The patch titled
Subject: mm: memcg: introduce memcontrol-v1.c
has been added to the -mm mm-unstable branch. Its filename is
mm-memcg-introduce-memcontrol-v1c.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-memcg-introduce-memcontrol-v1c.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: Roman Gushchin <roman.gushchin@xxxxxxxxx>
Subject: mm: memcg: introduce memcontrol-v1.c
Date: Mon, 24 Jun 2024 17:58:53 -0700
Patch series "mm: memcg: separate legacy cgroup v1 code and put under
config option", v2.
Cgroups v2 have been around for a while and many users have fully adopted
them, so they never use cgroups v1 features and functionality. Yet they
have to "pay" for the cgroup v1 support anyway:
1) the kernel binary contains an unused cgroup v1 code,
2) some code paths have additional checks which are not needed,
3) some common structures like task_struct and mem_cgroup contain unused
cgroup v1-specific members.
Cgroup v1's memory controller has a number of features that are not
supported by cgroup v2 and their implementation is pretty much self
contained. Most notably, these features are: soft limit reclaim, oom
handling in userspace, complicated event notification system, charge
migration. Cgroup v1-specific code in memcontrol.c is close to 4k lines
in size and it's intervened with generic and cgroup v2-specific code.
It's a burden on developers and maintainers.
This patchset aims to solve these problems by:
1) moving cgroup v1-specific memcg code to the new mm/memcontrol-v1.c file,
2) putting definitions shared by memcontrol.c and memcontrol-v1.c into the
mm/memcontrol-v1.h header,
3) introducing the CONFIG_MEMCG_V1 config option, turned off by default,
4) making memcontrol-v1.c to compile only if CONFIG_MEMCG_V1 is set.
If CONFIG_MEMCG_V1 is not set, cgroup v1 memory controller is still available
for mounting, however no memory-specific control knobs are present.
This patch (of 14):
This patch introduces the mm/memcontrol-v1.c source file which will be
used for all legacy (cgroup v1) memory cgroup code. It also introduces
mm/memcontrol-v1.h to keep declarations shared between mm/memcontrol.c and
mm/memcontrol-v1.c.
As of now, let's compile it if CONFIG_MEMCG is set, similar to
mm/memcontrol.c. Later on it can be switched to use a separate config
option, so that the legacy code won't be compiled if not required.
Link: https://lkml.kernel.org/r/20240625005906.106920-1-roman.gushchin@xxxxxxxxx
Link: https://lkml.kernel.org/r/20240625005906.106920-2-roman.gushchin@xxxxxxxxx
Signed-off-by: Roman Gushchin <roman.gushchin@xxxxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxxx>
Acked-by: Shakeel Butt <shakeel.butt@xxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Muchun Song <muchun.song@xxxxxxxxx>
Cc: Roman Gushchin <roman.gushchin@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/Makefile | 3 ++-
mm/memcontrol-v1.c | 3 +++
mm/memcontrol-v1.h | 7 +++++++
3 files changed, 12 insertions(+), 1 deletion(-)
--- a/mm/Makefile~mm-memcg-introduce-memcontrol-v1c
+++ a/mm/Makefile
@@ -26,6 +26,7 @@ KCOV_INSTRUMENT_page_alloc.o := n
KCOV_INSTRUMENT_debug-pagealloc.o := n
KCOV_INSTRUMENT_kmemleak.o := n
KCOV_INSTRUMENT_memcontrol.o := n
+KCOV_INSTRUMENT_memcontrol-v1.o := n
KCOV_INSTRUMENT_mmzone.o := n
KCOV_INSTRUMENT_vmstat.o := n
KCOV_INSTRUMENT_failslab.o := n
@@ -95,7 +96,7 @@ obj-$(CONFIG_NUMA) += memory-tiers.o
obj-$(CONFIG_DEVICE_MIGRATION) += migrate_device.o
obj-$(CONFIG_TRANSPARENT_HUGEPAGE) += huge_memory.o khugepaged.o
obj-$(CONFIG_PAGE_COUNTER) += page_counter.o
-obj-$(CONFIG_MEMCG) += memcontrol.o vmpressure.o
+obj-$(CONFIG_MEMCG) += memcontrol.o memcontrol-v1.o vmpressure.o
ifdef CONFIG_SWAP
obj-$(CONFIG_MEMCG) += swap_cgroup.o
endif
--- /dev/null
+++ a/mm/memcontrol-v1.c
@@ -0,0 +1,3 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include "memcontrol-v1.h"
--- /dev/null
+++ a/mm/memcontrol-v1.h
@@ -0,0 +1,7 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#ifndef __MM_MEMCONTROL_V1_H
+#define __MM_MEMCONTROL_V1_H
+
+
+#endif /* __MM_MEMCONTROL_V1_H */
_
Patches currently in -mm which might be from roman.gushchin@xxxxxxxxx are
mm-memcg-introduce-memcontrol-v1c.patch
mm-memcg-move-soft-limit-reclaim-code-to-memcontrol-v1c.patch
mm-memcg-rename-soft-limit-reclaim-related-functions.patch
mm-memcg-move-charge-migration-code-to-memcontrol-v1c.patch
mm-memcg-rename-charge-move-related-functions.patch
mm-memcg-move-legacy-memcg-event-code-into-memcontrol-v1c.patch
mm-memcg-rename-memcg_check_events.patch
mm-memcg-move-cgroup-v1-oom-handling-code-into-memcontrol-v1c.patch
mm-memcg-rename-memcg_oom_recover.patch
mm-memcg-move-cgroup-v1-interface-files-to-memcontrol-v1c.patch
mm-memcg-make-memcg1_update_tree-static.patch
mm-memcg-group-cgroup-v1-memcg-related-declarations.patch
mm-memcg-put-cgroup-v1-related-members-of-task_struct-under-config-option.patch
maintainers-add-mm-memcontrol-v1c-h-to-the-list-of-maintained-files.patch
