The patch titled
Subject: mm/vmscan.c: calculate reclaimed slab caches in all reclaim paths
has been removed from the -mm tree. Its filename was
mm-vmscan-calculate-reclaimed-slab-caches-in-all-reclaim-paths.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: Yafang Shao <laoar.shao@xxxxxxxxx>
Subject: mm/vmscan.c: calculate reclaimed slab caches in all reclaim paths
There are six different reclaim paths by now:
- kswapd reclaim path
- node reclaim path
- hibernate preallocate memory reclaim path
- direct reclaim path
- memcg reclaim path
- memcg softlimit reclaim path
The slab caches reclaimed in these paths are only calculated in the above
three paths.
There're some drawbacks if we don't calculate the reclaimed slab caches.
- The sc->nr_reclaimed isn't correct if there're some slab caches
relcaimed in this path.
- The slab caches may be reclaimed thoroughly if there're lots of
reclaimable slab caches and few page caches. Let's take an easy example
for this case. If one memcg is full of slab caches and the limit of it
is 512M, in other words there're approximately 512M slab caches in this
memcg. Then the limit of the memcg is reached and the memcg reclaim
begins, and then in this memcg reclaim path it will continuesly reclaim
the slab caches until the sc->priority drops to 0. After this reclaim
stops, you will find there're few slab caches left, which is less than
20M in my test case. While after this patch applied the number is
greater than 300M and the sc->priority only drops to 3.
Link: http://lkml.kernel.org/r/1561112086-6169-3-git-send-email-laoar.shao@xxxxxxxxx
Signed-off-by: Yafang Shao <laoar.shao@xxxxxxxxx>
Reviewed-by: Kirill Tkhai <ktkhai@xxxxxxxxxxxxx>
Reviewed-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Kirill Tkhai <ktkhai@xxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Vladimir Davydov <vdavydov.dev@xxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/vmscan.c | 7 +++++++
1 file changed, 7 insertions(+)
--- a/mm/vmscan.c~mm-vmscan-calculate-reclaimed-slab-caches-in-all-reclaim-paths
+++ a/mm/vmscan.c
@@ -3194,11 +3194,13 @@ unsigned long try_to_free_pages(struct z
if (throttle_direct_reclaim(sc.gfp_mask, zonelist, nodemask))
return 1;
+ current->reclaim_state = &sc.reclaim_state;
trace_mm_vmscan_direct_reclaim_begin(order, sc.gfp_mask);
nr_reclaimed = do_try_to_free_pages(zonelist, &sc);
trace_mm_vmscan_direct_reclaim_end(nr_reclaimed);
+ current->reclaim_state = NULL;
return nr_reclaimed;
}
@@ -3221,6 +3223,7 @@ unsigned long mem_cgroup_shrink_node(str
};
unsigned long lru_pages;
+ current->reclaim_state = &sc.reclaim_state;
sc.gfp_mask = (gfp_mask & GFP_RECLAIM_MASK) |
(GFP_HIGHUSER_MOVABLE & ~GFP_RECLAIM_MASK);
@@ -3238,7 +3241,9 @@ unsigned long mem_cgroup_shrink_node(str
trace_mm_vmscan_memcg_softlimit_reclaim_end(sc.nr_reclaimed);
+ current->reclaim_state = NULL;
*nr_scanned = sc.nr_scanned;
+
return sc.nr_reclaimed;
}
@@ -3265,6 +3270,7 @@ unsigned long try_to_free_mem_cgroup_pag
.may_shrinkslab = 1,
};
+ current->reclaim_state = &sc.reclaim_state;
/*
* Unlike direct reclaim via alloc_pages(), memcg's reclaim doesn't
* take care of from where we get pages. So the node where we start the
@@ -3285,6 +3291,7 @@ unsigned long try_to_free_mem_cgroup_pag
psi_memstall_leave(&pflags);
trace_mm_vmscan_memcg_reclaim_end(nr_reclaimed);
+ current->reclaim_state = NULL;
return nr_reclaimed;
}
_
Patches currently in -mm which might be from laoar.shao@xxxxxxxxx are
mm-vmscan-expose-cgroup_ino-for-memcg-reclaim-tracepoints.patch
