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author | Jens Axboe <jens.axboe@oracle.com> | 2010-03-19 08:05:10 +0100 |
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committer | Jens Axboe <jens.axboe@oracle.com> | 2010-03-19 08:05:10 +0100 |
commit | b4b7a4ef097f288f724420b473dbf92a89c0ab7e (patch) | |
tree | 23ad8101e3e77c32a8d1e1b95a9c1cd7f7a475b7 /mm/page_cgroup.c | |
parent | e9ce335df51ff782035a15c261a3c0c9892a1767 (diff) | |
parent | a3d3203e4bb40f253b1541e310dc0f9305be7c84 (diff) | |
download | op-kernel-dev-b4b7a4ef097f288f724420b473dbf92a89c0ab7e.zip op-kernel-dev-b4b7a4ef097f288f724420b473dbf92a89c0ab7e.tar.gz |
Merge branch 'master' into for-linus
Conflicts:
block/Kconfig
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'mm/page_cgroup.c')
-rw-r--r-- | mm/page_cgroup.c | 34 |
1 files changed, 32 insertions, 2 deletions
diff --git a/mm/page_cgroup.c b/mm/page_cgroup.c index 3d535d5..3dd8853 100644 --- a/mm/page_cgroup.c +++ b/mm/page_cgroup.c @@ -335,6 +335,37 @@ not_enough_page: } /** + * swap_cgroup_cmpxchg - cmpxchg mem_cgroup's id for this swp_entry. + * @end: swap entry to be cmpxchged + * @old: old id + * @new: new id + * + * Returns old id at success, 0 at failure. + * (There is no mem_cgroup useing 0 as its id) + */ +unsigned short swap_cgroup_cmpxchg(swp_entry_t ent, + unsigned short old, unsigned short new) +{ + int type = swp_type(ent); + unsigned long offset = swp_offset(ent); + unsigned long idx = offset / SC_PER_PAGE; + unsigned long pos = offset & SC_POS_MASK; + struct swap_cgroup_ctrl *ctrl; + struct page *mappage; + struct swap_cgroup *sc; + + ctrl = &swap_cgroup_ctrl[type]; + + mappage = ctrl->map[idx]; + sc = page_address(mappage); + sc += pos; + if (cmpxchg(&sc->id, old, new) == old) + return old; + else + return 0; +} + +/** * swap_cgroup_record - record mem_cgroup for this swp_entry. * @ent: swap entry to be recorded into * @mem: mem_cgroup to be recorded @@ -358,8 +389,7 @@ unsigned short swap_cgroup_record(swp_entry_t ent, unsigned short id) mappage = ctrl->map[idx]; sc = page_address(mappage); sc += pos; - old = sc->id; - sc->id = id; + old = xchg(&sc->id, id); return old; } |