The patch titled
Subject: zram: remove obsolete sysfs attrs
has been added to the -mm tree. Its filename is
zram-remove-obsolete-sysfs-attrs.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/zram-remove-obsolete-sysfs-attrs.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/zram-remove-obsolete-sysfs-attrs.patch
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------------------------------------------------------
From: Sergey Senozhatsky <sergey.senozhatsky.work@xxxxxxxxx>
Subject: zram: remove obsolete sysfs attrs
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.
Link: http://lkml.kernel.org/r/20170118035838.11090-1-sergey.senozhatsky@xxxxxxxxx
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx>
Cc: Minchan Kim <minchan@xxxxxxxxxx>
Cc: Jonathan Corbet <corbet@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
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(-)
diff -puN Documentation/ABI/obsolete/sysfs-block-zram~zram-remove-obsolete-sysfs-attrs /dev/null
--- 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 -puN Documentation/ABI/testing/sysfs-block-zram~zram-remove-obsolete-sysfs-attrs Documentation/ABI/testing/sysfs-block-zram
--- a/Documentation/ABI/testing/sysfs-block-zram~zram-remove-obsolete-sysfs-attrs
+++ a/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 -puN Documentation/blockdev/zram.txt~zram-remove-obsolete-sysfs-attrs Documentation/blockdev/zram.txt
--- a/Documentation/blockdev/zram.txt~zram-remove-obsolete-sysfs-attrs
+++ a/Documentation/blockdev/zram.txt
@@ -161,42 +161,14 @@ Name access descri
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 st
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 -puN drivers/block/zram/zram_drv.c~zram-remove-obsolete-sysfs-attrs drivers/block/zram/zram_drv.c
--- a/drivers/block/zram/zram_drv.c~zram-remove-obsolete-sysfs-attrs
+++ a/drivers/block/zram/zram_drv.c
@@ -45,27 +45,6 @@ static const char *default_compressor =
/* 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 devi
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 de
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 de
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,
_
Patches currently in -mm which might be from sergey.senozhatsky.work@xxxxxxxxx are
zram-remove-obsolete-sysfs-attrs.patch
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