mm: memcontrol: clean up reclaim size variable use in try_charge()

Charge reclaim and OOM currently use the charge batch variable, but
batching is already disabled at that point.  To simplify the charge
logic, the batch variable is reset to the original request size when
reclaim is entered, so it's functionally equal, but it's misleading.

Switch reclaim/OOM to nr_pages, which is the original request size.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index a6a062e409eb2a295cd1c98bb725a1d1136659c6..90dc501eaf3fbcbc7a60efeb1a4b3072220c04dc 100644 (file)
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2612,7 +2612,7 @@ retry:
 
        nr_reclaimed = mem_cgroup_reclaim(mem_over_limit, gfp_mask, flags);
 
-       if (mem_cgroup_margin(mem_over_limit) >= batch)
+       if (mem_cgroup_margin(mem_over_limit) >= nr_pages)
                goto retry;
 
        if (gfp_mask & __GFP_NORETRY)
@@ -2626,7 +2626,7 @@ retry:
         * unlikely to succeed so close to the limit, and we fall back
         * to regular pages anyway in case of failure.
         */
-       if (nr_reclaimed && batch <= (1 << PAGE_ALLOC_COSTLY_ORDER))
+       if (nr_reclaimed && nr_pages <= (1 << PAGE_ALLOC_COSTLY_ORDER))
                goto retry;
        /*
         * At task move, charge accounts can be doubly counted. So, it's
@@ -2644,7 +2644,7 @@ retry:
        if (fatal_signal_pending(current))
                goto bypass;
 
-       mem_cgroup_oom(mem_over_limit, gfp_mask, get_order(batch));
+       mem_cgroup_oom(mem_over_limit, gfp_mask, get_order(nr_pages));
 nomem:
        if (!(gfp_mask & __GFP_NOFAIL))
                return -ENOMEM;