BMC/Intel-BMC/linux.git/mm/zswap.c, branch dev

zswap: runtime enable/disable

2015-06-26T00:00:37+00:00

Change the "enabled" parameter to be configurable at runtime. Remove the enabled check from init(), and move it to the frontswap store() function; when enabled, pages will be stored, and when disabled, pages won't be stored. This is almost identical to Seth's patch from 2 years ago: http://lkml.iu.edu/hypermail/linux/kernel/1307.2/04289.html [akpm@linux-foundation.org: tweak documentation] Signed-off-by: Dan Streetman Suggested-by: Seth Jennings Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm/zpool: add name argument to create zpool

2015-02-13T02:54:12+00:00

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 Acked-by: Minchan Kim Cc: Seth Jennings Cc: Nitin Gupta Cc: Dan Streetman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm/zswap: delete unnecessary check before calling free_percpu()

2014-12-13T20:42:50+00:00

free_percpu() tests whether its argument is NULL and then returns immediately. Thus the test around the call is not needed. This issue was detected by using the Coccinelle software. Signed-off-by: Markus Elfring Cc: Seth Jennings Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm/zswap: add __init to some functions in zswap

2014-12-13T20:42:50+00:00

zswap_cpu_init/zswap_comp_exit/zswap_entry_cache_create is only called by __init init_zswap() Signed-off-by: Mahendran Ganesh Cc: Seth Jennings Cc: Dan Streetman Cc: Minchan Kim Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge Linus' tree to be be to apply submitted patches to newer code than

2014-11-20T13:42:02+00:00

current trivial.git base

zbud, zswap: change module author email

2014-11-13T08:05:47+00:00

Old email no longer viable. Signed-off-by: Seth Jennings Signed-off-by: Jiri Kosina

mm/zswap.c: add __init to zswap_entry_cache_destroy()

2014-08-08T22:57:18+00:00

zswap_entry_cache_destroy() is only called by __init init_zswap(). This patch also fixes function name zswap_entry_cache_ s/destory/destroy Signed-off-by: Fabian Frederick Acked-by: Seth Jennings Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: memcontrol: rewrite uncharge API

2014-08-08T22:57:17+00:00

The memcg uncharging code that is involved towards the end of a page's lifetime - truncation, reclaim, swapout, migration - is impressively complicated and fragile. Because anonymous and file pages were always charged before they had their page->mapping established, uncharges had to happen when the page type could still be known from the context; as in unmap for anonymous, page cache removal for file and shmem pages, and swap cache truncation for swap pages. However, these operations happen well before the page is actually freed, and so a lot of synchronization is necessary: - Charging, uncharging, page migration, and charge migration all need to take a per-page bit spinlock as they could race with uncharging. - Swap cache truncation happens during both swap-in and swap-out, and possibly repeatedly before the page is actually freed. This means that the memcg swapout code is called from many contexts that make no sense and it has to figure out the direction from page state to make sure memory and memory+swap are always correctly charged. - On page migration, the old page might be unmapped but then reused, so memcg code has to prevent untimely uncharging in that case. Because this code - which should be a simple charge transfer - is so special-cased, it is not reusable for replace_page_cache(). But now that charged pages always have a page->mapping, introduce mem_cgroup_uncharge(), which is called after the final put_page(), when we know for sure that nobody is looking at the page anymore. For page migration, introduce mem_cgroup_migrate(), which is called after the migration is successful and the new page is fully rmapped. Because the old page is no longer uncharged after migration, prevent double charges by decoupling the page's memcg association (PCG_USED and pc->mem_cgroup) from the page holding an actual charge. The new bits PCG_MEM and PCG_MEMSW represent the respective charges and are transferred to the new page during migration. mem_cgroup_migrate() is suitable for replace_page_cache() as well, which gets rid of mem_cgroup_replace_page_cache(). However, care needs to be taken because both the source and the target page can already be charged and on the LRU when fuse is splicing: grab the page lock on the charge moving side to prevent changing pc->mem_cgroup of a page under migration. Also, the lruvecs of both pages change as we uncharge the old and charge the new during migration, and putback may race with us, so grab the lru lock and isolate the pages iff on LRU to prevent races and ensure the pages are on the right lruvec afterward. Swap accounting is massively simplified: because the page is no longer uncharged as early as swap cache deletion, a new mem_cgroup_swapout() can transfer the page's memory+swap charge (PCG_MEMSW) to the swap entry before the final put_page() in page reclaim. Finally, page_cgroup changes are now protected by whatever protection the page itself offers: anonymous pages are charged under the page table lock, whereas page cache insertions, swapin, and migration hold the page lock. Uncharging happens under full exclusion with no outstanding references. Charging and uncharging also ensure that the page is off-LRU, which serializes against charge migration. Remove the very costly page_cgroup lock and set pc->flags non-atomically. [mhocko@suse.cz: mem_cgroup_charge_statistics needs preempt_disable] [vdavydov@parallels.com: fix flags definition] Signed-off-by: Johannes Weiner Cc: Hugh Dickins Cc: Tejun Heo Cc: Vladimir Davydov Tested-by: Jet Chen Acked-by: Michal Hocko Tested-by: Felipe Balbi Signed-off-by: Vladimir Davydov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm/zpool: update zswap to use zpool

2014-08-07T01:01:23+00:00

Change zswap to use the zpool api instead of directly using zbud. Add a boot-time param to allow selecting which zpool implementation to use, with zbud as the default. Signed-off-by: Dan Streetman Tested-by: Seth Jennings Cc: Weijie Yang Cc: Minchan Kim Cc: Nitin Gupta Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm/zswap: NUMA aware allocation for zswap_dstmem

2014-06-04T23:54:14+00:00

zswap_dstmem is a percpu block of memory, which should be allocated using kmalloc_node(), to get better NUMA locality. Without it, all the blocks are allocated from a single node. Signed-off-by: Eric Dumazet Acked-by: Seth Jennings Acked-by: David Rientjes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds