[PATCHv2 6/7] zram: export new 'mm_stat' sysfs attrs

Sergey Senozhatsky
2015-03-12T14:47:55Z

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 c02121f..7493096 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,
};

--
2.3.2.209.gd67f9d5