From b168ed458ddecc176f3b9a1f4bcd83d7a4541c14 Mon Sep 17 00:00:00 2001 From: Maarten Lankhorst Date: Wed, 4 Dec 2024 15:31:11 +0100 Subject: kernel/cgroup: Add "dmem" memory accounting cgroup This code is based on the RDMA and misc cgroup initially, but now uses page_counter. It uses the same min/low/max semantics as the memory cgroup as a result. There's a small mismatch as TTM uses u64, and page_counter long pages. In practice it's not a problem. 32-bits systems don't really come with >=4GB cards and as long as we're consistently wrong with units, it's fine. The device page size may not be in the same units as kernel page size, and each region might also have a different page size (VRAM vs GART for example). The interface is simple: - Call dmem_cgroup_register_region() - Use dmem_cgroup_try_charge to check if you can allocate a chunk of memory, use dmem_cgroup__uncharge when freeing it. This may return an error code, or -EAGAIN when the cgroup limit is reached. In that case a reference to the limiting pool is returned. - The limiting cs can be used as compare function for dmem_cgroup_state_evict_valuable. - After having evicted enough, drop reference to limiting cs with dmem_cgroup_pool_state_put. This API allows you to limit device resources with cgroups. You can see the supported cards in /sys/fs/cgroup/dmem.capacity You need to echo +dmem to cgroup.subtree_control, and then you can partition device memory. Co-developed-by: Friedrich Vock Signed-off-by: Friedrich Vock Co-developed-by: Maxime Ripard Signed-off-by: Maarten Lankhorst Acked-by: Tejun Heo Link: https://lore.kernel.org/r/20241204143112.1250983-1-dev@lankhorst.se Signed-off-by: Maxime Ripard --- init/Kconfig | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'init') diff --git a/init/Kconfig b/init/Kconfig index a20e6efd3f0f..61f50cafa815 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1128,6 +1128,7 @@ config CGROUP_PIDS config CGROUP_RDMA bool "RDMA controller" + select PAGE_COUNTER help Provides enforcement of RDMA resources defined by IB stack. It is fairly easy for consumers to exhaust RDMA resources, which @@ -1136,6 +1137,15 @@ config CGROUP_RDMA Attaching processes with active RDMA resources to the cgroup hierarchy is allowed even if can cross the hierarchy's limit. +config CGROUP_DMEM + bool "Device memory controller (DMEM)" + help + The DMEM controller allows compatible devices to restrict device + memory usage based on the cgroup hierarchy. + + As an example, it allows you to restrict VRAM usage for applications + in the DRM subsystem. + config CGROUP_FREEZER bool "Freezer controller" help -- cgit v1.2.3