The patch titled
Subject: mm: memcontrol: simplify move precharge function
has been removed from the -mm tree. Its filename was
mm-memcontrol-simplify-move-precharge-function.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: Johannes Weiner <hannes@xxxxxxxxxxx>
Subject: mm: memcontrol: simplify move precharge function
The move precharge function does some baroque things: it tries raw
res_counter charging of the entire amount first, and then falls back to a
loop of one-by-one charges, with checks for pending signals and
cond_resched() batching.
Just use mem_cgroup_try_charge() without __GFP_WAIT for the first bulk
charge attempt. In the one-by-one loop, remove the signal check (this is
already checked in try_charge), and simply call cond_resched() after every
charge - it's not that expensive.
Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Tejun Heo <tj@xxxxxxxxxx>
Cc: Vladimir Davydov <vdavydov@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memcontrol.c | 48 ++++++++++++++--------------------------------
1 file changed, 15 insertions(+), 33 deletions(-)
diff -puN mm/memcontrol.c~mm-memcontrol-simplify-move-precharge-function mm/memcontrol.c
--- a/mm/memcontrol.c~mm-memcontrol-simplify-move-precharge-function
+++ a/mm/memcontrol.c
@@ -6385,56 +6385,38 @@ static void mem_cgroup_css_reset(struct
#ifdef CONFIG_MMU
/* Handlers for move charge at task migration. */
-#define PRECHARGE_COUNT_AT_ONCE 256
static int mem_cgroup_do_precharge(unsigned long count)
{
int ret = 0;
- int batch_count = PRECHARGE_COUNT_AT_ONCE;
- struct mem_cgroup *memcg = mc.to;
- if (mem_cgroup_is_root(memcg)) {
+ if (mem_cgroup_is_root(mc.to)) {
mc.precharge += count;
/* we don't need css_get for root */
return ret;
}
- /* try to charge at once */
- if (count > 1) {
- struct res_counter *dummy;
- /*
- * "memcg" cannot be under rmdir() because we've already checked
- * by cgroup_lock_live_cgroup() that it is not removed and we
- * are still under the same cgroup_mutex. So we can postpone
- * css_get().
- */
- if (res_counter_charge(&memcg->res, PAGE_SIZE * count, &dummy))
- goto one_by_one;
- if (do_swap_account && res_counter_charge(&memcg->memsw,
- PAGE_SIZE * count, &dummy)) {
- res_counter_uncharge(&memcg->res, PAGE_SIZE * count);
- goto one_by_one;
- }
+
+ /* Try a single bulk charge without reclaim first */
+ ret = mem_cgroup_try_charge(mc.to, GFP_KERNEL & ~__GFP_WAIT, count);
+ if (!ret) {
mc.precharge += count;
return ret;
}
-one_by_one:
- /* fall back to one by one charge */
+
+ /* Try charges one by one with reclaim */
while (count--) {
- if (signal_pending(current)) {
- ret = -EINTR;
- break;
- }
- if (!batch_count--) {
- batch_count = PRECHARGE_COUNT_AT_ONCE;
- cond_resched();
- }
- ret = mem_cgroup_try_charge(memcg,
+ ret = mem_cgroup_try_charge(mc.to,
GFP_KERNEL & ~__GFP_NORETRY, 1);
+ /*
+ * In case of failure, any residual charges against
+ * mc.to will be dropped by mem_cgroup_clear_mc()
+ * later on.
+ */
if (ret)
- /* mem_cgroup_clear_mc() will do uncharge later */
return ret;
mc.precharge++;
+ cond_resched();
}
- return ret;
+ return 0;
}
/**
_
Patches currently in -mm which might be from hannes@xxxxxxxxxxx are
origin.patch
mm-memcontrol-rewrite-charge-api.patch
mm-memcontrol-rewrite-uncharge-api.patch
mm-memcontrol-use-page-lists-for-uncharge-batching.patch
mm-memcontrol-use-page-lists-for-uncharge-batching-fix-hugetlb-page-lru.patch
page-cgroup-trivial-cleanup.patch
page-cgroup-get-rid-of-nr_pcg_flags.patch
memcg-remove-lookup_cgroup_page-prototype.patch
mm-memcontrol-avoid-charge-statistics-churn-during-page-migration.patch
nilfs2-integrate-sysfs-support-into-driver-fix.patch
linux-next.patch
debugging-keep-track-of-page-owners.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
