| Message ID | 20240625005906.106920-1-roman.gushchin@linux.dev (mailing list archive) |
|---|---|
| Headers | show |
| Series | mm: memcg: separate legacy cgroup v1 code and put under config option | expand |
On Mon, Jun 24, 2024 at 05:58:52PM GMT, Roman Gushchin wrote: > 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 patchset is based against mm-unstable tree (b610f75d19a34), > however a version based on mm-stable can be found here: > https://github.com/rgushchin/linux/tree/memcontrol_v1.1-stable . > > v2: > - minor compilation fix > - #else/#endif comments fix (Lance Yang) > > v1: > - switched to CONFIG_MEMCG_V1 being off by default based on LSFMMBPF > discussion [1] > - switched to memcg1_ prefix (Johannes) > - many minor fixes > - dropped patches which put struct memcg members under CONFIG_MEMCG_V1 > (will post as a separate patchset) > > rfc: > https://lwn.net/Articles/973082/ > > [1]: https://lwn.net/Articles/974575/ > > MAINTAINERS | 2 + > include/linux/memcontrol.h | 156 ++++--- > init/Kconfig | 9 + > mm/Makefile | 2 + > mm/memcontrol-v1.c | 2933 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > mm/memcontrol-v1.h | 132 ++++++ > mm/memcontrol.c | 4169 +++++++++++++++++++++++++++--------------------------------------------------------------------------------------------------------------------------------------------------- > mm/vmscan.c | 10 +- > 8 files changed, 3794 insertions(+), 3619 deletions(-) > > Suggested-by: Matthew Wilcox (Oracle) <willy@infradead.org> > Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev> For the series: Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
On Tue, Jun 25, 2024 at 10:03:53AM -0700, Shakeel Butt wrote: > On Mon, Jun 24, 2024 at 05:58:52PM GMT, Roman Gushchin wrote: > > 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: > > ... > > Suggested-by: Matthew Wilcox (Oracle) <willy@infradead.org> > > Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev> > > For the series: > > Acked-by: Shakeel Butt <shakeel.butt@linux.dev> Thank you!
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 patchset is based against mm-unstable tree (b610f75d19a34), however a version based on mm-stable can be found here: https://github.com/rgushchin/linux/tree/memcontrol_v1.1-stable . v2: - minor compilation fix - #else/#endif comments fix (Lance Yang) v1: - switched to CONFIG_MEMCG_V1 being off by default based on LSFMMBPF discussion [1] - switched to memcg1_ prefix (Johannes) - many minor fixes - dropped patches which put struct memcg members under CONFIG_MEMCG_V1 (will post as a separate patchset) rfc: https://lwn.net/Articles/973082/ [1]: https://lwn.net/Articles/974575/ MAINTAINERS | 2 + include/linux/memcontrol.h | 156 ++++--- init/Kconfig | 9 + mm/Makefile | 2 + mm/memcontrol-v1.c | 2933 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ mm/memcontrol-v1.h | 132 ++++++ mm/memcontrol.c | 4169 +++++++++++++++++++++++++++--------------------------------------------------------------------------------------------------------------------------------------------------- mm/vmscan.c | 10 +- 8 files changed, 3794 insertions(+), 3619 deletions(-) Suggested-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev> Roman Gushchin (14): mm: memcg: introduce memcontrol-v1.c mm: memcg: move soft limit reclaim code to memcontrol-v1.c mm: memcg: rename soft limit reclaim-related functions mm: memcg: move charge migration code to memcontrol-v1.c mm: memcg: rename charge move-related functions mm: memcg: move legacy memcg event code into memcontrol-v1.c mm: memcg: rename memcg_check_events() mm: memcg: move cgroup v1 oom handling code into memcontrol-v1.c mm: memcg: rename memcg_oom_recover() mm: memcg: move cgroup v1 interface files to memcontrol-v1.c mm: memcg: make memcg1_update_tree() static mm: memcg: group cgroup v1 memcg related declarations mm: memcg: put cgroup v1-related members of task_struct under config option MAINTAINERS: add mm/memcontrol-v1.c/h to the list of maintained files MAINTAINERS | 2 + include/linux/memcontrol.h | 156 +- init/Kconfig | 9 + mm/Makefile | 2 + mm/memcontrol-v1.c | 2933 +++++++++++++++++++++++++ mm/memcontrol-v1.h | 132 ++ mm/memcontrol.c | 4141 ++++++------------------------------ mm/vmscan.c | 10 +- 8 files changed, 3780 insertions(+), 3605 deletions(-) create mode 100644 mm/memcontrol-v1.c create mode 100644 mm/memcontrol-v1.h