Re: [PATCH] zram: remove obsolete sysfs attrs

[Sergey Senozhatsky]

sorry, forgot to Cc Jonathan Corbet
https://marc.info/?l=linux-kernel&m=148471192416338



On (01/18/17 12:58), Sergey Senozhatsky wrote:
> Date: Wed, 18 Jan 2017 12:58:38 +0900
> From: Sergey Senozhatsky <sergey.senozhatsky.work@xxxxxxxxx>
> To: Minchan Kim <minchan@xxxxxxxxxx>, Andrew Morton
>  <akpm@xxxxxxxxxxxxxxxxxxxx>
> Cc: zhouxianrong@xxxxxxxxxx, linux-kernel@xxxxxxxxxxxxxxx,
>  sergey.senozhatsky@xxxxxxxxx, sergey.senozhatsky.work@xxxxxxxxx
> Subject: [PATCH] zram: remove obsolete sysfs attrs
> X-Mailer: git-send-email 2.11.0
> 
> We had a deprecated_attr_warn() warning for 2 years and now the
> time has come and we finally can do the cleanup.
> 
> The plan was as follows:
> 
> : per-stat sysfs attributes are considered to be deprecated.
> : The basic strategy is:
> : -- the existing RW nodes will be downgraded to WO nodes (in linux 4.11)
> : -- deprecated RO sysfs nodes will eventually be removed (in linux 4.11)
> :
> : The list of deprecated attributes can be found here:
> : Documentation/ABI/obsolete/sysfs-block-zram
> :
> : Basically, every attribute that has its own read accessible sysfs
> : node (e.g. num_reads) *AND* is accessible via one of the stat files
> : (zram<id>/stat or zram<id>/io_stat or zram<id>/mm_stat) is considered
> : to be deprecated.
> 
> The patch also removes `obsolete/sysfs-block-zram', clean ups
> `testing/sysfs-block-zram' and tweaks zram.txt files.
> 
> Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx>
> ---
>  Documentation/ABI/obsolete/sysfs-block-zram | 119 ----------------------------
>  Documentation/ABI/testing/sysfs-block-zram  | 101 ++---------------------
>  Documentation/blockdev/zram.txt             |  74 ++++++++---------
>  drivers/block/zram/zram_drv.c               | 101 +----------------------
>  4 files changed, 42 insertions(+), 353 deletions(-)
>  delete mode 100644 Documentation/ABI/obsolete/sysfs-block-zram
> 
> diff --git a/Documentation/ABI/obsolete/sysfs-block-zram b/Documentation/ABI/obsolete/sysfs-block-zram
> deleted file mode 100644
> index 720ea92cfb2e..000000000000
> --- a/Documentation/ABI/obsolete/sysfs-block-zram
> +++ /dev/null
> @@ -1,119 +0,0 @@
> -What:		/sys/block/zram<id>/num_reads
> -Date:		August 2015
> -Contact:	Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx>
> -Description:
> -		The num_reads file is read-only and specifies the number of
> -		reads (failed or successful) done on this device.
> -		Now accessible via zram<id>/stat node.
> -
> -What:		/sys/block/zram<id>/num_writes
> -Date:		August 2015
> -Contact:	Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx>
> -Description:
> -		The num_writes file is read-only and specifies the number of
> -		writes (failed or successful) done on this device.
> -		Now accessible via zram<id>/stat node.
> -
> -What:		/sys/block/zram<id>/invalid_io
> -Date:		August 2015
> -Contact:	Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx>
> -Description:
> -		The invalid_io file is read-only and specifies the number of
> -		non-page-size-aligned I/O requests issued to this device.
> -		Now accessible via zram<id>/io_stat node.
> -
> -What:		/sys/block/zram<id>/failed_reads
> -Date:		August 2015
> -Contact:	Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx>
> -Description:
> -		The failed_reads file is read-only and specifies the number of
> -		failed reads happened on this device.
> -		Now accessible via zram<id>/io_stat node.
> -
> -What:		/sys/block/zram<id>/failed_writes
> -Date:		August 2015
> -Contact:	Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx>
> -Description:
> -		The failed_writes file is read-only and specifies the number of
> -		failed writes happened on this device.
> -		Now accessible via zram<id>/io_stat node.
> -
> -What:		/sys/block/zram<id>/notify_free
> -Date:		August 2015
> -Contact:	Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx>
> -Description:
> -		The notify_free file is read-only. Depending on device usage
> -		scenario it may account a) the number of pages freed because
> -		of swap slot free notifications or b) the number of pages freed
> -		because of REQ_DISCARD requests sent by bio. The former ones
> -		are sent to a swap block device when a swap slot is freed, which
> -		implies that this disk is being used as a swap disk. The latter
> -		ones are sent by filesystem mounted with discard option,
> -		whenever some data blocks are getting discarded.
> -		Now accessible via zram<id>/io_stat node.
> -
> -What:		/sys/block/zram<id>/zero_pages
> -Date:		August 2015
> -Contact:	Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx>
> -Description:
> -		The zero_pages file is read-only and specifies number of zero
> -		filled pages written to this disk. No memory is allocated for
> -		such pages.
> -		Now accessible via zram<id>/mm_stat node.
> -
> -What:		/sys/block/zram<id>/orig_data_size
> -Date:		August 2015
> -Contact:	Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx>
> -Description:
> -		The orig_data_size file is read-only and specifies uncompressed
> -		size of data stored in this disk. This excludes zero-filled
> -		pages (zero_pages) since no memory is allocated for them.
> -		Unit: bytes
> -		Now accessible via zram<id>/mm_stat node.
> -
> -What:		/sys/block/zram<id>/compr_data_size
> -Date:		August 2015
> -Contact:	Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx>
> -Description:
> -		The compr_data_size file is read-only and specifies compressed
> -		size of data stored in this disk. So, compression ratio can be
> -		calculated using orig_data_size and this statistic.
> -		Unit: bytes
> -		Now accessible via zram<id>/mm_stat node.
> -
> -What:		/sys/block/zram<id>/mem_used_total
> -Date:		August 2015
> -Contact:	Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx>
> -Description:
> -		The mem_used_total file is read-only and specifies the amount
> -		of memory, including allocator fragmentation and metadata
> -		overhead, allocated for this disk. So, allocator space
> -		efficiency can be calculated using compr_data_size and this
> -		statistic.
> -		Unit: bytes
> -		Now accessible via zram<id>/mm_stat node.
> -
> -What:		/sys/block/zram<id>/mem_used_max
> -Date:		August 2015
> -Contact:	Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx>
> -Description:
> -		The mem_used_max file is read/write and specifies the amount
> -		of maximum memory zram have consumed to store compressed data.
> -		For resetting the value, you should write "0". Otherwise,
> -		you could see -EINVAL.
> -		Unit: bytes
> -		Downgraded to write-only node: so it's possible to set new
> -		value only; its current value is stored in zram<id>/mm_stat
> -		node.
> -
> -What:		/sys/block/zram<id>/mem_limit
> -Date:		August 2015
> -Contact:	Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx>
> -Description:
> -		The mem_limit file is read/write and specifies the maximum
> -		amount of memory ZRAM can use to store the compressed data.
> -		The limit could be changed in run time and "0" means disable
> -		the limit.  No limit is the initial state.  Unit: bytes
> -		Downgraded to write-only node: so it's possible to set new
> -		value only; its current value is stored in zram<id>/mm_stat
> -		node.
> diff --git a/Documentation/ABI/testing/sysfs-block-zram b/Documentation/ABI/testing/sysfs-block-zram
> index 4518d30b8c2e..451b6d882b2c 100644
> --- a/Documentation/ABI/testing/sysfs-block-zram
> +++ b/Documentation/ABI/testing/sysfs-block-zram
> @@ -22,41 +22,6 @@ Description:
>  		device. The reset operation frees all the memory associated
>  		with this device.
>  
> -What:		/sys/block/zram<id>/num_reads
> -Date:		August 2010
> -Contact:	Nitin Gupta <ngupta@xxxxxxxxxx>
> -Description:
> -		The num_reads file is read-only and specifies the number of
> -		reads (failed or successful) done on this device.
> -
> -What:		/sys/block/zram<id>/num_writes
> -Date:		August 2010
> -Contact:	Nitin Gupta <ngupta@xxxxxxxxxx>
> -Description:
> -		The num_writes file is read-only and specifies the number of
> -		writes (failed or successful) done on this device.
> -
> -What:		/sys/block/zram<id>/invalid_io
> -Date:		August 2010
> -Contact:	Nitin Gupta <ngupta@xxxxxxxxxx>
> -Description:
> -		The invalid_io file is read-only and specifies the number of
> -		non-page-size-aligned I/O requests issued to this device.
> -
> -What:		/sys/block/zram<id>/failed_reads
> -Date:		February 2014
> -Contact:	Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx>
> -Description:
> -		The failed_reads file is read-only and specifies the number of
> -		failed reads happened on this device.
> -
> -What:		/sys/block/zram<id>/failed_writes
> -Date:		February 2014
> -Contact:	Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx>
> -Description:
> -		The failed_writes file is read-only and specifies the number of
> -		failed writes happened on this device.
> -
>  What:		/sys/block/zram<id>/max_comp_streams
>  Date:		February 2014
>  Contact:	Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx>
> @@ -73,74 +38,24 @@ Description:
>  		available and selected compression algorithms, change
>  		compression algorithm selection.
>  
> -What:		/sys/block/zram<id>/notify_free
> -Date:		August 2010
> -Contact:	Nitin Gupta <ngupta@xxxxxxxxxx>
> -Description:
> -		The notify_free file is read-only. Depending on device usage
> -		scenario it may account a) the number of pages freed because
> -		of swap slot free notifications or b) the number of pages freed
> -		because of REQ_DISCARD requests sent by bio. The former ones
> -		are sent to a swap block device when a swap slot is freed, which
> -		implies that this disk is being used as a swap disk. The latter
> -		ones are sent by filesystem mounted with discard option,
> -		whenever some data blocks are getting discarded.
> -
> -What:		/sys/block/zram<id>/zero_pages
> -Date:		August 2010
> -Contact:	Nitin Gupta <ngupta@xxxxxxxxxx>
> -Description:
> -		The zero_pages file is read-only and specifies number of zero
> -		filled pages written to this disk. No memory is allocated for
> -		such pages.
> -
> -What:		/sys/block/zram<id>/orig_data_size
> -Date:		August 2010
> -Contact:	Nitin Gupta <ngupta@xxxxxxxxxx>
> -Description:
> -		The orig_data_size file is read-only and specifies uncompressed
> -		size of data stored in this disk. This excludes zero-filled
> -		pages (zero_pages) since no memory is allocated for them.
> -		Unit: bytes
> -
> -What:		/sys/block/zram<id>/compr_data_size
> -Date:		August 2010
> -Contact:	Nitin Gupta <ngupta@xxxxxxxxxx>
> -Description:
> -		The compr_data_size file is read-only and specifies compressed
> -		size of data stored in this disk. So, compression ratio can be
> -		calculated using orig_data_size and this statistic.
> -		Unit: bytes
> -
> -What:		/sys/block/zram<id>/mem_used_total
> -Date:		August 2010
> -Contact:	Nitin Gupta <ngupta@xxxxxxxxxx>
> -Description:
> -		The mem_used_total file is read-only and specifies the amount
> -		of memory, including allocator fragmentation and metadata
> -		overhead, allocated for this disk. So, allocator space
> -		efficiency can be calculated using compr_data_size and this
> -		statistic.
> -		Unit: bytes
> -
>  What:		/sys/block/zram<id>/mem_used_max
>  Date:		August 2014
>  Contact:	Minchan Kim <minchan@xxxxxxxxxx>
>  Description:
> -		The mem_used_max file is read/write and specifies the amount
> -		of maximum memory zram have consumed to store compressed data.
> -		For resetting the value, you should write "0". Otherwise,
> -		you could see -EINVAL.
> +		The mem_used_max file is write-only and is used to reset
> +		the counter of maximum memory zram have consumed to store
> +		compressed data. For resetting the value, you should write
> +		"0". Otherwise, you could see -EINVAL.
>  		Unit: bytes
>  
>  What:		/sys/block/zram<id>/mem_limit
>  Date:		August 2014
>  Contact:	Minchan Kim <minchan@xxxxxxxxxx>
>  Description:
> -		The mem_limit file is read/write and specifies the maximum
> -		amount of memory ZRAM can use to store the compressed data.  The
> -		limit could be changed in run time and "0" means disable the
> -		limit.  No limit is the initial state.  Unit: bytes
> +		The mem_limit file is write-only and specifies the maximum
> +		amount of memory ZRAM can use to store the compressed data.
> +		The limit could be changed in run time and "0" means disable
> +		the limit. No limit is the initial state.  Unit: bytes
>  
>  What:		/sys/block/zram<id>/compact
>  Date:		August 2015
> diff --git a/Documentation/blockdev/zram.txt b/Documentation/blockdev/zram.txt
> index 0535ae1f73e5..1c0c08d9206b 100644
> --- a/Documentation/blockdev/zram.txt
> +++ b/Documentation/blockdev/zram.txt
> @@ -161,42 +161,14 @@ Name            access            description
>  disksize          RW    show and set the device's disk size
>  initstate         RO    shows the initialization state of the device
>  reset             WO    trigger device reset
> -num_reads         RO    the number of reads
> -failed_reads      RO    the number of failed reads
> -num_write         RO    the number of writes
> -failed_writes     RO    the number of failed writes
> -invalid_io        RO    the number of non-page-size-aligned I/O requests
> +mem_used_max      WO    reset the `mem_used_max' counter (see later)
> +mem_limit         WO    specifies the maximum amount of memory ZRAM can use
> +                        to store the compressed data
>  max_comp_streams  RW    the number of possible concurrent compress operations
>  comp_algorithm    RW    show and change the compression algorithm
> -notify_free       RO    the number of notifications to free pages (either
> -                        slot free notifications or REQ_DISCARD requests)
> -zero_pages        RO    the number of zero filled pages written to this disk
> -orig_data_size    RO    uncompressed size of data stored in this disk
> -compr_data_size   RO    compressed size of data stored in this disk
> -mem_used_total    RO    the amount of memory allocated for this disk
> -mem_used_max      RW    the maximum amount of memory zram have consumed to
> -                        store the data (to reset this counter to the actual
> -                        current value, write 1 to this attribute)
> -mem_limit         RW    the maximum amount of memory ZRAM can use to store
> -                        the compressed data
> -pages_compacted   RO    the number of pages freed during compaction
> -                        (available only via zram<id>/mm_stat node)
>  compact           WO    trigger memory compaction
>  debug_stat        RO    this file is used for zram debugging purposes
>  
> -WARNING
> -=======
> -per-stat sysfs attributes are considered to be deprecated.
> -The basic strategy is:
> --- the existing RW nodes will be downgraded to WO nodes (in linux 4.11)
> --- deprecated RO sysfs nodes will eventually be removed (in linux 4.11)
> -
> -The list of deprecated attributes can be found here:
> -Documentation/ABI/obsolete/sysfs-block-zram
> -
> -Basically, every attribute that has its own read accessible sysfs node
> -(e.g. num_reads) *AND* is accessible via one of the stat files (zram<id>/stat
> -or zram<id>/io_stat or zram<id>/mm_stat) is considered to be deprecated.
>  
>  User space is advised to use the following files to read the device statistics.
>  
> @@ -211,22 +183,40 @@ The stat file represents device's I/O statistics not accounted by block
>  layer and, thus, not available in zram<id>/stat file. It consists of a
>  single line of text and contains the following stats separated by
>  whitespace:
> -	failed_reads
> -	failed_writes
> -	invalid_io
> -	notify_free
> + failed_reads     the number of failed reads
> + failed_writes    the number of failed writes
> + invalid_io       the number of non-page-size-aligned I/O requests
> + notify_free      Depending on device usage scenario it may account
> +                  a) the number of pages freed because of swap slot free
> +                  notifications or b) the number of pages freed because of
> +                  REQ_DISCARD requests sent by bio. The former ones are
> +                  sent to a swap block device when a swap slot is freed,
> +                  which implies that this disk is being used as a swap disk.
> +                  The latter ones are sent by filesystem mounted with
> +                  discard option, whenever some data blocks are getting
> +                  discarded.
>  
>  File /sys/block/zram<id>/mm_stat
>  
>  The stat file represents device's mm statistics. It consists of a single
>  line of text and contains the following stats separated by whitespace:
> -	orig_data_size
> -	compr_data_size
> -	mem_used_total
> -	mem_limit
> -	mem_used_max
> -	zero_pages
> -	num_migrated
> + orig_data_size   uncompressed size of data stored in this disk.
> +                  This excludes zero-filled pages (zero_pages) since no
> +                  memory is allocated for them.
> +                  Unit: bytes
> + compr_data_size  compressed size of data stored in this disk
> + mem_used_total   the amount of memory allocated for this disk. This
> +                  includes allocator fragmentation and metadata overhead,
> +                  allocated for this disk. So, allocator space efficiency
> +                  can be calculated using compr_data_size and this statistic.
> +                  Unit: bytes
> + mem_limit        the maximum amount of memory ZRAM can use to store
> +                  the compressed data
> + mem_used_max     the maximum amount of memory zram have consumed to
> +                  store the data
> + zero_pages       the number of zero filled pages written to this disk.
> +                  No memory is allocated for such pages.
> + pages_compacted  the number of pages freed during compaction
>  
>  9) Deactivate:
>  	swapoff /dev/zram0
> diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
> index e5ab7d9e8c45..85737b6474ac 100644
> --- a/drivers/block/zram/zram_drv.c
> +++ b/drivers/block/zram/zram_drv.c
> @@ -45,27 +45,6 @@ static const char *default_compressor = "lzo";
>  /* Module params (documentation at end) */
>  static unsigned int num_devices = 1;
>  
> -static inline void deprecated_attr_warn(const char *name)
> -{
> -	pr_warn_once("%d (%s) Attribute %s (and others) will be removed. %s\n",
> -			task_pid_nr(current),
> -			current->comm,
> -			name,
> -			"See zram documentation.");
> -}
> -
> -#define ZRAM_ATTR_RO(name)						\
> -static ssize_t name##_show(struct device *d,				\
> -				struct device_attribute *attr, char *b)	\
> -{									\
> -	struct zram *zram = dev_to_zram(d);				\
> -									\
> -	deprecated_attr_warn(__stringify(name));			\
> -	return scnprintf(b, PAGE_SIZE, "%llu\n",			\
> -		(u64)atomic64_read(&zram->stats.name));			\
> -}									\
> -static DEVICE_ATTR_RO(name);
> -
>  static inline bool init_done(struct zram *zram)
>  {
>  	return zram->disksize;
> @@ -218,47 +197,6 @@ static ssize_t disksize_show(struct device *dev,
>  	return scnprintf(buf, PAGE_SIZE, "%llu\n", zram->disksize);
>  }
>  
> -static ssize_t orig_data_size_show(struct device *dev,
> -		struct device_attribute *attr, char *buf)
> -{
> -	struct zram *zram = dev_to_zram(dev);
> -
> -	deprecated_attr_warn("orig_data_size");
> -	return scnprintf(buf, PAGE_SIZE, "%llu\n",
> -		(u64)(atomic64_read(&zram->stats.pages_stored)) << PAGE_SHIFT);
> -}
> -
> -static ssize_t mem_used_total_show(struct device *dev,
> -		struct device_attribute *attr, char *buf)
> -{
> -	u64 val = 0;
> -	struct zram *zram = dev_to_zram(dev);
> -
> -	deprecated_attr_warn("mem_used_total");
> -	down_read(&zram->init_lock);
> -	if (init_done(zram)) {
> -		struct zram_meta *meta = zram->meta;
> -		val = zs_get_total_pages(meta->mem_pool);
> -	}
> -	up_read(&zram->init_lock);
> -
> -	return scnprintf(buf, PAGE_SIZE, "%llu\n", val << PAGE_SHIFT);
> -}
> -
> -static ssize_t mem_limit_show(struct device *dev,
> -		struct device_attribute *attr, char *buf)
> -{
> -	u64 val;
> -	struct zram *zram = dev_to_zram(dev);
> -
> -	deprecated_attr_warn("mem_limit");
> -	down_read(&zram->init_lock);
> -	val = zram->limit_pages;
> -	up_read(&zram->init_lock);
> -
> -	return scnprintf(buf, PAGE_SIZE, "%llu\n", val << PAGE_SHIFT);
> -}
> -
>  static ssize_t mem_limit_store(struct device *dev,
>  		struct device_attribute *attr, const char *buf, size_t len)
>  {
> @@ -277,21 +215,6 @@ static ssize_t mem_limit_store(struct device *dev,
>  	return len;
>  }
>  
> -static ssize_t mem_used_max_show(struct device *dev,
> -		struct device_attribute *attr, char *buf)
> -{
> -	u64 val = 0;
> -	struct zram *zram = dev_to_zram(dev);
> -
> -	deprecated_attr_warn("mem_used_max");
> -	down_read(&zram->init_lock);
> -	if (init_done(zram))
> -		val = atomic_long_read(&zram->stats.max_used_pages);
> -	up_read(&zram->init_lock);
> -
> -	return scnprintf(buf, PAGE_SIZE, "%llu\n", val << PAGE_SHIFT);
> -}
> -
>  static ssize_t mem_used_max_store(struct device *dev,
>  		struct device_attribute *attr, const char *buf, size_t len)
>  {
> @@ -467,14 +390,6 @@ static ssize_t debug_stat_show(struct device *dev,
>  static DEVICE_ATTR_RO(io_stat);
>  static DEVICE_ATTR_RO(mm_stat);
>  static DEVICE_ATTR_RO(debug_stat);
> -ZRAM_ATTR_RO(num_reads);
> -ZRAM_ATTR_RO(num_writes);
> -ZRAM_ATTR_RO(failed_reads);
> -ZRAM_ATTR_RO(failed_writes);
> -ZRAM_ATTR_RO(invalid_io);
> -ZRAM_ATTR_RO(notify_free);
> -ZRAM_ATTR_RO(zero_pages);
> -ZRAM_ATTR_RO(compr_data_size);
>  
>  static inline bool zram_meta_get(struct zram *zram)
>  {
> @@ -1188,10 +1103,8 @@ static DEVICE_ATTR_WO(compact);
>  static DEVICE_ATTR_RW(disksize);
>  static DEVICE_ATTR_RO(initstate);
>  static DEVICE_ATTR_WO(reset);
> -static DEVICE_ATTR_RO(orig_data_size);
> -static DEVICE_ATTR_RO(mem_used_total);
> -static DEVICE_ATTR_RW(mem_limit);
> -static DEVICE_ATTR_RW(mem_used_max);
> +static DEVICE_ATTR_WO(mem_limit);
> +static DEVICE_ATTR_WO(mem_used_max);
>  static DEVICE_ATTR_RW(max_comp_streams);
>  static DEVICE_ATTR_RW(comp_algorithm);
>  
> @@ -1199,17 +1112,7 @@ static struct attribute *zram_disk_attrs[] = {
>  	&dev_attr_disksize.attr,
>  	&dev_attr_initstate.attr,
>  	&dev_attr_reset.attr,
> -	&dev_attr_num_reads.attr,
> -	&dev_attr_num_writes.attr,
> -	&dev_attr_failed_reads.attr,
> -	&dev_attr_failed_writes.attr,
>  	&dev_attr_compact.attr,
> -	&dev_attr_invalid_io.attr,
> -	&dev_attr_notify_free.attr,
> -	&dev_attr_zero_pages.attr,
> -	&dev_attr_orig_data_size.attr,
> -	&dev_attr_compr_data_size.attr,
> -	&dev_attr_mem_used_total.attr,
>  	&dev_attr_mem_limit.attr,
>  	&dev_attr_mem_used_max.attr,
>  	&dev_attr_max_comp_streams.attr,
> -- 
> 2.11.0
>