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* [PATCH v2] dma-buf: Delete the DMA-BUF attachment sysfs statistics
@ 2021-07-13  4:07 Hridya Valsaraju
  2021-07-20  9:11 ` Christian König
  0 siblings, 1 reply; 3+ messages in thread
From: Hridya Valsaraju @ 2021-07-13  4:07 UTC (permalink / raw)
  To: christian.koenig, Sumit Semwal, Hridya Valsaraju,
	Greg Kroah-Hartman, Daniel Vetter, linux-kernel, linux-media,
	dri-devel, linaro-mm-sig
  Cc: kernel-team, john.stultz, surenb, daniel

The DMA-BUF attachment statistics form a subset of the DMA-BUF
sysfs statistics that recently merged to the drm-misc tree. They are not
UABI yet since they have not merged to the upstream Linux kernel.

Since there has been a reported a performance regression due to the
overhead of sysfs directory creation/teardown during
dma_buf_attach()/dma_buf_detach(), this patch deletes the DMA-BUF
attachment statistics from sysfs.

Fixes: bdb8d06dfefd (dmabuf: Add the capability to expose DMA-BUF stats
in sysfs)
Signed-off-by: Hridya Valsaraju <hridya@google.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

Changes in v2:
Updated commit message to clarify that the sysfs files being removed
have not yet merged to upstream Linux and are hence not ABI.

Hi Christian,

I have updated the commit message as per your suggestion. Please do take
another look when you get a chance.

Thanks,
Hridya

 .../ABI/testing/sysfs-kernel-dmabuf-buffers   |  28 ----
 drivers/dma-buf/dma-buf-sysfs-stats.c         | 140 +-----------------
 drivers/dma-buf/dma-buf-sysfs-stats.h         |  27 ----
 drivers/dma-buf/dma-buf.c                     |  16 --
 include/linux/dma-buf.h                       |  17 ---
 5 files changed, 4 insertions(+), 224 deletions(-)

diff --git a/Documentation/ABI/testing/sysfs-kernel-dmabuf-buffers b/Documentation/ABI/testing/sysfs-kernel-dmabuf-buffers
index a243984ed420..5d3bc997dc64 100644
--- a/Documentation/ABI/testing/sysfs-kernel-dmabuf-buffers
+++ b/Documentation/ABI/testing/sysfs-kernel-dmabuf-buffers
@@ -22,31 +22,3 @@ KernelVersion:	v5.13
 Contact:	Hridya Valsaraju <hridya@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:		May 2021
-KernelVersion:	v5.13
-Contact:	Hridya Valsaraju <hridya@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:		May 2021
-KernelVersion:	v5.13
-Contact:	Hridya Valsaraju <hridya@google.com>
-Description:	This directory will contain information on the attached device
-		and the number of current distinct device mappings.
-
-What:		/sys/kernel/dmabuf/buffers/<inode_number>/attachments/<attachment_uid>/device
-Date:		May 2021
-KernelVersion:	v5.13
-Contact:	Hridya Valsaraju <hridya@google.com>
-Description:	This file is read-only and is a symlink to the attached device's
-		sysfs entry.
-
-What:		/sys/kernel/dmabuf/buffers/<inode_number>/attachments/<attachment_uid>/map_counter
-Date:		May 2021
-KernelVersion:	v5.13
-Contact:	Hridya Valsaraju <hridya@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/dma-buf-sysfs-stats.c b/drivers/dma-buf/dma-buf-sysfs-stats.c
index a2638e84199c..053baadcada9 100644
--- a/drivers/dma-buf/dma-buf-sysfs-stats.c
+++ b/drivers/dma-buf/dma-buf-sysfs-stats.c
@@ -40,14 +40,11 @@
  *
  * * ``/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 information in the interface can also be used to derive per-exporter and
- * per-device usage statistics. The data from the interface can be gathered
- * on error conditions or other important events to provide a snapshot of
- * DMA-BUF usage. It can also be collected periodically by telemetry to monitor
- * various metrics.
+ * The information in the interface can also be used to derive per-exporter
+ * statistics. The data from the interface can be gathered on error conditions
+ * or other important events to provide a snapshot of DMA-BUF usage.
+ * It can also be collected periodically by telemetry to monitor various metrics.
  *
  * Detailed documentation about the interface is present in
  * Documentation/ABI/testing/sysfs-kernel-dmabuf-buffers.
@@ -121,120 +118,6 @@ static struct kobj_type dma_buf_ktype = {
 	.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;
@@ -243,7 +126,6 @@ void dma_buf_stats_teardown(struct dma_buf *dmabuf)
 	if (!sysfs_entry)
 		return;
 
-	kset_unregister(sysfs_entry->attach_stats_kset);
 	kobject_del(&sysfs_entry->kobj);
 	kobject_put(&sysfs_entry->kobj);
 }
@@ -290,7 +172,6 @@ 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;
@@ -315,21 +196,8 @@ int dma_buf_stats_setup(struct dma_buf *dmabuf)
 	if (ret)
 		goto err_sysfs_dmabuf;
 
-	/* create the directory for attachment stats */
-	attach_stats_kset = kset_create_and_add("attachments",
-						&dmabuf_sysfs_no_uevent_ops,
-						&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;
diff --git a/drivers/dma-buf/dma-buf-sysfs-stats.h b/drivers/dma-buf/dma-buf-sysfs-stats.h
index 5f4703249117..a49c6e2650cc 100644
--- a/drivers/dma-buf/dma-buf-sysfs-stats.h
+++ b/drivers/dma-buf/dma-buf-sysfs-stats.h
@@ -14,23 +14,8 @@ 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)
@@ -44,19 +29,7 @@ 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 510b42771974..b1a6db71c656 100644
--- a/drivers/dma-buf/dma-buf.c
+++ b/drivers/dma-buf/dma-buf.c
@@ -738,7 +738,6 @@ 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);
@@ -764,13 +763,8 @@ 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.
@@ -797,7 +791,6 @@ 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;
@@ -814,7 +807,6 @@ 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);
 }
@@ -864,7 +856,6 @@ void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach)
 			dma_resv_lock(attach->dmabuf->resv, NULL);
 
 		__unmap_dma_buf(attach, attach->sgt, attach->dir);
-		dma_buf_update_attachment_map_count(attach, -1 /* delta */);
 
 		if (dma_buf_is_dynamic(attach->dmabuf)) {
 			dmabuf->ops->unpin(attach);
@@ -878,7 +869,6 @@ 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);
@@ -1020,10 +1010,6 @@ 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);
@@ -1061,8 +1047,6 @@ 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);
 
diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h
index 2b814fde0d11..678b2006be78 100644
--- a/include/linux/dma-buf.h
+++ b/include/linux/dma-buf.h
@@ -444,15 +444,6 @@ struct dma_buf {
 	struct dma_buf_sysfs_entry {
 		struct kobject kobj;
 		struct dma_buf *dmabuf;
-
-		/**
-		 * @sysfs_entry.attachment_uid:
-		 *
-		 * This is protected by the dma_resv_lock() on @resv and is
-		 * incremented on each attach.
-		 */
-		unsigned int attachment_uid;
-		struct kset *attach_stats_kset;
 	} *sysfs_entry;
 #endif
 };
@@ -504,7 +495,6 @@ 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
@@ -525,13 +515,6 @@ 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
 };
 
 /**
-- 
2.32.0.93.g670b81a890-goog


^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCH v2] dma-buf: Delete the DMA-BUF attachment sysfs statistics
  2021-07-13  4:07 [PATCH v2] dma-buf: Delete the DMA-BUF attachment sysfs statistics Hridya Valsaraju
@ 2021-07-20  9:11 ` Christian König
  2021-07-20 23:53   ` Hridya Valsaraju
  0 siblings, 1 reply; 3+ messages in thread
From: Christian König @ 2021-07-20  9:11 UTC (permalink / raw)
  To: Hridya Valsaraju, Sumit Semwal, Greg Kroah-Hartman,
	Daniel Vetter, linux-kernel, linux-media, dri-devel,
	linaro-mm-sig
  Cc: kernel-team, john.stultz, surenb, daniel

Am 13.07.21 um 06:07 schrieb Hridya Valsaraju:
> The DMA-BUF attachment statistics form a subset of the DMA-BUF
> sysfs statistics that recently merged to the drm-misc tree. They are not
> UABI yet since they have not merged to the upstream Linux kernel.
>
> Since there has been a reported a performance regression due to the
> overhead of sysfs directory creation/teardown during
> dma_buf_attach()/dma_buf_detach(), this patch deletes the DMA-BUF
> attachment statistics from sysfs.
>
> Fixes: bdb8d06dfefd (dmabuf: Add the capability to expose DMA-BUF stats
> in sysfs)
> Signed-off-by: Hridya Valsaraju <hridya@google.com>
> Reviewed-by: Christian König <christian.koenig@amd.com>
> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> ---
>
> Changes in v2:
> Updated commit message to clarify that the sysfs files being removed
> have not yet merged to upstream Linux and are hence not ABI.
>
> Hi Christian,
>
> I have updated the commit message as per your suggestion. Please do take
> another look when you get a chance.

I've just pushed that one to drm-misc-next. Sorry for the delay.

Regards,
Christian.

>
> Thanks,
> Hridya
>
>   .../ABI/testing/sysfs-kernel-dmabuf-buffers   |  28 ----
>   drivers/dma-buf/dma-buf-sysfs-stats.c         | 140 +-----------------
>   drivers/dma-buf/dma-buf-sysfs-stats.h         |  27 ----
>   drivers/dma-buf/dma-buf.c                     |  16 --
>   include/linux/dma-buf.h                       |  17 ---
>   5 files changed, 4 insertions(+), 224 deletions(-)
>
> diff --git a/Documentation/ABI/testing/sysfs-kernel-dmabuf-buffers b/Documentation/ABI/testing/sysfs-kernel-dmabuf-buffers
> index a243984ed420..5d3bc997dc64 100644
> --- a/Documentation/ABI/testing/sysfs-kernel-dmabuf-buffers
> +++ b/Documentation/ABI/testing/sysfs-kernel-dmabuf-buffers
> @@ -22,31 +22,3 @@ KernelVersion:	v5.13
>   Contact:	Hridya Valsaraju <hridya@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:		May 2021
> -KernelVersion:	v5.13
> -Contact:	Hridya Valsaraju <hridya@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:		May 2021
> -KernelVersion:	v5.13
> -Contact:	Hridya Valsaraju <hridya@google.com>
> -Description:	This directory will contain information on the attached device
> -		and the number of current distinct device mappings.
> -
> -What:		/sys/kernel/dmabuf/buffers/<inode_number>/attachments/<attachment_uid>/device
> -Date:		May 2021
> -KernelVersion:	v5.13
> -Contact:	Hridya Valsaraju <hridya@google.com>
> -Description:	This file is read-only and is a symlink to the attached device's
> -		sysfs entry.
> -
> -What:		/sys/kernel/dmabuf/buffers/<inode_number>/attachments/<attachment_uid>/map_counter
> -Date:		May 2021
> -KernelVersion:	v5.13
> -Contact:	Hridya Valsaraju <hridya@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/dma-buf-sysfs-stats.c b/drivers/dma-buf/dma-buf-sysfs-stats.c
> index a2638e84199c..053baadcada9 100644
> --- a/drivers/dma-buf/dma-buf-sysfs-stats.c
> +++ b/drivers/dma-buf/dma-buf-sysfs-stats.c
> @@ -40,14 +40,11 @@
>    *
>    * * ``/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 information in the interface can also be used to derive per-exporter and
> - * per-device usage statistics. The data from the interface can be gathered
> - * on error conditions or other important events to provide a snapshot of
> - * DMA-BUF usage. It can also be collected periodically by telemetry to monitor
> - * various metrics.
> + * The information in the interface can also be used to derive per-exporter
> + * statistics. The data from the interface can be gathered on error conditions
> + * or other important events to provide a snapshot of DMA-BUF usage.
> + * It can also be collected periodically by telemetry to monitor various metrics.
>    *
>    * Detailed documentation about the interface is present in
>    * Documentation/ABI/testing/sysfs-kernel-dmabuf-buffers.
> @@ -121,120 +118,6 @@ static struct kobj_type dma_buf_ktype = {
>   	.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;
> @@ -243,7 +126,6 @@ void dma_buf_stats_teardown(struct dma_buf *dmabuf)
>   	if (!sysfs_entry)
>   		return;
>   
> -	kset_unregister(sysfs_entry->attach_stats_kset);
>   	kobject_del(&sysfs_entry->kobj);
>   	kobject_put(&sysfs_entry->kobj);
>   }
> @@ -290,7 +172,6 @@ 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;
> @@ -315,21 +196,8 @@ int dma_buf_stats_setup(struct dma_buf *dmabuf)
>   	if (ret)
>   		goto err_sysfs_dmabuf;
>   
> -	/* create the directory for attachment stats */
> -	attach_stats_kset = kset_create_and_add("attachments",
> -						&dmabuf_sysfs_no_uevent_ops,
> -						&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;
> diff --git a/drivers/dma-buf/dma-buf-sysfs-stats.h b/drivers/dma-buf/dma-buf-sysfs-stats.h
> index 5f4703249117..a49c6e2650cc 100644
> --- a/drivers/dma-buf/dma-buf-sysfs-stats.h
> +++ b/drivers/dma-buf/dma-buf-sysfs-stats.h
> @@ -14,23 +14,8 @@ 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)
> @@ -44,19 +29,7 @@ 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 510b42771974..b1a6db71c656 100644
> --- a/drivers/dma-buf/dma-buf.c
> +++ b/drivers/dma-buf/dma-buf.c
> @@ -738,7 +738,6 @@ 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);
> @@ -764,13 +763,8 @@ 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.
> @@ -797,7 +791,6 @@ 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;
> @@ -814,7 +807,6 @@ 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);
>   }
> @@ -864,7 +856,6 @@ void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach)
>   			dma_resv_lock(attach->dmabuf->resv, NULL);
>   
>   		__unmap_dma_buf(attach, attach->sgt, attach->dir);
> -		dma_buf_update_attachment_map_count(attach, -1 /* delta */);
>   
>   		if (dma_buf_is_dynamic(attach->dmabuf)) {
>   			dmabuf->ops->unpin(attach);
> @@ -878,7 +869,6 @@ 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);
> @@ -1020,10 +1010,6 @@ 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);
> @@ -1061,8 +1047,6 @@ 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);
>   
> diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h
> index 2b814fde0d11..678b2006be78 100644
> --- a/include/linux/dma-buf.h
> +++ b/include/linux/dma-buf.h
> @@ -444,15 +444,6 @@ struct dma_buf {
>   	struct dma_buf_sysfs_entry {
>   		struct kobject kobj;
>   		struct dma_buf *dmabuf;
> -
> -		/**
> -		 * @sysfs_entry.attachment_uid:
> -		 *
> -		 * This is protected by the dma_resv_lock() on @resv and is
> -		 * incremented on each attach.
> -		 */
> -		unsigned int attachment_uid;
> -		struct kset *attach_stats_kset;
>   	} *sysfs_entry;
>   #endif
>   };
> @@ -504,7 +495,6 @@ 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
> @@ -525,13 +515,6 @@ 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
>   };
>   
>   /**


^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH v2] dma-buf: Delete the DMA-BUF attachment sysfs statistics
  2021-07-20  9:11 ` Christian König
@ 2021-07-20 23:53   ` Hridya Valsaraju
  0 siblings, 0 replies; 3+ messages in thread
From: Hridya Valsaraju @ 2021-07-20 23:53 UTC (permalink / raw)
  To: Christian König
  Cc: Sumit Semwal, Greg Kroah-Hartman, Daniel Vetter, linux-kernel,
	linux-media, dri-devel, linaro-mm-sig, kernel-team, john.stultz,
	surenb, daniel

On Tue, Jul 20, 2021 at 2:11 AM Christian König
<christian.koenig@amd.com> wrote:
>
> Am 13.07.21 um 06:07 schrieb Hridya Valsaraju:
> > The DMA-BUF attachment statistics form a subset of the DMA-BUF
> > sysfs statistics that recently merged to the drm-misc tree. They are not
> > UABI yet since they have not merged to the upstream Linux kernel.
> >
> > Since there has been a reported a performance regression due to the
> > overhead of sysfs directory creation/teardown during
> > dma_buf_attach()/dma_buf_detach(), this patch deletes the DMA-BUF
> > attachment statistics from sysfs.
> >
> > Fixes: bdb8d06dfefd (dmabuf: Add the capability to expose DMA-BUF stats
> > in sysfs)
> > Signed-off-by: Hridya Valsaraju <hridya@google.com>
> > Reviewed-by: Christian König <christian.koenig@amd.com>
> > Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> > ---
> >
> > Changes in v2:
> > Updated commit message to clarify that the sysfs files being removed
> > have not yet merged to upstream Linux and are hence not ABI.
> >
> > Hi Christian,
> >
> > I have updated the commit message as per your suggestion. Please do take
> > another look when you get a chance.
>
> I've just pushed that one to drm-misc-next. Sorry for the delay.

No worries at all, thank you Christian.

Regards,
Hridya

>
> Regards,
> Christian.
>
> >
> > Thanks,
> > Hridya
> >
> >   .../ABI/testing/sysfs-kernel-dmabuf-buffers   |  28 ----
> >   drivers/dma-buf/dma-buf-sysfs-stats.c         | 140 +-----------------
> >   drivers/dma-buf/dma-buf-sysfs-stats.h         |  27 ----
> >   drivers/dma-buf/dma-buf.c                     |  16 --
> >   include/linux/dma-buf.h                       |  17 ---
> >   5 files changed, 4 insertions(+), 224 deletions(-)
> >
> > diff --git a/Documentation/ABI/testing/sysfs-kernel-dmabuf-buffers b/Documentation/ABI/testing/sysfs-kernel-dmabuf-buffers
> > index a243984ed420..5d3bc997dc64 100644
> > --- a/Documentation/ABI/testing/sysfs-kernel-dmabuf-buffers
> > +++ b/Documentation/ABI/testing/sysfs-kernel-dmabuf-buffers
> > @@ -22,31 +22,3 @@ KernelVersion:     v5.13
> >   Contact:    Hridya Valsaraju <hridya@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:                May 2021
> > -KernelVersion:       v5.13
> > -Contact:     Hridya Valsaraju <hridya@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:                May 2021
> > -KernelVersion:       v5.13
> > -Contact:     Hridya Valsaraju <hridya@google.com>
> > -Description: This directory will contain information on the attached device
> > -             and the number of current distinct device mappings.
> > -
> > -What:                /sys/kernel/dmabuf/buffers/<inode_number>/attachments/<attachment_uid>/device
> > -Date:                May 2021
> > -KernelVersion:       v5.13
> > -Contact:     Hridya Valsaraju <hridya@google.com>
> > -Description: This file is read-only and is a symlink to the attached device's
> > -             sysfs entry.
> > -
> > -What:                /sys/kernel/dmabuf/buffers/<inode_number>/attachments/<attachment_uid>/map_counter
> > -Date:                May 2021
> > -KernelVersion:       v5.13
> > -Contact:     Hridya Valsaraju <hridya@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/dma-buf-sysfs-stats.c b/drivers/dma-buf/dma-buf-sysfs-stats.c
> > index a2638e84199c..053baadcada9 100644
> > --- a/drivers/dma-buf/dma-buf-sysfs-stats.c
> > +++ b/drivers/dma-buf/dma-buf-sysfs-stats.c
> > @@ -40,14 +40,11 @@
> >    *
> >    * * ``/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 information in the interface can also be used to derive per-exporter and
> > - * per-device usage statistics. The data from the interface can be gathered
> > - * on error conditions or other important events to provide a snapshot of
> > - * DMA-BUF usage. It can also be collected periodically by telemetry to monitor
> > - * various metrics.
> > + * The information in the interface can also be used to derive per-exporter
> > + * statistics. The data from the interface can be gathered on error conditions
> > + * or other important events to provide a snapshot of DMA-BUF usage.
> > + * It can also be collected periodically by telemetry to monitor various metrics.
> >    *
> >    * Detailed documentation about the interface is present in
> >    * Documentation/ABI/testing/sysfs-kernel-dmabuf-buffers.
> > @@ -121,120 +118,6 @@ static struct kobj_type dma_buf_ktype = {
> >       .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;
> > @@ -243,7 +126,6 @@ void dma_buf_stats_teardown(struct dma_buf *dmabuf)
> >       if (!sysfs_entry)
> >               return;
> >
> > -     kset_unregister(sysfs_entry->attach_stats_kset);
> >       kobject_del(&sysfs_entry->kobj);
> >       kobject_put(&sysfs_entry->kobj);
> >   }
> > @@ -290,7 +172,6 @@ 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;
> > @@ -315,21 +196,8 @@ int dma_buf_stats_setup(struct dma_buf *dmabuf)
> >       if (ret)
> >               goto err_sysfs_dmabuf;
> >
> > -     /* create the directory for attachment stats */
> > -     attach_stats_kset = kset_create_and_add("attachments",
> > -                                             &dmabuf_sysfs_no_uevent_ops,
> > -                                             &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;
> > diff --git a/drivers/dma-buf/dma-buf-sysfs-stats.h b/drivers/dma-buf/dma-buf-sysfs-stats.h
> > index 5f4703249117..a49c6e2650cc 100644
> > --- a/drivers/dma-buf/dma-buf-sysfs-stats.h
> > +++ b/drivers/dma-buf/dma-buf-sysfs-stats.h
> > @@ -14,23 +14,8 @@ 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)
> > @@ -44,19 +29,7 @@ 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 510b42771974..b1a6db71c656 100644
> > --- a/drivers/dma-buf/dma-buf.c
> > +++ b/drivers/dma-buf/dma-buf.c
> > @@ -738,7 +738,6 @@ 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);
> > @@ -764,13 +763,8 @@ 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.
> > @@ -797,7 +791,6 @@ 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;
> > @@ -814,7 +807,6 @@ 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);
> >   }
> > @@ -864,7 +856,6 @@ void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach)
> >                       dma_resv_lock(attach->dmabuf->resv, NULL);
> >
> >               __unmap_dma_buf(attach, attach->sgt, attach->dir);
> > -             dma_buf_update_attachment_map_count(attach, -1 /* delta */);
> >
> >               if (dma_buf_is_dynamic(attach->dmabuf)) {
> >                       dmabuf->ops->unpin(attach);
> > @@ -878,7 +869,6 @@ 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);
> > @@ -1020,10 +1010,6 @@ 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);
> > @@ -1061,8 +1047,6 @@ 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);
> >
> > diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h
> > index 2b814fde0d11..678b2006be78 100644
> > --- a/include/linux/dma-buf.h
> > +++ b/include/linux/dma-buf.h
> > @@ -444,15 +444,6 @@ struct dma_buf {
> >       struct dma_buf_sysfs_entry {
> >               struct kobject kobj;
> >               struct dma_buf *dmabuf;
> > -
> > -             /**
> > -              * @sysfs_entry.attachment_uid:
> > -              *
> > -              * This is protected by the dma_resv_lock() on @resv and is
> > -              * incremented on each attach.
> > -              */
> > -             unsigned int attachment_uid;
> > -             struct kset *attach_stats_kset;
> >       } *sysfs_entry;
> >   #endif
> >   };
> > @@ -504,7 +495,6 @@ 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
> > @@ -525,13 +515,6 @@ 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
> >   };
> >
> >   /**
>

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2021-07-20 23:56 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-07-13  4:07 [PATCH v2] dma-buf: Delete the DMA-BUF attachment sysfs statistics Hridya Valsaraju
2021-07-20  9:11 ` Christian König
2021-07-20 23:53   ` Hridya Valsaraju

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