The patch titled
Subject: memcg: initiate deprecation of v1 soft limit
has been added to the -mm mm-unstable branch. Its filename is
memcg-initiate-deprecation-of-v1-soft-limit.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/memcg-initiate-deprecation-of-v1-soft-limit.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Shakeel Butt <shakeel.butt@xxxxxxxxx>
Subject: memcg: initiate deprecation of v1 soft limit
Date: Wed, 14 Aug 2024 15:00:19 -0700
Memcg v1 provides soft limit functionality for the best effort memory
sharing between multiple workloads on a system. It is usually triggered
through kswapd and at the moment does not reclaim kernel memory.
Memcg v2 provides more straightforward best effort (memory.low) and hard
protection (memory.min) functionalities. Let's initiate the deprecation
of soft limit from v1 and gather if v2 needs something more to move the
existing v1 users to v2 regarding soft limit.
Link: https://lkml.kernel.org/r/20240814220021.3208384-3-shakeel.butt@xxxxxxxxx
Signed-off-by: Shakeel Butt <shakeel.butt@xxxxxxxxx>
Reviewed-by: T.J. Mercier <tjmercier@xxxxxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxxx>
Acked-by: Roman Gushchin <roman.gushchin@xxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Muchun Song <muchun.song@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
Documentation/admin-guide/cgroup-v1/memory.rst | 8 ++++++--
mm/memcontrol-v1.c | 3 +++
2 files changed, 9 insertions(+), 2 deletions(-)
--- a/Documentation/admin-guide/cgroup-v1/memory.rst~memcg-initiate-deprecation-of-v1-soft-limit
+++ a/Documentation/admin-guide/cgroup-v1/memory.rst
@@ -78,6 +78,8 @@ Brief summary of control files.
memory.memsw.max_usage_in_bytes show max memory+Swap usage recorded
memory.soft_limit_in_bytes set/show soft limit of memory usage
This knob is not available on CONFIG_PREEMPT_RT systems.
+ This knob is deprecated and shouldn't be
+ used.
memory.stat show various statistics
memory.use_hierarchy set/show hierarchical account enabled
This knob is deprecated and shouldn't be
@@ -701,8 +703,10 @@ For compatibility reasons writing 1 to m
# echo 1 > memory.use_hierarchy
-7. Soft limits
-==============
+7. Soft limits (DEPRECATED)
+===========================
+
+THIS IS DEPRECATED!
Soft limits allow for greater sharing of memory. The idea behind soft limits
is to allow control groups to use as much of the memory as needed, provided
--- a/mm/memcontrol-v1.c~memcg-initiate-deprecation-of-v1-soft-limit
+++ a/mm/memcontrol-v1.c
@@ -2542,6 +2542,9 @@ static ssize_t mem_cgroup_write(struct k
if (IS_ENABLED(CONFIG_PREEMPT_RT)) {
ret = -EOPNOTSUPP;
} else {
+ pr_warn_once("soft_limit_in_bytes is deprecated and will be removed. "
+ "Please report your usecase to linux-mm@xxxxxxxxx if you "
+ "depend on this functionality.\n");
WRITE_ONCE(memcg->soft_limit, nr_pages);
ret = 0;
}
_
Patches currently in -mm which might be from shakeel.butt@xxxxxxxxx are
memcg-increase-the-valid-index-range-for-memcg-stats.patch
memcg-replace-memcg-id-idr-with-xarray.patch
memcg-replace-memcg-id-idr-with-xarray-v2.patch
memcg-use-ratelimited-stats-flush-in-the-reclaim.patch
memcg-move-v1-only-percpu-stats-in-separate-struct.patch
memcg-move-mem_cgroup_event_ratelimit-to-v1-code.patch
memcg-move-mem_cgroup_charge_statistics-to-v1-code.patch
memcg-move-v1-events-and-statistics-code-to-v1-file.patch
memcg-make-v1-only-functions-static.patch
memcg-allocate-v1-event-percpu-only-on-v1-deployment.patch
memcg-make-pgpgin-and-pgpgout-v1-only.patch
memcg-initiate-deprecation-of-v1-tcp-accounting.patch
memcg-initiate-deprecation-of-v1-soft-limit.patch
memcg-initiate-deprecation-of-oom_control.patch
memcg-initiate-deprecation-of-pressure_level.patch
