Update Linux to v5.4.148
Sourced from [1]
[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.4.148.tar.gz
Change-Id: Ib3d26c5ba9b022e2e03533005c4fed4d7c30b61b
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index ae703ea..b6d0b68 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -356,17 +356,54 @@
return !cgroup_subsys_enabled(memory_cgrp_subsys);
}
-static inline unsigned long mem_cgroup_protection(struct mem_cgroup *memcg,
- bool in_low_reclaim)
+static inline void mem_cgroup_protection(struct mem_cgroup *root,
+ struct mem_cgroup *memcg,
+ unsigned long *min,
+ unsigned long *low)
{
+ *min = *low = 0;
+
if (mem_cgroup_disabled())
- return 0;
+ return;
- if (in_low_reclaim)
- return READ_ONCE(memcg->memory.emin);
+ /*
+ * There is no reclaim protection applied to a targeted reclaim.
+ * We are special casing this specific case here because
+ * mem_cgroup_protected calculation is not robust enough to keep
+ * the protection invariant for calculated effective values for
+ * parallel reclaimers with different reclaim target. This is
+ * especially a problem for tail memcgs (as they have pages on LRU)
+ * which would want to have effective values 0 for targeted reclaim
+ * but a different value for external reclaim.
+ *
+ * Example
+ * Let's have global and A's reclaim in parallel:
+ * |
+ * A (low=2G, usage = 3G, max = 3G, children_low_usage = 1.5G)
+ * |\
+ * | C (low = 1G, usage = 2.5G)
+ * B (low = 1G, usage = 0.5G)
+ *
+ * For the global reclaim
+ * A.elow = A.low
+ * B.elow = min(B.usage, B.low) because children_low_usage <= A.elow
+ * C.elow = min(C.usage, C.low)
+ *
+ * With the effective values resetting we have A reclaim
+ * A.elow = 0
+ * B.elow = B.low
+ * C.elow = C.low
+ *
+ * If the global reclaim races with A's reclaim then
+ * B.elow = C.elow = 0 because children_low_usage > A.elow)
+ * is possible and reclaiming B would be violating the protection.
+ *
+ */
+ if (root == memcg)
+ return;
- return max(READ_ONCE(memcg->memory.emin),
- READ_ONCE(memcg->memory.elow));
+ *min = READ_ONCE(memcg->memory.emin);
+ *low = READ_ONCE(memcg->memory.elow);
}
enum mem_cgroup_protection mem_cgroup_protected(struct mem_cgroup *root,
@@ -705,6 +742,7 @@
void __mod_lruvec_state(struct lruvec *lruvec, enum node_stat_item idx,
int val);
void __mod_lruvec_slab_state(void *p, enum node_stat_item idx, int val);
+void mod_memcg_obj_state(void *p, int idx, int val);
static inline void mod_lruvec_state(struct lruvec *lruvec,
enum node_stat_item idx, int val)
@@ -792,6 +830,8 @@
atomic_long_inc(&memcg->memory_events[event]);
cgroup_file_notify(&memcg->events_file);
+ if (!cgroup_subsys_on_dfl(memory_cgrp_subsys))
+ break;
if (cgrp_dfl_root.flags & CGRP_ROOT_MEMORY_LOCAL_EVENTS)
break;
} while ((memcg = parent_mem_cgroup(memcg)) &&
@@ -844,10 +884,12 @@
{
}
-static inline unsigned long mem_cgroup_protection(struct mem_cgroup *memcg,
- bool in_low_reclaim)
+static inline void mem_cgroup_protection(struct mem_cgroup *root,
+ struct mem_cgroup *memcg,
+ unsigned long *min,
+ unsigned long *low)
{
- return 0;
+ *min = *low = 0;
}
static inline enum mem_cgroup_protection mem_cgroup_protected(
@@ -1128,6 +1170,10 @@
__mod_node_page_state(page_pgdat(page), idx, val);
}
+static inline void mod_memcg_obj_state(void *p, int idx, int val)
+{
+}
+
static inline
unsigned long mem_cgroup_soft_limit_reclaim(pg_data_t *pgdat, int order,
gfp_t gfp_mask,
@@ -1432,6 +1478,8 @@
return memcg ? memcg->kmemcg_id : -1;
}
+struct mem_cgroup *mem_cgroup_from_obj(void *p);
+
#else
static inline int memcg_kmem_charge(struct page *page, gfp_t gfp, int order)
@@ -1473,6 +1521,11 @@
{
}
+static inline struct mem_cgroup *mem_cgroup_from_obj(void *p)
+{
+ return NULL;
+}
+
#endif /* CONFIG_MEMCG_KMEM */
#endif /* _LINUX_MEMCONTROL_H */