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authorMinchan Kim <minchan@kernel.org>2018-12-28 00:36:51 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2018-12-28 12:11:49 -0800
commit23eddf39b2c28c05cb8f8203d38e61807d701b38 (patch)
tree30ec9421877d6171486386bb32122e7a077480bb /drivers/block
parenta939888ec38bf1f33e4a903056677e92a4844244 (diff)
zram: add bd_stat statistics
bd_stat represents things that happened in the backing device. Currently it supports bd_counts, bd_reads and bd_writes which are helpful to understand wearout of flash and memory saving. [minchan@kernel.org: v4] Link: http://lkml.kernel.org/r/20181203024045.153534-7-minchan@kernel.org Link: http://lkml.kernel.org/r/20181127055429.251614-7-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Joey Pabalinas <joeypabalinas@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/block')
-rw-r--r--drivers/block/zram/zram_drv.c29
-rw-r--r--drivers/block/zram/zram_drv.h5
2 files changed, 34 insertions, 0 deletions
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 6b5a886c8f32..f1832fa3ba41 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -502,6 +502,7 @@ retry:
if (test_and_set_bit(blk_idx, zram->bitmap))
goto retry;
+ atomic64_inc(&zram->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(&zram->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(&zram->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(&zram->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(&zram->init_lock);
+ ret = scnprintf(buf, PAGE_SIZE,
+ "%8llu %8llu %8llu\n",
+ (u64)atomic64_read(&zram->stats.bd_count) * (PAGE_SHIFT - 12),
+ (u64)atomic64_read(&zram->stats.bd_reads) * (PAGE_SHIFT - 12),
+ (u64)atomic64_read(&zram->stats.bd_writes) * (PAGE_SHIFT - 12));
+ up_read(&zram->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
&dev_attr_io_stat.attr,
&dev_attr_mm_stat.attr,
+#ifdef CONFIG_ZRAM_WRITEBACK
+ &dev_attr_bd_stat.attr,
+#endif
&dev_attr_debug_stat.attr,
NULL,
};
diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h
index 1ad74f030b6d..bc477803530d 100644
--- a/drivers/block/zram/zram_drv.h
+++ b/drivers/block/zram/zram_drv.h
@@ -82,6 +82,11 @@ struct zram_stats {
atomic_long_t max_used_pages; /* no. of maximum pages stored */
atomic64_t writestall; /* no. of write slow paths */
atomic64_t miss_free; /* no. of missed free */
+#ifdef CONFIG_ZRAM_WRITEBACK
+ atomic64_t bd_count; /* no. of pages in backing device */
+ atomic64_t bd_reads; /* no. of reads from backing device */
+ atomic64_t bd_writes; /* no. of writes from backing device */
+#endif
};
struct zram {