mbox series

[v3,0/3] samples: introduce cgroup events listeners

Message ID 20231123071945.25811-1-ddrokosov@salutedevices.com
Headers
Series samples: introduce cgroup events listeners |

Message

Dmitry Rokosov Nov. 23, 2023, 7:19 a.m. UTC 
  To begin with, this patch series relocates the cgroup example code to
the samples/cgroup directory, which is the appropriate location for such
code snippets.

Furthermore, a new memcg events listener is introduced. This
listener is a simple yet effective tool for monitoring memory events and
managing counter changes during runtime.

Additionally, as per Andrew Morton's suggestion, a helpful reminder
comment is included in the memcontrol implementation. This comment
serves to ensure that the samples code is updated whenever new events
are added.

Changes v3 since v2 at [2]:
    - rename cgroup_v2_event_listener to memcg_event_listener per
      Andrew's suggestion

Changes v2 since v1 at [1]:
    - create new samples subdir - cgroup
    - move cgroup_event_listener for cgroup v1 to samples/cgroup
    - add a reminder comment to memcontrol implementation

Links:
    [1] - https://lore.kernel.org/all/20231013184107.28734-1-ddrokosov@salutedevices.com/
    [2] - https://lore.kernel.org/all/20231110082045.19407-1-ddrokosov@salutedevices.com/

Dmitry Rokosov (3):
  samples: introduce new samples subdir for cgroup
  samples/cgroup: introduce memcg memory.events listener
  mm: memcg: add reminder comment for the memcg v2 events

 MAINTAINERS                                   |   1 +
 mm/memcontrol.c                               |   4 +
 samples/Kconfig                               |   6 +
 samples/Makefile                              |   1 +
 samples/cgroup/Makefile                       |   5 +
 .../cgroup/cgroup_event_listener.c            |   0
 samples/cgroup/memcg_event_listener.c         | 330 ++++++++++++++++++
 tools/cgroup/Makefile                         |  11 -
 8 files changed, 347 insertions(+), 11 deletions(-)
 create mode 100644 samples/cgroup/Makefile
 rename {tools => samples}/cgroup/cgroup_event_listener.c (100%)
 create mode 100644 samples/cgroup/memcg_event_listener.c
 delete mode 100644 tools/cgroup/Makefile

Comments

Andrew Morton Nov. 24, 2023, 7:42 p.m. UTC | #1 
On Thu, 23 Nov 2023 10:19:42 +0300 Dmitry Rokosov <ddrokosov@salutedevices.com> wrote:

> To begin with, this patch series relocates the cgroup example code to
> the samples/cgroup directory, which is the appropriate location for such
> code snippets.

butbut.  Didn't we decide to do s/cgroup/memcg/ throughout?
Dmitry Rokosov Nov. 24, 2023, 8:06 p.m. UTC | #2 
On Fri, Nov 24, 2023 at 11:42:30AM -0800, Andrew Morton wrote:
> On Thu, 23 Nov 2023 10:19:42 +0300 Dmitry Rokosov <ddrokosov@salutedevices.com> wrote:
> 
> > To begin with, this patch series relocates the cgroup example code to
> > the samples/cgroup directory, which is the appropriate location for such
> > code snippets.
> 
> butbut.  Didn't we decide to do s/cgroup/memcg/ throughout?

I believe the samples directory should be named "samples/cgroup" instead
of "memcg" because the cgroup v1 event listener cannot be renamed to
"memcg" due to the common naming of cgroup v1 event_control (this sample
uses that control to access eventfd).

Additionally, I think it would be a good idea to add the new samples for
cgroup helpers in that directory.

That's why I have only renamed the new memcg listener.
Dmitry Rokosov Nov. 25, 2023, 8:07 a.m. UTC | #3 
Andrew,

On Fri, Nov 24, 2023 at 11:06:33PM +0300, Dmitry Rokosov wrote:
> On Fri, Nov 24, 2023 at 11:42:30AM -0800, Andrew Morton wrote:
> > On Thu, 23 Nov 2023 10:19:42 +0300 Dmitry Rokosov <ddrokosov@salutedevices.com> wrote:
> > 
> > > To begin with, this patch series relocates the cgroup example code to
> > > the samples/cgroup directory, which is the appropriate location for such
> > > code snippets.
> > 
> > butbut.  Didn't we decide to do s/cgroup/memcg/ throughout?
> 
> I believe the samples directory should be named "samples/cgroup" instead
> of "memcg" because the cgroup v1 event listener cannot be renamed to
> "memcg" due to the common naming of cgroup v1 event_control (this sample
> uses that control to access eventfd).
> 
> Additionally, I think it would be a good idea to add the new samples for
> cgroup helpers in that directory.
> 
> That's why I have only renamed the new memcg listener.

I looked into this more deeply. And yes, the old cgroup.event_control
has the common name, but it's used in the memcg implementation only.

So, if we plan to introduce new samples for cgroup, I suggest we use the
following naming convention:

1) Directory: samples/cgroup
2) V1 sample: memcg_v1_event_listener
3) V2 sample: memcg_v2_event_listener

Please let me know what you think about this. If it's okay with you, I
will prepare the v4 version with the above changes. I would appreciate
any feedback on that!"