This patch allows statistics to be enabled for each DMA-BUF in sysfs by enabling the config CONFIG_DMABUF_SYSFS_STATS.
The following stats will be exposed by the interface: /sys/kernel/dmabuf/buffers/<inode_number>/exporter_name /sys/kernel/dmabuf/buffers/<inode_number>/size /sys/kernel/dmabuf/buffers/<inode_number>/attachments/<attach_uid>/device /sys/kernel/dmabuf/buffers/<inode_number>/attachments/<attach_uid>/map_counter The inode_number is unique for each DMA-BUF and was added earlier [1] in order to allow userspace to track DMA-BUF usage across different processes. Currently, this information is exposed in /sys/kernel/debug/dma_buf/bufinfo. However, since debugfs is considered unsafe to be mounted in production, it is being duplicated in sysfs. This information will be used to derive DMA-BUF per-exporter stats and per-device usage stats for Android Bug reports. The corresponding userspace changes can be found at [2]. Telemetry tools will also capture this information(along with other memory metrics) periodically as well as on important events like a foreground app kill (which might have been triggered by Low Memory Killer). It will also contribute to provide a snapshot of the system memory usage on other events such as OOM kills and Application Not Responding events. A shell script that can be run on a classic Linux environment to read out the DMA-BUF statistics can be found at [3](suggested by John Stultz). The patch contains the following improvements over the previous version: 1) Each attachment is represented by its own directory to allow creating a symlink to the importing device and to also provide room for future expansion. 2) The number of distinct mappings of each attachment is exposed in a separate file. 3) The per-buffer statistics are now in /sys/kernel/dmabuf/buffers inorder to make the interface expandable in future. All of the improvements above are based on suggestions/feedback from Daniel Vetter and Christian König. [1]: https://lore.kernel.org/patchwork/patch/1088791/ [2]: https://android-review.googlesource.com/q/topic:%22dmabuf-sysfs%22+(status:open%20OR%20status:merged) [3]: https://android-review.googlesource.com/c/platform/system/memory/libmeminfo/+/1549734 Signed-off-by: Hridya Valsaraju <hri...@google.com> Reported-by: kernel test robot <l...@intel.com> --- Changes in v3: Fix a warning reported by the kernel test robot. Changes in v2: -Move statistics to /sys/kernel/dmabuf/buffers in oder to allow addition of other DMA-BUF-related sysfs stats in future. Based on feedback from Daniel Vetter. -Each attachment has its own directory to represent attaching devices as symlinks and to introduce map_count as a separate file. Based on feedback from Daniel Vetter and Christian König. Thank you both! -Commit messages updated to point to userspace code in AOSP that will read the DMA-BUF sysfs stats. .../ABI/testing/sysfs-kernel-dmabuf-buffers | 52 ++++ drivers/dma-buf/Kconfig | 11 + drivers/dma-buf/Makefile | 1 + drivers/dma-buf/dma-buf-sysfs-stats.c | 285 ++++++++++++++++++ drivers/dma-buf/dma-buf-sysfs-stats.h | 62 ++++ drivers/dma-buf/dma-buf.c | 37 +++ include/linux/dma-buf.h | 20 ++ 7 files changed, 468 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-kernel-dmabuf-buffers create mode 100644 drivers/dma-buf/dma-buf-sysfs-stats.c create mode 100644 drivers/dma-buf/dma-buf-sysfs-stats.h diff --git a/Documentation/ABI/testing/sysfs-kernel-dmabuf-buffers b/Documentation/ABI/testing/sysfs-kernel-dmabuf-buffers new file mode 100644 index 000000000000..6f7c65209f07 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-kernel-dmabuf-buffers @@ -0,0 +1,52 @@ +What: /sys/kernel/dmabuf/buffers +Date: January 2021 +KernelVersion: v5.12 +Contact: Hridya Valsaraju <hri...@google.com> +Description: The /sys/kernel/dmabuf/buffers directory contains a + snapshot of the internal state of every DMA-BUF. + /sys/kernel/dmabuf/buffers/<inode_number> will contain the + statistics for the DMA-BUF with the unique inode number + <inode_number> +Users: kernel memory tuning/debugging tools + +What: /sys/kernel/dmabuf/buffers/<inode_number>/exporter_name +Date: January 2021 +KernelVersion: v5.12 +Contact: Hridya Valsaraju <hri...@google.com> +Description: This file is read-only and contains the name of the exporter of + the DMA-BUF. + +What: /sys/kernel/dmabuf/buffers/<inode_number>/size +Date: January 2021 +KernelVersion: v5.12 +Contact: Hridya Valsaraju <hri...@google.com> +Description: This file is read-only and specifies the size of the DMA-BUF in + bytes. + +What: /sys/kernel/dmabuf/buffers/<inode_number>/attachments +Date: January 2021 +KernelVersion: v5.12 +Contact: Hridya Valsaraju <hri...@google.com> +Description: This directory will contain subdirectories representing every + attachment of the DMA-BUF. + +What: /sys/kernel/dmabuf/buffers/<inode_number>/attachments/<attachment_uid> +Date: January 2021 +KernelVersion: v5.12 +Contact: Hridya Valsaraju <hri...@google.com> +Description: This directory will contain information on the attaching device + and the number of current distinct device mappings. + +What: /sys/kernel/dmabuf/buffers/<inode_number>/attachments/<attachment_uid>/device +Date: January 2021 +KernelVersion: v5.12 +Contact: Hridya Valsaraju <hri...@google.com> +Description: This file is read-only and is a symlink to the attaching devices's + sysfs entry. + +What: /sys/kernel/dmabuf/buffers/<inode_number>/attachments/<attachment_uid>/map_counter +Date: January 2021 +KernelVersion: v5.12 +Contact: Hridya Valsaraju <hri...@google.com> +Description: This file is read-only and contains a map_counter indicating the + number of distinct device mappings of the attachment. diff --git a/drivers/dma-buf/Kconfig b/drivers/dma-buf/Kconfig index 4f8224a6ac95..27e6a2dafeaa 100644 --- a/drivers/dma-buf/Kconfig +++ b/drivers/dma-buf/Kconfig @@ -64,6 +64,17 @@ menuconfig DMABUF_HEAPS allows userspace to allocate dma-bufs that can be shared between drivers. +menuconfig DMABUF_SYSFS_STATS + bool "DMA-BUF sysfs statistics" + select DMA_SHARED_BUFFER + help + Choose this option to enable DMA-BUF sysfs statistics + in location /sys/kernel/dmabuf/buffers. + + /sys/kernel/dmabuf/buffers/<inode_number> will contain + statistics for the DMA-BUF with the unique inode number + <inode_number>. + source "drivers/dma-buf/heaps/Kconfig" endmenu diff --git a/drivers/dma-buf/Makefile b/drivers/dma-buf/Makefile index 995e05f609ff..40d81f23cacf 100644 --- a/drivers/dma-buf/Makefile +++ b/drivers/dma-buf/Makefile @@ -6,6 +6,7 @@ obj-$(CONFIG_DMABUF_HEAPS) += heaps/ obj-$(CONFIG_SYNC_FILE) += sync_file.o obj-$(CONFIG_SW_SYNC) += sw_sync.o sync_debug.o obj-$(CONFIG_UDMABUF) += udmabuf.o +obj-$(CONFIG_DMABUF_SYSFS_STATS) += dma-buf-sysfs-stats.o dmabuf_selftests-y := \ selftest.o \ diff --git a/drivers/dma-buf/dma-buf-sysfs-stats.c b/drivers/dma-buf/dma-buf-sysfs-stats.c new file mode 100644 index 000000000000..5dc2e17f3054 --- /dev/null +++ b/drivers/dma-buf/dma-buf-sysfs-stats.c @@ -0,0 +1,285 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * DMA-BUF sysfs statistics. + * + * Copyright (C) 2021 Google LLC. + */ + +#include <linux/dma-buf.h> +#include <linux/dma-resv.h> +#include <linux/kobject.h> +#include <linux/printk.h> +#include <linux/slab.h> +#include <linux/sysfs.h> + +#include "dma-buf-sysfs-stats.h" + +#define to_dma_buf_entry_from_kobj(x) container_of(x, struct dma_buf_sysfs_entry, kobj) + +struct dma_buf_stats_attribute { + struct attribute attr; + ssize_t (*show)(struct dma_buf *dmabuf, + struct dma_buf_stats_attribute *attr, char *buf); +}; +#define to_dma_buf_stats_attr(x) container_of(x, struct dma_buf_stats_attribute, attr) + +static ssize_t dma_buf_stats_attribute_show(struct kobject *kobj, + struct attribute *attr, + char *buf) +{ + struct dma_buf_stats_attribute *attribute; + struct dma_buf_sysfs_entry *sysfs_entry; + struct dma_buf *dmabuf; + + attribute = to_dma_buf_stats_attr(attr); + sysfs_entry = to_dma_buf_entry_from_kobj(kobj); + dmabuf = sysfs_entry->dmabuf; + + if (!dmabuf || !attribute->show) + return -EIO; + + return attribute->show(dmabuf, attribute, buf); +} + +static const struct sysfs_ops dma_buf_stats_sysfs_ops = { + .show = dma_buf_stats_attribute_show, +}; + +static ssize_t exporter_name_show(struct dma_buf *dmabuf, + struct dma_buf_stats_attribute *attr, + char *buf) +{ + return sysfs_emit(buf, "%s\n", dmabuf->exp_name); +} + +static ssize_t size_show(struct dma_buf *dmabuf, + struct dma_buf_stats_attribute *attr, + char *buf) +{ + return sysfs_emit(buf, "%zu\n", dmabuf->size); +} + +static struct dma_buf_stats_attribute exporter_name_attribute = + __ATTR_RO(exporter_name); +static struct dma_buf_stats_attribute size_attribute = __ATTR_RO(size); + +static struct attribute *dma_buf_stats_default_attrs[] = { + &exporter_name_attribute.attr, + &size_attribute.attr, + NULL, +}; +ATTRIBUTE_GROUPS(dma_buf_stats_default); + +static void dma_buf_sysfs_release(struct kobject *kobj) +{ + struct dma_buf_sysfs_entry *sysfs_entry; + + sysfs_entry = to_dma_buf_entry_from_kobj(kobj); + kfree(sysfs_entry); +} + +static struct kobj_type dma_buf_ktype = { + .sysfs_ops = &dma_buf_stats_sysfs_ops, + .release = dma_buf_sysfs_release, + .default_groups = dma_buf_stats_default_groups, +}; + +#define to_dma_buf_attach_entry_from_kobj(x) container_of(x, struct dma_buf_attach_sysfs_entry, kobj) + +struct dma_buf_attach_stats_attribute { + struct attribute attr; + ssize_t (*show)(struct dma_buf_attach_sysfs_entry *sysfs_entry, + struct dma_buf_attach_stats_attribute *attr, char *buf); +}; +#define to_dma_buf_attach_stats_attr(x) container_of(x, struct dma_buf_attach_stats_attribute, attr) + +static ssize_t dma_buf_attach_stats_attribute_show(struct kobject *kobj, + struct attribute *attr, + char *buf) +{ + struct dma_buf_attach_stats_attribute *attribute; + struct dma_buf_attach_sysfs_entry *sysfs_entry; + + attribute = to_dma_buf_attach_stats_attr(attr); + sysfs_entry = to_dma_buf_attach_entry_from_kobj(kobj); + + if (!attribute->show) + return -EIO; + + return attribute->show(sysfs_entry, attribute, buf); +} + +static const struct sysfs_ops dma_buf_attach_stats_sysfs_ops = { + .show = dma_buf_attach_stats_attribute_show, +}; + +static ssize_t map_counter_show(struct dma_buf_attach_sysfs_entry *sysfs_entry, + struct dma_buf_attach_stats_attribute *attr, + char *buf) +{ + return sysfs_emit(buf, "%u\n", sysfs_entry->map_counter); +} + +static struct dma_buf_attach_stats_attribute map_counter_attribute = + __ATTR_RO(map_counter); + +static struct attribute *dma_buf_attach_stats_default_attrs[] = { + &map_counter_attribute.attr, + NULL, +}; +ATTRIBUTE_GROUPS(dma_buf_attach_stats_default); + +static void dma_buf_attach_sysfs_release(struct kobject *kobj) +{ + struct dma_buf_attach_sysfs_entry *sysfs_entry; + + sysfs_entry = to_dma_buf_attach_entry_from_kobj(kobj); + kfree(sysfs_entry); +} + +static struct kobj_type dma_buf_attach_ktype = { + .sysfs_ops = &dma_buf_attach_stats_sysfs_ops, + .release = dma_buf_attach_sysfs_release, + .default_groups = dma_buf_attach_stats_default_groups, +}; + +void dma_buf_attach_stats_teardown(struct dma_buf_attachment *attach) +{ + struct dma_buf_attach_sysfs_entry *sysfs_entry; + + sysfs_entry = attach->sysfs_entry; + if (!sysfs_entry) + return; + + sysfs_delete_link(&sysfs_entry->kobj, &attach->dev->kobj, "device"); + + kobject_del(&sysfs_entry->kobj); + kobject_put(&sysfs_entry->kobj); +} + +int dma_buf_attach_stats_setup(struct dma_buf_attachment *attach, + unsigned int uid) +{ + struct dma_buf_attach_sysfs_entry *sysfs_entry; + int ret; + struct dma_buf *dmabuf; + + if (!attach) + return -EINVAL; + + dmabuf = attach->dmabuf; + + sysfs_entry = kzalloc(sizeof(struct dma_buf_attach_sysfs_entry), + GFP_KERNEL); + if (!sysfs_entry) + return -ENOMEM; + + sysfs_entry->kobj.kset = dmabuf->sysfs_entry->attach_stats_kset; + + attach->sysfs_entry = sysfs_entry; + + ret = kobject_init_and_add(&sysfs_entry->kobj, &dma_buf_attach_ktype, + NULL, "%u", uid); + if (ret) + goto kobj_err; + + ret = sysfs_create_link(&sysfs_entry->kobj, &attach->dev->kobj, + "device"); + if (ret) + goto link_err; + + return 0; + +link_err: + kobject_del(&sysfs_entry->kobj); +kobj_err: + kobject_put(&sysfs_entry->kobj); + attach->sysfs_entry = NULL; + + return ret; +} +void dma_buf_stats_teardown(struct dma_buf *dmabuf) +{ + struct dma_buf_sysfs_entry *sysfs_entry; + + sysfs_entry = dmabuf->sysfs_entry; + if (!sysfs_entry) + return; + + kset_unregister(sysfs_entry->attach_stats_kset); + kobject_del(&sysfs_entry->kobj); + kobject_put(&sysfs_entry->kobj); +} + +static struct kset *dma_buf_stats_kset; +static struct kset *dma_buf_per_buffer_stats_kset; +int dma_buf_init_sysfs_statistics(void) +{ + dma_buf_stats_kset = kset_create_and_add("dmabuf", NULL, kernel_kobj); + if (!dma_buf_stats_kset) + return -ENOMEM; + + dma_buf_per_buffer_stats_kset = kset_create_and_add("buffers", NULL, + &dma_buf_stats_kset->kobj); + if (!dma_buf_per_buffer_stats_kset) { + kset_unregister(dma_buf_stats_kset); + return -ENOMEM; + } + + return 0; +} + +void dma_buf_uninit_sysfs_statistics(void) +{ + kset_unregister(dma_buf_per_buffer_stats_kset); + kset_unregister(dma_buf_stats_kset); +} + +int dma_buf_stats_setup(struct dma_buf *dmabuf) +{ + struct dma_buf_sysfs_entry *sysfs_entry; + int ret; + struct kset *attach_stats_kset; + + if (!dmabuf || !dmabuf->file) + return -EINVAL; + + if (!dmabuf->exp_name) { + pr_err("exporter name must not be empty if stats needed\n"); + return -EINVAL; + } + + sysfs_entry = kzalloc(sizeof(struct dma_buf_sysfs_entry), GFP_KERNEL); + if (!sysfs_entry) + return -ENOMEM; + + sysfs_entry->kobj.kset = dma_buf_per_buffer_stats_kset; + sysfs_entry->dmabuf = dmabuf; + + dmabuf->sysfs_entry = sysfs_entry; + + /* create the directory for buffer stats */ + ret = kobject_init_and_add(&sysfs_entry->kobj, &dma_buf_ktype, NULL, + "%lu", file_inode(dmabuf->file)->i_ino); + if (ret) + goto err_sysfs_dmabuf; + + /* create the directory for attachment stats */ + attach_stats_kset = kset_create_and_add("attachments", NULL, + &sysfs_entry->kobj); + if (!attach_stats_kset) { + ret = -ENOMEM; + goto err_sysfs_attach; + } + + sysfs_entry->attach_stats_kset = attach_stats_kset; + + return 0; + +err_sysfs_attach: + kobject_del(&sysfs_entry->kobj); +err_sysfs_dmabuf: + kobject_put(&sysfs_entry->kobj); + dmabuf->sysfs_entry = NULL; + return ret; +} diff --git a/drivers/dma-buf/dma-buf-sysfs-stats.h b/drivers/dma-buf/dma-buf-sysfs-stats.h new file mode 100644 index 000000000000..5f4703249117 --- /dev/null +++ b/drivers/dma-buf/dma-buf-sysfs-stats.h @@ -0,0 +1,62 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * DMA-BUF sysfs statistics. + * + * Copyright (C) 2021 Google LLC. + */ + +#ifndef _DMA_BUF_SYSFS_STATS_H +#define _DMA_BUF_SYSFS_STATS_H + +#ifdef CONFIG_DMABUF_SYSFS_STATS + +int dma_buf_init_sysfs_statistics(void); +void dma_buf_uninit_sysfs_statistics(void); + +int dma_buf_stats_setup(struct dma_buf *dmabuf); +int dma_buf_attach_stats_setup(struct dma_buf_attachment *attach, + unsigned int uid); +static inline void dma_buf_update_attachment_map_count(struct dma_buf_attachment *attach, + int delta) +{ + struct dma_buf_attach_sysfs_entry *entry = attach->sysfs_entry; + + entry->map_counter += delta; +} +void dma_buf_stats_teardown(struct dma_buf *dmabuf); +void dma_buf_attach_stats_teardown(struct dma_buf_attachment *attach); +static inline unsigned int dma_buf_update_attach_uid(struct dma_buf *dmabuf) +{ + struct dma_buf_sysfs_entry *entry = dmabuf->sysfs_entry; + + return entry->attachment_uid++; +} +#else + +static inline int dma_buf_init_sysfs_statistics(void) +{ + return 0; +} + +static inline void dma_buf_uninit_sysfs_statistics(void) {} + +static inline int dma_buf_stats_setup(struct dma_buf *dmabuf) +{ + return 0; +} +static inline int dma_buf_attach_stats_setup(struct dma_buf_attachment *attach, + unsigned int uid) +{ + return 0; +} + +static inline void dma_buf_stats_teardown(struct dma_buf *dmabuf) {} +static inline void dma_buf_attach_stats_teardown(struct dma_buf_attachment *attach) {} +static inline void dma_buf_update_attachment_map_count(struct dma_buf_attachment *attach, + int delta) {} +static inline unsigned int dma_buf_update_attach_uid(struct dma_buf *dmabuf) +{ + return 0; +} +#endif +#endif // _DMA_BUF_SYSFS_STATS_H diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c index 9ad6397aaa97..29f9ea18eb47 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c @@ -29,6 +29,8 @@ #include <uapi/linux/dma-buf.h> #include <uapi/linux/magic.h> +#include "dma-buf-sysfs-stats.h" + static inline int is_dma_buf_file(struct file *); struct dma_buf_list { @@ -79,6 +81,7 @@ static void dma_buf_release(struct dentry *dentry) if (dmabuf->resv == (struct dma_resv *)&dmabuf[1]) dma_resv_fini(dmabuf->resv); + dma_buf_stats_teardown(dmabuf); module_put(dmabuf->owner); kfree(dmabuf->name); kfree(dmabuf); @@ -579,6 +582,10 @@ struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info) file->f_mode |= FMODE_LSEEK; dmabuf->file = file; + ret = dma_buf_stats_setup(dmabuf); + if (ret) + goto err_sysfs; + mutex_init(&dmabuf->lock); INIT_LIST_HEAD(&dmabuf->attachments); @@ -588,6 +595,14 @@ struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info) return dmabuf; +err_sysfs: + /* + * Set file->f_path.dentry->d_fsdata to NULL so that when + * dma_buf_release() gets invoked by dentry_ops, it exits + * early before calling the release() dma_buf op. + */ + file->f_path.dentry->d_fsdata = NULL; + fput(file); err_dmabuf: kfree(dmabuf); err_module: @@ -692,6 +707,7 @@ dma_buf_dynamic_attach(struct dma_buf *dmabuf, struct device *dev, { struct dma_buf_attachment *attach; int ret; + unsigned int attach_uid; if (WARN_ON(!dmabuf || !dev)) return ERR_PTR(-EINVAL); @@ -717,8 +733,13 @@ dma_buf_dynamic_attach(struct dma_buf *dmabuf, struct device *dev, } dma_resv_lock(dmabuf->resv, NULL); list_add(&attach->node, &dmabuf->attachments); + attach_uid = dma_buf_update_attach_uid(dmabuf); dma_resv_unlock(dmabuf->resv); + ret = dma_buf_attach_stats_setup(attach, attach_uid); + if (ret) + goto err_sysfs; + /* When either the importer or the exporter can't handle dynamic * mappings we cache the mapping here to avoid issues with the * reservation object lock. @@ -745,6 +766,7 @@ dma_buf_dynamic_attach(struct dma_buf *dmabuf, struct device *dev, dma_resv_unlock(attach->dmabuf->resv); attach->sgt = sgt; attach->dir = DMA_BIDIRECTIONAL; + dma_buf_update_attachment_map_count(attach, 1 /* delta */); } return attach; @@ -761,6 +783,7 @@ dma_buf_dynamic_attach(struct dma_buf *dmabuf, struct device *dev, if (dma_buf_is_dynamic(attach->dmabuf)) dma_resv_unlock(attach->dmabuf->resv); +err_sysfs: dma_buf_detach(dmabuf, attach); return ERR_PTR(ret); } @@ -799,6 +822,7 @@ void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach) dma_resv_lock(attach->dmabuf->resv, NULL); dmabuf->ops->unmap_dma_buf(attach, attach->sgt, attach->dir); + dma_buf_update_attachment_map_count(attach, -1 /* delta */); if (dma_buf_is_dynamic(attach->dmabuf)) { dma_buf_unpin(attach); @@ -812,6 +836,7 @@ void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach) if (dmabuf->ops->detach) dmabuf->ops->detach(dmabuf, attach); + dma_buf_attach_stats_teardown(attach); kfree(attach); } EXPORT_SYMBOL_GPL(dma_buf_detach); @@ -938,6 +963,9 @@ struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach, } #endif /* CONFIG_DMA_API_DEBUG */ + if (!IS_ERR(sg_table)) + dma_buf_update_attachment_map_count(attach, 1 /* delta */); + return sg_table; } EXPORT_SYMBOL_GPL(dma_buf_map_attachment); @@ -975,6 +1003,8 @@ void dma_buf_unmap_attachment(struct dma_buf_attachment *attach, if (dma_buf_is_dynamic(attach->dmabuf) && !IS_ENABLED(CONFIG_DMABUF_MOVE_NOTIFY)) dma_buf_unpin(attach); + + dma_buf_update_attachment_map_count(attach, -1 /* delta */); } EXPORT_SYMBOL_GPL(dma_buf_unmap_attachment); @@ -1412,6 +1442,12 @@ static inline void dma_buf_uninit_debugfs(void) static int __init dma_buf_init(void) { + int ret; + + ret = dma_buf_init_sysfs_statistics(); + if (ret) + return ret; + dma_buf_mnt = kern_mount(&dma_buf_fs_type); if (IS_ERR(dma_buf_mnt)) return PTR_ERR(dma_buf_mnt); @@ -1427,5 +1463,6 @@ static void __exit dma_buf_deinit(void) { dma_buf_uninit_debugfs(); kern_unmount(dma_buf_mnt); + dma_buf_uninit_sysfs_statistics(); } __exitcall(dma_buf_deinit); diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h index cf72699cb2bc..4ae5cc38a4a7 100644 --- a/include/linux/dma-buf.h +++ b/include/linux/dma-buf.h @@ -294,6 +294,9 @@ struct dma_buf_ops { * @poll: for userspace poll support * @cb_excl: for userspace poll support * @cb_shared: for userspace poll support + * @sysfs_entry: for exposing information about this buffer in sysfs. + * The attachment_uid member of @sysfs_entry is protected by dma_resv lock + * and is incremented on each attach. * * This represents a shared buffer, created by calling dma_buf_export(). The * userspace representation is a normal file descriptor, which can be created by @@ -329,6 +332,15 @@ struct dma_buf { __poll_t active; } cb_excl, cb_shared; +#ifdef CONFIG_DMABUF_SYSFS_STATS + /* for sysfs stats */ + struct dma_buf_sysfs_entry { + struct kobject kobj; + struct dma_buf *dmabuf; + unsigned int attachment_uid; + struct kset *attach_stats_kset; + } *sysfs_entry; +#endif }; /** @@ -378,6 +390,7 @@ struct dma_buf_attach_ops { * @importer_ops: importer operations for this attachment, if provided * dma_buf_map/unmap_attachment() must be called with the dma_resv lock held. * @importer_priv: importer specific attachment data. + * @sysfs_entry: For exposing information about this attachment in sysfs. * * This structure holds the attachment information between the dma_buf buffer * and its user device(s). The list contains one attachment struct per device @@ -398,6 +411,13 @@ struct dma_buf_attachment { const struct dma_buf_attach_ops *importer_ops; void *importer_priv; void *priv; +#ifdef CONFIG_DMABUF_SYSFS_STATS + /* for sysfs stats */ + struct dma_buf_attach_sysfs_entry { + struct kobject kobj; + unsigned int map_counter; + } *sysfs_entry; +#endif }; /** -- 2.30.0.280.ga3ce27912f-goog
