Currently the kernel force charges the allocations which have __GFP_HIGH
flag without triggering the memory reclaim. __GFP_HIGH indicates that
the caller is high priority and since commit 869712fd3de5 ("mm:
memcontrol: fix network errors from failing __GFP_ATOMIC charges") the
kernel let such allocations do force charging. Please note that
__GFP_ATOMIC has been replaced by __GFP_HIGH.
__GFP_HIGH does not tell if the caller can block or can trigger reclaim.
There are separate checks to determine that. So, there is no need to
skip reclaim for __GFP_HIGH allocations. So, handle __GFP_HIGH together
with __GFP_NOFAIL which also does force charging.
Please note that this is a noop change as there are no __GFP_HIGH
allocators in kernel which also have __GFP_ACCOUNT (or SLAB_ACCOUNT) and
does not allow reclaim for now. The reason for this patch is to simplify
the reasoning of the following patches.
Signed-off-by: Shakeel Butt <shakeelb@xxxxxxxxxx>
---
mm/memcontrol.c | 17 +++++++----------
1 file changed, 7 insertions(+), 10 deletions(-)
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index c40c27822802..ae73a40818b0 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2560,15 +2560,6 @@ static int try_charge_memcg(struct mem_cgroup *memcg, gfp_t gfp_mask,
goto retry;
}
- /*
- * Memcg doesn't have a dedicated reserve for atomic
- * allocations. But like the global atomic pool, we need to
- * put the burden of reclaim on regular allocation requests
- * and let these go through as privileged allocations.
- */
- if (gfp_mask & __GFP_HIGH)
- goto force;
-
/*
* Prevent unbounded recursion when reclaim operations need to
* allocate memory. This might exceed the limits temporarily,
@@ -2642,7 +2633,13 @@ static int try_charge_memcg(struct mem_cgroup *memcg, gfp_t gfp_mask,
goto retry;
}
nomem:
- if (!(gfp_mask & __GFP_NOFAIL))
+ /*
+ * Memcg doesn't have a dedicated reserve for atomic
+ * allocations. But like the global atomic pool, we need to
+ * put the burden of reclaim on regular allocation requests
+ * and let these go through as privileged allocations.
+ */
+ if (!(gfp_mask & (__GFP_NOFAIL | __GFP_HIGH)))
return -ENOMEM;
force:
/*
--
2.35.1.265.g69c8d7142f-goog
