* [PATCH v7 1/6] gpu: rfc: Proposal for a GPU cgroup controller
2022-05-10 23:56 [PATCH v7 0/6] Proposal for a GPU cgroup controller T.J. Mercier
@ 2022-05-10 23:56 ` T.J. Mercier
[not found] ` <20220510235653.933868-1-tjmercier-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
` (3 subsequent siblings)
4 siblings, 0 replies; 21+ messages in thread
From: T.J. Mercier @ 2022-05-10 23:56 UTC (permalink / raw)
To: tjmercier, Tejun Heo, Zefan Li, Johannes Weiner, Jonathan Corbet
Cc: daniel, hridya, christian.koenig, jstultz, tkjos, cmllamas,
surenb, kaleshsingh, Kenny.Ho, mkoutny, skhan, kernel-team,
cgroups, linux-doc, linux-kernel
From: Hridya Valsaraju <hridya@google.com>
This patch adds a proposal for a new GPU cgroup controller for
accounting/limiting GPU and GPU-related memory allocations.
The proposed controller is based on the DRM cgroup controller[1] and
follows the design of the RDMA cgroup controller.
The new cgroup controller would:
* Allow setting per-device limits on the total size of buffers
allocated by device within a cgroup.
* Expose a per-device/allocator breakdown of the buffers charged to a
cgroup.
The prototype in the following patches is only for memory accounting
using the GPU cgroup controller and does not implement limit setting.
[1]: https://lore.kernel.org/amd-gfx/20210126214626.16260-1-brian.welty@intel.com/
Signed-off-by: Hridya Valsaraju <hridya@google.com>
Signed-off-by: T.J. Mercier <tjmercier@google.com>
---
v7 changes
Remove comment about duplicate name rejection which is not relevant to
cgroups users per Michal Koutn√Ω.
v6 changes
Move documentation into cgroup-v2.rst per Tejun Heo.
v5 changes
Drop the global GPU cgroup "total" (sum of all device totals) portion
of the design since there is no currently known use for this per
Tejun Heo.
Update for renamed functions/variables.
v3 changes
Remove Upstreaming Plan from gpu-cgroup.rst per John Stultz.
Use more common dual author commit message format per John Stultz.
---
Documentation/admin-guide/cgroup-v2.rst | 23 +++++++++++++++++++++++
1 file changed, 23 insertions(+)
diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst
index 69d7a6983f78..2e1d26e327c7 100644
--- a/Documentation/admin-guide/cgroup-v2.rst
+++ b/Documentation/admin-guide/cgroup-v2.rst
@@ -2352,6 +2352,29 @@ first, and stays charged to that cgroup until that resource is freed. Migrating
a process to a different cgroup does not move the charge to the destination
cgroup where the process has moved.
+
+GPU
+---
+
+The GPU controller accounts for device and system memory allocated by the GPU
+and related subsystems for graphics use. Resource limits are not currently
+supported.
+
+GPU Interface Files
+~~~~~~~~~~~~~~~~~~~~
+
+ gpu.memory.current
+ A read-only file containing memory allocations in flat-keyed format. The key
+ is a string representing the device name. The value is the size of the memory
+ charged to the device in bytes. The device names are globally unique.::
+
+ $ cat /sys/kernel/fs/cgroup1/gpu.memory.current
+ dev1 4194304
+ dev2 104857600
+
+ The device name string is set by a device driver when it registers with the
+ GPU cgroup controller to participate in resource accounting.
+
Others
------
--
2.36.0.512.ge40c2bad7a-goog
^ permalink raw reply related [flat|nested] 21+ messages in thread[parent not found: <20220510235653.933868-1-tjmercier-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>]
* [PATCH v7 2/6] cgroup: gpu: Add a cgroup controller for allocator attribution of GPU memory
[not found] ` <20220510235653.933868-1-tjmercier-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
@ 2022-05-10 23:56 ` T.J. Mercier
2022-05-10 23:56 ` [PATCH v7 4/6] dmabuf: Add gpu cgroup charge transfer function T.J. Mercier
1 sibling, 0 replies; 21+ messages in thread
From: T.J. Mercier @ 2022-05-10 23:56 UTC (permalink / raw)
To: tjmercier-hpIqsD4AKlfQT0dZR+AlfA, Tejun Heo, Zefan Li,
Johannes Weiner
Cc: daniel-/w4YWyX8dFk, hridya-hpIqsD4AKlfQT0dZR+AlfA,
christian.koenig-5C7GfCeVMHo, jstultz-hpIqsD4AKlfQT0dZR+AlfA,
tkjos-z5hGa2qSFaRBDgjK7y7TUQ, cmllamas-hpIqsD4AKlfQT0dZR+AlfA,
surenb-hpIqsD4AKlfQT0dZR+AlfA, kaleshsingh-hpIqsD4AKlfQT0dZR+AlfA,
Kenny.Ho-5C7GfCeVMHo, mkoutny-IBi9RG/b67k,
skhan-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r,
kernel-team-z5hGa2qSFaRBDgjK7y7TUQ,
linux-kernel-u79uwXL29TY76Z2rM5mHXA,
cgroups-u79uwXL29TY76Z2rM5mHXA
From: Hridya Valsaraju <hridya-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
The cgroup controller provides accounting for GPU and GPU-related
memory allocations. The memory being accounted can be device memory or
memory allocated from pools dedicated to serve GPU-related tasks.
This patch adds APIs to:
-allow a device to register for memory accounting using the GPU cgroup
controller.
-charge and uncharge allocated memory to a cgroup.
When the cgroup controller is enabled, it would expose information about
the memory allocated by each device(registered for GPU cgroup memory
accounting) for each cgroup.
The API/UAPI can be extended to set per-device/total allocation limits
in the future.
The cgroup controller has been named following the discussion in [1].
[1]: https://lore.kernel.org/amd-gfx/YCJp%2F%2FkMC7YjVMXv-dv86pmgwkMBes7Z6vYuT8fd9D2ou9A/h@public.gmane.orgl/
Signed-off-by: Hridya Valsaraju <hridya-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
Signed-off-by: T.J. Mercier <tjmercier-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
---
v7 changes
Hide gpucg and gpucg_bucket struct definitions per Michal Koutný.
This means gpucg_register_bucket now returns an internally allocated
struct gpucg_bucket.
Move all public function documentation to the cgroup_gpu.h header.
v5 changes
Support all strings for gpucg_register_device instead of just string
literals.
Enforce globally unique gpucg_bucket names.
Constrain gpucg_bucket name lengths to 64 bytes.
Obtain just a single css refcount instead of nr_pages for each
charge.
Rename:
gpucg_try_charge -> gpucg_charge
find_cg_rpool_locked -> cg_rpool_find_locked
init_cg_rpool -> cg_rpool_init
get_cg_rpool_locked -> cg_rpool_get_locked
"gpu cgroup controller" -> "GPU controller"
gpucg_device -> gpucg_bucket
usage -> size
v4 changes
Adjust gpucg_try_charge critical section for future charge transfer
functionality.
v3 changes
Use more common dual author commit message format per John Stultz.
v2 changes
Fix incorrect Kconfig help section indentation per Randy Dunlap.
---
include/linux/cgroup_gpu.h | 122 ++++++++++++
include/linux/cgroup_subsys.h | 4 +
init/Kconfig | 7 +
kernel/cgroup/Makefile | 1 +
kernel/cgroup/gpu.c | 339 ++++++++++++++++++++++++++++++++++
5 files changed, 473 insertions(+)
create mode 100644 include/linux/cgroup_gpu.h
create mode 100644 kernel/cgroup/gpu.c
diff --git a/include/linux/cgroup_gpu.h b/include/linux/cgroup_gpu.h
new file mode 100644
index 000000000000..cb228a16aa1f
--- /dev/null
+++ b/include/linux/cgroup_gpu.h
@@ -0,0 +1,122 @@
+/* SPDX-License-Identifier: MIT
+ * Copyright 2019 Advanced Micro Devices, Inc.
+ * Copyright (C) 2022 Google LLC.
+ */
+#ifndef _CGROUP_GPU_H
+#define _CGROUP_GPU_H
+
+#include <linux/cgroup.h>
+
+#define GPUCG_BUCKET_NAME_MAX_LEN 64
+
+struct gpucg;
+struct gpucg_bucket;
+
+#ifdef CONFIG_CGROUP_GPU
+
+/**
+ * css_to_gpucg - get the corresponding gpucg ref from a cgroup_subsys_state
+ * @css: the target cgroup_subsys_state
+ *
+ * Returns: gpu cgroup that contains the @css
+ */
+struct gpucg *css_to_gpucg(struct cgroup_subsys_state *css);
+
+/**
+ * gpucg_get - get the gpucg reference that a task belongs to
+ * @task: the target task
+ *
+ * This increases the reference count of the css that the @task belongs to.
+ *
+ * Returns: reference to the gpu cgroup the task belongs to.
+ */
+struct gpucg *gpucg_get(struct task_struct *task);
+
+/**
+ * gpucg_put - put a gpucg reference
+ * @gpucg: the target gpucg
+ *
+ * Put a reference obtained via gpucg_get
+ */
+void gpucg_put(struct gpucg *gpucg);
+
+/**
+ * gpucg_parent - find the parent of a gpu cgroup
+ * @cg: the target gpucg
+ *
+ * This does not increase the reference count of the parent cgroup
+ *
+ * Returns: parent gpu cgroup of @cg
+ */
+struct gpucg *gpucg_parent(struct gpucg *cg);
+
+/**
+ * gpucg_charge - charge memory to the specified gpucg and gpucg_bucket.
+ * Caller must hold a reference to @gpucg obtained through gpucg_get(). The size of the memory is
+ * rounded up to be a multiple of the page size.
+ *
+ * @gpucg: The gpu cgroup to charge the memory to.
+ * @bucket: The bucket to charge the memory to.
+ * @size: The size of memory to charge in bytes.
+ * This size will be rounded up to the nearest page size.
+ *
+ * Return: returns 0 if the charging is successful and otherwise returns an error code.
+ */
+int gpucg_charge(struct gpucg *gpucg, struct gpucg_bucket *bucket, u64 size);
+
+/**
+ * gpucg_uncharge - uncharge memory from the specified gpucg and gpucg_bucket.
+ * The caller must hold a reference to @gpucg obtained through gpucg_get().
+ *
+ * @gpucg: The gpu cgroup to uncharge the memory from.
+ * @bucket: The bucket to uncharge the memory from.
+ * @size: The size of memory to uncharge in bytes.
+ * This size will be rounded up to the nearest page size.
+ */
+void gpucg_uncharge(struct gpucg *gpucg, struct gpucg_bucket *bucket, u64 size);
+
+/**
+ * gpucg_register_bucket - Registers a bucket for memory accounting using the GPU cgroup controller.
+ *
+ * @name: Pointer to a null-terminated string to denote the name of the bucket. This name should be
+ * globally unique, and should not exceed @GPUCG_BUCKET_NAME_MAX_LEN bytes.
+ *
+ * @bucket must remain valid. @name will be copied.
+ *
+ * Returns a pointer to a newly allocated bucket on success, or an errno code otherwise. As buckets
+ * cannot be unregistered, this can never be freed.
+ */
+struct gpucg_bucket *gpucg_register_bucket(const char *name);
+#else /* CONFIG_CGROUP_GPU */
+
+static inline struct gpucg *css_to_gpucg(struct cgroup_subsys_state *css)
+{
+ return NULL;
+}
+
+static inline struct gpucg *gpucg_get(struct task_struct *task)
+{
+ return NULL;
+}
+
+static inline void gpucg_put(struct gpucg *gpucg) {}
+
+static inline struct gpucg *gpucg_parent(struct gpucg *cg)
+{
+ return NULL;
+}
+
+static inline int gpucg_charge(struct gpucg *gpucg,
+ struct gpucg_bucket *bucket,
+ u64 size)
+{
+ return 0;
+}
+
+static inline void gpucg_uncharge(struct gpucg *gpucg,
+ struct gpucg_bucket *bucket,
+ u64 size) {}
+
+static inline struct gpucg_bucket *gpucg_register_bucket(const char *name) {}
+#endif /* CONFIG_CGROUP_GPU */
+#endif /* _CGROUP_GPU_H */
diff --git a/include/linux/cgroup_subsys.h b/include/linux/cgroup_subsys.h
index 445235487230..46a2a7b93c41 100644
--- a/include/linux/cgroup_subsys.h
+++ b/include/linux/cgroup_subsys.h
@@ -65,6 +65,10 @@ SUBSYS(rdma)
SUBSYS(misc)
#endif
+#if IS_ENABLED(CONFIG_CGROUP_GPU)
+SUBSYS(gpu)
+#endif
+
/*
* The following subsystems are not supported on the default hierarchy.
*/
diff --git a/init/Kconfig b/init/Kconfig
index ddcbefe535e9..2e00a190e170 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -984,6 +984,13 @@ config BLK_CGROUP
See Documentation/admin-guide/cgroup-v1/blkio-controller.rst for more information.
+config CGROUP_GPU
+ bool "GPU controller (EXPERIMENTAL)"
+ select PAGE_COUNTER
+ help
+ Provides accounting and limit setting for memory allocations by the GPU and
+ GPU-related subsystems.
+
config CGROUP_WRITEBACK
bool
depends on MEMCG && BLK_CGROUP
diff --git a/kernel/cgroup/Makefile b/kernel/cgroup/Makefile
index 12f8457ad1f9..be95a5a532fc 100644
--- a/kernel/cgroup/Makefile
+++ b/kernel/cgroup/Makefile
@@ -7,3 +7,4 @@ obj-$(CONFIG_CGROUP_RDMA) += rdma.o
obj-$(CONFIG_CPUSETS) += cpuset.o
obj-$(CONFIG_CGROUP_MISC) += misc.o
obj-$(CONFIG_CGROUP_DEBUG) += debug.o
+obj-$(CONFIG_CGROUP_GPU) += gpu.o
diff --git a/kernel/cgroup/gpu.c b/kernel/cgroup/gpu.c
new file mode 100644
index 000000000000..ad16ea15d427
--- /dev/null
+++ b/kernel/cgroup/gpu.c
@@ -0,0 +1,339 @@
+// SPDX-License-Identifier: MIT
+// Copyright 2019 Advanced Micro Devices, Inc.
+// Copyright (C) 2022 Google LLC.
+
+#include <linux/cgroup.h>
+#include <linux/cgroup_gpu.h>
+#include <linux/err.h>
+#include <linux/gfp.h>
+#include <linux/list.h>
+#include <linux/mm.h>
+#include <linux/page_counter.h>
+#include <linux/seq_file.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+
+static struct gpucg *root_gpucg __read_mostly;
+
+/*
+ * Protects list of resource pools maintained on per cgroup basis and list
+ * of buckets registered for memory accounting using the GPU cgroup controller.
+ */
+static DEFINE_MUTEX(gpucg_mutex);
+static LIST_HEAD(gpucg_buckets);
+
+/* The GPU cgroup controller data structure */
+struct gpucg {
+ struct cgroup_subsys_state css;
+
+ /* list of all resource pools that belong to this cgroup */
+ struct list_head rpools;
+};
+
+/* A named entity representing bucket of tracked memory. */
+struct gpucg_bucket {
+ /* list of various resource pools in various cgroups that the bucket is part of */
+ struct list_head rpools;
+
+ /* list of all buckets registered for GPU cgroup accounting */
+ struct list_head bucket_node;
+
+ /* string to be used as identifier for accounting and limit setting */
+ const char *name;
+};
+
+struct gpucg_resource_pool {
+ /* The bucket whose resource usage is tracked by this resource pool */
+ struct gpucg_bucket *bucket;
+
+ /* list of all resource pools for the cgroup */
+ struct list_head cg_node;
+
+ /* list maintained by the gpucg_bucket to keep track of its resource pools */
+ struct list_head bucket_node;
+
+ /* tracks memory usage of the resource pool */
+ struct page_counter total;
+};
+
+static void free_cg_rpool_locked(struct gpucg_resource_pool *rpool)
+{
+ lockdep_assert_held(&gpucg_mutex);
+
+ list_del(&rpool->cg_node);
+ list_del(&rpool->bucket_node);
+ kfree(rpool);
+}
+
+static void gpucg_css_free(struct cgroup_subsys_state *css)
+{
+ struct gpucg_resource_pool *rpool, *tmp;
+ struct gpucg *gpucg = css_to_gpucg(css);
+
+ // delete all resource pools
+ mutex_lock(&gpucg_mutex);
+ list_for_each_entry_safe(rpool, tmp, &gpucg->rpools, cg_node)
+ free_cg_rpool_locked(rpool);
+ mutex_unlock(&gpucg_mutex);
+
+ kfree(gpucg);
+}
+
+static struct cgroup_subsys_state *
+gpucg_css_alloc(struct cgroup_subsys_state *parent_css)
+{
+ struct gpucg *gpucg, *parent;
+
+ gpucg = kzalloc(sizeof(struct gpucg), GFP_KERNEL);
+ if (!gpucg)
+ return ERR_PTR(-ENOMEM);
+
+ parent = css_to_gpucg(parent_css);
+ if (!parent)
+ root_gpucg = gpucg;
+
+ INIT_LIST_HEAD(&gpucg->rpools);
+
+ return &gpucg->css;
+}
+
+static struct gpucg_resource_pool *cg_rpool_find_locked(
+ struct gpucg *cg,
+ struct gpucg_bucket *bucket)
+{
+ struct gpucg_resource_pool *rpool;
+
+ lockdep_assert_held(&gpucg_mutex);
+
+ list_for_each_entry(rpool, &cg->rpools, cg_node)
+ if (rpool->bucket == bucket)
+ return rpool;
+
+ return NULL;
+}
+
+static struct gpucg_resource_pool *cg_rpool_init(struct gpucg *cg,
+ struct gpucg_bucket *bucket)
+{
+ struct gpucg_resource_pool *rpool = kzalloc(sizeof(*rpool),
+ GFP_KERNEL);
+ if (!rpool)
+ return ERR_PTR(-ENOMEM);
+
+ rpool->bucket = bucket;
+
+ page_counter_init(&rpool->total, NULL);
+ INIT_LIST_HEAD(&rpool->cg_node);
+ INIT_LIST_HEAD(&rpool->bucket_node);
+ list_add_tail(&rpool->cg_node, &cg->rpools);
+ list_add_tail(&rpool->bucket_node, &bucket->rpools);
+
+ return rpool;
+}
+
+/**
+ * get_cg_rpool_locked - find the resource pool for the specified bucket and
+ * specified cgroup. If the resource pool does not exist for the cg, it is
+ * created in a hierarchical manner in the cgroup and its ancestor cgroups who
+ * do not already have a resource pool entry for the bucket.
+ *
+ * @cg: The cgroup to find the resource pool for.
+ * @bucket: The bucket associated with the returned resource pool.
+ *
+ * Return: return resource pool entry corresponding to the specified bucket in
+ * the specified cgroup (hierarchically creating them if not existing already).
+ *
+ */
+static struct gpucg_resource_pool *
+cg_rpool_get_locked(struct gpucg *cg, struct gpucg_bucket *bucket)
+{
+ struct gpucg *parent_cg, *p, *stop_cg;
+ struct gpucg_resource_pool *rpool, *tmp_rpool;
+ struct gpucg_resource_pool *parent_rpool = NULL, *leaf_rpool = NULL;
+
+ rpool = cg_rpool_find_locked(cg, bucket);
+ if (rpool)
+ return rpool;
+
+ stop_cg = cg;
+ do {
+ rpool = cg_rpool_init(stop_cg, bucket);
+ if (IS_ERR(rpool))
+ goto err;
+
+ if (!leaf_rpool)
+ leaf_rpool = rpool;
+
+ stop_cg = gpucg_parent(stop_cg);
+ if (!stop_cg)
+ break;
+
+ rpool = cg_rpool_find_locked(stop_cg, bucket);
+ } while (!rpool);
+
+ /*
+ * Re-initialize page counters of all rpools created in this invocation
+ * to enable hierarchical charging.
+ * stop_cg is the first ancestor cg who already had a resource pool for
+ * the bucket. It can also be NULL if no ancestors had a pre-existing
+ * resource pool for the bucket before this invocation.
+ */
+ rpool = leaf_rpool;
+ for (p = cg; p != stop_cg; p = parent_cg) {
+ parent_cg = gpucg_parent(p);
+ if (!parent_cg)
+ break;
+ parent_rpool = cg_rpool_find_locked(parent_cg, bucket);
+ page_counter_init(&rpool->total, &parent_rpool->total);
+
+ rpool = parent_rpool;
+ }
+
+ return leaf_rpool;
+err:
+ for (p = cg; p != stop_cg; p = gpucg_parent(p)) {
+ tmp_rpool = cg_rpool_find_locked(p, bucket);
+ free_cg_rpool_locked(tmp_rpool);
+ }
+ return rpool;
+}
+
+struct gpucg *css_to_gpucg(struct cgroup_subsys_state *css)
+{
+ return css ? container_of(css, struct gpucg, css) : NULL;
+}
+
+struct gpucg *gpucg_get(struct task_struct *task)
+{
+ if (!cgroup_subsys_enabled(gpu_cgrp_subsys))
+ return NULL;
+ return css_to_gpucg(task_get_css(task, gpu_cgrp_id));
+}
+
+void gpucg_put(struct gpucg *gpucg)
+{
+ if (gpucg)
+ css_put(&gpucg->css);
+}
+
+struct gpucg *gpucg_parent(struct gpucg *cg)
+{
+ return css_to_gpucg(cg->css.parent);
+}
+
+int gpucg_charge(struct gpucg *gpucg, struct gpucg_bucket *bucket, u64 size)
+{
+ struct page_counter *counter;
+ u64 nr_pages;
+ struct gpucg_resource_pool *rp;
+ int ret = 0;
+
+ nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
+
+ mutex_lock(&gpucg_mutex);
+ rp = cg_rpool_get_locked(gpucg, bucket);
+ /*
+ * Continue to hold gpucg_mutex because we use it to block charges while transfers are in
+ * progress to avoid potentially exceeding a limit.
+ */
+ if (IS_ERR(rp)) {
+ mutex_unlock(&gpucg_mutex);
+ return PTR_ERR(rp);
+ }
+
+ if (page_counter_try_charge(&rp->total, nr_pages, &counter))
+ css_get(&gpucg->css);
+ else
+ ret = -ENOMEM;
+ mutex_unlock(&gpucg_mutex);
+
+ return ret;
+}
+
+void gpucg_uncharge(struct gpucg *gpucg, struct gpucg_bucket *bucket, u64 size)
+{
+ u64 nr_pages;
+ struct gpucg_resource_pool *rp;
+
+ mutex_lock(&gpucg_mutex);
+ rp = cg_rpool_find_locked(gpucg, bucket);
+ /*
+ * gpucg_mutex can be unlocked here, rp will stay valid until gpucg is freed and there are
+ * active refs on gpucg. Uncharges are fine while transfers are in progress since there is
+ * no potential to exceed a limit while uncharging and transferring.
+ */
+ mutex_unlock(&gpucg_mutex);
+
+ if (unlikely(!rp)) {
+ pr_err("Resource pool not found, incorrect charge/uncharge ordering?\n");
+ return;
+ }
+
+ nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
+ page_counter_uncharge(&rp->total, nr_pages);
+ css_put(&gpucg->css);
+}
+
+struct gpucg_bucket *gpucg_register_bucket(const char *name)
+{
+ struct gpucg_bucket *bucket, *b;
+
+ if (!name)
+ return ERR_PTR(-EINVAL);
+
+ if (strlen(name) >= GPUCG_BUCKET_NAME_MAX_LEN)
+ return ERR_PTR(-ENAMETOOLONG);
+
+ bucket = kzalloc(sizeof(struct gpucg_bucket), GFP_KERNEL);
+ if (!bucket)
+ return ERR_PTR(-ENOMEM);
+
+ INIT_LIST_HEAD(&bucket->bucket_node);
+ INIT_LIST_HEAD(&bucket->rpools);
+ bucket->name = kstrdup_const(name, GFP_KERNEL);
+
+ mutex_lock(&gpucg_mutex);
+ list_for_each_entry(b, &gpucg_buckets, bucket_node) {
+ if (strncmp(b->name, bucket->name, GPUCG_BUCKET_NAME_MAX_LEN) == 0) {
+ mutex_unlock(&gpucg_mutex);
+ kfree_const(bucket->name);
+ kfree(bucket);
+ return ERR_PTR(-EEXIST);
+ }
+ }
+ list_add_tail(&bucket->bucket_node, &gpucg_buckets);
+ mutex_unlock(&gpucg_mutex);
+
+ return bucket;
+}
+
+static int gpucg_resource_show(struct seq_file *sf, void *v)
+{
+ struct gpucg_resource_pool *rpool;
+ struct gpucg *cg = css_to_gpucg(seq_css(sf));
+
+ mutex_lock(&gpucg_mutex);
+ list_for_each_entry(rpool, &cg->rpools, cg_node) {
+ seq_printf(sf, "%s %lu\n", rpool->bucket->name,
+ page_counter_read(&rpool->total) * PAGE_SIZE);
+ }
+ mutex_unlock(&gpucg_mutex);
+
+ return 0;
+}
+
+struct cftype files[] = {
+ {
+ .name = "memory.current",
+ .seq_show = gpucg_resource_show,
+ },
+ { } /* terminate */
+};
+
+struct cgroup_subsys gpu_cgrp_subsys = {
+ .css_alloc = gpucg_css_alloc,
+ .css_free = gpucg_css_free,
+ .early_init = false,
+ .legacy_cftypes = files,
+ .dfl_cftypes = files,
+};
--
2.36.0.512.ge40c2bad7a-goog
^ permalink raw reply related [flat|nested] 21+ messages in thread* [PATCH v7 4/6] dmabuf: Add gpu cgroup charge transfer function
[not found] ` <20220510235653.933868-1-tjmercier-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2022-05-10 23:56 ` [PATCH v7 2/6] cgroup: gpu: Add a cgroup controller for allocator attribution of GPU memory T.J. Mercier
@ 2022-05-10 23:56 ` T.J. Mercier
1 sibling, 0 replies; 21+ messages in thread
From: T.J. Mercier @ 2022-05-10 23:56 UTC (permalink / raw)
To: tjmercier-hpIqsD4AKlfQT0dZR+AlfA, Sumit Semwal,
Christian König, Tejun Heo, Zefan Li, Johannes Weiner
Cc: daniel-/w4YWyX8dFk, hridya-hpIqsD4AKlfQT0dZR+AlfA,
jstultz-hpIqsD4AKlfQT0dZR+AlfA, tkjos-z5hGa2qSFaRBDgjK7y7TUQ,
cmllamas-hpIqsD4AKlfQT0dZR+AlfA, surenb-hpIqsD4AKlfQT0dZR+AlfA,
kaleshsingh-hpIqsD4AKlfQT0dZR+AlfA, Kenny.Ho-5C7GfCeVMHo,
mkoutny-IBi9RG/b67k, skhan-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r,
kernel-team-z5hGa2qSFaRBDgjK7y7TUQ,
linux-media-u79uwXL29TY76Z2rM5mHXA,
dri-devel-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW,
linaro-mm-sig-cunTk1MwBs8s++Sfvej+rw,
linux-kernel-u79uwXL29TY76Z2rM5mHXA,
cgroups-u79uwXL29TY76Z2rM5mHXA
The dma_buf_transfer_charge function provides a way for processes to
transfer charge of a buffer to a different process. This is essential
for the cases where a central allocator process does allocations for
various subsystems, hands over the fd to the client who requested the
memory and drops all references to the allocated memory.
Originally-by: Hridya Valsaraju <hridya-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
Signed-off-by: T.J. Mercier <tjmercier-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
---
v5 changes
Fix commit message which still contained the old name for
dma_buf_transfer_charge per Michal Koutný.
Modify the dma_buf_transfer_charge API to accept a task_struct instead
of a gpucg. This avoids requiring the caller to manage the refcount
of the gpucg upon failure and confusing ownership transfer logic.
v4 changes
Adjust ordering of charge/uncharge during transfer to avoid potentially
hitting cgroup limit per Michal Koutný.
v3 changes
Use more common dual author commit message format per John Stultz.
v2 changes
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.
---
drivers/dma-buf/dma-buf.c | 57 ++++++++++++++++++++++++++++++++++++++
include/linux/cgroup_gpu.h | 24 ++++++++++++++++
include/linux/dma-buf.h | 6 ++++
kernel/cgroup/gpu.c | 51 ++++++++++++++++++++++++++++++++++
4 files changed, 138 insertions(+)
diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
index bc89c44bd9b9..f3fb844925e2 100644
--- a/drivers/dma-buf/dma-buf.c
+++ b/drivers/dma-buf/dma-buf.c
@@ -1341,6 +1341,63 @@ void dma_buf_vunmap(struct dma_buf *dmabuf, struct iosys_map *map)
}
EXPORT_SYMBOL_NS_GPL(dma_buf_vunmap, DMA_BUF);
+/**
+ * dma_buf_transfer_charge - Change the GPU cgroup to which the provided dma_buf is charged.
+ * @dmabuf: [in] buffer whose charge will be migrated to a different GPU cgroup
+ * @target: [in] the task_struct of the destination process for the GPU cgroup charge
+ *
+ * Only tasks that belong to the same cgroup the buffer is currently charged to
+ * may call this function, otherwise it will return -EPERM.
+ *
+ * Returns 0 on success, or a negative errno code otherwise.
+ */
+int dma_buf_transfer_charge(struct dma_buf *dmabuf, struct task_struct *target)
+{
+ struct gpucg *current_gpucg, *target_gpucg, *to_release;
+ int ret;
+
+ if (!dmabuf->gpucg || !dmabuf->gpucg_bucket) {
+ /* This dmabuf is not tracked under GPU cgroup accounting */
+ return 0;
+ }
+
+ current_gpucg = gpucg_get(current);
+ target_gpucg = gpucg_get(target);
+ to_release = target_gpucg;
+
+ /* If the source and destination cgroups are the same, don't do anything. */
+ if (current_gpucg == target_gpucg) {
+ ret = 0;
+ goto skip_transfer;
+ }
+
+ /*
+ * Verify that the cgroup of the process requesting the transfer
+ * is the same as the one the buffer is currently charged to.
+ */
+ mutex_lock(&dmabuf->lock);
+ if (current_gpucg != dmabuf->gpucg) {
+ ret = -EPERM;
+ goto err;
+ }
+
+ ret = gpucg_transfer_charge(
+ dmabuf->gpucg, target_gpucg, dmabuf->gpucg_bucket, dmabuf->size);
+ if (ret)
+ goto err;
+
+ to_release = dmabuf->gpucg;
+ dmabuf->gpucg = target_gpucg;
+
+err:
+ mutex_unlock(&dmabuf->lock);
+skip_transfer:
+ gpucg_put(current_gpucg);
+ gpucg_put(to_release);
+ return ret;
+}
+EXPORT_SYMBOL_NS_GPL(dma_buf_transfer_charge, DMA_BUF);
+
#ifdef CONFIG_DEBUG_FS
static int dma_buf_debug_show(struct seq_file *s, void *unused)
{
diff --git a/include/linux/cgroup_gpu.h b/include/linux/cgroup_gpu.h
index cb228a16aa1f..7eb68f1507fb 100644
--- a/include/linux/cgroup_gpu.h
+++ b/include/linux/cgroup_gpu.h
@@ -75,6 +75,22 @@ int gpucg_charge(struct gpucg *gpucg, struct gpucg_bucket *bucket, u64 size);
*/
void gpucg_uncharge(struct gpucg *gpucg, struct gpucg_bucket *bucket, u64 size);
+/**
+ * gpucg_transfer_charge - Transfer a GPU charge from one cgroup to another.
+ *
+ * @source: [in] The GPU cgroup the charge will be transferred from.
+ * @dest: [in] The GPU cgroup the charge will be transferred to.
+ * @bucket: [in] The GPU cgroup bucket corresponding to the charge.
+ * @size: [in] The size of the memory in bytes.
+ * This size will be rounded up to the nearest page size.
+ *
+ * Returns 0 on success, or a negative errno code otherwise.
+ */
+int gpucg_transfer_charge(struct gpucg *source,
+ struct gpucg *dest,
+ struct gpucg_bucket *bucket,
+ u64 size);
+
/**
* gpucg_register_bucket - Registers a bucket for memory accounting using the GPU cgroup controller.
*
@@ -117,6 +133,14 @@ static inline void gpucg_uncharge(struct gpucg *gpucg,
struct gpucg_bucket *bucket,
u64 size) {}
+static inline int gpucg_transfer_charge(struct gpucg *source,
+ struct gpucg *dest,
+ struct gpucg_bucket *bucket,
+ u64 size)
+{
+ return 0;
+}
+
static inline struct gpucg_bucket *gpucg_register_bucket(const char *name) {}
#endif /* CONFIG_CGROUP_GPU */
#endif /* _CGROUP_GPU_H */
diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h
index 8e7c55c830b3..438ad8577b76 100644
--- a/include/linux/dma-buf.h
+++ b/include/linux/dma-buf.h
@@ -18,6 +18,7 @@
#include <linux/file.h>
#include <linux/err.h>
#include <linux/scatterlist.h>
+#include <linux/sched.h>
#include <linux/list.h>
#include <linux/dma-mapping.h>
#include <linux/fs.h>
@@ -650,9 +651,14 @@ void dma_buf_vunmap(struct dma_buf *dmabuf, struct iosys_map *map);
void dma_buf_exp_info_set_gpucg(struct dma_buf_export_info *exp_info,
struct gpucg *gpucg,
struct gpucg_bucket *gpucg_bucket);
+
+int dma_buf_transfer_charge(struct dma_buf *dmabuf, struct task_struct *target);
#else/* CONFIG_CGROUP_GPU */
static inline void dma_buf_exp_info_set_gpucg(struct dma_buf_export_info *exp_info,
struct gpucg *gpucg,
struct gpucg_bucket *gpucg_bucket) {}
+
+static inline int dma_buf_transfer_charge(struct dma_buf *dmabuf, struct task_struct *target)
+{ return 0; }
#endif /* CONFIG_CGROUP_GPU */
#endif /* __DMA_BUF_H__ */
diff --git a/kernel/cgroup/gpu.c b/kernel/cgroup/gpu.c
index ad16ea15d427..038ea873a9d3 100644
--- a/kernel/cgroup/gpu.c
+++ b/kernel/cgroup/gpu.c
@@ -274,6 +274,57 @@ void gpucg_uncharge(struct gpucg *gpucg, struct gpucg_bucket *bucket, u64 size)
css_put(&gpucg->css);
}
+int gpucg_transfer_charge(struct gpucg *source,
+ struct gpucg *dest,
+ struct gpucg_bucket *bucket,
+ u64 size)
+{
+ struct page_counter *counter;
+ u64 nr_pages;
+ struct gpucg_resource_pool *rp_source, *rp_dest;
+ int ret = 0;
+
+ nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
+
+ mutex_lock(&gpucg_mutex);
+ rp_source = cg_rpool_find_locked(source, bucket);
+ if (unlikely(!rp_source)) {
+ ret = -ENOENT;
+ goto exit_early;
+ }
+
+ rp_dest = cg_rpool_get_locked(dest, bucket);
+ if (IS_ERR(rp_dest)) {
+ ret = PTR_ERR(rp_dest);
+ goto exit_early;
+ }
+
+ /*
+ * First uncharge from the pool it's currently charged to. This ordering avoids double
+ * charging while the transfer is in progress, which could cause us to hit a limit.
+ * If the try_charge fails for this transfer, we need to be able to reverse this uncharge,
+ * so we continue to hold the gpucg_mutex here.
+ */
+ page_counter_uncharge(&rp_source->total, nr_pages);
+ css_put(&source->css);
+
+ /* Now attempt the new charge */
+ if (page_counter_try_charge(&rp_dest->total, nr_pages, &counter)) {
+ css_get(&dest->css);
+ } else {
+ /*
+ * The new charge failed, so reverse the uncharge from above. This should always
+ * succeed since charges on source are blocked by gpucg_mutex.
+ */
+ WARN_ON(!page_counter_try_charge(&rp_source->total, nr_pages, &counter));
+ css_get(&source->css);
+ ret = -ENOMEM;
+ }
+exit_early:
+ mutex_unlock(&gpucg_mutex);
+ return ret;
+}
+
struct gpucg_bucket *gpucg_register_bucket(const char *name)
{
struct gpucg_bucket *bucket, *b;
--
2.36.0.512.ge40c2bad7a-goog
^ permalink raw reply related [flat|nested] 21+ messages in thread
* Re: [PATCH v7 0/6] Proposal for a GPU cgroup controller
2022-05-10 23:56 [PATCH v7 0/6] Proposal for a GPU cgroup controller T.J. Mercier
2022-05-10 23:56 ` [PATCH v7 1/6] gpu: rfc: " T.J. Mercier
[not found] ` <20220510235653.933868-1-tjmercier-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
@ 2022-05-11 13:21 ` Nicolas Dufresne
2022-05-11 20:31 ` T.J. Mercier
2022-05-19 9:30 ` [PATCH v7 1/6] gpu: rfc: " eballetbo
2022-05-19 10:52 ` [PATCH v7 2/6] cgroup: gpu: Add a cgroup controller for allocator attribution of GPU memory eballetbo
4 siblings, 1 reply; 21+ messages in thread
From: Nicolas Dufresne @ 2022-05-11 13:21 UTC (permalink / raw)
To: T.J. Mercier, Tejun Heo, Zefan Li, Johannes Weiner,
Jonathan Corbet, Greg Kroah-Hartman, Arve Hjønnevåg,
Todd Kjos, Martijn Coenen, Joel Fernandes, Christian Brauner,
Hridya Valsaraju, Suren Baghdasaryan, Sumit Semwal,
Christian König, Benjamin Gaignard, Liam Mark, Laura Abbott,
Brian Starkey
Cc: daniel, jstultz, cmllamas, kaleshsingh, Kenny.Ho, mkoutny, skhan,
kernel-team, cgroups, linux-doc, linux-kernel, linux-media,
dri-devel, linaro-mm-sig, linux-kselftest
Hi,
Le mardi 10 mai 2022 à 23:56 +0000, T.J. Mercier a écrit :
> 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.
I'm sorry, since I'm not in-depth technically involve. But from reading the
topic I don't understand the bound this creates between DMABuf Heaps and GPU. Is
this an attempt to really track the DMABuf allocated by userland, or just
something for GPU ? What about V4L2 devices ? Any way this can be clarified,
specially what would other subsystem needs to have cgroup DMABuf allocation
controller support ?
>
> Changelog:
> v7:
> Hide gpucg and gpucg_bucket struct definitions per Michal Koutný.
> This means gpucg_register_bucket now returns an internally allocated
> struct gpucg_bucket.
>
> Move all public function documentation to the cgroup_gpu.h header.
>
> Remove comment in documentation about duplicate name rejection which
> is not relevant to cgroups users per Michal Koutný.
>
> v6:
> Move documentation into cgroup-v2.rst per Tejun Heo.
>
> Rename BINDER_FD{A}_FLAG_SENDER_NO_NEED ->
> BINDER_FD{A}_FLAG_XFER_CHARGE per Carlos Llamas.
>
> Return error on transfer failure per Carlos Llamas.
>
> v5:
> Rebase on top of v5.18-rc3
>
> Drop the global GPU cgroup "total" (sum of all device totals) portion
> of the design since there is no currently known use for this per
> Tejun Heo.
>
> Fix commit message which still contained the old name for
> dma_buf_transfer_charge per Michal Koutný.
>
> Remove all GPU cgroup code except what's necessary to support charge transfer
> from dma_buf. Previously charging was done in export, but for non-Android
> graphics use-cases this is not ideal since there may be a delay between
> allocation and export, during which time there is no accounting.
>
> Merge dmabuf: Use the GPU cgroup charge/uncharge APIs patch into
> dmabuf: heaps: export system_heap buffers with GPU cgroup charging as a
> result of above.
>
> Put the charge and uncharge code in the same file (system_heap_allocate,
> system_heap_dma_buf_release) instead of splitting them between the heap and
> the dma_buf_release. This avoids asymmetric management of the gpucg charges.
>
> Modify the dma_buf_transfer_charge API to accept a task_struct instead
> of a gpucg. This avoids requiring the caller to manage the refcount
> of the gpucg upon failure and confusing ownership transfer logic.
>
> Support all strings for gpucg_register_bucket instead of just string
> literals.
>
> Enforce globally unique gpucg_bucket names.
>
> Constrain gpucg_bucket name lengths to 64 bytes.
>
> Append "-heap" to gpucg_bucket names from dmabuf-heaps.
>
> Drop patch 7 from the series, which changed the types of
> binder_transaction_data's sender_pid and sender_euid fields. This was
> done in another commit here:
> https://lore.kernel.org/all/20220210021129.3386083-4-masahiroy@kernel.org/
>
> Rename:
> gpucg_try_charge -> gpucg_charge
> find_cg_rpool_locked -> cg_rpool_find_locked
> init_cg_rpool -> cg_rpool_init
> get_cg_rpool_locked -> cg_rpool_get_locked
> "gpu cgroup controller" -> "GPU controller"
> gpucg_device -> gpucg_bucket
> usage -> size
>
> Tests:
> Support both binder_fd_array_object and binder_fd_object. This is
> necessary because new versions of Android will use binder_fd_object
> instead of binder_fd_array_object, and we need to support both.
>
> Tests for both binder_fd_array_object and binder_fd_object.
>
> For binder_utils return error codes instead of
> struct binder{fs}_ctx.
>
> Use ifdef __ANDROID__ to choose platform-dependent temp path instead
> of a runtime fallback.
>
> Ensure binderfs_mntpt ends with a trailing '/' character instead of
> prepending it where used.
>
> v4:
> Skip test if not run as root per Shuah Khan
>
> Add better test logging for abnormal child termination per Shuah Khan
>
> Adjust ordering of charge/uncharge during transfer to avoid potentially
> hitting cgroup limit per Michal Koutný
>
> Adjust gpucg_try_charge critical section for charge transfer functionality
>
> Fix uninitialized return code error for dmabuf_try_charge error case
>
> 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-brian.welty@intel.com/#22624705
> [2]: https://lore.kernel.org/amd-gfx/20210126214626.16260-1-brian.welty@intel.com/
> [3]: https://lore.kernel.org/amd-gfx/YCVOl8%2F87bqRSQei@phenom.ffwll.local/
>
> Hridya Valsaraju (3):
> gpu: rfc: Proposal for a GPU cgroup controller
> cgroup: gpu: Add a cgroup controller for allocator attribution of GPU
> memory
> binder: Add flags to relinquish ownership of fds
>
> T.J. Mercier (3):
> dmabuf: heaps: export system_heap buffers with GPU cgroup charging
> dmabuf: Add gpu cgroup charge transfer function
> selftests: Add binder cgroup gpu memory transfer tests
>
> Documentation/admin-guide/cgroup-v2.rst | 23 +
> drivers/android/binder.c | 31 +-
> drivers/dma-buf/dma-buf.c | 80 ++-
> drivers/dma-buf/dma-heap.c | 38 ++
> drivers/dma-buf/heaps/system_heap.c | 28 +-
> include/linux/cgroup_gpu.h | 146 +++++
> include/linux/cgroup_subsys.h | 4 +
> include/linux/dma-buf.h | 49 +-
> include/linux/dma-heap.h | 15 +
> include/uapi/linux/android/binder.h | 23 +-
> init/Kconfig | 7 +
> kernel/cgroup/Makefile | 1 +
> kernel/cgroup/gpu.c | 390 +++++++++++++
> .../selftests/drivers/android/binder/Makefile | 8 +
> .../drivers/android/binder/binder_util.c | 250 +++++++++
> .../drivers/android/binder/binder_util.h | 32 ++
> .../selftests/drivers/android/binder/config | 4 +
> .../binder/test_dmabuf_cgroup_transfer.c | 526 ++++++++++++++++++
> 18 files changed, 1632 insertions(+), 23 deletions(-)
> 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
>
^ permalink raw reply [flat|nested] 21+ messages in thread* Re: [PATCH v7 0/6] Proposal for a GPU cgroup controller
2022-05-11 13:21 ` [PATCH v7 0/6] Proposal for a GPU cgroup controller Nicolas Dufresne
@ 2022-05-11 20:31 ` T.J. Mercier
[not found] ` <CABdmKX3ZV6-u-oLvW_wWavAMBfrsZ=C_rCgK_Uz4VjxcRvRFew-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
0 siblings, 1 reply; 21+ messages in thread
From: T.J. Mercier @ 2022-05-11 20:31 UTC (permalink / raw)
To: Nicolas Dufresne
Cc: Tejun Heo, Zefan Li, Johannes Weiner, Jonathan Corbet,
Greg Kroah-Hartman, Arve Hjønnevåg, Todd Kjos,
Martijn Coenen, Joel Fernandes, Christian Brauner,
Hridya Valsaraju, Suren Baghdasaryan, Sumit Semwal,
Christian König, Benjamin Gaignard, Liam Mark, Laura Abbott,
Brian Starkey, John Stultz
On Wed, May 11, 2022 at 6:21 AM Nicolas Dufresne <nicolas@ndufresne.ca> wrote:
>
> Hi,
>
> Le mardi 10 mai 2022 à 23:56 +0000, T.J. Mercier a écrit :
> > 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.
>
> I'm sorry, since I'm not in-depth technically involve. But from reading the
> topic I don't understand the bound this creates between DMABuf Heaps and GPU. Is
> this an attempt to really track the DMABuf allocated by userland, or just
> something for GPU ? What about V4L2 devices ? Any way this can be clarified,
> specially what would other subsystem needs to have cgroup DMABuf allocation
> controller support ?
>
Hi Nicolas,
The link between dmabufs, dmabuf heaps, and "GPU memory" is maybe
somewhat of an Androidism. However this change aims to be usable for
tracking all GPU related allocations. It's just that this initial
series only adds support for tracking dmabufs allocated from dmabuf
heaps.
In Android most graphics buffers are dma buffers allocated from a
dmabuf heap, so that is why these dmabuf heap allocations are being
tracked under the GPU cgroup. Other dmabuf exporters like V4L2 might
also want to track their buffers, but would probably want to do so
under a bucket name of something like "v4l2". Same goes for GEM
dmabufs. The naming scheme for this is still yet to be decided. It
would be cool to be able to attribute memory at the driver level, or
even different types of memory at the driver level, but I imagine
there is a point of diminishing returns for fine-grained
naming/bucketing.
So far, I haven't tried to create a strict definition of what is and
is not "GPU memory" for the purpose of this accounting, so I don't
think we should be restricted to tracking just dmabufs. I don't see
why this couldn't be anything a driver wants to consider as GPU memory
as long as it is named/bucketed appropriately, such as both on-package
graphics card memory use and CPU memory dedicated for graphics use
like for host/device transfers.
Is that helpful?
Best,
T.J.
> >
> > Changelog:
> > v7:
> > Hide gpucg and gpucg_bucket struct definitions per Michal Koutný.
> > This means gpucg_register_bucket now returns an internally allocated
> > struct gpucg_bucket.
> >
> > Move all public function documentation to the cgroup_gpu.h header.
> >
> > Remove comment in documentation about duplicate name rejection which
> > is not relevant to cgroups users per Michal Koutný.
> >
> > v6:
> > Move documentation into cgroup-v2.rst per Tejun Heo.
> >
> > Rename BINDER_FD{A}_FLAG_SENDER_NO_NEED ->
> > BINDER_FD{A}_FLAG_XFER_CHARGE per Carlos Llamas.
> >
> > Return error on transfer failure per Carlos Llamas.
> >
> > v5:
> > Rebase on top of v5.18-rc3
> >
> > Drop the global GPU cgroup "total" (sum of all device totals) portion
> > of the design since there is no currently known use for this per
> > Tejun Heo.
> >
> > Fix commit message which still contained the old name for
> > dma_buf_transfer_charge per Michal Koutný.
> >
> > Remove all GPU cgroup code except what's necessary to support charge transfer
> > from dma_buf. Previously charging was done in export, but for non-Android
> > graphics use-cases this is not ideal since there may be a delay between
> > allocation and export, during which time there is no accounting.
> >
> > Merge dmabuf: Use the GPU cgroup charge/uncharge APIs patch into
> > dmabuf: heaps: export system_heap buffers with GPU cgroup charging as a
> > result of above.
> >
> > Put the charge and uncharge code in the same file (system_heap_allocate,
> > system_heap_dma_buf_release) instead of splitting them between the heap and
> > the dma_buf_release. This avoids asymmetric management of the gpucg charges.
> >
> > Modify the dma_buf_transfer_charge API to accept a task_struct instead
> > of a gpucg. This avoids requiring the caller to manage the refcount
> > of the gpucg upon failure and confusing ownership transfer logic.
> >
> > Support all strings for gpucg_register_bucket instead of just string
> > literals.
> >
> > Enforce globally unique gpucg_bucket names.
> >
> > Constrain gpucg_bucket name lengths to 64 bytes.
> >
> > Append "-heap" to gpucg_bucket names from dmabuf-heaps.
> >
> > Drop patch 7 from the series, which changed the types of
> > binder_transaction_data's sender_pid and sender_euid fields. This was
> > done in another commit here:
> > https://lore.kernel.org/all/20220210021129.3386083-4-masahiroy@kernel.org/
> >
> > Rename:
> > gpucg_try_charge -> gpucg_charge
> > find_cg_rpool_locked -> cg_rpool_find_locked
> > init_cg_rpool -> cg_rpool_init
> > get_cg_rpool_locked -> cg_rpool_get_locked
> > "gpu cgroup controller" -> "GPU controller"
> > gpucg_device -> gpucg_bucket
> > usage -> size
> >
> > Tests:
> > Support both binder_fd_array_object and binder_fd_object. This is
> > necessary because new versions of Android will use binder_fd_object
> > instead of binder_fd_array_object, and we need to support both.
> >
> > Tests for both binder_fd_array_object and binder_fd_object.
> >
> > For binder_utils return error codes instead of
> > struct binder{fs}_ctx.
> >
> > Use ifdef __ANDROID__ to choose platform-dependent temp path instead
> > of a runtime fallback.
> >
> > Ensure binderfs_mntpt ends with a trailing '/' character instead of
> > prepending it where used.
> >
> > v4:
> > Skip test if not run as root per Shuah Khan
> >
> > Add better test logging for abnormal child termination per Shuah Khan
> >
> > Adjust ordering of charge/uncharge during transfer to avoid potentially
> > hitting cgroup limit per Michal Koutný
> >
> > Adjust gpucg_try_charge critical section for charge transfer functionality
> >
> > Fix uninitialized return code error for dmabuf_try_charge error case
> >
> > 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-brian.welty@intel.com/#22624705
> > [2]: https://lore.kernel.org/amd-gfx/20210126214626.16260-1-brian.welty@intel.com/
> > [3]: https://lore.kernel.org/amd-gfx/YCVOl8%2F87bqRSQei@phenom.ffwll.local/
> >
> > Hridya Valsaraju (3):
> > gpu: rfc: Proposal for a GPU cgroup controller
> > cgroup: gpu: Add a cgroup controller for allocator attribution of GPU
> > memory
> > binder: Add flags to relinquish ownership of fds
> >
> > T.J. Mercier (3):
> > dmabuf: heaps: export system_heap buffers with GPU cgroup charging
> > dmabuf: Add gpu cgroup charge transfer function
> > selftests: Add binder cgroup gpu memory transfer tests
> >
> > Documentation/admin-guide/cgroup-v2.rst | 23 +
> > drivers/android/binder.c | 31 +-
> > drivers/dma-buf/dma-buf.c | 80 ++-
> > drivers/dma-buf/dma-heap.c | 38 ++
> > drivers/dma-buf/heaps/system_heap.c | 28 +-
> > include/linux/cgroup_gpu.h | 146 +++++
> > include/linux/cgroup_subsys.h | 4 +
> > include/linux/dma-buf.h | 49 +-
> > include/linux/dma-heap.h | 15 +
> > include/uapi/linux/android/binder.h | 23 +-
> > init/Kconfig | 7 +
> > kernel/cgroup/Makefile | 1 +
> > kernel/cgroup/gpu.c | 390 +++++++++++++
> > .../selftests/drivers/android/binder/Makefile | 8 +
> > .../drivers/android/binder/binder_util.c | 250 +++++++++
> > .../drivers/android/binder/binder_util.h | 32 ++
> > .../selftests/drivers/android/binder/config | 4 +
> > .../binder/test_dmabuf_cgroup_transfer.c | 526 ++++++++++++++++++
> > 18 files changed, 1632 insertions(+), 23 deletions(-)
> > 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
> >
>
^ permalink raw reply [flat|nested] 21+ messages in thread
* Re: [PATCH v7 1/6] gpu: rfc: Proposal for a GPU cgroup controller
2022-05-10 23:56 [PATCH v7 0/6] Proposal for a GPU cgroup controller T.J. Mercier
` (2 preceding siblings ...)
2022-05-11 13:21 ` [PATCH v7 0/6] Proposal for a GPU cgroup controller Nicolas Dufresne
@ 2022-05-19 9:30 ` eballetbo
[not found] ` <20220519093034.541481-1-eballetbo-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
2022-05-19 10:52 ` [PATCH v7 2/6] cgroup: gpu: Add a cgroup controller for allocator attribution of GPU memory eballetbo
4 siblings, 1 reply; 21+ messages in thread
From: eballetbo @ 2022-05-19 9:30 UTC (permalink / raw)
To: lizefan.x, corbet, joel, arve, tjmercier, maco, benjamin.gaignard,
tj, brauner, sumit.semwal, tkjos, surenb, hannes, Brian.Starkey,
christian.koenig, gregkh, lmark, john.stultz, hridya, shuah,
labbott
Cc: Enric Balletbo i Serra, cgroups, kernel-team, linux-media,
dri-devel, linaro-mm-sig, cmllamas, daniel, Kenny.Ho,
linux-kselftest, kaleshsingh, mkoutny, jstultz, linux-doc,
linux-kernel, skhan
From: Enric Balletbo i Serra <eballetbo@kernel.org>
On Tue, 10 May 2022 23:56:45 +0000, T.J. Mercier wrote:
> From: Hridya Valsaraju <hridya@google.com>
>
Hi T.J. Mercier,
Many thanks for this effort. It caught my attention because we might have a use
case where this feature can be useful for us. Hence I'd like to jump and be part
of the discussion, I'd really appreciate if you can cc'me for next versions.
While reading the full patchset I was a bit confused about the status of this
proposal. In fact, the rfc in the subject combined with the number of iterations
(already seven) confused me. So I'm wondering if this is a RFC or a 'real'
proposal already that you want to land.
If this is still a RFC I'd remove the 'rfc: Proposal' and use the more canonical
way that is put RFC in the []. I.e [PATCH RFC v7] cgroup: Add a GPU cgroup
controller.
If it is not, I'd just remove the RFC and make the subject in the cgroup
subsystem instead of the gpu. I.E [PATCH v7] cgroup: Add a GPU cgroup
I don't want to nitpick but IMO that helps new people to join to the history of
the patchset.
> This patch adds a proposal for a new GPU cgroup controller for
> accounting/limiting GPU and GPU-related memory allocations.
As far as I can see the only thing that is adding here is the accounting, so I'd
remove any reference to limiting and just explain what the patch really
introduces, not the future, otherwise is confusing an you expect more than the
patch really does.
It is important maintain the commit message sync with what the patch really
does.
> The proposed controller is based on the DRM cgroup controller[1] and
> follows the design of the RDMA cgroup controller.
>
> The new cgroup controller would:
> * Allow setting per-device limits on the total size of buffers
> allocated by device within a cgroup.
> * Expose a per-device/allocator breakdown of the buffers charged to a
> cgroup.
>
> The prototype in the following patches is only for memory accounting
> using the GPU cgroup controller and does not implement limit setting.
>
> [1]: https://lore.kernel.org/amd-gfx/20210126214626.16260-1-brian.welty@intel.com/
>
I think this is material for the cover more than the commit message. When I read
this I was expecting all this in this patch.
> Signed-off-by: Hridya Valsaraju <hridya@google.com>
> Signed-off-by: T.J. Mercier <tjmercier@google.com>
> ---
> v7 changes
> Remove comment about duplicate name rejection which is not relevant to
> cgroups users per Michal Koutný.
>
> v6 changes
> Move documentation into cgroup-v2.rst per Tejun Heo.
>
> v5 changes
> Drop the global GPU cgroup "total" (sum of all device totals) portion
> of the design since there is no currently known use for this per
> Tejun Heo.
>
> Update for renamed functions/variables.
>
> v3 changes
> Remove Upstreaming Plan from gpu-cgroup.rst per John Stultz.
>
> Use more common dual author commit message format per John Stultz.
> ---
> Documentation/admin-guide/cgroup-v2.rst | 23 +++++++++++++++++++++++
> 1 file changed, 23 insertions(+)
>
> diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst
> index 69d7a6983f78..2e1d26e327c7 100644
> --- a/Documentation/admin-guide/cgroup-v2.rst
> +++ b/Documentation/admin-guide/cgroup-v2.rst
> @@ -2352,6 +2352,29 @@ first, and stays charged to that cgroup until that resource is freed. Migrating
> a process to a different cgroup does not move the charge to the destination
> cgroup where the process has moved.
>
> +
> +GPU
> +---
> +
> +The GPU controller accounts for device and system memory allocated by the GPU
> +and related subsystems for graphics use. Resource limits are not currently
> +supported.
> +
> +GPU Interface Files
> +~~~~~~~~~~~~~~~~~~~~
> +
> + gpu.memory.current
> + A read-only file containing memory allocations in flat-keyed format. The key
> + is a string representing the device name. The value is the size of the memory
> + charged to the device in bytes. The device names are globally unique.::
> +
> + $ cat /sys/kernel/fs/cgroup1/gpu.memory.current
I think this is outdated, you are using cgroup v2, right?
> + dev1 4194304
> + dev2 104857600
> +
When I applied the full series I was expecting see the memory allocated by the
gpu devices or users of the gpu in this file but, after some experiments, what I
saw is the memory allocated via any process that uses the dma-buf heap API (not
necessary gpu users). For example, if you create a small program that allocates
some memory via the dma-buf heap API and then you cat the gpu.memory.current
file, you see that the memory accounted is not related to the gpu.
This is really confusing, looks to me that the patches evolved to account memory
that is not really related to the GPU but allocated vi the dma-buf heap API. IMO
the name of the file should be according to what really does to avoid
confusions.
So, is this patchset meant to be GPU specific? If the answer is yes that's good
but that's not what I experienced. I'm missing something?
If the answer is that evolved to track dma-buf heap allocations I think all the
patches need some rework to adapt the wording as right now, the gpu wording
seems confusing to me.
> + The device name string is set by a device driver when it registers with the
> + GPU cgroup controller to participate in resource accounting.
> +
> Others
> ------
>
>
Thanks,
Enric
^ permalink raw reply [flat|nested] 21+ messages in thread* Re: [PATCH v7 2/6] cgroup: gpu: Add a cgroup controller for allocator attribution of GPU memory
2022-05-10 23:56 [PATCH v7 0/6] Proposal for a GPU cgroup controller T.J. Mercier
` (3 preceding siblings ...)
2022-05-19 9:30 ` [PATCH v7 1/6] gpu: rfc: " eballetbo
@ 2022-05-19 10:52 ` eballetbo
2022-05-20 16:33 ` T.J. Mercier
4 siblings, 1 reply; 21+ messages in thread
From: eballetbo @ 2022-05-19 10:52 UTC (permalink / raw)
To: lizefan.x, corbet, joel, arve, tjmercier, maco, benjamin.gaignard,
tj, brauner, sumit.semwal, tkjos, surenb, hannes, Brian.Starkey,
christian.koenig, gregkh, lmark, john.stultz, hridya, shuah,
labbott
Cc: Enric Balletbo i Serra, cgroups, kernel-team, linux-media,
dri-devel, linaro-mm-sig, cmllamas, daniel, Kenny.Ho,
linux-kselftest, kaleshsingh, mkoutny, jstultz, linux-doc,
linux-kernel, skhan
From: Enric Balletbo i Serra <eballetbo@kernel.org>
On Tue, 10 May 2022 23:56:46 +0000, T.J. Mercier wrote
> From: Hridya Valsaraju <hridya@google.com>
>
> The cgroup controller provides accounting for GPU and GPU-related
> memory allocations. The memory being accounted can be device memory or
> memory allocated from pools dedicated to serve GPU-related tasks.
>
> This patch adds APIs to:
> -allow a device to register for memory accounting using the GPU cgroup
> controller.
> -charge and uncharge allocated memory to a cgroup.
>
> When the cgroup controller is enabled, it would expose information about
> the memory allocated by each device(registered for GPU cgroup memory
> accounting) for each cgroup.
>
> The API/UAPI can be extended to set per-device/total allocation limits
> in the future.
>
> The cgroup controller has been named following the discussion in [1].
>
> [1]: https://lore.kernel.org/amd-gfx/YCJp%2F%2FkMC7YjVMXv@phenom.ffwll.local/
>
> Signed-off-by: Hridya Valsaraju <hridya@google.com>
> Signed-off-by: T.J. Mercier <tjmercier@google.com>
> ---
> v7 changes
> Hide gpucg and gpucg_bucket struct definitions per Michal Koutný.
> This means gpucg_register_bucket now returns an internally allocated
> struct gpucg_bucket.
>
> Move all public function documentation to the cgroup_gpu.h header.
>
> v5 changes
> Support all strings for gpucg_register_device instead of just string
> literals.
>
> Enforce globally unique gpucg_bucket names.
>
> Constrain gpucg_bucket name lengths to 64 bytes.
>
> Obtain just a single css refcount instead of nr_pages for each
> charge.
>
> Rename:
> gpucg_try_charge -> gpucg_charge
> find_cg_rpool_locked -> cg_rpool_find_locked
> init_cg_rpool -> cg_rpool_init
> get_cg_rpool_locked -> cg_rpool_get_locked
> "gpu cgroup controller" -> "GPU controller"
> gpucg_device -> gpucg_bucket
> usage -> size
>
> v4 changes
> Adjust gpucg_try_charge critical section for future charge transfer
> functionality.
>
> v3 changes
> Use more common dual author commit message format per John Stultz.
>
> v2 changes
> Fix incorrect Kconfig help section indentation per Randy Dunlap.
> ---
> include/linux/cgroup_gpu.h | 122 ++++++++++++
> include/linux/cgroup_subsys.h | 4 +
> init/Kconfig | 7 +
> kernel/cgroup/Makefile | 1 +
> kernel/cgroup/gpu.c | 339 ++++++++++++++++++++++++++++++++++
> 5 files changed, 473 insertions(+)
> create mode 100644 include/linux/cgroup_gpu.h
> create mode 100644 kernel/cgroup/gpu.c
>
> diff --git a/include/linux/cgroup_gpu.h b/include/linux/cgroup_gpu.h
> new file mode 100644
> index 000000000000..cb228a16aa1f
> --- /dev/null
> +++ b/include/linux/cgroup_gpu.h
> @@ -0,0 +1,122 @@
> +/* SPDX-License-Identifier: MIT
> + * Copyright 2019 Advanced Micro Devices, Inc.
> + * Copyright (C) 2022 Google LLC.
> + */
> +#ifndef _CGROUP_GPU_H
> +#define _CGROUP_GPU_H
> +
> +#include <linux/cgroup.h>
> +
> +#define GPUCG_BUCKET_NAME_MAX_LEN 64
> +
> +struct gpucg;
> +struct gpucg_bucket;
> +
> +#ifdef CONFIG_CGROUP_GPU
> +
> +/**
> + * css_to_gpucg - get the corresponding gpucg ref from a cgroup_subsys_state
> + * @css: the target cgroup_subsys_state
> + *
> + * Returns: gpu cgroup that contains the @css
> + */
> +struct gpucg *css_to_gpucg(struct cgroup_subsys_state *css);
> +
> +/**
> + * gpucg_get - get the gpucg reference that a task belongs to
> + * @task: the target task
> + *
> + * This increases the reference count of the css that the @task belongs to.
> + *
> + * Returns: reference to the gpu cgroup the task belongs to.
> + */
> +struct gpucg *gpucg_get(struct task_struct *task);
> +
> +/**
> + * gpucg_put - put a gpucg reference
> + * @gpucg: the target gpucg
> + *
> + * Put a reference obtained via gpucg_get
> + */
> +void gpucg_put(struct gpucg *gpucg);
> +
> +/**
> + * gpucg_parent - find the parent of a gpu cgroup
> + * @cg: the target gpucg
> + *
> + * This does not increase the reference count of the parent cgroup
> + *
> + * Returns: parent gpu cgroup of @cg
> + */
> +struct gpucg *gpucg_parent(struct gpucg *cg);
> +
> +/**
> + * gpucg_charge - charge memory to the specified gpucg and gpucg_bucket.
> + * Caller must hold a reference to @gpucg obtained through gpucg_get(). The size of the memory is
> + * rounded up to be a multiple of the page size.
> + *
> + * @gpucg: The gpu cgroup to charge the memory to.
> + * @bucket: The bucket to charge the memory to.
> + * @size: The size of memory to charge in bytes.
> + * This size will be rounded up to the nearest page size.
> + *
> + * Return: returns 0 if the charging is successful and otherwise returns an error code.
> + */
> +int gpucg_charge(struct gpucg *gpucg, struct gpucg_bucket *bucket, u64 size);
> +
> +/**
> + * gpucg_uncharge - uncharge memory from the specified gpucg and gpucg_bucket.
> + * The caller must hold a reference to @gpucg obtained through gpucg_get().
> + *
> + * @gpucg: The gpu cgroup to uncharge the memory from.
> + * @bucket: The bucket to uncharge the memory from.
> + * @size: The size of memory to uncharge in bytes.
> + * This size will be rounded up to the nearest page size.
> + */
> +void gpucg_uncharge(struct gpucg *gpucg, struct gpucg_bucket *bucket, u64 size);
> +
> +/**
> + * gpucg_register_bucket - Registers a bucket for memory accounting using the GPU cgroup controller.
> + *
> + * @name: Pointer to a null-terminated string to denote the name of the bucket. This name should be
> + * globally unique, and should not exceed @GPUCG_BUCKET_NAME_MAX_LEN bytes.
> + *
> + * @bucket must remain valid. @name will be copied.
> + *
> + * Returns a pointer to a newly allocated bucket on success, or an errno code otherwise. As buckets
> + * cannot be unregistered, this can never be freed.
> + */
> +struct gpucg_bucket *gpucg_register_bucket(const char *name);
> +#else /* CONFIG_CGROUP_GPU */
> +
> +static inline struct gpucg *css_to_gpucg(struct cgroup_subsys_state *css)
> +{
> + return NULL;
> +}
> +
> +static inline struct gpucg *gpucg_get(struct task_struct *task)
> +{
> + return NULL;
> +}
> +
> +static inline void gpucg_put(struct gpucg *gpucg) {}
> +
> +static inline struct gpucg *gpucg_parent(struct gpucg *cg)
> +{
> + return NULL;
> +}
> +
> +static inline int gpucg_charge(struct gpucg *gpucg,
> + struct gpucg_bucket *bucket,
> + u64 size)
> +{
> + return 0;
> +}
> +
> +static inline void gpucg_uncharge(struct gpucg *gpucg,
> + struct gpucg_bucket *bucket,
> + u64 size) {}
> +
> +static inline struct gpucg_bucket *gpucg_register_bucket(const char *name) {}
I think this needs to return NULL, otherwise you'll get a compiler error when
CONFIG_CGROUP_GPU is not set.
I found other build errors when CONFIG_CGROUP_GPU is not set, please fix them in
the next versioon.
Thanks,
Enric
> +#endif /* CONFIG_CGROUP_GPU */
> +#endif /* _CGROUP_GPU_H */
> diff --git a/include/linux/cgroup_subsys.h b/include/linux/cgroup_subsys.h
> index 445235487230..46a2a7b93c41 100644
> --- a/include/linux/cgroup_subsys.h
> +++ b/include/linux/cgroup_subsys.h
> @@ -65,6 +65,10 @@ SUBSYS(rdma)
> SUBSYS(misc)
> #endif
>
> +#if IS_ENABLED(CONFIG_CGROUP_GPU)
> +SUBSYS(gpu)
> +#endif
> +
> /*
> * The following subsystems are not supported on the default hierarchy.
> */
> diff --git a/init/Kconfig b/init/Kconfig
> index ddcbefe535e9..2e00a190e170 100644
> --- a/init/Kconfig
> +++ b/init/Kconfig
> @@ -984,6 +984,13 @@ config BLK_CGROUP
>
> See Documentation/admin-guide/cgroup-v1/blkio-controller.rst for more information.
>
> +config CGROUP_GPU
> + bool "GPU controller (EXPERIMENTAL)"
> + select PAGE_COUNTER
> + help
> + Provides accounting and limit setting for memory allocations by the GPU and
> + GPU-related subsystems.
> +
> config CGROUP_WRITEBACK
> bool
> depends on MEMCG && BLK_CGROUP
> diff --git a/kernel/cgroup/Makefile b/kernel/cgroup/Makefile
> index 12f8457ad1f9..be95a5a532fc 100644
> --- a/kernel/cgroup/Makefile
> +++ b/kernel/cgroup/Makefile
> @@ -7,3 +7,4 @@ obj-$(CONFIG_CGROUP_RDMA) += rdma.o
> obj-$(CONFIG_CPUSETS) += cpuset.o
> obj-$(CONFIG_CGROUP_MISC) += misc.o
> obj-$(CONFIG_CGROUP_DEBUG) += debug.o
> +obj-$(CONFIG_CGROUP_GPU) += gpu.o
> diff --git a/kernel/cgroup/gpu.c b/kernel/cgroup/gpu.c
> new file mode 100644
> index 000000000000..ad16ea15d427
> --- /dev/null
> +++ b/kernel/cgroup/gpu.c
> @@ -0,0 +1,339 @@
> +// SPDX-License-Identifier: MIT
> +// Copyright 2019 Advanced Micro Devices, Inc.
> +// Copyright (C) 2022 Google LLC.
> +
> +#include <linux/cgroup.h>
> +#include <linux/cgroup_gpu.h>
> +#include <linux/err.h>
> +#include <linux/gfp.h>
> +#include <linux/list.h>
> +#include <linux/mm.h>
> +#include <linux/page_counter.h>
> +#include <linux/seq_file.h>
> +#include <linux/slab.h>
> +#include <linux/string.h>
> +
> +static struct gpucg *root_gpucg __read_mostly;
> +
> +/*
> + * Protects list of resource pools maintained on per cgroup basis and list
> + * of buckets registered for memory accounting using the GPU cgroup controller.
> + */
> +static DEFINE_MUTEX(gpucg_mutex);
> +static LIST_HEAD(gpucg_buckets);
> +
> +/* The GPU cgroup controller data structure */
> +struct gpucg {
> + struct cgroup_subsys_state css;
> +
> + /* list of all resource pools that belong to this cgroup */
> + struct list_head rpools;
> +};
> +
> +/* A named entity representing bucket of tracked memory. */
> +struct gpucg_bucket {
> + /* list of various resource pools in various cgroups that the bucket is part of */
> + struct list_head rpools;
> +
> + /* list of all buckets registered for GPU cgroup accounting */
> + struct list_head bucket_node;
> +
> + /* string to be used as identifier for accounting and limit setting */
> + const char *name;
> +};
> +
> +struct gpucg_resource_pool {
> + /* The bucket whose resource usage is tracked by this resource pool */
> + struct gpucg_bucket *bucket;
> +
> + /* list of all resource pools for the cgroup */
> + struct list_head cg_node;
> +
> + /* list maintained by the gpucg_bucket to keep track of its resource pools */
> + struct list_head bucket_node;
> +
> + /* tracks memory usage of the resource pool */
> + struct page_counter total;
> +};
> +
> +static void free_cg_rpool_locked(struct gpucg_resource_pool *rpool)
> +{
> + lockdep_assert_held(&gpucg_mutex);
> +
> + list_del(&rpool->cg_node);
> + list_del(&rpool->bucket_node);
> + kfree(rpool);
> +}
> +
> +static void gpucg_css_free(struct cgroup_subsys_state *css)
> +{
> + struct gpucg_resource_pool *rpool, *tmp;
> + struct gpucg *gpucg = css_to_gpucg(css);
> +
> + // delete all resource pools
> + mutex_lock(&gpucg_mutex);
> + list_for_each_entry_safe(rpool, tmp, &gpucg->rpools, cg_node)
> + free_cg_rpool_locked(rpool);
> + mutex_unlock(&gpucg_mutex);
> +
> + kfree(gpucg);
> +}
> +
> +static struct cgroup_subsys_state *
> +gpucg_css_alloc(struct cgroup_subsys_state *parent_css)
> +{
> + struct gpucg *gpucg, *parent;
> +
> + gpucg = kzalloc(sizeof(struct gpucg), GFP_KERNEL);
> + if (!gpucg)
> + return ERR_PTR(-ENOMEM);
> +
> + parent = css_to_gpucg(parent_css);
> + if (!parent)
> + root_gpucg = gpucg;
> +
> + INIT_LIST_HEAD(&gpucg->rpools);
> +
> + return &gpucg->css;
> +}
> +
> +static struct gpucg_resource_pool *cg_rpool_find_locked(
> + struct gpucg *cg,
> + struct gpucg_bucket *bucket)
> +{
> + struct gpucg_resource_pool *rpool;
> +
> + lockdep_assert_held(&gpucg_mutex);
> +
> + list_for_each_entry(rpool, &cg->rpools, cg_node)
> + if (rpool->bucket == bucket)
> + return rpool;
> +
> + return NULL;
> +}
> +
> +static struct gpucg_resource_pool *cg_rpool_init(struct gpucg *cg,
> + struct gpucg_bucket *bucket)
> +{
> + struct gpucg_resource_pool *rpool = kzalloc(sizeof(*rpool),
> + GFP_KERNEL);
> + if (!rpool)
> + return ERR_PTR(-ENOMEM);
> +
> + rpool->bucket = bucket;
> +
> + page_counter_init(&rpool->total, NULL);
> + INIT_LIST_HEAD(&rpool->cg_node);
> + INIT_LIST_HEAD(&rpool->bucket_node);
> + list_add_tail(&rpool->cg_node, &cg->rpools);
> + list_add_tail(&rpool->bucket_node, &bucket->rpools);
> +
> + return rpool;
> +}
> +
> +/**
> + * get_cg_rpool_locked - find the resource pool for the specified bucket and
> + * specified cgroup. If the resource pool does not exist for the cg, it is
> + * created in a hierarchical manner in the cgroup and its ancestor cgroups who
> + * do not already have a resource pool entry for the bucket.
> + *
> + * @cg: The cgroup to find the resource pool for.
> + * @bucket: The bucket associated with the returned resource pool.
> + *
> + * Return: return resource pool entry corresponding to the specified bucket in
> + * the specified cgroup (hierarchically creating them if not existing already).
> + *
> + */
> +static struct gpucg_resource_pool *
> +cg_rpool_get_locked(struct gpucg *cg, struct gpucg_bucket *bucket)
> +{
> + struct gpucg *parent_cg, *p, *stop_cg;
> + struct gpucg_resource_pool *rpool, *tmp_rpool;
> + struct gpucg_resource_pool *parent_rpool = NULL, *leaf_rpool = NULL;
> +
> + rpool = cg_rpool_find_locked(cg, bucket);
> + if (rpool)
> + return rpool;
> +
> + stop_cg = cg;
> + do {
> + rpool = cg_rpool_init(stop_cg, bucket);
> + if (IS_ERR(rpool))
> + goto err;
> +
> + if (!leaf_rpool)
> + leaf_rpool = rpool;
> +
> + stop_cg = gpucg_parent(stop_cg);
> + if (!stop_cg)
> + break;
> +
> + rpool = cg_rpool_find_locked(stop_cg, bucket);
> + } while (!rpool);
> +
> + /*
> + * Re-initialize page counters of all rpools created in this invocation
> + * to enable hierarchical charging.
> + * stop_cg is the first ancestor cg who already had a resource pool for
> + * the bucket. It can also be NULL if no ancestors had a pre-existing
> + * resource pool for the bucket before this invocation.
> + */
> + rpool = leaf_rpool;
> + for (p = cg; p != stop_cg; p = parent_cg) {
> + parent_cg = gpucg_parent(p);
> + if (!parent_cg)
> + break;
> + parent_rpool = cg_rpool_find_locked(parent_cg, bucket);
> + page_counter_init(&rpool->total, &parent_rpool->total);
> +
> + rpool = parent_rpool;
> + }
> +
> + return leaf_rpool;
> +err:
> + for (p = cg; p != stop_cg; p = gpucg_parent(p)) {
> + tmp_rpool = cg_rpool_find_locked(p, bucket);
> + free_cg_rpool_locked(tmp_rpool);
> + }
> + return rpool;
> +}
> +
> +struct gpucg *css_to_gpucg(struct cgroup_subsys_state *css)
> +{
> + return css ? container_of(css, struct gpucg, css) : NULL;
> +}
> +
> +struct gpucg *gpucg_get(struct task_struct *task)
> +{
> + if (!cgroup_subsys_enabled(gpu_cgrp_subsys))
> + return NULL;
> + return css_to_gpucg(task_get_css(task, gpu_cgrp_id));
> +}
> +
> +void gpucg_put(struct gpucg *gpucg)
> +{
> + if (gpucg)
> + css_put(&gpucg->css);
> +}
> +
> +struct gpucg *gpucg_parent(struct gpucg *cg)
> +{
> + return css_to_gpucg(cg->css.parent);
> +}
> +
> +int gpucg_charge(struct gpucg *gpucg, struct gpucg_bucket *bucket, u64 size)
> +{
> + struct page_counter *counter;
> + u64 nr_pages;
> + struct gpucg_resource_pool *rp;
> + int ret = 0;
> +
> + nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
> +
> + mutex_lock(&gpucg_mutex);
> + rp = cg_rpool_get_locked(gpucg, bucket);
> + /*
> + * Continue to hold gpucg_mutex because we use it to block charges while transfers are in
> + * progress to avoid potentially exceeding a limit.
> + */
> + if (IS_ERR(rp)) {
> + mutex_unlock(&gpucg_mutex);
> + return PTR_ERR(rp);
> + }
> +
> + if (page_counter_try_charge(&rp->total, nr_pages, &counter))
> + css_get(&gpucg->css);
> + else
> + ret = -ENOMEM;
> + mutex_unlock(&gpucg_mutex);
> +
> + return ret;
> +}
> +
> +void gpucg_uncharge(struct gpucg *gpucg, struct gpucg_bucket *bucket, u64 size)
> +{
> + u64 nr_pages;
> + struct gpucg_resource_pool *rp;
> +
> + mutex_lock(&gpucg_mutex);
> + rp = cg_rpool_find_locked(gpucg, bucket);
> + /*
> + * gpucg_mutex can be unlocked here, rp will stay valid until gpucg is freed and there are
> + * active refs on gpucg. Uncharges are fine while transfers are in progress since there is
> + * no potential to exceed a limit while uncharging and transferring.
> + */
> + mutex_unlock(&gpucg_mutex);
> +
> + if (unlikely(!rp)) {
> + pr_err("Resource pool not found, incorrect charge/uncharge ordering?\n");
> + return;
> + }
> +
> + nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
> + page_counter_uncharge(&rp->total, nr_pages);
> + css_put(&gpucg->css);
> +}
> +
> +struct gpucg_bucket *gpucg_register_bucket(const char *name)
> +{
> + struct gpucg_bucket *bucket, *b;
> +
> + if (!name)
> + return ERR_PTR(-EINVAL);
> +
> + if (strlen(name) >= GPUCG_BUCKET_NAME_MAX_LEN)
> + return ERR_PTR(-ENAMETOOLONG);
> +
> + bucket = kzalloc(sizeof(struct gpucg_bucket), GFP_KERNEL);
> + if (!bucket)
> + return ERR_PTR(-ENOMEM);
> +
> + INIT_LIST_HEAD(&bucket->bucket_node);
> + INIT_LIST_HEAD(&bucket->rpools);
> + bucket->name = kstrdup_const(name, GFP_KERNEL);
> +
> + mutex_lock(&gpucg_mutex);
> + list_for_each_entry(b, &gpucg_buckets, bucket_node) {
> + if (strncmp(b->name, bucket->name, GPUCG_BUCKET_NAME_MAX_LEN) == 0) {
> + mutex_unlock(&gpucg_mutex);
> + kfree_const(bucket->name);
> + kfree(bucket);
> + return ERR_PTR(-EEXIST);
> + }
> + }
> + list_add_tail(&bucket->bucket_node, &gpucg_buckets);
> + mutex_unlock(&gpucg_mutex);
> +
> + return bucket;
> +}
> +
> +static int gpucg_resource_show(struct seq_file *sf, void *v)
> +{
> + struct gpucg_resource_pool *rpool;
> + struct gpucg *cg = css_to_gpucg(seq_css(sf));
> +
> + mutex_lock(&gpucg_mutex);
> + list_for_each_entry(rpool, &cg->rpools, cg_node) {
> + seq_printf(sf, "%s %lu\n", rpool->bucket->name,
> + page_counter_read(&rpool->total) * PAGE_SIZE);
> + }
> + mutex_unlock(&gpucg_mutex);
> +
> + return 0;
> +}
> +
> +struct cftype files[] = {
> + {
> + .name = "memory.current",
> + .seq_show = gpucg_resource_show,
> + },
> + { } /* terminate */
> +};
> +
> +struct cgroup_subsys gpu_cgrp_subsys = {
> + .css_alloc = gpucg_css_alloc,
> + .css_free = gpucg_css_free,
> + .early_init = false,
> + .legacy_cftypes = files,
> + .dfl_cftypes = files,
> +};
>
> --
> 2.36.0.512.ge40c2bad7a-goog
>
>
^ permalink raw reply [flat|nested] 21+ messages in thread* Re: [PATCH v7 2/6] cgroup: gpu: Add a cgroup controller for allocator attribution of GPU memory
2022-05-19 10:52 ` [PATCH v7 2/6] cgroup: gpu: Add a cgroup controller for allocator attribution of GPU memory eballetbo
@ 2022-05-20 16:33 ` T.J. Mercier
0 siblings, 0 replies; 21+ messages in thread
From: T.J. Mercier @ 2022-05-20 16:33 UTC (permalink / raw)
To: eballetbo
Cc: Zefan Li, Jonathan Corbet, Joel Fernandes,
Arve Hjønnevåg, Martijn Coenen, Benjamin Gaignard,
Tejun Heo, Christian Brauner, Sumit Semwal, Todd Kjos,
Suren Baghdasaryan, Johannes Weiner, Brian Starkey,
Christian König, Greg Kroah-Hartman, Liam Mark, John Stultz,
Hridya Valsaraju, Shuah Khan
On Thu, May 19, 2022 at 3:53 AM <eballetbo@kernel.org> wrote:
>
> From: Enric Balletbo i Serra <eballetbo@kernel.org>
>
> On Tue, 10 May 2022 23:56:46 +0000, T.J. Mercier wrote
> > From: Hridya Valsaraju <hridya@google.com>
> >
> > The cgroup controller provides accounting for GPU and GPU-related
> > memory allocations. The memory being accounted can be device memory or
> > memory allocated from pools dedicated to serve GPU-related tasks.
> >
> > This patch adds APIs to:
> > -allow a device to register for memory accounting using the GPU cgroup
> > controller.
> > -charge and uncharge allocated memory to a cgroup.
> >
> > When the cgroup controller is enabled, it would expose information about
> > the memory allocated by each device(registered for GPU cgroup memory
> > accounting) for each cgroup.
> >
> > The API/UAPI can be extended to set per-device/total allocation limits
> > in the future.
> >
> > The cgroup controller has been named following the discussion in [1].
> >
> > [1]: https://lore.kernel.org/amd-gfx/YCJp%2F%2FkMC7YjVMXv@phenom.ffwll.local/
> >
> > Signed-off-by: Hridya Valsaraju <hridya@google.com>
> > Signed-off-by: T.J. Mercier <tjmercier@google.com>
> > ---
> > v7 changes
> > Hide gpucg and gpucg_bucket struct definitions per Michal Koutný.
> > This means gpucg_register_bucket now returns an internally allocated
> > struct gpucg_bucket.
> >
> > Move all public function documentation to the cgroup_gpu.h header.
> >
> > v5 changes
> > Support all strings for gpucg_register_device instead of just string
> > literals.
> >
> > Enforce globally unique gpucg_bucket names.
> >
> > Constrain gpucg_bucket name lengths to 64 bytes.
> >
> > Obtain just a single css refcount instead of nr_pages for each
> > charge.
> >
> > Rename:
> > gpucg_try_charge -> gpucg_charge
> > find_cg_rpool_locked -> cg_rpool_find_locked
> > init_cg_rpool -> cg_rpool_init
> > get_cg_rpool_locked -> cg_rpool_get_locked
> > "gpu cgroup controller" -> "GPU controller"
> > gpucg_device -> gpucg_bucket
> > usage -> size
> >
> > v4 changes
> > Adjust gpucg_try_charge critical section for future charge transfer
> > functionality.
> >
> > v3 changes
> > Use more common dual author commit message format per John Stultz.
> >
> > v2 changes
> > Fix incorrect Kconfig help section indentation per Randy Dunlap.
> > ---
> > include/linux/cgroup_gpu.h | 122 ++++++++++++
> > include/linux/cgroup_subsys.h | 4 +
> > init/Kconfig | 7 +
> > kernel/cgroup/Makefile | 1 +
> > kernel/cgroup/gpu.c | 339 ++++++++++++++++++++++++++++++++++
> > 5 files changed, 473 insertions(+)
> > create mode 100644 include/linux/cgroup_gpu.h
> > create mode 100644 kernel/cgroup/gpu.c
> >
> > diff --git a/include/linux/cgroup_gpu.h b/include/linux/cgroup_gpu.h
> > new file mode 100644
> > index 000000000000..cb228a16aa1f
> > --- /dev/null
> > +++ b/include/linux/cgroup_gpu.h
> > @@ -0,0 +1,122 @@
> > +/* SPDX-License-Identifier: MIT
> > + * Copyright 2019 Advanced Micro Devices, Inc.
> > + * Copyright (C) 2022 Google LLC.
> > + */
> > +#ifndef _CGROUP_GPU_H
> > +#define _CGROUP_GPU_H
> > +
> > +#include <linux/cgroup.h>
> > +
> > +#define GPUCG_BUCKET_NAME_MAX_LEN 64
> > +
> > +struct gpucg;
> > +struct gpucg_bucket;
> > +
> > +#ifdef CONFIG_CGROUP_GPU
> > +
> > +/**
> > + * css_to_gpucg - get the corresponding gpucg ref from a cgroup_subsys_state
> > + * @css: the target cgroup_subsys_state
> > + *
> > + * Returns: gpu cgroup that contains the @css
> > + */
> > +struct gpucg *css_to_gpucg(struct cgroup_subsys_state *css);
> > +
> > +/**
> > + * gpucg_get - get the gpucg reference that a task belongs to
> > + * @task: the target task
> > + *
> > + * This increases the reference count of the css that the @task belongs to.
> > + *
> > + * Returns: reference to the gpu cgroup the task belongs to.
> > + */
> > +struct gpucg *gpucg_get(struct task_struct *task);
> > +
> > +/**
> > + * gpucg_put - put a gpucg reference
> > + * @gpucg: the target gpucg
> > + *
> > + * Put a reference obtained via gpucg_get
> > + */
> > +void gpucg_put(struct gpucg *gpucg);
> > +
> > +/**
> > + * gpucg_parent - find the parent of a gpu cgroup
> > + * @cg: the target gpucg
> > + *
> > + * This does not increase the reference count of the parent cgroup
> > + *
> > + * Returns: parent gpu cgroup of @cg
> > + */
> > +struct gpucg *gpucg_parent(struct gpucg *cg);
> > +
> > +/**
> > + * gpucg_charge - charge memory to the specified gpucg and gpucg_bucket.
> > + * Caller must hold a reference to @gpucg obtained through gpucg_get(). The size of the memory is
> > + * rounded up to be a multiple of the page size.
> > + *
> > + * @gpucg: The gpu cgroup to charge the memory to.
> > + * @bucket: The bucket to charge the memory to.
> > + * @size: The size of memory to charge in bytes.
> > + * This size will be rounded up to the nearest page size.
> > + *
> > + * Return: returns 0 if the charging is successful and otherwise returns an error code.
> > + */
> > +int gpucg_charge(struct gpucg *gpucg, struct gpucg_bucket *bucket, u64 size);
> > +
> > +/**
> > + * gpucg_uncharge - uncharge memory from the specified gpucg and gpucg_bucket.
> > + * The caller must hold a reference to @gpucg obtained through gpucg_get().
> > + *
> > + * @gpucg: The gpu cgroup to uncharge the memory from.
> > + * @bucket: The bucket to uncharge the memory from.
> > + * @size: The size of memory to uncharge in bytes.
> > + * This size will be rounded up to the nearest page size.
> > + */
> > +void gpucg_uncharge(struct gpucg *gpucg, struct gpucg_bucket *bucket, u64 size);
> > +
> > +/**
> > + * gpucg_register_bucket - Registers a bucket for memory accounting using the GPU cgroup controller.
> > + *
> > + * @name: Pointer to a null-terminated string to denote the name of the bucket. This name should be
> > + * globally unique, and should not exceed @GPUCG_BUCKET_NAME_MAX_LEN bytes.
> > + *
> > + * @bucket must remain valid. @name will be copied.
> > + *
> > + * Returns a pointer to a newly allocated bucket on success, or an errno code otherwise. As buckets
> > + * cannot be unregistered, this can never be freed.
> > + */
> > +struct gpucg_bucket *gpucg_register_bucket(const char *name);
> > +#else /* CONFIG_CGROUP_GPU */
> > +
> > +static inline struct gpucg *css_to_gpucg(struct cgroup_subsys_state *css)
> > +{
> > + return NULL;
> > +}
> > +
> > +static inline struct gpucg *gpucg_get(struct task_struct *task)
> > +{
> > + return NULL;
> > +}
> > +
> > +static inline void gpucg_put(struct gpucg *gpucg) {}
> > +
> > +static inline struct gpucg *gpucg_parent(struct gpucg *cg)
> > +{
> > + return NULL;
> > +}
> > +
> > +static inline int gpucg_charge(struct gpucg *gpucg,
> > + struct gpucg_bucket *bucket,
> > + u64 size)
> > +{
> > + return 0;
> > +}
> > +
> > +static inline void gpucg_uncharge(struct gpucg *gpucg,
> > + struct gpucg_bucket *bucket,
> > + u64 size) {}
> > +
> > +static inline struct gpucg_bucket *gpucg_register_bucket(const char *name) {}
>
> I think this needs to return NULL, otherwise you'll get a compiler error when
> CONFIG_CGROUP_GPU is not set.
>
> I found other build errors when CONFIG_CGROUP_GPU is not set, please fix them in
> the next versioon.
>
> Thanks,
> Enric
>
Thanks. I have been building each patch with allnoconfig and
allyesconfig before posting, but clearly this was not sufficient. I'll
fix this up.
> > +#endif /* CONFIG_CGROUP_GPU */
> > +#endif /* _CGROUP_GPU_H */
> > diff --git a/include/linux/cgroup_subsys.h b/include/linux/cgroup_subsys.h
> > index 445235487230..46a2a7b93c41 100644
> > --- a/include/linux/cgroup_subsys.h
> > +++ b/include/linux/cgroup_subsys.h
> > @@ -65,6 +65,10 @@ SUBSYS(rdma)
> > SUBSYS(misc)
> > #endif
> >
> > +#if IS_ENABLED(CONFIG_CGROUP_GPU)
> > +SUBSYS(gpu)
> > +#endif
> > +
> > /*
> > * The following subsystems are not supported on the default hierarchy.
> > */
> > diff --git a/init/Kconfig b/init/Kconfig
> > index ddcbefe535e9..2e00a190e170 100644
> > --- a/init/Kconfig
> > +++ b/init/Kconfig
> > @@ -984,6 +984,13 @@ config BLK_CGROUP
> >
> > See Documentation/admin-guide/cgroup-v1/blkio-controller.rst for more information.
> >
> > +config CGROUP_GPU
> > + bool "GPU controller (EXPERIMENTAL)"
> > + select PAGE_COUNTER
> > + help
> > + Provides accounting and limit setting for memory allocations by the GPU and
> > + GPU-related subsystems.
> > +
> > config CGROUP_WRITEBACK
> > bool
> > depends on MEMCG && BLK_CGROUP
> > diff --git a/kernel/cgroup/Makefile b/kernel/cgroup/Makefile
> > index 12f8457ad1f9..be95a5a532fc 100644
> > --- a/kernel/cgroup/Makefile
> > +++ b/kernel/cgroup/Makefile
> > @@ -7,3 +7,4 @@ obj-$(CONFIG_CGROUP_RDMA) += rdma.o
> > obj-$(CONFIG_CPUSETS) += cpuset.o
> > obj-$(CONFIG_CGROUP_MISC) += misc.o
> > obj-$(CONFIG_CGROUP_DEBUG) += debug.o
> > +obj-$(CONFIG_CGROUP_GPU) += gpu.o
> > diff --git a/kernel/cgroup/gpu.c b/kernel/cgroup/gpu.c
> > new file mode 100644
> > index 000000000000..ad16ea15d427
> > --- /dev/null
> > +++ b/kernel/cgroup/gpu.c
> > @@ -0,0 +1,339 @@
> > +// SPDX-License-Identifier: MIT
> > +// Copyright 2019 Advanced Micro Devices, Inc.
> > +// Copyright (C) 2022 Google LLC.
> > +
> > +#include <linux/cgroup.h>
> > +#include <linux/cgroup_gpu.h>
> > +#include <linux/err.h>
> > +#include <linux/gfp.h>
> > +#include <linux/list.h>
> > +#include <linux/mm.h>
> > +#include <linux/page_counter.h>
> > +#include <linux/seq_file.h>
> > +#include <linux/slab.h>
> > +#include <linux/string.h>
> > +
> > +static struct gpucg *root_gpucg __read_mostly;
> > +
> > +/*
> > + * Protects list of resource pools maintained on per cgroup basis and list
> > + * of buckets registered for memory accounting using the GPU cgroup controller.
> > + */
> > +static DEFINE_MUTEX(gpucg_mutex);
> > +static LIST_HEAD(gpucg_buckets);
> > +
> > +/* The GPU cgroup controller data structure */
> > +struct gpucg {
> > + struct cgroup_subsys_state css;
> > +
> > + /* list of all resource pools that belong to this cgroup */
> > + struct list_head rpools;
> > +};
> > +
> > +/* A named entity representing bucket of tracked memory. */
> > +struct gpucg_bucket {
> > + /* list of various resource pools in various cgroups that the bucket is part of */
> > + struct list_head rpools;
> > +
> > + /* list of all buckets registered for GPU cgroup accounting */
> > + struct list_head bucket_node;
> > +
> > + /* string to be used as identifier for accounting and limit setting */
> > + const char *name;
> > +};
> > +
> > +struct gpucg_resource_pool {
> > + /* The bucket whose resource usage is tracked by this resource pool */
> > + struct gpucg_bucket *bucket;
> > +
> > + /* list of all resource pools for the cgroup */
> > + struct list_head cg_node;
> > +
> > + /* list maintained by the gpucg_bucket to keep track of its resource pools */
> > + struct list_head bucket_node;
> > +
> > + /* tracks memory usage of the resource pool */
> > + struct page_counter total;
> > +};
> > +
> > +static void free_cg_rpool_locked(struct gpucg_resource_pool *rpool)
> > +{
> > + lockdep_assert_held(&gpucg_mutex);
> > +
> > + list_del(&rpool->cg_node);
> > + list_del(&rpool->bucket_node);
> > + kfree(rpool);
> > +}
> > +
> > +static void gpucg_css_free(struct cgroup_subsys_state *css)
> > +{
> > + struct gpucg_resource_pool *rpool, *tmp;
> > + struct gpucg *gpucg = css_to_gpucg(css);
> > +
> > + // delete all resource pools
> > + mutex_lock(&gpucg_mutex);
> > + list_for_each_entry_safe(rpool, tmp, &gpucg->rpools, cg_node)
> > + free_cg_rpool_locked(rpool);
> > + mutex_unlock(&gpucg_mutex);
> > +
> > + kfree(gpucg);
> > +}
> > +
> > +static struct cgroup_subsys_state *
> > +gpucg_css_alloc(struct cgroup_subsys_state *parent_css)
> > +{
> > + struct gpucg *gpucg, *parent;
> > +
> > + gpucg = kzalloc(sizeof(struct gpucg), GFP_KERNEL);
> > + if (!gpucg)
> > + return ERR_PTR(-ENOMEM);
> > +
> > + parent = css_to_gpucg(parent_css);
> > + if (!parent)
> > + root_gpucg = gpucg;
> > +
> > + INIT_LIST_HEAD(&gpucg->rpools);
> > +
> > + return &gpucg->css;
> > +}
> > +
> > +static struct gpucg_resource_pool *cg_rpool_find_locked(
> > + struct gpucg *cg,
> > + struct gpucg_bucket *bucket)
> > +{
> > + struct gpucg_resource_pool *rpool;
> > +
> > + lockdep_assert_held(&gpucg_mutex);
> > +
> > + list_for_each_entry(rpool, &cg->rpools, cg_node)
> > + if (rpool->bucket == bucket)
> > + return rpool;
> > +
> > + return NULL;
> > +}
> > +
> > +static struct gpucg_resource_pool *cg_rpool_init(struct gpucg *cg,
> > + struct gpucg_bucket *bucket)
> > +{
> > + struct gpucg_resource_pool *rpool = kzalloc(sizeof(*rpool),
> > + GFP_KERNEL);
> > + if (!rpool)
> > + return ERR_PTR(-ENOMEM);
> > +
> > + rpool->bucket = bucket;
> > +
> > + page_counter_init(&rpool->total, NULL);
> > + INIT_LIST_HEAD(&rpool->cg_node);
> > + INIT_LIST_HEAD(&rpool->bucket_node);
> > + list_add_tail(&rpool->cg_node, &cg->rpools);
> > + list_add_tail(&rpool->bucket_node, &bucket->rpools);
> > +
> > + return rpool;
> > +}
> > +
> > +/**
> > + * get_cg_rpool_locked - find the resource pool for the specified bucket and
> > + * specified cgroup. If the resource pool does not exist for the cg, it is
> > + * created in a hierarchical manner in the cgroup and its ancestor cgroups who
> > + * do not already have a resource pool entry for the bucket.
> > + *
> > + * @cg: The cgroup to find the resource pool for.
> > + * @bucket: The bucket associated with the returned resource pool.
> > + *
> > + * Return: return resource pool entry corresponding to the specified bucket in
> > + * the specified cgroup (hierarchically creating them if not existing already).
> > + *
> > + */
> > +static struct gpucg_resource_pool *
> > +cg_rpool_get_locked(struct gpucg *cg, struct gpucg_bucket *bucket)
> > +{
> > + struct gpucg *parent_cg, *p, *stop_cg;
> > + struct gpucg_resource_pool *rpool, *tmp_rpool;
> > + struct gpucg_resource_pool *parent_rpool = NULL, *leaf_rpool = NULL;
> > +
> > + rpool = cg_rpool_find_locked(cg, bucket);
> > + if (rpool)
> > + return rpool;
> > +
> > + stop_cg = cg;
> > + do {
> > + rpool = cg_rpool_init(stop_cg, bucket);
> > + if (IS_ERR(rpool))
> > + goto err;
> > +
> > + if (!leaf_rpool)
> > + leaf_rpool = rpool;
> > +
> > + stop_cg = gpucg_parent(stop_cg);
> > + if (!stop_cg)
> > + break;
> > +
> > + rpool = cg_rpool_find_locked(stop_cg, bucket);
> > + } while (!rpool);
> > +
> > + /*
> > + * Re-initialize page counters of all rpools created in this invocation
> > + * to enable hierarchical charging.
> > + * stop_cg is the first ancestor cg who already had a resource pool for
> > + * the bucket. It can also be NULL if no ancestors had a pre-existing
> > + * resource pool for the bucket before this invocation.
> > + */
> > + rpool = leaf_rpool;
> > + for (p = cg; p != stop_cg; p = parent_cg) {
> > + parent_cg = gpucg_parent(p);
> > + if (!parent_cg)
> > + break;
> > + parent_rpool = cg_rpool_find_locked(parent_cg, bucket);
> > + page_counter_init(&rpool->total, &parent_rpool->total);
> > +
> > + rpool = parent_rpool;
> > + }
> > +
> > + return leaf_rpool;
> > +err:
> > + for (p = cg; p != stop_cg; p = gpucg_parent(p)) {
> > + tmp_rpool = cg_rpool_find_locked(p, bucket);
> > + free_cg_rpool_locked(tmp_rpool);
> > + }
> > + return rpool;
> > +}
> > +
> > +struct gpucg *css_to_gpucg(struct cgroup_subsys_state *css)
> > +{
> > + return css ? container_of(css, struct gpucg, css) : NULL;
> > +}
> > +
> > +struct gpucg *gpucg_get(struct task_struct *task)
> > +{
> > + if (!cgroup_subsys_enabled(gpu_cgrp_subsys))
> > + return NULL;
> > + return css_to_gpucg(task_get_css(task, gpu_cgrp_id));
> > +}
> > +
> > +void gpucg_put(struct gpucg *gpucg)
> > +{
> > + if (gpucg)
> > + css_put(&gpucg->css);
> > +}
> > +
> > +struct gpucg *gpucg_parent(struct gpucg *cg)
> > +{
> > + return css_to_gpucg(cg->css.parent);
> > +}
> > +
> > +int gpucg_charge(struct gpucg *gpucg, struct gpucg_bucket *bucket, u64 size)
> > +{
> > + struct page_counter *counter;
> > + u64 nr_pages;
> > + struct gpucg_resource_pool *rp;
> > + int ret = 0;
> > +
> > + nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
> > +
> > + mutex_lock(&gpucg_mutex);
> > + rp = cg_rpool_get_locked(gpucg, bucket);
> > + /*
> > + * Continue to hold gpucg_mutex because we use it to block charges while transfers are in
> > + * progress to avoid potentially exceeding a limit.
> > + */
> > + if (IS_ERR(rp)) {
> > + mutex_unlock(&gpucg_mutex);
> > + return PTR_ERR(rp);
> > + }
> > +
> > + if (page_counter_try_charge(&rp->total, nr_pages, &counter))
> > + css_get(&gpucg->css);
> > + else
> > + ret = -ENOMEM;
> > + mutex_unlock(&gpucg_mutex);
> > +
> > + return ret;
> > +}
> > +
> > +void gpucg_uncharge(struct gpucg *gpucg, struct gpucg_bucket *bucket, u64 size)
> > +{
> > + u64 nr_pages;
> > + struct gpucg_resource_pool *rp;
> > +
> > + mutex_lock(&gpucg_mutex);
> > + rp = cg_rpool_find_locked(gpucg, bucket);
> > + /*
> > + * gpucg_mutex can be unlocked here, rp will stay valid until gpucg is freed and there are
> > + * active refs on gpucg. Uncharges are fine while transfers are in progress since there is
> > + * no potential to exceed a limit while uncharging and transferring.
> > + */
> > + mutex_unlock(&gpucg_mutex);
> > +
> > + if (unlikely(!rp)) {
> > + pr_err("Resource pool not found, incorrect charge/uncharge ordering?\n");
> > + return;
> > + }
> > +
> > + nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
> > + page_counter_uncharge(&rp->total, nr_pages);
> > + css_put(&gpucg->css);
> > +}
> > +
> > +struct gpucg_bucket *gpucg_register_bucket(const char *name)
> > +{
> > + struct gpucg_bucket *bucket, *b;
> > +
> > + if (!name)
> > + return ERR_PTR(-EINVAL);
> > +
> > + if (strlen(name) >= GPUCG_BUCKET_NAME_MAX_LEN)
> > + return ERR_PTR(-ENAMETOOLONG);
> > +
> > + bucket = kzalloc(sizeof(struct gpucg_bucket), GFP_KERNEL);
> > + if (!bucket)
> > + return ERR_PTR(-ENOMEM);
> > +
> > + INIT_LIST_HEAD(&bucket->bucket_node);
> > + INIT_LIST_HEAD(&bucket->rpools);
> > + bucket->name = kstrdup_const(name, GFP_KERNEL);
> > +
> > + mutex_lock(&gpucg_mutex);
> > + list_for_each_entry(b, &gpucg_buckets, bucket_node) {
> > + if (strncmp(b->name, bucket->name, GPUCG_BUCKET_NAME_MAX_LEN) == 0) {
> > + mutex_unlock(&gpucg_mutex);
> > + kfree_const(bucket->name);
> > + kfree(bucket);
> > + return ERR_PTR(-EEXIST);
> > + }
> > + }
> > + list_add_tail(&bucket->bucket_node, &gpucg_buckets);
> > + mutex_unlock(&gpucg_mutex);
> > +
> > + return bucket;
> > +}
> > +
> > +static int gpucg_resource_show(struct seq_file *sf, void *v)
> > +{
> > + struct gpucg_resource_pool *rpool;
> > + struct gpucg *cg = css_to_gpucg(seq_css(sf));
> > +
> > + mutex_lock(&gpucg_mutex);
> > + list_for_each_entry(rpool, &cg->rpools, cg_node) {
> > + seq_printf(sf, "%s %lu\n", rpool->bucket->name,
> > + page_counter_read(&rpool->total) * PAGE_SIZE);
> > + }
> > + mutex_unlock(&gpucg_mutex);
> > +
> > + return 0;
> > +}
> > +
> > +struct cftype files[] = {
> > + {
> > + .name = "memory.current",
> > + .seq_show = gpucg_resource_show,
> > + },
> > + { } /* terminate */
> > +};
> > +
> > +struct cgroup_subsys gpu_cgrp_subsys = {
> > + .css_alloc = gpucg_css_alloc,
> > + .css_free = gpucg_css_free,
> > + .early_init = false,
> > + .legacy_cftypes = files,
> > + .dfl_cftypes = files,
> > +};
> >
> > --
> > 2.36.0.512.ge40c2bad7a-goog
> >
> >
>
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