On Mon, Mar 21, 2022 at 04:54:26PM -0700, "T.J. Mercier"
<tjmercier(a)google.com> wrote:
> Since the charge is duplicated in two cgroups for a short period
> before it is uncharged from the source cgroup I guess the situation
> you're thinking about is a global (or common ancestor) limit?
The common ancestor was on my mind (after the self-shortcut).
> I can see how that would be a problem for transfers done this way and
> an alternative would be to swap the order of the charge operations:
> first uncharge, then try_charge. To be certain the uncharge is
> reversible if the try_charge fails, I think I'd need either a mutex
> used at all gpucg_*charge call sites or access to the gpucg_mutex,
Yes, that'd provide safe conditions for such operations, although I'm
not sure these special types of memory can afford global lock on their
fast paths.
> which implies adding transfer support to gpu.c as part of the gpucg_*
> API itself and calling it here. Am I following correctly here?
My idea was to provide a special API (apart from
gpucp_{try_charge,uncharge}) to facilitate transfers...
> This series doesn't actually add limit support just accounting, but
> I'd like to get it right here.
...which could be implemented (or changed) depending on how the charging
is realized internally.
Michal
This patch series revisits the proposal for a GPU cgroup controller to
track and limit memory allocations by various device/allocator
subsystems. The patch series also contains a simple prototype to
illustrate how Android intends to implement DMA-BUF allocator
attribution using the GPU cgroup controller. The prototype does not
include resource limit enforcements.
Changelog:
v3:
Remove Upstreaming Plan from gpu-cgroup.rst per John Stultz
Use more common dual author commit message format per John Stultz
Remove android from binder changes title per Todd Kjos
Add a kselftest for this new behavior per Greg Kroah-Hartman
Include details on behavior for all combinations of kernel/userspace
versions in changelog (thanks Suren Baghdasaryan) per Greg Kroah-Hartman.
Fix pid and uid types in binder UAPI header
v2:
See the previous revision of this change submitted by Hridya Valsaraju
at: https://lore.kernel.org/all/20220115010622.3185921-1-hridya@google.com/
Move dma-buf cgroup charge transfer from a dma_buf_op defined by every
heap to a single dma-buf function for all heaps per Daniel Vetter and
Christian König. Pointers to struct gpucg and struct gpucg_device
tracking the current associations were added to the dma_buf struct to
achieve this.
Fix incorrect Kconfig help section indentation per Randy Dunlap.
History of the GPU cgroup controller
====================================
The GPU/DRM cgroup controller came into being when a consensus[1]
was reached that the resources it tracked were unsuitable to be integrated
into memcg. Originally, the proposed controller was specific to the DRM
subsystem and was intended to track GEM buffers and GPU-specific
resources[2]. In order to help establish a unified memory accounting model
for all GPU and all related subsystems, Daniel Vetter put forth a
suggestion to move it out of the DRM subsystem so that it can be used by
other DMA-BUF exporters as well[3]. This RFC proposes an interface that
does the same.
[1]: https://patchwork.kernel.org/project/dri-devel/cover/20190501140438.9506-1-…
[2]: https://lore.kernel.org/amd-gfx/20210126214626.16260-1-brian.welty@intel.co…
[3]: https://lore.kernel.org/amd-gfx/YCVOl8%2F87bqRSQei@phenom.ffwll.local/
Hridya Valsaraju (5):
gpu: rfc: Proposal for a GPU cgroup controller
cgroup: gpu: Add a cgroup controller for allocator attribution of GPU
memory
dmabuf: heaps: export system_heap buffers with GPU cgroup charging
dmabuf: Add gpu cgroup charge transfer function
binder: Add a buffer flag to relinquish ownership of fds
T.J. Mercier (3):
dmabuf: Use the GPU cgroup charge/uncharge APIs
binder: use __kernel_pid_t and __kernel_uid_t for userspace
selftests: Add binder cgroup gpu memory transfer test
Documentation/gpu/rfc/gpu-cgroup.rst | 183 +++++++
Documentation/gpu/rfc/index.rst | 4 +
drivers/android/binder.c | 26 +
drivers/dma-buf/dma-buf.c | 100 ++++
drivers/dma-buf/dma-heap.c | 27 +
drivers/dma-buf/heaps/system_heap.c | 3 +
include/linux/cgroup_gpu.h | 127 +++++
include/linux/cgroup_subsys.h | 4 +
include/linux/dma-buf.h | 22 +-
include/linux/dma-heap.h | 11 +
include/uapi/linux/android/binder.h | 5 +-
init/Kconfig | 7 +
kernel/cgroup/Makefile | 1 +
kernel/cgroup/gpu.c | 304 +++++++++++
.../selftests/drivers/android/binder/Makefile | 8 +
.../drivers/android/binder/binder_util.c | 254 +++++++++
.../drivers/android/binder/binder_util.h | 32 ++
.../selftests/drivers/android/binder/config | 4 +
.../binder/test_dmabuf_cgroup_transfer.c | 480 ++++++++++++++++++
19 files changed, 1598 insertions(+), 4 deletions(-)
create mode 100644 Documentation/gpu/rfc/gpu-cgroup.rst
create mode 100644 include/linux/cgroup_gpu.h
create mode 100644 kernel/cgroup/gpu.c
create mode 100644 tools/testing/selftests/drivers/android/binder/Makefile
create mode 100644 tools/testing/selftests/drivers/android/binder/binder_util.c
create mode 100644 tools/testing/selftests/drivers/android/binder/binder_util.h
create mode 100644 tools/testing/selftests/drivers/android/binder/config
create mode 100644 tools/testing/selftests/drivers/android/binder/test_dmabuf_cgroup_transfer.c
--
2.35.1.616.g0bdcbb4464-goog