not add documentation for the fields. Add rudimentary documentation. Link: https://lkml.kernel.org/r/20210520084809.8576-10-mgorman@techsingularity.net Fixes: 479305fd7172 ("zpool: remove zpool_evict()") Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Reviewed-by: Yang Shi <shy828301@gmail.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Dan Streetman <ddstreet@ieee.org> Cc: David Hildenbrand <david@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30mm/zbud: don't export any zbud APIMiaohe Lin
The zbud doesn't need to export any API and it is meant to be used via zpool API since the commit 12d79d64bfd3 ("mm/zpool: update zswap to use zpool"). So we can remove the unneeded zbud.h and move down zpool API to avoid any forward declaration. [linmiaohe@huawei.com: fix unused function warnings when CONFIG_ZPOOL is disabled] Link: https://lkml.kernel.org/r/20210619025508.1239386-1-linmiaohe@huawei.com Link: https://lkml.kernel.org/r/20210608114515.206992-3-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Dan Streetman <ddstreet@ieee.org> Cc: Seth Jennings <sjenning@redhat.com> Cc: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30mm/zbud: reuse unbuddied[0] as buddied in zbud_poolMiaohe Lin
Patch series "Cleanups for zbud", v2. This series contains just cleanups to save some possible memory in zbud_pool and avoid exporting any unneeded zbud API. More details can be found in the respective changelogs This patch (of 2): Since commit 9d8c5b5284e4 ("mm: zbud: fix condition check on allocation size"), zbud_pool.unbuddied[0] is always unused. We can reuse it as buddied field to save some possible memory. Link: https://lkml.kernel.org/r/20210608114515.206992-1-linmiaohe@huawei.com Link: https://lkml.kernel.org/r/20210608114515.206992-2-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Seth Jennings <sjenning@redhat.com> Cc: Dan Streetman <ddstreet@ieee.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-26mm: set the sleep_mapped to true for zbud and z3foldTian Tao
zpool driver adds a flag to indicate whether the zpool driver can enter an atomic context after mapping. This patch sets it true for z3fold and zbud. Link: https://lkml.kernel.org/r/1611035683-12732-3-git-send-email-tiantao6@hisilicon.com Signed-off-by: Tian Tao <tiantao6@hisilicon.com> Reviewed-by: Vitaly Wool <vitaly.wool@konsulko.com> Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Reported-by: Mike Galbraith <efault@gmx.de> Cc: Seth Jennings <sjenning@redhat.com> Cc: Dan Streetman <ddstreet@ieee.org> Cc: Barry Song <song.bao.hua@hisilicon.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13mm/zbud: remove redundant initializationXiang Chen
zhdr is already initialized in the front of the function, so remove redundant initialization here. Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Seth Jennings <sjenning@redhat.com> Cc: Dan Streetman <ddstreet@ieee.org> Link: https://lkml.kernel.org/r/1600419885-191907-1-git-send-email-chenxiang66@hisilicon.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04mm: use false for bool variableZou Wei
Fixes coccicheck warnings: mm/zbud.c:246:1-20: WARNING: Assignment of 0/1 to bool variable mm/mremap.c:777:2-8: WARNING: Assignment of 0/1 to bool variable mm/huge_memory.c:525:9-10: WARNING: return of 0/1 in function 'is_transparent_hugepage' with return type bool Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Zou Wei <zou_wei@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/1586835930-47076-1-git-send-email-zou_wei@huawei.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-05-21treewide: Add SPDX license identifier for more missed filesThomas Gleixner
Add SPDX license identifiers to all files which: - Have no license information of any form - Have MODULE_LICENCE("GPL*") inside which was used in the initial scan/conversion to ignore the file These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-06mm: docs: fix parameter names mismatchMike Rapoport
There are several places where parameter descriptions do no match the actual code. Fix it. Link: http://lkml.kernel.org/r/1516700871-22279-3-git-send-email-rppt@linux.vnet.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-15mm/zbud.c: use list_last_entry() instead of list_tail_entry()Geliang Tang
list_last_entry*( has been defined in list.h, so replace list_tail_entry() with it. Signed-off-by: Geliang Tang <geliangtang@163.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>
2015-11-06mm: zsmalloc: constify struct zs_pool nameSergey SENOZHATSKY
Constify `struct zs_pool' ->name. [akpm@inux-foundation.org: constify zpool_create_pool()'s `type' arg also] Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: Dan Streetman <ddstreet@ieee.org> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-08mm: zbud: constify the zbud_opsKrzysztof Kozlowski
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>
2015-09-08mm: zpool: constify the zpool_opsKrzysztof Kozlowski
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>
2015-06-25zpool: remove zpool_evict()Dan Streetman
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>
2015-02-12mm/zpool: add name argument to create zpoolGanesh Mahendran
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 Shin
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 Kosina
current trivial.git base
2014-11-13zbud, zswap: change module author emailSeth Jennings
Old email no longer viable. Signed-off-by: Seth Jennings <sjennings@variantweb.net> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2014-10-09zbud: avoid accessing last unused freelistChao Yu
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>
2014-08-29mm/zpool: use prefixed module loadingKees Cook
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>
2014-08-06mm/zpool: zbud/zsmalloc implement zpoolDan Streetman
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>
2014-08-06mm/zbud: change zbud_alloc size type to size_tDan Streetman
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>
2014-06-04mm/zbud.c: make size unsigned like unique callsiteFabian Frederick
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>
2013-09-11mm/zbud: fix some trivial typos in commentsJianguo Wu
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>
2013-07-31mm: zbud: fix condition check on allocation sizeHeesub Shin
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>
2013-07-10zbud: add to mm/Seth Jennings
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>