@@ -2300,41 +2300,48 @@ static void high_work_func(struct work_struct *work)
#define MEMCG_DELAY_PRECISION_SHIFT 20
#define MEMCG_DELAY_SCALING_SHIFT 14
-/*
- * Get the number of jiffies that we should penalise a mischievous cgroup which
- * is exceeding its memory.high by checking both it and its ancestors.
- */
-static unsigned long calculate_high_delay(struct mem_cgroup *memcg,
- unsigned int nr_pages)
+static u64 calculate_overage(unsigned long usage, unsigned long high)
{
- unsigned long penalty_jiffies;
- u64 max_overage = 0;
-
- do {
- unsigned long usage, high;
- u64 overage;
+ u64 overage;
- usage = page_counter_read(&memcg->memory);
- high = READ_ONCE(memcg->high);
+ if (usage <= high)
+ return 0;
- if (usage <= high)
- continue;
+ /*
+ * Prevent division by 0 in overage calculation by acting as if
+ * it was a threshold of 1 page
+ */
+ high = max(high, 1UL);
- /*
- * Prevent division by 0 in overage calculation by acting as if
- * it was a threshold of 1 page
- */
- high = max(high, 1UL);
+ overage = usage - high;
+ overage <<= MEMCG_DELAY_PRECISION_SHIFT;
+ return div64_u64(overage, high);
+}
- overage = usage - high;
- overage <<= MEMCG_DELAY_PRECISION_SHIFT;
- overage = div64_u64(overage, high);
+static u64 mem_find_max_overage(struct mem_cgroup *memcg)
+{
+ u64 overage, max_overage = 0;
- if (overage > max_overage)
- max_overage = overage;
+ do {
+ overage = calculate_overage(page_counter_read(&memcg->memory),
+ READ_ONCE(memcg->high));
+ max_overage = max(overage, max_overage);
} while ((memcg = parent_mem_cgroup(memcg)) &&
!mem_cgroup_is_root(memcg));
+ return max_overage;
+}
+
+/*
+ * Get the number of jiffies that we should penalise a mischievous cgroup which
+ * is exceeding its memory.high by checking both it and its ancestors.
+ */
+static unsigned long calculate_high_delay(struct mem_cgroup *memcg,
+ unsigned int nr_pages,
+ u64 max_overage)
+{
+ unsigned long penalty_jiffies;
+
if (!max_overage)
return 0;
@@ -2390,7 +2397,8 @@ void mem_cgroup_handle_over_high(void)
* memory.high is breached and reclaim is unable to keep up. Throttle
* allocators proactively to slow down excessive growth.
*/
- penalty_jiffies = calculate_high_delay(memcg, nr_pages);
+ penalty_jiffies = calculate_high_delay(memcg, nr_pages,
+ mem_find_max_overage(memcg));
/*
* Don't sleep if the amount of jiffies this memcg owes us is so low
Slice the memory overage calculation logic a little bit so we can reuse it to apply a similar penalty to the swap. The logic which accesses the memory-specific fields (use and high values) has to be taken out of calculate_high_delay(). Signed-off-by: Jakub Kicinski <kuba@kernel.org> --- v4: calculate max outside of calculate_overage() --- mm/memcontrol.c | 62 ++++++++++++++++++++++++++++--------------------- 1 file changed, 35 insertions(+), 27 deletions(-)