* [PATCHv3 1/7] zram: remove `num_migrated' device attr
2015-03-13 10:29 [PATCHv3 0/7] new zram statistics reporting scheme Sergey Senozhatsky
@ 2015-03-13 10:29 ` Sergey Senozhatsky
2015-03-13 10:29 ` [PATCHv3 2/7] zram: move compact_store() to sysfs functions area Sergey Senozhatsky
` (5 subsequent siblings)
6 siblings, 0 replies; 8+ messages in thread
From: Sergey Senozhatsky @ 2015-03-13 10:29 UTC (permalink / raw)
To: Andrew Morton, Minchan Kim
Cc: Nitin Gupta, linux-kernel, Sergey Senozhatsky, Sergey Senozhatsky
Remove sysfs `num_migrated' attribute. We are moving away from
per-stat device attrs towards 3 stat files that will accumulate
io and mm stats in a format similar to block layer statistics in
/sys/block/<dev>/stat. That will be easier to use in user space,
and reduce the number of syscalls needed to read zram device
statistics.
`num_migrated' will return back in zram<id>/mm_stat file.
Acked-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
---
Documentation/ABI/testing/sysfs-block-zram | 7 -------
drivers/block/zram/zram_drv.c | 2 --
2 files changed, 9 deletions(-)
diff --git a/Documentation/ABI/testing/sysfs-block-zram b/Documentation/ABI/testing/sysfs-block-zram
index bede902..91ad707 100644
--- a/Documentation/ABI/testing/sysfs-block-zram
+++ b/Documentation/ABI/testing/sysfs-block-zram
@@ -149,10 +149,3 @@ Description:
The compact file is write-only and trigger compaction for
allocator zrm uses. The allocator moves some objects so that
it could free fragment space.
-
-What: /sys/block/zram<id>/num_migrated
-Date: August 2015
-Contact: Minchan Kim <minchan@kernel.org>
-Description:
- The compact file is read-only and shows how many object
- migrated by compaction.
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 0194799..660999f 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -392,7 +392,6 @@ ZRAM_ATTR_RO(invalid_io);
ZRAM_ATTR_RO(notify_free);
ZRAM_ATTR_RO(zero_pages);
ZRAM_ATTR_RO(compr_data_size);
-ZRAM_ATTR_RO(num_migrated);
static inline bool zram_meta_get(struct zram *zram)
{
@@ -1069,7 +1068,6 @@ static struct attribute *zram_disk_attrs[] = {
&dev_attr_num_writes.attr,
&dev_attr_failed_reads.attr,
&dev_attr_failed_writes.attr,
- &dev_attr_num_migrated.attr,
&dev_attr_compact.attr,
&dev_attr_invalid_io.attr,
&dev_attr_notify_free.attr,
--
2.3.2.223.g7a9409c
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [PATCHv3 2/7] zram: move compact_store() to sysfs functions area
2015-03-13 10:29 [PATCHv3 0/7] new zram statistics reporting scheme Sergey Senozhatsky
2015-03-13 10:29 ` [PATCHv3 1/7] zram: remove `num_migrated' device attr Sergey Senozhatsky
@ 2015-03-13 10:29 ` Sergey Senozhatsky
2015-03-13 10:29 ` [PATCHv3 3/7] zram: use generic start/end io accounting Sergey Senozhatsky
` (4 subsequent siblings)
6 siblings, 0 replies; 8+ messages in thread
From: Sergey Senozhatsky @ 2015-03-13 10:29 UTC (permalink / raw)
To: Andrew Morton, Minchan Kim
Cc: Nitin Gupta, linux-kernel, Sergey Senozhatsky, Sergey Senozhatsky
A cosmetic change. We have a new code layout and keep zram per-device
sysfs store and show functions in one place. Move compact_store() to
that handlers block to conform to current layout.
Acked-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
---
drivers/block/zram/zram_drv.c | 42 +++++++++++++++++++++---------------------
1 file changed, 21 insertions(+), 21 deletions(-)
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 660999f..2d5848a 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -67,27 +67,6 @@ static inline struct zram *dev_to_zram(struct device *dev)
return (struct zram *)dev_to_disk(dev)->private_data;
}
-static ssize_t compact_store(struct device *dev,
- struct device_attribute *attr, const char *buf, size_t len)
-{
- unsigned long nr_migrated;
- struct zram *zram = dev_to_zram(dev);
- struct zram_meta *meta;
-
- down_read(&zram->init_lock);
- if (!init_done(zram)) {
- up_read(&zram->init_lock);
- return -EINVAL;
- }
-
- meta = zram->meta;
- nr_migrated = zs_compact(meta->mem_pool);
- atomic64_add(nr_migrated, &zram->stats.num_migrated);
- up_read(&zram->init_lock);
-
- return len;
-}
-
/* flag operations require table entry bit_spin_lock() being held */
static int zram_test_flag(struct zram_meta *meta, u32 index,
enum zram_pageflags flag)
@@ -384,6 +363,27 @@ static ssize_t comp_algorithm_store(struct device *dev,
return len;
}
+static ssize_t compact_store(struct device *dev,
+ struct device_attribute *attr, const char *buf, size_t len)
+{
+ unsigned long nr_migrated;
+ struct zram *zram = dev_to_zram(dev);
+ struct zram_meta *meta;
+
+ down_read(&zram->init_lock);
+ if (!init_done(zram)) {
+ up_read(&zram->init_lock);
+ return -EINVAL;
+ }
+
+ meta = zram->meta;
+ nr_migrated = zs_compact(meta->mem_pool);
+ atomic64_add(nr_migrated, &zram->stats.num_migrated);
+ up_read(&zram->init_lock);
+
+ return len;
+}
+
ZRAM_ATTR_RO(num_reads);
ZRAM_ATTR_RO(num_writes);
ZRAM_ATTR_RO(failed_reads);
--
2.3.2.223.g7a9409c
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [PATCHv3 3/7] zram: use generic start/end io accounting
2015-03-13 10:29 [PATCHv3 0/7] new zram statistics reporting scheme Sergey Senozhatsky
2015-03-13 10:29 ` [PATCHv3 1/7] zram: remove `num_migrated' device attr Sergey Senozhatsky
2015-03-13 10:29 ` [PATCHv3 2/7] zram: move compact_store() to sysfs functions area Sergey Senozhatsky
@ 2015-03-13 10:29 ` Sergey Senozhatsky
2015-03-13 10:29 ` [PATCHv3 4/7] zram: describe device attrs in documentation Sergey Senozhatsky
` (3 subsequent siblings)
6 siblings, 0 replies; 8+ messages in thread
From: Sergey Senozhatsky @ 2015-03-13 10:29 UTC (permalink / raw)
To: Andrew Morton, Minchan Kim
Cc: Nitin Gupta, linux-kernel, Sergey Senozhatsky, Sergey Senozhatsky
Use bio generic_start_io_acct() and generic_end_io_acct() to account
device's block layer statistics. This will let users to monitor zram
activities using sysstat and similar packages/tools.
Apart from the usual per-stat sysfs attr, zram IO stats are now also
available in '/sys/block/zram<id>/stat' and '/proc/diskstats' files.
We will slowly get rid of per-stat sysfs files.
Acked-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
---
drivers/block/zram/zram_drv.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 2d5848a..6adccdf 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -743,8 +743,12 @@ static void zram_bio_discard(struct zram *zram, u32 index,
static int zram_bvec_rw(struct zram *zram, struct bio_vec *bvec, u32 index,
int offset, int rw)
{
+ unsigned long start_time = jiffies;
int ret;
+ generic_start_io_acct(rw, bvec->bv_len >> SECTOR_SHIFT,
+ &zram->disk->part0);
+
if (rw == READ) {
atomic64_inc(&zram->stats.num_reads);
ret = zram_bvec_read(zram, bvec, index, offset);
@@ -753,6 +757,8 @@ static int zram_bvec_rw(struct zram *zram, struct bio_vec *bvec, u32 index,
ret = zram_bvec_write(zram, bvec, index, offset);
}
+ generic_end_io_acct(rw, &zram->disk->part0, start_time);
+
if (unlikely(ret)) {
if (rw == READ)
atomic64_inc(&zram->stats.failed_reads);
--
2.3.2.223.g7a9409c
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [PATCHv3 4/7] zram: describe device attrs in documentation
2015-03-13 10:29 [PATCHv3 0/7] new zram statistics reporting scheme Sergey Senozhatsky
` (2 preceding siblings ...)
2015-03-13 10:29 ` [PATCHv3 3/7] zram: use generic start/end io accounting Sergey Senozhatsky
@ 2015-03-13 10:29 ` Sergey Senozhatsky
2015-03-13 10:29 ` [PATCHv3 5/7] zram: export new 'io_stat' sysfs attrs Sergey Senozhatsky
` (2 subsequent siblings)
6 siblings, 0 replies; 8+ messages in thread
From: Sergey Senozhatsky @ 2015-03-13 10:29 UTC (permalink / raw)
To: Andrew Morton, Minchan Kim
Cc: Nitin Gupta, linux-kernel, Sergey Senozhatsky, Sergey Senozhatsky
Briefly describe exported device stat attrs in zram documentation.
We will eventually get rid of per-stat sysfs nodes and, thus,
clean up Documentation/ABI/testing/sysfs-block-zram file, which is
the only source of information about device sysfs nodes.
Add `num_migrated' description, since there is no independent
`num_migrated' sysfs node (and no corresponding sysfs-block-zram
entry), it will be exported via zram<id>/mm_stat file.
At this point we can provide minimal description, because
sysfs-block-zram still contains detailed information.
Acked-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
---
Documentation/blockdev/zram.txt | 49 +++++++++++++++++++++++++++++------------
1 file changed, 35 insertions(+), 14 deletions(-)
diff --git a/Documentation/blockdev/zram.txt b/Documentation/blockdev/zram.txt
index 902c97c..5d5e8be 100644
--- a/Documentation/blockdev/zram.txt
+++ b/Documentation/blockdev/zram.txt
@@ -117,20 +117,41 @@ execute
echo X > /sys/class/zram-control/zram_remove
8) Stats:
- Per-device statistics are exported as various nodes under
- /sys/block/zram<id>/
- disksize
- num_reads
- num_writes
- failed_reads
- failed_writes
- invalid_io
- notify_free
- zero_pages
- orig_data_size
- compr_data_size
- mem_used_total
- mem_used_max
+Per-device statistics are exported as various nodes under /sys/block/zram<id>/
+
+A brief description of exported device attritbutes. For more details please
+read Documentation/ABI/testing/sysfs-block-zram.
+
+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
+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 memory zram have consumed to
+ store compressed data
+mem_limit RW the maximum amount of memory ZRAM can use to store
+ the compressed data
+num_migrated RO the number of objects migrated migrated by compaction
+compact WO trigger memory compaction
+
+
+File /sys/block/zram<id>/stat
+
+Represents block layer statistics. Read Documentation/block/stat.txt for
+details.
9) Deactivate:
swapoff /dev/zram0
--
2.3.2.223.g7a9409c
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [PATCHv3 5/7] zram: export new 'io_stat' sysfs attrs
2015-03-13 10:29 [PATCHv3 0/7] new zram statistics reporting scheme Sergey Senozhatsky
` (3 preceding siblings ...)
2015-03-13 10:29 ` [PATCHv3 4/7] zram: describe device attrs in documentation Sergey Senozhatsky
@ 2015-03-13 10:29 ` Sergey Senozhatsky
2015-03-13 10:29 ` [PATCHv3 6/7] zram: export new 'mm_stat' " Sergey Senozhatsky
2015-03-13 10:29 ` [PATCHv3 7/7] zram: deprecate zram attrs sysfs nodes Sergey Senozhatsky
6 siblings, 0 replies; 8+ messages in thread
From: Sergey Senozhatsky @ 2015-03-13 10:29 UTC (permalink / raw)
To: Andrew Morton, Minchan Kim
Cc: Nitin Gupta, linux-kernel, Sergey Senozhatsky, Sergey Senozhatsky
Per-device `zram<id>/io_stat' file provides accumulated I/O statistics
of particular zram device in a format similar to block layer statistics.
The file consists of a single line and represents the following stats
(separated by whitespace):
failed_reads
failed_writes
invalid_io
notify_free
Acked-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
---
Documentation/ABI/testing/sysfs-block-zram | 9 +++++++++
Documentation/blockdev/zram.txt | 12 ++++++++++++
drivers/block/zram/zram_drv.c | 20 ++++++++++++++++++++
3 files changed, 41 insertions(+)
diff --git a/Documentation/ABI/testing/sysfs-block-zram b/Documentation/ABI/testing/sysfs-block-zram
index 91ad707..a7f622f 100644
--- a/Documentation/ABI/testing/sysfs-block-zram
+++ b/Documentation/ABI/testing/sysfs-block-zram
@@ -149,3 +149,12 @@ Description:
The compact file is write-only and trigger compaction for
allocator zrm uses. The allocator moves some objects so that
it could free fragment space.
+
+What: /sys/block/zram<id>/io_stat
+Date: August 2015
+Contact: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
+Description:
+ The io_stat file is read-only and accumulates device's I/O
+ statistics not accounted by block layer. For example,
+ failed_reads, failed_writes, etc. File format is similar to
+ block layer statistics file format.
diff --git a/Documentation/blockdev/zram.txt b/Documentation/blockdev/zram.txt
index 5d5e8be..5ed4dd5 100644
--- a/Documentation/blockdev/zram.txt
+++ b/Documentation/blockdev/zram.txt
@@ -153,6 +153,18 @@ File /sys/block/zram<id>/stat
Represents block layer statistics. Read Documentation/block/stat.txt for
details.
+
+File /sys/block/zram<id>/io_stat
+
+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
+
9) Deactivate:
swapoff /dev/zram0
umount /dev/zram1
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 6adccdf..99d9286 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -384,6 +384,25 @@ static ssize_t compact_store(struct device *dev,
return len;
}
+static ssize_t io_stat_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct zram *zram = dev_to_zram(dev);
+ ssize_t ret;
+
+ down_read(&zram->init_lock);
+ ret = scnprintf(buf, PAGE_SIZE,
+ "%8llu %8llu %8llu %8llu\n",
+ (u64)atomic64_read(&zram->stats.failed_reads),
+ (u64)atomic64_read(&zram->stats.failed_writes),
+ (u64)atomic64_read(&zram->stats.invalid_io),
+ (u64)atomic64_read(&zram->stats.notify_free));
+ up_read(&zram->init_lock);
+
+ return ret;
+}
+
+static DEVICE_ATTR_RO(io_stat);
ZRAM_ATTR_RO(num_reads);
ZRAM_ATTR_RO(num_writes);
ZRAM_ATTR_RO(failed_reads);
@@ -1085,6 +1104,7 @@ static struct attribute *zram_disk_attrs[] = {
&dev_attr_mem_used_max.attr,
&dev_attr_max_comp_streams.attr,
&dev_attr_comp_algorithm.attr,
+ &dev_attr_io_stat.attr,
NULL,
};
--
2.3.2.223.g7a9409c
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [PATCHv3 6/7] zram: export new 'mm_stat' sysfs attrs
2015-03-13 10:29 [PATCHv3 0/7] new zram statistics reporting scheme Sergey Senozhatsky
` (4 preceding siblings ...)
2015-03-13 10:29 ` [PATCHv3 5/7] zram: export new 'io_stat' sysfs attrs Sergey Senozhatsky
@ 2015-03-13 10:29 ` Sergey Senozhatsky
2015-03-13 10:29 ` [PATCHv3 7/7] zram: deprecate zram attrs sysfs nodes Sergey Senozhatsky
6 siblings, 0 replies; 8+ messages in thread
From: Sergey Senozhatsky @ 2015-03-13 10:29 UTC (permalink / raw)
To: Andrew Morton, Minchan Kim
Cc: Nitin Gupta, linux-kernel, Sergey Senozhatsky, Sergey Senozhatsky
Per-device `zram<id>/mm_stat' file provides mm statistics of a
particular zram device in a format similar to block layer statistics.
The file consists of a single line and represents the following stats
(separated by whitespace):
orig_data_size
compr_data_size
mem_used_total
mem_limit
mem_used_max
zero_pages
num_migrated
Acked-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
---
Documentation/ABI/testing/sysfs-block-zram | 8 ++++++++
Documentation/blockdev/zram.txt | 14 ++++++++++++++
drivers/block/zram/zram_drv.c | 31 ++++++++++++++++++++++++++++++
3 files changed, 53 insertions(+)
diff --git a/Documentation/ABI/testing/sysfs-block-zram b/Documentation/ABI/testing/sysfs-block-zram
index a7f622f..2e69e83 100644
--- a/Documentation/ABI/testing/sysfs-block-zram
+++ b/Documentation/ABI/testing/sysfs-block-zram
@@ -158,3 +158,11 @@ Description:
statistics not accounted by block layer. For example,
failed_reads, failed_writes, etc. File format is similar to
block layer statistics file format.
+
+What: /sys/block/zram<id>/mm_stat
+Date: August 2015
+Contact: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
+Description:
+ The mm_stat file is read-only and represents device's mm
+ statistics (orig_data_size, compr_data_size, etc.) in a format
+ similar to block layer statistics file format.
diff --git a/Documentation/blockdev/zram.txt b/Documentation/blockdev/zram.txt
index 5ed4dd5..b133138 100644
--- a/Documentation/blockdev/zram.txt
+++ b/Documentation/blockdev/zram.txt
@@ -165,6 +165,20 @@ whitespace:
invalid_io
notify_free
+
+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
+
+
9) Deactivate:
swapoff /dev/zram0
umount /dev/zram1
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 99d9286..f2dc90d 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -402,7 +402,37 @@ static ssize_t io_stat_show(struct device *dev,
return ret;
}
+static ssize_t mm_stat_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct zram *zram = dev_to_zram(dev);
+ u64 orig_size, mem_used = 0;
+ long max_used;
+ ssize_t ret;
+
+ down_read(&zram->init_lock);
+ if (init_done(zram))
+ mem_used = zs_get_total_pages(zram->meta->mem_pool);
+
+ orig_size = atomic64_read(&zram->stats.pages_stored);
+ max_used = atomic_long_read(&zram->stats.max_used_pages);
+
+ ret = scnprintf(buf, PAGE_SIZE,
+ "%8llu %8llu %8llu %8lu %8ld %8llu %8llu\n",
+ orig_size << PAGE_SHIFT,
+ (u64)atomic64_read(&zram->stats.compr_data_size),
+ mem_used << PAGE_SHIFT,
+ zram->limit_pages << PAGE_SHIFT,
+ max_used << PAGE_SHIFT,
+ (u64)atomic64_read(&zram->stats.zero_pages),
+ (u64)atomic64_read(&zram->stats.num_migrated));
+ up_read(&zram->init_lock);
+
+ return ret;
+}
+
static DEVICE_ATTR_RO(io_stat);
+static DEVICE_ATTR_RO(mm_stat);
ZRAM_ATTR_RO(num_reads);
ZRAM_ATTR_RO(num_writes);
ZRAM_ATTR_RO(failed_reads);
@@ -1105,6 +1135,7 @@ static struct attribute *zram_disk_attrs[] = {
&dev_attr_max_comp_streams.attr,
&dev_attr_comp_algorithm.attr,
&dev_attr_io_stat.attr,
+ &dev_attr_mm_stat.attr,
NULL,
};
--
2.3.2.223.g7a9409c
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [PATCHv3 7/7] zram: deprecate zram attrs sysfs nodes
2015-03-13 10:29 [PATCHv3 0/7] new zram statistics reporting scheme Sergey Senozhatsky
` (5 preceding siblings ...)
2015-03-13 10:29 ` [PATCHv3 6/7] zram: export new 'mm_stat' " Sergey Senozhatsky
@ 2015-03-13 10:29 ` Sergey Senozhatsky
6 siblings, 0 replies; 8+ messages in thread
From: Sergey Senozhatsky @ 2015-03-13 10:29 UTC (permalink / raw)
To: Andrew Morton, Minchan Kim
Cc: Nitin Gupta, linux-kernel, Sergey Senozhatsky, Sergey Senozhatsky
Add Documentation/ABI/obsolete/sysfs-block-zram file and list
obsolete and deprecated attributes there. The patch also adds
additional information to zram documentation and describes the
basic strategy:
- the existing RW nodes will be downgraded to WO nodes (in 4.11)
- deprecated RO sysfs nodes will eventually be removed (in 4.11)
Users will be additionally notified about deprecated attr usage
by pr_warn_once() (added to every deprecated attr _show()), as
suggested by Minchan Kim.
User space is advised to use zram<id>/stat, zram<id>/io_stat and
zram<id>/mm_stat files.
Reported-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
---
Documentation/ABI/obsolete/sysfs-block-zram | 119 ++++++++++++++++++++++++++++
Documentation/blockdev/zram.txt | 16 ++++
drivers/block/zram/zram_drv.c | 15 ++++
3 files changed, 150 insertions(+)
create mode 100644 Documentation/ABI/obsolete/sysfs-block-zram
diff --git a/Documentation/ABI/obsolete/sysfs-block-zram b/Documentation/ABI/obsolete/sysfs-block-zram
new file mode 100644
index 0000000..720ea92
--- /dev/null
+++ b/Documentation/ABI/obsolete/sysfs-block-zram
@@ -0,0 +1,119 @@
+What: /sys/block/zram<id>/num_reads
+Date: August 2015
+Contact: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
+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@gmail.com>
+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@gmail.com>
+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@gmail.com>
+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@gmail.com>
+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@gmail.com>
+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@gmail.com>
+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@gmail.com>
+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@gmail.com>
+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@gmail.com>
+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@gmail.com>
+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@gmail.com>
+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/blockdev/zram.txt b/Documentation/blockdev/zram.txt
index b133138..44b1a77 100644
--- a/Documentation/blockdev/zram.txt
+++ b/Documentation/blockdev/zram.txt
@@ -148,6 +148,22 @@ num_migrated RO the number of objects migrated migrated by compaction
compact WO trigger memory compaction
+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.
+
File /sys/block/zram<id>/stat
Represents block layer statistics. Read Documentation/block/stat.txt for
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index f2dc90d..759ee093 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -47,11 +47,22 @@ 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)); \
} \
@@ -206,6 +217,7 @@ static ssize_t orig_data_size_show(struct device *dev,
{
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);
}
@@ -216,6 +228,7 @@ static ssize_t mem_used_total_show(struct device *dev,
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;
@@ -245,6 +258,7 @@ static ssize_t mem_limit_show(struct device *dev,
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);
@@ -276,6 +290,7 @@ static ssize_t mem_used_max_show(struct device *dev,
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);
--
2.3.2.223.g7a9409c
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