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

--- 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 | 127 ++++++++++++++ include/linux/cgroup_subsys.h | 4 + init/Kconfig | 7 + kernel/cgroup/Makefile | 1 + kernel/cgroup/gpu.c | 303 ++++++++++++++++++++++++++++++++++ 5 files changed, 442 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..c90069719022 --- /dev/null +++ b/include/linux/cgroup_gpu.h @@ -0,0 +1,127 @@ +/* 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> +#include <linux/page_counter.h> + +#ifdef CONFIG_CGROUP_GPU + /* 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; +}; + +struct gpucg_device { + /* + * list of various resource pools in various cgroups that the device is + * part of. + */ + struct list_head rpools; + + /* list of all devices registered for GPU cgroup accounting */ + struct list_head dev_node; + + /* + * pointer to string literal to be used as identifier for accounting and + * limit setting + */ + const char *name; +}; + +/** + * 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 + */ +static inline struct gpucg *css_to_gpucg(struct cgroup_subsys_state *css) +{ + return css ? container_of(css, struct gpucg, css) : NULL; +} + +/** + * 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. + */ +static inline 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)); +} + +/** + * gpucg_put - put a gpucg reference + * @gpucg: the target gpucg + * + * Put a reference obtained via gpucg_get + */ +static inline void gpucg_put(struct gpucg *gpucg) +{ + if (gpucg) + css_put(&gpucg->css); +} + +/** + * 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 + */ +static inline struct gpucg *gpucg_parent(struct gpucg *cg) +{ + return css_to_gpucg(cg->css.parent); +} + +int gpucg_try_charge(struct gpucg *gpucg, struct gpucg_device *device, u64 usage); +void gpucg_uncharge(struct gpucg *gpucg, struct gpucg_device *device, u64 usage); +void gpucg_register_device(struct gpucg_device *gpucg_dev, const char *name); +#else /* CONFIG_CGROUP_GPU */ + +struct gpucg; +struct gpucg_device; + +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_try_charge(struct gpucg *gpucg, + struct gpucg_device *device, + u64 usage) +{ + return 0; +} + +static inline void gpucg_uncharge(struct gpucg *gpucg, + struct gpucg_device *device, + u64 usage) {} + +static inline void gpucg_register_device(struct gpucg_device *gpucg_dev, + 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 e9119bf54b1f..43568472930a 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -980,6 +980,13 @@ config BLK_CGROUP

See Documentation/admin-guide/cgroup-v1/blkio-controller.rst for more information.

+config CGROUP_GPU + bool "gpu cgroup 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..ac4c470914b5 --- /dev/null +++ b/kernel/cgroup/gpu.c @@ -0,0 +1,303 @@ +// 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/mm.h> +#include <linux/page_counter.h> +#include <linux/seq_file.h> +#include <linux/slab.h> + +static struct gpucg *root_gpucg __read_mostly; + +/* + * Protects list of resource pools maintained on per cgroup basis + * and list of devices registered for memory accounting using the GPU cgroup + * controller. + */ +static DEFINE_MUTEX(gpucg_mutex); +static LIST_HEAD(gpucg_devices); + +struct gpucg_resource_pool { + /* The device whose resource usage is tracked by this resource pool */ + struct gpucg_device *device; + + /* list of all resource pools for the cgroup */ + struct list_head cg_node; + + /* list maintained by the gpucg_device to keep track of its resource pools */ + struct list_head dev_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->dev_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 *find_cg_rpool_locked( + struct gpucg *cg, + struct gpucg_device *device) +{ + struct gpucg_resource_pool *pool; + + lockdep_assert_held(&gpucg_mutex); + + list_for_each_entry(pool, &cg->rpools, cg_node) + if (pool->device == device) + return pool; + + return NULL; +} + +static struct gpucg_resource_pool *init_cg_rpool(struct gpucg *cg, + struct gpucg_device *device) +{ + struct gpucg_resource_pool *rpool = kzalloc(sizeof(*rpool), + GFP_KERNEL); + if (!rpool) + return ERR_PTR(-ENOMEM); + + rpool->device = device; + + page_counter_init(&rpool->total, NULL); + INIT_LIST_HEAD(&rpool->cg_node); + INIT_LIST_HEAD(&rpool->dev_node); + list_add_tail(&rpool->cg_node, &cg->rpools); + list_add_tail(&rpool->dev_node, &device->rpools); + + return rpool; +} + +/** + * get_cg_rpool_locked - find the resource pool for the specified device 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 device. + * + * @cg: The cgroup to find the resource pool for. + * @device: The device associated with the returned resource pool. + * + * Return: return resource pool entry corresponding to the specified device in + * the specified cgroup (hierarchically creating them if not existing already). + * + */ +static struct gpucg_resource_pool * +get_cg_rpool_locked(struct gpucg *cg, struct gpucg_device *device) +{ + 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 = find_cg_rpool_locked(cg, device); + if (rpool) + return rpool; + + stop_cg = cg; + do { + rpool = init_cg_rpool(stop_cg, device); + if (IS_ERR(rpool)) + goto err; + + if (!leaf_rpool) + leaf_rpool = rpool; + + stop_cg = gpucg_parent(stop_cg); + if (!stop_cg) + break; + + rpool = find_cg_rpool_locked(stop_cg, device); + } 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 device. It can also be NULL if no ancestors had a pre-existing + * resource pool for the device 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 = find_cg_rpool_locked(parent_cg, device); + 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 = find_cg_rpool_locked(p, device); + free_cg_rpool_locked(tmp_rpool); + } + return rpool; +} + +/** + * gpucg_try_charge - charge memory to the specified gpucg and gpucg_device. + * 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. + * @device: The device to charge the memory to. + * @usage: size of memory to charge in bytes. + * + * Return: returns 0 if the charging is successful and otherwise returns an + * error code. + */ +int gpucg_try_charge(struct gpucg *gpucg, struct gpucg_device *device, u64 usage) +{ + struct page_counter *counter; + u64 nr_pages; + struct gpucg_resource_pool *rp; + int ret = 0; + + nr_pages = PAGE_ALIGN(usage) >> PAGE_SHIFT; + + mutex_lock(&gpucg_mutex); + rp = get_cg_rpool_locked(gpucg, device); + /* + * Continue to hold gpucg_mutex because we use it to block charges + * while transfers are in progress. + */ + if (IS_ERR(rp)) { + mutex_unlock(&gpucg_mutex); + return PTR_ERR(rp); + } + + if (page_counter_try_charge(&rp->total, nr_pages, &counter)) + css_get_many(&gpucg->css, nr_pages); + else + ret = -ENOMEM; + mutex_unlock(&gpucg_mutex); + + return ret; +} + +/** + * gpucg_uncharge - uncharge memory from the specified gpucg and gpucg_device. + * The caller must hold a reference to @gpucg obtained through gpucg_get(). + * + * @gpucg: The gpu cgroup to uncharge the memory from. + * @device: The device to uncharge the memory from. + * @usage: size of memory to uncharge in bytes. + */ +void gpucg_uncharge(struct gpucg *gpucg, struct gpucg_device *device, u64 usage) +{ + u64 nr_pages; + struct gpucg_resource_pool *rp; + + mutex_lock(&gpucg_mutex); + rp = find_cg_rpool_locked(gpucg, device); + /* + * 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. + */ + mutex_unlock(&gpucg_mutex); + + if (unlikely(!rp)) { + pr_err("Resource pool not found, incorrect charge/uncharge ordering?\n"); + return; + } + + nr_pages = PAGE_ALIGN(usage) >> PAGE_SHIFT; + page_counter_uncharge(&rp->total, nr_pages); + css_put_many(&gpucg->css, nr_pages); +} + +/** + * gpucg_register_device - Registers a device for memory accounting using the + * GPU cgroup controller. + * + * @device: The device to register for memory accounting. + * @name: Pointer to a string literal to denote the name of the device. + * + * Both @device andd @name must remain valid. + */ +void gpucg_register_device(struct gpucg_device *device, const char *name) +{ + if (!device) + return; + + INIT_LIST_HEAD(&device->dev_node); + INIT_LIST_HEAD(&device->rpools); + + mutex_lock(&gpucg_mutex); + list_add_tail(&device->dev_node, &gpucg_devices); + mutex_unlock(&gpucg_mutex); + + device->name = name; +} + +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->device->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, +};

From: Hridya Valsaraju hridya@google.com

All DMA heaps now register a new GPU cgroup device upon creation, and the system_heap now exports buffers associated with its GPU cgroup device for tracking purposes.

Signed-off-by: Hridya Valsaraju hridya@google.com Signed-off-by: T.J. Mercier tjmercier@google.com

--- 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-heap.c | 27 +++++++++++++++++++++++++++ drivers/dma-buf/heaps/system_heap.c | 3 +++ include/linux/dma-heap.h | 11 +++++++++++ 3 files changed, 41 insertions(+)

diff --git a/drivers/dma-buf/dma-heap.c b/drivers/dma-buf/dma-heap.c index 8f5848aa144f..885072427775 100644 --- a/drivers/dma-buf/dma-heap.c +++ b/drivers/dma-buf/dma-heap.c @@ -7,6 +7,7 @@ */

#include <linux/cdev.h> +#include <linux/cgroup_gpu.h> #include <linux/debugfs.h> #include <linux/device.h> #include <linux/dma-buf.h> @@ -31,6 +32,7 @@ * @heap_devt heap device node * @list list head connecting to list of heaps * @heap_cdev heap char device + * @gpucg_dev gpu cgroup device for memory accounting * * Represents a heap of memory from which buffers can be made. */ @@ -41,6 +43,9 @@ struct dma_heap { dev_t heap_devt; struct list_head list; struct cdev heap_cdev; +#ifdef CONFIG_CGROUP_GPU + struct gpucg_device gpucg_dev; +#endif };

static LIST_HEAD(heap_list); @@ -216,6 +221,26 @@ const char *dma_heap_get_name(struct dma_heap *heap) return heap->name; }

+#ifdef CONFIG_CGROUP_GPU +/** + * dma_heap_get_gpucg_dev() - get struct gpucg_device for the heap. + * @heap: DMA-Heap to get the gpucg_device struct for. + * + * Returns: + * The gpucg_device struct for the heap. NULL if the GPU cgroup controller is + * not enabled. + */ +struct gpucg_device *dma_heap_get_gpucg_dev(struct dma_heap *heap) +{ + return &heap->gpucg_dev; +} +#else /* CONFIG_CGROUP_GPU */ +struct gpucg_device *dma_heap_get_gpucg_dev(struct dma_heap *heap) +{ + return NULL; +} +#endif /* CONFIG_CGROUP_GPU */ + struct dma_heap *dma_heap_add(const struct dma_heap_export_info *exp_info) { struct dma_heap *heap, *h, *err_ret; @@ -288,6 +313,8 @@ struct dma_heap *dma_heap_add(const struct dma_heap_export_info *exp_info) list_add(&heap->list, &heap_list); mutex_unlock(&heap_list_lock);

+ gpucg_register_device(dma_heap_get_gpucg_dev(heap), exp_info->name); + return heap;

err2: diff --git a/drivers/dma-buf/heaps/system_heap.c b/drivers/dma-buf/heaps/system_heap.c index ab7fd896d2c4..752a05c3cfe2 100644 --- a/drivers/dma-buf/heaps/system_heap.c +++ b/drivers/dma-buf/heaps/system_heap.c @@ -395,6 +395,9 @@ static struct dma_buf *system_heap_allocate(struct dma_heap *heap, exp_info.ops = &system_heap_buf_ops; exp_info.size = buffer->len; exp_info.flags = fd_flags; +#ifdef CONFIG_CGROUP_GPU + exp_info.gpucg_dev = dma_heap_get_gpucg_dev(heap); +#endif exp_info.priv = buffer; dmabuf = dma_buf_export(&exp_info); if (IS_ERR(dmabuf)) { diff --git a/include/linux/dma-heap.h b/include/linux/dma-heap.h index 0c05561cad6e..e447a61d054e 100644 --- a/include/linux/dma-heap.h +++ b/include/linux/dma-heap.h @@ -10,6 +10,7 @@ #define _DMA_HEAPS_H

#include <linux/cdev.h> +#include <linux/cgroup_gpu.h> #include <linux/types.h>

struct dma_heap; @@ -59,6 +60,16 @@ void *dma_heap_get_drvdata(struct dma_heap *heap); */ const char *dma_heap_get_name(struct dma_heap *heap);

+/** + * dma_heap_get_gpucg_dev() - get a pointer to the struct gpucg_device for the + * heap. + * @heap: DMA-Heap to retrieve gpucg_device for. + * + * Returns: + * The gpucg_device struct for the heap. + */ +struct gpucg_device *dma_heap_get_gpucg_dev(struct dma_heap *heap); + /** * dma_heap_add - adds a heap to dmabuf heaps * @exp_info: information needed to register this heap

From: Hridya Valsaraju hridya@google.com

This patch introduces a buffer flag BINDER_BUFFER_FLAG_SENDER_NO_NEED that a process sending an fd array to another process over binder IPC can set to relinquish ownership of the fds being sent for memory accounting purposes. If the flag is found to be set during the fd array translation and the fd is for a DMA-BUF, the buffer is uncharged from the sender's cgroup and charged to the receiving process's cgroup instead.

It is up to the sending process to ensure that it closes the fds regardless of whether the transfer failed or succeeded.

Most graphics shared memory allocations in Android are done by the graphics allocator HAL process. On requests from clients, the HAL process allocates memory and sends the fds to the clients over binder IPC. The graphics allocator HAL will not retain any references to the buffers. When the HAL sets the BINDER_BUFFER_FLAG_SENDER_NO_NEED for fd arrays holding DMA-BUF fds, the gpu cgroup controller will be able to correctly charge the buffers to the client processes instead of the graphics allocator HAL.

Since this is a new feature exposed to userspace, the kernel and userspace must be compatible for the accounting to work for transfers. In all cases the allocation and transport of DMA buffers via binder will succeed, but only when both the kernel supports, and userspace depends on this feature will the transfer accounting work. The possible scenarios are detailed below:

1. new kernel + old userspace The kernel supports the feature but userspace does not use it. The old userspace won't mount the new cgroup controller, accounting is not performed, charge is not transferred.

2. old kernel + new userspace The new cgroup controller is not supported by the kernel, accounting is not performed, charge is not transferred.

3. old kernel + old userspace Same as #2

4. new kernel + new userspace Cgroup is mounted, feature is supported and used.

Signed-off-by: Hridya Valsaraju hridya@google.com Signed-off-by: T.J. Mercier tjmercier@google.com

--- v3 changes Remove android from title per Todd Kjos.

Use more common dual author commit message format per John Stultz.

Include details on behavior for all combinations of kernel/userspace versions in changelog (thanks Suren Baghdasaryan) per Greg Kroah-Hartman.

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/android/binder.c | 26 ++++++++++++++++++++++++++ include/uapi/linux/android/binder.h | 1 + 2 files changed, 27 insertions(+)

diff --git a/drivers/android/binder.c b/drivers/android/binder.c index 8351c5638880..4357d2efc8e1 100644 --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -42,6 +42,7 @@

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

+#include <linux/dma-buf.h> #include <linux/fdtable.h> #include <linux/file.h> #include <linux/freezer.h> @@ -2482,8 +2483,10 @@ static int binder_translate_fd_array(struct list_head *pf_head, { binder_size_t fdi, fd_buf_size; binder_size_t fda_offset; + bool transfer_gpu_charge = false; const void __user *sender_ufda_base; struct binder_proc *proc = thread->proc; + struct binder_proc *target_proc = t->to_proc; int ret;

fd_buf_size = sizeof(u32) * fda->num_fds; @@ -2521,8 +2524,15 @@ static int binder_translate_fd_array(struct list_head *pf_head, if (ret) return ret;

+ if (IS_ENABLED(CONFIG_CGROUP_GPU) && + parent->flags & BINDER_BUFFER_FLAG_SENDER_NO_NEED) + transfer_gpu_charge = true; + for (fdi = 0; fdi < fda->num_fds; fdi++) { u32 fd; + struct dma_buf *dmabuf; + struct gpucg *gpucg; + binder_size_t offset = fda_offset + fdi * sizeof(fd); binder_size_t sender_uoffset = fdi * sizeof(fd);

@@ -2532,6 +2542,22 @@ static int binder_translate_fd_array(struct list_head *pf_head, in_reply_to); if (ret) return ret > 0 ? -EINVAL : ret; + + if (!transfer_gpu_charge) + continue; + + dmabuf = dma_buf_get(fd); + if (IS_ERR(dmabuf)) + continue; + + gpucg = gpucg_get(target_proc->tsk); + ret = dma_buf_transfer_charge(dmabuf, gpucg); + if (ret) { + pr_warn("%d:%d Unable to transfer DMA-BUF fd charge to %d", + proc->pid, thread->pid, target_proc->pid); + gpucg_put(gpucg); + } + dma_buf_put(dmabuf); } return 0; } diff --git a/include/uapi/linux/android/binder.h b/include/uapi/linux/android/binder.h index 3246f2c74696..169fd5069a1a 100644 --- a/include/uapi/linux/android/binder.h +++ b/include/uapi/linux/android/binder.h @@ -137,6 +137,7 @@ struct binder_buffer_object {

enum { BINDER_BUFFER_FLAG_HAS_PARENT = 0x01, + BINDER_BUFFER_FLAG_SENDER_NO_NEED = 0x02, };

/* struct binder_fd_array_object - object describing an array of fds in a buffer

This test verifies that the cgroup GPU memory charge is transferred correctly when a dmabuf is passed between processes in two different cgroups and the sender specifies BINDER_BUFFER_FLAG_SENDER_NO_NEED in the binder transaction data containing the dmabuf file descriptor.

Signed-off-by: T.J. Mercier tjmercier@google.com --- v4 changes Skip test if not run as root per Shuah Khan.

Add better logging for abnormal child termination per Shuah Khan. --- .../selftests/drivers/android/binder/Makefile | 8 + .../drivers/android/binder/binder_util.c | 254 +++++++++ .../drivers/android/binder/binder_util.h | 32 ++ .../selftests/drivers/android/binder/config | 4 + .../binder/test_dmabuf_cgroup_transfer.c | 484 ++++++++++++++++++ 5 files changed, 782 insertions(+) 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

diff --git a/tools/testing/selftests/drivers/android/binder/Makefile b/tools/testing/selftests/drivers/android/binder/Makefile new file mode 100644 index 000000000000..726439d10675 --- /dev/null +++ b/tools/testing/selftests/drivers/android/binder/Makefile @@ -0,0 +1,8 @@ +# SPDX-License-Identifier: GPL-2.0 +CFLAGS += -Wall + +TEST_GEN_PROGS = test_dmabuf_cgroup_transfer + +include ../../../lib.mk + +$(OUTPUT)/test_dmabuf_cgroup_transfer: ../../../cgroup/cgroup_util.c binder_util.c diff --git a/tools/testing/selftests/drivers/android/binder/binder_util.c b/tools/testing/selftests/drivers/android/binder/binder_util.c new file mode 100644 index 000000000000..c9dcf5b9d42b --- /dev/null +++ b/tools/testing/selftests/drivers/android/binder/binder_util.c @@ -0,0 +1,254 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include "binder_util.h" + +#include <errno.h> +#include <fcntl.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include <sys/ioctl.h> +#include <sys/mman.h> +#include <sys/mount.h> + +#include <linux/limits.h> +#include <linux/android/binder.h> +#include <linux/android/binderfs.h> + +static const size_t BINDER_MMAP_SIZE = 64 * 1024; + +static void binderfs_unmount(const char *mountpoint) +{ + if (umount2(mountpoint, MNT_DETACH)) + fprintf(stderr, "Failed to unmount binderfs at %s: %s\n", + mountpoint, strerror(errno)); + else + fprintf(stderr, "Binderfs unmounted: %s\n", mountpoint); + + if (rmdir(mountpoint)) + fprintf(stderr, "Failed to remove binderfs mount %s: %s\n", + mountpoint, strerror(errno)); + else + fprintf(stderr, "Binderfs mountpoint destroyed: %s\n", mountpoint); +} + +struct binderfs_ctx create_binderfs(const char *name) +{ + int fd, ret, saved_errno; + struct binderfs_device device = { 0 }; + struct binderfs_ctx ctx = { 0 }; + + /* + * P_tmpdir is set to "/tmp/" on Android platforms where Binder is most + * commonly used, but this path does not actually exist on Android. We + * will first try using "/data/local/tmp" and fallback to P_tmpdir if + * that fails for non-Android platforms. + */ + static const char tmpdir[] = "/data/local/tmp"; + static const size_t MAX_TMPDIR_SIZE = + sizeof(tmpdir) > sizeof(P_tmpdir) ? + sizeof(tmpdir) : sizeof(P_tmpdir); + static const char template[] = "/binderfs_XXXXXX"; + + char *mkdtemp_result; + char binderfs_mntpt[MAX_TMPDIR_SIZE + sizeof(template)]; + char device_path[MAX_TMPDIR_SIZE + sizeof(template) + BINDERFS_MAX_NAME]; + + snprintf(binderfs_mntpt, sizeof(binderfs_mntpt), "%s%s", tmpdir, template); + + mkdtemp_result = mkdtemp(binderfs_mntpt); + if (mkdtemp_result == NULL) { + fprintf(stderr, "Failed to create binderfs mountpoint at %s: %s.\n", + binderfs_mntpt, strerror(errno)); + fprintf(stderr, "Trying fallback mountpoint...\n"); + snprintf(binderfs_mntpt, sizeof(binderfs_mntpt), "%s%s", P_tmpdir, template); + if (mkdtemp(binderfs_mntpt) == NULL) { + fprintf(stderr, "Failed to create binderfs mountpoint at %s: %s\n", + binderfs_mntpt, strerror(errno)); + return ctx; + } + } + fprintf(stderr, "Binderfs mountpoint created at %s\n", binderfs_mntpt); + + if (mount(NULL, binderfs_mntpt, "binder", 0, 0)) { + perror("Could not mount binderfs"); + rmdir(binderfs_mntpt); + return ctx; + } + fprintf(stderr, "Binderfs mounted at %s\n", binderfs_mntpt); + + strncpy(device.name, name, sizeof(device.name)); + snprintf(device_path, sizeof(device_path), "%s/binder-control", binderfs_mntpt); + fd = open(device_path, O_RDONLY | O_CLOEXEC); + if (!fd) { + perror("Failed to open binder-control device"); + binderfs_unmount(binderfs_mntpt); + return ctx; + } + + ret = ioctl(fd, BINDER_CTL_ADD, &device); + saved_errno = errno; + close(fd); + errno = saved_errno; + if (ret) { + perror("Failed to allocate new binder device"); + binderfs_unmount(binderfs_mntpt); + return ctx; + } + + fprintf(stderr, "Allocated new binder device with major %d, minor %d, and name %s at %s\n", + device.major, device.minor, device.name, binderfs_mntpt); + + ctx.name = strdup(name); + ctx.mountpoint = strdup(binderfs_mntpt); + return ctx; +} + +void destroy_binderfs(struct binderfs_ctx *ctx) +{ + char path[PATH_MAX]; + + snprintf(path, sizeof(path), "%s/%s", ctx->mountpoint, ctx->name); + + if (unlink(path)) + fprintf(stderr, "Failed to unlink binder device %s: %s\n", path, strerror(errno)); + else + fprintf(stderr, "Destroyed binder %s at %s\n", ctx->name, ctx->mountpoint); + + binderfs_unmount(ctx->mountpoint); + + free(ctx->name); + free(ctx->mountpoint); +} + +struct binder_ctx open_binder(struct binderfs_ctx *bfs_ctx) +{ + struct binder_ctx ctx = {.fd = -1, .memory = NULL}; + char path[PATH_MAX]; + + snprintf(path, sizeof(path), "%s/%s", bfs_ctx->mountpoint, bfs_ctx->name); + ctx.fd = open(path, O_RDWR | O_NONBLOCK | O_CLOEXEC); + if (ctx.fd < 0) { + fprintf(stderr, "Error opening binder device %s: %s\n", path, strerror(errno)); + return ctx; + } + + ctx.memory = mmap(NULL, BINDER_MMAP_SIZE, PROT_READ, MAP_SHARED, ctx.fd, 0); + if (ctx.memory == NULL) { + perror("Error mapping binder memory"); + close(ctx.fd); + ctx.fd = -1; + } + + return ctx; +} + +void close_binder(struct binder_ctx *ctx) +{ + if (munmap(ctx->memory, BINDER_MMAP_SIZE)) + perror("Failed to unmap binder memory"); + ctx->memory = NULL; + + if (close(ctx->fd)) + perror("Failed to close binder"); + ctx->fd = -1; +} + +int become_binder_context_manager(int binder_fd) +{ + return ioctl(binder_fd, BINDER_SET_CONTEXT_MGR, 0); +} + +int do_binder_write_read(int binder_fd, void *writebuf, binder_size_t writesize, + void *readbuf, binder_size_t readsize) +{ + int err; + struct binder_write_read bwr = { + .write_buffer = (binder_uintptr_t)writebuf, + .write_size = writesize, + .read_buffer = (binder_uintptr_t)readbuf, + .read_size = readsize + }; + + do { + if (ioctl(binder_fd, BINDER_WRITE_READ, &bwr) >= 0) + err = 0; + else + err = -errno; + } while (err == -EINTR); + + if (err < 0) { + perror("BINDER_WRITE_READ"); + return -1; + } + + if (bwr.write_consumed < writesize) { + fprintf(stderr, "Binder did not consume full write buffer %llu %llu\n", + bwr.write_consumed, writesize); + return -1; + } + + return bwr.read_consumed; +} + +static const char *reply_string(int cmd) +{ + switch (cmd) { + case BR_ERROR: + return("BR_ERROR"); + case BR_OK: + return("BR_OK"); + case BR_TRANSACTION_SEC_CTX: + return("BR_TRANSACTION_SEC_CTX"); + case BR_TRANSACTION: + return("BR_TRANSACTION"); + case BR_REPLY: + return("BR_REPLY"); + case BR_ACQUIRE_RESULT: + return("BR_ACQUIRE_RESULT"); + case BR_DEAD_REPLY: + return("BR_DEAD_REPLY"); + case BR_TRANSACTION_COMPLETE: + return("BR_TRANSACTION_COMPLETE"); + case BR_INCREFS: + return("BR_INCREFS"); + case BR_ACQUIRE: + return("BR_ACQUIRE"); + case BR_RELEASE: + return("BR_RELEASE"); + case BR_DECREFS: + return("BR_DECREFS"); + case BR_ATTEMPT_ACQUIRE: + return("BR_ATTEMPT_ACQUIRE"); + case BR_NOOP: + return("BR_NOOP"); + case BR_SPAWN_LOOPER: + return("BR_SPAWN_LOOPER"); + case BR_FINISHED: + return("BR_FINISHED"); + case BR_DEAD_BINDER: + return("BR_DEAD_BINDER"); + case BR_CLEAR_DEATH_NOTIFICATION_DONE: + return("BR_CLEAR_DEATH_NOTIFICATION_DONE"); + case BR_FAILED_REPLY: + return("BR_FAILED_REPLY"); + case BR_FROZEN_REPLY: + return("BR_FROZEN_REPLY"); + case BR_ONEWAY_SPAM_SUSPECT: + return("BR_ONEWAY_SPAM_SUSPECT"); + default: + return("Unknown"); + }; +} + +int expect_binder_reply(int32_t actual, int32_t expected) +{ + if (actual != expected) { + fprintf(stderr, "Expected %s but received %s\n", + reply_string(expected), reply_string(actual)); + return -1; + } + return 0; +} + diff --git a/tools/testing/selftests/drivers/android/binder/binder_util.h b/tools/testing/selftests/drivers/android/binder/binder_util.h new file mode 100644 index 000000000000..807f5abe987e --- /dev/null +++ b/tools/testing/selftests/drivers/android/binder/binder_util.h @@ -0,0 +1,32 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef SELFTEST_BINDER_UTIL_H +#define SELFTEST_BINDER_UTIL_H + +#include <stdint.h> + +#include <linux/android/binder.h> + +struct binderfs_ctx { + char *name; + char *mountpoint; +}; + +struct binder_ctx { + int fd; + void *memory; +}; + +struct binderfs_ctx create_binderfs(const char *name); +void destroy_binderfs(struct binderfs_ctx *ctx); + +struct binder_ctx open_binder(struct binderfs_ctx *bfs_ctx); +void close_binder(struct binder_ctx *ctx); + +int become_binder_context_manager(int binder_fd); + +int do_binder_write_read(int binder_fd, void *writebuf, binder_size_t writesize, + void *readbuf, binder_size_t readsize); + +int expect_binder_reply(int32_t actual, int32_t expected); +#endif diff --git a/tools/testing/selftests/drivers/android/binder/config b/tools/testing/selftests/drivers/android/binder/config new file mode 100644 index 000000000000..fcc5f8f693b3 --- /dev/null +++ b/tools/testing/selftests/drivers/android/binder/config @@ -0,0 +1,4 @@ +CONFIG_CGROUP_GPU=y +CONFIG_ANDROID=y +CONFIG_ANDROID_BINDERFS=y +CONFIG_ANDROID_BINDER_IPC=y diff --git a/tools/testing/selftests/drivers/android/binder/test_dmabuf_cgroup_transfer.c b/tools/testing/selftests/drivers/android/binder/test_dmabuf_cgroup_transfer.c new file mode 100644 index 000000000000..586465d7bf6d --- /dev/null +++ b/tools/testing/selftests/drivers/android/binder/test_dmabuf_cgroup_transfer.c @@ -0,0 +1,484 @@ +// SPDX-License-Identifier: GPL-2.0 + +/* + * This test verifies that the cgroup GPU memory charge is transferred correctly + * when a dmabuf is passed between processes in two different cgroups and the + * sender specifies BINDER_BUFFER_FLAG_SENDER_NO_NEED in the binder transaction + * data containing the dmabuf file descriptor. + * + * The gpu_cgroup_dmabuf_transfer test function becomes the binder context + * manager, then forks a child who initiates a transaction with the context + * manager by specifying a target of 0. The context manager reply contains a + * dmabuf file descriptor which was allocated by the gpu_cgroup_dmabuf_transfer + * test function, but should be charged to the child cgroup after the binder + * transaction. + */ + +#include <errno.h> +#include <fcntl.h> +#include <stddef.h> +#include <stdint.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include <sys/epoll.h> +#include <sys/ioctl.h> +#include <sys/types.h> +#include <sys/wait.h> + +#include "binder_util.h" +#include "../../../cgroup/cgroup_util.h" +#include "../../../kselftest.h" +#include "../../../kselftest_harness.h" + +#include <linux/limits.h> +#include <linux/dma-heap.h> +#include <linux/android/binder.h> + +#define UNUSED(x) ((void)(x)) + +static const unsigned int BINDER_CODE = 8675309; /* Any number will work here */ + +struct cgroup_ctx { + char *root; + char *source; + char *dest; +}; + +void destroy_cgroups(struct __test_metadata *_metadata, struct cgroup_ctx *ctx) +{ + if (ctx->source != NULL) { + TH_LOG("Destroying cgroup: %s", ctx->source); + rmdir(ctx->source); + free(ctx->source); + } + + if (ctx->dest != NULL) { + TH_LOG("Destroying cgroup: %s", ctx->dest); + rmdir(ctx->dest); + free(ctx->dest); + } + + free(ctx->root); + ctx->root = ctx->source = ctx->dest = NULL; +} + +struct cgroup_ctx create_cgroups(struct __test_metadata *_metadata) +{ + struct cgroup_ctx ctx = {0}; + char root[PATH_MAX], *tmp; + static const char template[] = "/gpucg_XXXXXX"; + + if (cg_find_unified_root(root, sizeof(root))) { + TH_LOG("Could not find cgroups root"); + return ctx; + } + + if (cg_read_strstr(root, "cgroup.controllers", "gpu")) { + TH_LOG("Could not find GPU controller"); + return ctx; + } + + if (cg_write(root, "cgroup.subtree_control", "+gpu")) { + TH_LOG("Could not enable GPU controller"); + return ctx; + } + + ctx.root = strdup(root); + + snprintf(root, sizeof(root), "%s/%s", ctx.root, template); + tmp = mkdtemp(root); + if (tmp == NULL) { + TH_LOG("%s - Could not create source cgroup", strerror(errno)); + destroy_cgroups(_metadata, &ctx); + return ctx; + } + ctx.source = strdup(tmp); + + snprintf(root, sizeof(root), "%s/%s", ctx.root, template); + tmp = mkdtemp(root); + if (tmp == NULL) { + TH_LOG("%s - Could not create destination cgroup", strerror(errno)); + destroy_cgroups(_metadata, &ctx); + return ctx; + } + ctx.dest = strdup(tmp); + + TH_LOG("Created cgroups: %s %s", ctx.source, ctx.dest); + + return ctx; +} + +int dmabuf_heap_alloc(int fd, size_t len, int *dmabuf_fd) +{ + struct dma_heap_allocation_data data = { + .len = len, + .fd = 0, + .fd_flags = O_RDONLY | O_CLOEXEC, + .heap_flags = 0, + }; + int ret; + + if (!dmabuf_fd) + return -EINVAL; + + ret = ioctl(fd, DMA_HEAP_IOCTL_ALLOC, &data); + if (ret < 0) + return ret; + *dmabuf_fd = (int)data.fd; + return ret; +} + +/* The system heap is known to export dmabufs with support for cgroup tracking */ +int alloc_dmabuf_from_system_heap(struct __test_metadata *_metadata, size_t bytes) +{ + int heap_fd = -1, dmabuf_fd = -1; + static const char * const heap_path = "/dev/dma_heap/system"; + + heap_fd = open(heap_path, O_RDONLY); + if (heap_fd < 0) { + TH_LOG("%s - open %s failed!\n", strerror(errno), heap_path); + return -1; + } + + if (dmabuf_heap_alloc(heap_fd, bytes, &dmabuf_fd)) + TH_LOG("dmabuf allocation failed! - %s", strerror(errno)); + close(heap_fd); + + return dmabuf_fd; +} + +int binder_request_dmabuf(int binder_fd) +{ + int ret; + + /* + * We just send an empty binder_buffer_object to initiate a transaction + * with the context manager, who should respond with a single dmabuf + * inside a binder_fd_array_object. + */ + + struct binder_buffer_object bbo = { + .hdr.type = BINDER_TYPE_PTR, + .flags = 0, + .buffer = 0, + .length = 0, + .parent = 0, /* No parent */ + .parent_offset = 0 /* No parent */ + }; + + binder_size_t offsets[] = {0}; + + struct { + int32_t cmd; + struct binder_transaction_data btd; + } __attribute__((packed)) bc = { + .cmd = BC_TRANSACTION, + .btd = { + .target = { 0 }, + .cookie = 0, + .code = BINDER_CODE, + .flags = TF_ACCEPT_FDS, /* We expect a FDA in the reply */ + .data_size = sizeof(bbo), + .offsets_size = sizeof(offsets), + .data.ptr = { + (binder_uintptr_t)&bbo, + (binder_uintptr_t)offsets + } + }, + }; + + struct { + int32_t reply_noop; + } __attribute__((packed)) br; + + ret = do_binder_write_read(binder_fd, &bc, sizeof(bc), &br, sizeof(br)); + if (ret >= sizeof(br) && expect_binder_reply(br.reply_noop, BR_NOOP)) { + return -1; + } else if (ret < sizeof(br)) { + fprintf(stderr, "Not enough bytes in binder reply %d\n", ret); + return -1; + } + return 0; +} + +int send_dmabuf_reply(int binder_fd, struct binder_transaction_data *tr, int dmabuf_fd) +{ + int ret; + /* + * The trailing 0 is to achieve the necessary alignment for the binder + * buffer_size. + */ + int fdarray[] = { dmabuf_fd, 0 }; + + struct binder_buffer_object bbo = { + .hdr.type = BINDER_TYPE_PTR, + .flags = BINDER_BUFFER_FLAG_SENDER_NO_NEED, + .buffer = (binder_uintptr_t)fdarray, + .length = sizeof(fdarray), + .parent = 0, /* No parent */ + .parent_offset = 0 /* No parent */ + }; + + struct binder_fd_array_object bfdao = { + .hdr.type = BINDER_TYPE_FDA, + .num_fds = 1, + .parent = 0, /* The binder_buffer_object */ + .parent_offset = 0 /* FDs follow immediately */ + }; + + uint64_t sz = sizeof(fdarray); + uint8_t data[sizeof(sz) + sizeof(bbo) + sizeof(bfdao)]; + binder_size_t offsets[] = {sizeof(sz), sizeof(sz)+sizeof(bbo)}; + + memcpy(data, &sz, sizeof(sz)); + memcpy(data + sizeof(sz), &bbo, sizeof(bbo)); + memcpy(data + sizeof(sz) + sizeof(bbo), &bfdao, sizeof(bfdao)); + + struct { + int32_t cmd; + struct binder_transaction_data_sg btd; + } __attribute__((packed)) bc = { + .cmd = BC_REPLY_SG, + .btd.transaction_data = { + .target = { tr->target.handle }, + .cookie = tr->cookie, + .code = BINDER_CODE, + .flags = 0, + .data_size = sizeof(data), + .offsets_size = sizeof(offsets), + .data.ptr = { + (binder_uintptr_t)data, + (binder_uintptr_t)offsets + } + }, + .btd.buffers_size = sizeof(fdarray) + }; + + struct { + int32_t reply_noop; + } __attribute__((packed)) br; + + ret = do_binder_write_read(binder_fd, &bc, sizeof(bc), &br, sizeof(br)); + if (ret >= sizeof(br) && expect_binder_reply(br.reply_noop, BR_NOOP)) { + return -1; + } else if (ret < sizeof(br)) { + fprintf(stderr, "Not enough bytes in binder reply %d\n", ret); + return -1; + } + return 0; +} + +struct binder_transaction_data *binder_wait_for_transaction(int binder_fd, + uint32_t *readbuf, + size_t readsize) +{ + static const int MAX_EVENTS = 1, EPOLL_WAIT_TIME_MS = 3 * 1000; + struct binder_reply { + int32_t reply0; + int32_t reply1; + struct binder_transaction_data btd; + } *br; + struct binder_transaction_data *ret = NULL; + struct epoll_event events[MAX_EVENTS]; + int epoll_fd, num_events, readcount; + uint32_t bc[] = { BC_ENTER_LOOPER }; + + do_binder_write_read(binder_fd, &bc, sizeof(bc), NULL, 0); + + epoll_fd = epoll_create1(EPOLL_CLOEXEC); + if (epoll_fd == -1) { + perror("epoll_create"); + return NULL; + } + + events[0].events = EPOLLIN; + if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, binder_fd, &events[0])) { + perror("epoll_ctl add"); + goto err_close; + } + + num_events = epoll_wait(epoll_fd, events, MAX_EVENTS, EPOLL_WAIT_TIME_MS); + if (num_events < 0) { + perror("epoll_wait"); + goto err_ctl; + } else if (num_events == 0) { + fprintf(stderr, "No events\n"); + goto err_ctl; + } + + readcount = do_binder_write_read(binder_fd, NULL, 0, readbuf, readsize); + fprintf(stderr, "Read %d bytes from binder\n", readcount); + + if (readcount < (int)sizeof(struct binder_reply)) { + fprintf(stderr, "read_consumed not large enough\n"); + goto err_ctl; + } + + br = (struct binder_reply *)readbuf; + if (expect_binder_reply(br->reply0, BR_NOOP)) + goto err_ctl; + + if (br->reply1 == BR_TRANSACTION) { + if (br->btd.code == BINDER_CODE) + ret = &br->btd; + else + fprintf(stderr, "Received transaction with unexpected code: %u\n", + br->btd.code); + } else { + expect_binder_reply(br->reply1, BR_TRANSACTION_COMPLETE); + } + +err_ctl: + if (epoll_ctl(epoll_fd, EPOLL_CTL_DEL, binder_fd, NULL)) + perror("epoll_ctl del"); +err_close: + close(epoll_fd); + return ret; +} + +static int child_request_dmabuf_transfer(const char *cgroup, void *arg) +{ + UNUSED(cgroup); + int ret = -1; + uint32_t readbuf[32]; + struct binderfs_ctx bfs_ctx = *(struct binderfs_ctx *)arg; + struct binder_ctx b_ctx; + + fprintf(stderr, "Child PID: %d\n", getpid()); + + b_ctx = open_binder(&bfs_ctx); + if (b_ctx.fd < 0) { + fprintf(stderr, "Child unable to open binder\n"); + return -1; + } + + if (binder_request_dmabuf(b_ctx.fd)) + goto err; + + /* The child must stay alive until the binder reply is received */ + if (binder_wait_for_transaction(b_ctx.fd, readbuf, sizeof(readbuf)) == NULL) + ret = 0; + + /* + * We don't close the received dmabuf here so that the parent can + * inspect the cgroup gpu memory charges to verify the charge transfer + * completed successfully. + */ +err: + close_binder(&b_ctx); + fprintf(stderr, "Child done\n"); + return ret; +} + +TEST(gpu_cgroup_dmabuf_transfer) +{ + static const char * const GPUMEM_FILENAME = "gpu.memory.current"; + static const size_t ONE_MiB = 1024 * 1024; + + int ret, dmabuf_fd; + uint32_t readbuf[32]; + long memsize; + pid_t child_pid; + struct binderfs_ctx bfs_ctx; + struct binder_ctx b_ctx; + struct cgroup_ctx cg_ctx; + struct binder_transaction_data *tr; + struct flat_binder_object *fbo; + struct binder_buffer_object *bbo; + + if (geteuid() != 0) + ksft_exit_skip("Need to be root to mount binderfs\n"); + + bfs_ctx = create_binderfs("testbinder"); + if (bfs_ctx.name == NULL) + ksft_exit_skip("The Android binderfs filesystem is not available\n"); + + cg_ctx = create_cgroups(_metadata); + if (cg_ctx.root == NULL) { + destroy_binderfs(&bfs_ctx); + ksft_exit_skip("cgroup v2 isn't mounted\n"); + } + + ASSERT_EQ(cg_enter_current(cg_ctx.source), 0) { + TH_LOG("Could not move parent to cgroup: %s", cg_ctx.source); + goto err_cg; + } + + dmabuf_fd = alloc_dmabuf_from_system_heap(_metadata, ONE_MiB); + ASSERT_GE(dmabuf_fd, 0) { + goto err_cg; + } + TH_LOG("Allocated dmabuf"); + + memsize = cg_read_key_long(cg_ctx.source, GPUMEM_FILENAME, "system"); + ASSERT_EQ(memsize, ONE_MiB) { + TH_LOG("GPU memory used after allocation: %ld but it should be %lu", + memsize, (unsigned long)ONE_MiB); + goto err_dmabuf; + } + + b_ctx = open_binder(&bfs_ctx); + ASSERT_GE(b_ctx.fd, 0) { + TH_LOG("Parent unable to open binder"); + goto err_dmabuf; + } + TH_LOG("Opened binder at %s/%s", bfs_ctx.mountpoint, bfs_ctx.name); + + ASSERT_EQ(become_binder_context_manager(b_ctx.fd), 0) { + TH_LOG("Cannot become context manager: %s", strerror(errno)); + goto err_binder; + } + + child_pid = cg_run_nowait(cg_ctx.dest, child_request_dmabuf_transfer, &bfs_ctx); + ASSERT_GT(child_pid, 0) { + TH_LOG("Error forking: %s", strerror(errno)); + goto err_binder; + } + + tr = binder_wait_for_transaction(b_ctx.fd, readbuf, sizeof(readbuf)); + ASSERT_NE(tr, NULL) { + TH_LOG("Error receiving transaction request from child"); + goto err_child; + } + fbo = (struct flat_binder_object *)tr->data.ptr.buffer; + ASSERT_EQ(fbo->hdr.type, BINDER_TYPE_PTR) { + TH_LOG("Did not receive a buffer object from child"); + goto err_child; + } + bbo = (struct binder_buffer_object *)fbo; + ASSERT_EQ(bbo->length, 0) { + TH_LOG("Did not receive an empty buffer object from child"); + goto err_child; + } + + TH_LOG("Received transaction from child"); + send_dmabuf_reply(b_ctx.fd, tr, dmabuf_fd); + + ASSERT_EQ(cg_read_key_long(cg_ctx.dest, GPUMEM_FILENAME, "system"), ONE_MiB) { + TH_LOG("Destination cgroup does not have system charge!"); + goto err_child; + } + ASSERT_EQ(cg_read_key_long(cg_ctx.source, GPUMEM_FILENAME, "system"), 0) { + TH_LOG("Source cgroup still has system charge!"); + goto err_child; + } + TH_LOG("Charge transfer succeeded!"); + +err_child: + waitpid(child_pid, &ret, 0); + if (WIFEXITED(ret)) + TH_LOG("Child %d terminated normally with %d", child_pid, WEXITSTATUS(ret)); + else if (WIFSIGNALED(ret)) + TH_LOG("Child %d terminated with signal %d\n", child_pid, WTERMSIG(ret)); +err_binder: + close_binder(&b_ctx); +err_dmabuf: + close(dmabuf_fd); +err_cg: + destroy_cgroups(_metadata, &cg_ctx); + destroy_binderfs(&bfs_ctx); +} + +TEST_HARNESS_MAIN

On Mon, Mar 28, 2022 at 7:36 AM Daniel Vetter daniel@ffwll.ch wrote:

On Mon, Mar 28, 2022 at 03:59:43AM +0000, T.J. Mercier wrote:

...

From: Hridya Valsaraju hridya@google.com

All DMA heaps now register a new GPU cgroup device upon creation, and the system_heap now exports buffers associated with its GPU cgroup device for tracking purposes.

Signed-off-by: Hridya Valsaraju hridya@google.com Signed-off-by: T.J. Mercier tjmercier@google.com

---

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.

Apologies for being out of the loop quite a bit. I scrolled through this all and I think it looks good to get going.

The only thing I have is whether we should move the cgroup controllers out of dma-buf heaps, since that's rather android centric. E.g.

• a system gpucg_device which is used by all the various single page allocators (dma-buf heap but also shmem helpers and really anything else)
• same for cma, again both for dma-buf heaps and also for the gem cma helpers in drm

Thanks Daniel, in general that makes sense to me as an approach to making this more universal. However for the Android case I'm not sure if the part about a single system gpucg_device would be sufficient, because there are at least 12 different graphics related heaps that could potentially be accounted/limited differently. [1] So that raises the question of how fine grained we want this to be... I tend towards separating them all, but I haven't formed a strong opinion about this at the moment. It sounds like you are in favor of a smaller, more rigidly defined set of them? Either way, we need to add code for accounting at points where we know memory is specifically for graphics use and not something else right? (I.E. Whether it is a dma-buf heap or somewhere like drm_gem_object_init.) So IIUC the only question is what to use for the gpucg_device(s) at these locations.

[1] https://cs.android.com/android/platform/superproject/+/master:hardware/googl...

Otherwise this will only work on non-upstream android where gpu drivers allocate everything from dma-buf heap. If you use something like the x86 android project with mesa drivers, then driver-internal buffers will be allocated through gem and not through dma-buf heaps. Or at least I think that's how it works.

But also meh, we can fix this fairly easily later on by adding these standard gpucg_dev somwehere with a bit of kerneldoc.

This is what I was thinking would happen next, but IDK if anyone sees a more central place to do this type of use-specific accounting.

Anyway has my all my ack, but don't count this as my in-depth review :-) -Daniel

Thanks again for taking a look!

...

---

drivers/dma-buf/dma-heap.c | 27 +++++++++++++++++++++++++++ drivers/dma-buf/heaps/system_heap.c | 3 +++ include/linux/dma-heap.h | 11 +++++++++++ 3 files changed, 41 insertions(+)

diff --git a/drivers/dma-buf/dma-heap.c b/drivers/dma-buf/dma-heap.c index 8f5848aa144f..885072427775 100644 --- a/drivers/dma-buf/dma-heap.c +++ b/drivers/dma-buf/dma-heap.c @@ -7,6 +7,7 @@ */

#include <linux/cdev.h> +#include <linux/cgroup_gpu.h> #include <linux/debugfs.h> #include <linux/device.h> #include <linux/dma-buf.h> @@ -31,6 +32,7 @@

• @heap_devt heap device node
• @list list head connecting to list of heaps
• @heap_cdev heap char device

• • @gpucg_dev gpu cgroup device for memory accounting
  • Represents a heap of memory from which buffers can be made.
  */

@@ -41,6 +43,9 @@ struct dma_heap { dev_t heap_devt; struct list_head list; struct cdev heap_cdev; +#ifdef CONFIG_CGROUP_GPU

• struct gpucg_device gpucg_dev;
  

+#endif };

static LIST_HEAD(heap_list); @@ -216,6 +221,26 @@ const char *dma_heap_get_name(struct dma_heap *heap) return heap->name; }

+#ifdef CONFIG_CGROUP_GPU +/**

• • dma_heap_get_gpucg_dev() - get struct gpucg_device for the heap.
• • @heap: DMA-Heap to get the gpucg_device struct for.
• • Returns:
• • The gpucg_device struct for the heap. NULL if the GPU cgroup controller is
• • not enabled.
• */

+struct gpucg_device *dma_heap_get_gpucg_dev(struct dma_heap *heap) +{

• return &heap->gpucg_dev;
  

+} +#else /* CONFIG_CGROUP_GPU */ +struct gpucg_device *dma_heap_get_gpucg_dev(struct dma_heap *heap) +{

• return NULL;
  

+} +#endif /* CONFIG_CGROUP_GPU */

struct dma_heap *dma_heap_add(const struct dma_heap_export_info *exp_info) { struct dma_heap *heap, *h, *err_ret; @@ -288,6 +313,8 @@ struct dma_heap *dma_heap_add(const struct dma_heap_export_info *exp_info) list_add(&heap->list, &heap_list); mutex_unlock(&heap_list_lock);

• gpucg_register_device(dma_heap_get_gpucg_dev(heap), exp_info->name);
  

• return heap;
  
  

err2: diff --git a/drivers/dma-buf/heaps/system_heap.c b/drivers/dma-buf/heaps/system_heap.c index ab7fd896d2c4..752a05c3cfe2 100644 --- a/drivers/dma-buf/heaps/system_heap.c +++ b/drivers/dma-buf/heaps/system_heap.c @@ -395,6 +395,9 @@ static struct dma_buf *system_heap_allocate(struct dma_heap *heap, exp_info.ops = &system_heap_buf_ops; exp_info.size = buffer->len; exp_info.flags = fd_flags; +#ifdef CONFIG_CGROUP_GPU

• exp_info.gpucg_dev = dma_heap_get_gpucg_dev(heap);
  

+#endif exp_info.priv = buffer; dmabuf = dma_buf_export(&exp_info); if (IS_ERR(dmabuf)) { diff --git a/include/linux/dma-heap.h b/include/linux/dma-heap.h index 0c05561cad6e..e447a61d054e 100644 --- a/include/linux/dma-heap.h +++ b/include/linux/dma-heap.h @@ -10,6 +10,7 @@ #define _DMA_HEAPS_H

#include <linux/cdev.h> +#include <linux/cgroup_gpu.h> #include <linux/types.h>

struct dma_heap; @@ -59,6 +60,16 @@ void *dma_heap_get_drvdata(struct dma_heap *heap); */ const char *dma_heap_get_name(struct dma_heap *heap);

+/**

• • dma_heap_get_gpucg_dev() - get a pointer to the struct gpucg_device for the
• • heap.
• • @heap: DMA-Heap to retrieve gpucg_device for.
• • Returns:
• • The gpucg_device struct for the heap.
• */

+struct gpucg_device *dma_heap_get_gpucg_dev(struct dma_heap *heap);

/**

• dma_heap_add - adds a heap to dmabuf heaps
• @exp_info: information needed to register this heap

-- 2.35.1.1021.g381101b075-goog

-- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch