[PATCH v3 6/7] zram: add bd_stat statistics
bd_stat represents things happened in backing device. Currently,
it supports bd_counts, bd_reads and bd_writes which are helpful
to understand wearout of flash and memory saving.
Signed-off-by: Minchan Kim
---
Documentation/ABI/testing/sysfs-block-zram | 8 ++
Documentation/blockdev/zram.txt| 11
drivers/block/zram/zram_drv.c | 29 ++
drivers/block/zram/zram_drv.h | 5
4 files changed, 53 insertions(+)
diff --git a/Documentation/ABI/testing/sysfs-block-zram
b/Documentation/ABI/testing/sysfs-block-zram
index d1f80b077885..65fc33b2f53b 100644
--- a/Documentation/ABI/testing/sysfs-block-zram
+++ b/Documentation/ABI/testing/sysfs-block-zram
@@ -113,3 +113,11 @@ Contact: Minchan Kim
Description:
The writeback file is write-only and trigger idle and/or
huge page writeback to backing device.
+
+What: /sys/block/zram/bd_stat
+Date: November 2018
+Contact: Minchan Kim
+Description:
+ The bd_stat file is read-only and represents backing device's
+ statistics (bd_count, bd_reads, bd_writes) in a format
+ similar to block layer statistics file format.
diff --git a/Documentation/blockdev/zram.txt b/Documentation/blockdev/zram.txt
index 806cdaabac83..906df97527a7 100644
--- a/Documentation/blockdev/zram.txt
+++ b/Documentation/blockdev/zram.txt
@@ -221,6 +221,17 @@ The stat file represents device's mm statistics. It
consists of a single
pages_compacted the number of pages freed during compaction
huge_pages the number of incompressible pages
+File /sys/block/zram/bd_stat
+
+The stat file represents device's backing device statistics. It consists of
+a single line of text and contains the following stats separated by whitespace:
+ bd_count size of data written in backing device.
+ Unit: 4K bytes
+ bd_reads the number of reads from backing device
+ Unit: 4K bytes
+ bd_writes the number of writes to backing device
+ Unit: 4K bytes
+
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 6b5a886c8f32..67168a6ecca6 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -502,6 +502,7 @@ static unsigned long alloc_block_bdev(struct zram *zram)
if (test_and_set_bit(blk_idx, zram->bitmap))
goto retry;
+ atomic64_inc(>stats.bd_count);
return blk_idx;
}
@@ -511,6 +512,7 @@ static void free_block_bdev(struct zram *zram, unsigned
long blk_idx)
was_set = test_and_clear_bit(blk_idx, zram->bitmap);
WARN_ON_ONCE(!was_set);
+ atomic64_dec(>stats.bd_count);
}
static void zram_page_end_io(struct bio *bio)
@@ -668,6 +670,7 @@ static ssize_t writeback_store(struct device *dev,
continue;
}
+ atomic64_inc(>stats.bd_writes);
/*
* We released zram_slot_lock so need to check if the slot was
* changed. If there is freeing for the slot, we can catch it
@@ -757,6 +760,7 @@ static int read_from_bdev_sync(struct zram *zram, struct
bio_vec *bvec,
static int read_from_bdev(struct zram *zram, struct bio_vec *bvec,
unsigned long entry, struct bio *parent, bool sync)
{
+ atomic64_inc(>stats.bd_reads);
if (sync)
return read_from_bdev_sync(zram, bvec, entry, parent);
else
@@ -1013,6 +1017,25 @@ static ssize_t mm_stat_show(struct device *dev,
return ret;
}
+#ifdef CONFIG_ZRAM_WRITEBACK
+static ssize_t bd_stat_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct zram *zram = dev_to_zram(dev);
+ ssize_t ret;
+
+ down_read(>init_lock);
+ ret = scnprintf(buf, PAGE_SIZE,
+ "%8llu %8llu %8llu\n",
+ (u64)atomic64_read(>stats.bd_count),
+ (u64)atomic64_read(>stats.bd_reads),
+ (u64)atomic64_read(>stats.bd_writes));
+ up_read(>init_lock);
+
+ return ret;
+}
+#endif
+
static ssize_t debug_stat_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
@@ -1033,6 +1056,9 @@ static ssize_t debug_stat_show(struct device *dev,
static DEVICE_ATTR_RO(io_stat);
static DEVICE_ATTR_RO(mm_stat);
+#ifdef CONFIG_ZRAM_WRITEBACK
+static DEVICE_ATTR_RO(bd_stat);
+#endif
static DEVICE_ATTR_RO(debug_stat);
static void zram_meta_free(struct zram *zram, u64 disksize)
@@ -1759,6 +1785,9 @@ static struct attribute *zram_disk_attrs[] = {
#endif
_attr_io_stat.attr,
_attr_mm_stat.attr,
+#ifdef CONFIG_ZRAM_WRITEBACK
+ _attr_bd_stat.attr,
+#endif
_attr_debug_stat.attr,
NULL,
};
diff --git a/drivers/block/zram/zram_drv.h
[PATCH v3 6/7] zram: add bd_stat statistics
bd_stat represents things happened in backing device. Currently,
it supports bd_counts, bd_reads and bd_writes which are helpful
to understand wearout of flash and memory saving.
Signed-off-by: Minchan Kim
---
Documentation/ABI/testing/sysfs-block-zram | 8 ++
Documentation/blockdev/zram.txt| 11
drivers/block/zram/zram_drv.c | 29 ++
drivers/block/zram/zram_drv.h | 5
4 files changed, 53 insertions(+)
diff --git a/Documentation/ABI/testing/sysfs-block-zram
b/Documentation/ABI/testing/sysfs-block-zram
index d1f80b077885..65fc33b2f53b 100644
--- a/Documentation/ABI/testing/sysfs-block-zram
+++ b/Documentation/ABI/testing/sysfs-block-zram
@@ -113,3 +113,11 @@ Contact: Minchan Kim
Description:
The writeback file is write-only and trigger idle and/or
huge page writeback to backing device.
+
+What: /sys/block/zram/bd_stat
+Date: November 2018
+Contact: Minchan Kim
+Description:
+ The bd_stat file is read-only and represents backing device's
+ statistics (bd_count, bd_reads, bd_writes) in a format
+ similar to block layer statistics file format.
diff --git a/Documentation/blockdev/zram.txt b/Documentation/blockdev/zram.txt
index 806cdaabac83..906df97527a7 100644
--- a/Documentation/blockdev/zram.txt
+++ b/Documentation/blockdev/zram.txt
@@ -221,6 +221,17 @@ The stat file represents device's mm statistics. It
consists of a single
pages_compacted the number of pages freed during compaction
huge_pages the number of incompressible pages
+File /sys/block/zram/bd_stat
+
+The stat file represents device's backing device statistics. It consists of
+a single line of text and contains the following stats separated by whitespace:
+ bd_count size of data written in backing device.
+ Unit: 4K bytes
+ bd_reads the number of reads from backing device
+ Unit: 4K bytes
+ bd_writes the number of writes to backing device
+ Unit: 4K bytes
+
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 6b5a886c8f32..67168a6ecca6 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -502,6 +502,7 @@ static unsigned long alloc_block_bdev(struct zram *zram)
if (test_and_set_bit(blk_idx, zram->bitmap))
goto retry;
+ atomic64_inc(>stats.bd_count);
return blk_idx;
}
@@ -511,6 +512,7 @@ static void free_block_bdev(struct zram *zram, unsigned
long blk_idx)
was_set = test_and_clear_bit(blk_idx, zram->bitmap);
WARN_ON_ONCE(!was_set);
+ atomic64_dec(>stats.bd_count);
}
static void zram_page_end_io(struct bio *bio)
@@ -668,6 +670,7 @@ static ssize_t writeback_store(struct device *dev,
continue;
}
+ atomic64_inc(>stats.bd_writes);
/*
* We released zram_slot_lock so need to check if the slot was
* changed. If there is freeing for the slot, we can catch it
@@ -757,6 +760,7 @@ static int read_from_bdev_sync(struct zram *zram, struct
bio_vec *bvec,
static int read_from_bdev(struct zram *zram, struct bio_vec *bvec,
unsigned long entry, struct bio *parent, bool sync)
{
+ atomic64_inc(>stats.bd_reads);
if (sync)
return read_from_bdev_sync(zram, bvec, entry, parent);
else
@@ -1013,6 +1017,25 @@ static ssize_t mm_stat_show(struct device *dev,
return ret;
}
+#ifdef CONFIG_ZRAM_WRITEBACK
+static ssize_t bd_stat_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct zram *zram = dev_to_zram(dev);
+ ssize_t ret;
+
+ down_read(>init_lock);
+ ret = scnprintf(buf, PAGE_SIZE,
+ "%8llu %8llu %8llu\n",
+ (u64)atomic64_read(>stats.bd_count),
+ (u64)atomic64_read(>stats.bd_reads),
+ (u64)atomic64_read(>stats.bd_writes));
+ up_read(>init_lock);
+
+ return ret;
+}
+#endif
+
static ssize_t debug_stat_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
@@ -1033,6 +1056,9 @@ static ssize_t debug_stat_show(struct device *dev,
static DEVICE_ATTR_RO(io_stat);
static DEVICE_ATTR_RO(mm_stat);
+#ifdef CONFIG_ZRAM_WRITEBACK
+static DEVICE_ATTR_RO(bd_stat);
+#endif
static DEVICE_ATTR_RO(debug_stat);
static void zram_meta_free(struct zram *zram, u64 disksize)
@@ -1759,6 +1785,9 @@ static struct attribute *zram_disk_attrs[] = {
#endif
_attr_io_stat.attr,
_attr_mm_stat.attr,
+#ifdef CONFIG_ZRAM_WRITEBACK
+ _attr_bd_stat.attr,
+#endif
_attr_debug_stat.attr,
NULL,
};
diff --git a/drivers/block/zram/zram_drv.h
