This patchset includes zram stats clean up and enhancements.
Sergey Senozhatsky (8):
zram: drop `init_done' struct zram member
zram: do not pass rw argument to __zram_make_request()
zram: remove good and bad compress stats
zram: use atomic64_t for all zram stats
zram: remove zram stats code duplication
zram: report failed read and write stats
zram: drop not used table `count' member
zram: move zram size warning to documentation
Documentation/blockdev/zram.txt | 5 ++
drivers/block/zram/zram_drv.c | 175 +++++++++++++---------------------------
drivers/block/zram/zram_drv.h | 10 +--
3 files changed, 64 insertions(+), 126 deletions(-)
--
1.8.5.3.493.gb139ac2
Introduce init_done() helper function which allows us to drop
`init_done' struct zram member. init_done() uses the fact that
->init_done == 1 equals to ->meta != NULL.
Acked-by: Minchan Kim <[email protected]>
Acked-by: Jerome Marchand <[email protected]>
Signed-off-by: Sergey Senozhatsky <[email protected]>
---
drivers/block/zram/zram_drv.c | 21 +++++++++++----------
drivers/block/zram/zram_drv.h | 1 -
2 files changed, 11 insertions(+), 11 deletions(-)
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 011e55d..c323e05 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -42,6 +42,11 @@ static struct zram *zram_devices;
/* Module params (documentation at end) */
static unsigned int num_devices = 1;
+static inline int init_done(struct zram *zram)
+{
+ return zram->meta != NULL;
+}
+
static inline struct zram *dev_to_zram(struct device *dev)
{
return (struct zram *)dev_to_disk(dev)->private_data;
@@ -60,7 +65,7 @@ static ssize_t initstate_show(struct device *dev,
{
struct zram *zram = dev_to_zram(dev);
- return sprintf(buf, "%u\n", zram->init_done);
+ return sprintf(buf, "%u\n", init_done(zram));
}
static ssize_t num_reads_show(struct device *dev,
@@ -133,7 +138,7 @@ static ssize_t mem_used_total_show(struct device *dev,
struct zram_meta *meta = zram->meta;
down_read(&zram->init_lock);
- if (zram->init_done)
+ if (init_done(zram))
val = zs_get_total_size_bytes(meta->mem_pool);
up_read(&zram->init_lock);
@@ -546,14 +551,12 @@ static void zram_reset_device(struct zram *zram, bool reset_capacity)
struct zram_meta *meta;
down_write(&zram->init_lock);
- if (!zram->init_done) {
+ if (!init_done(zram)) {
up_write(&zram->init_lock);
return;
}
meta = zram->meta;
- zram->init_done = 0;
-
/* Free all pages that are still in this zram device */
for (index = 0; index < zram->disksize >> PAGE_SHIFT; index++) {
unsigned long handle = meta->table[index].handle;
@@ -594,8 +597,6 @@ static void zram_init_device(struct zram *zram, struct zram_meta *meta)
queue_flag_set_unlocked(QUEUE_FLAG_NONROT, zram->disk->queue);
zram->meta = meta;
- zram->init_done = 1;
-
pr_debug("Initialization done!\n");
}
@@ -613,7 +614,7 @@ static ssize_t disksize_store(struct device *dev,
disksize = PAGE_ALIGN(disksize);
meta = zram_meta_alloc(disksize);
down_write(&zram->init_lock);
- if (zram->init_done) {
+ if (init_done(zram)) {
up_write(&zram->init_lock);
zram_meta_free(meta);
pr_info("Cannot change disksize for initialized device\n");
@@ -734,7 +735,7 @@ static void zram_make_request(struct request_queue *queue, struct bio *bio)
struct zram *zram = queue->queuedata;
down_read(&zram->init_lock);
- if (unlikely(!zram->init_done))
+ if (unlikely(!init_done(zram)))
goto error;
if (!valid_io_request(zram, bio)) {
@@ -857,7 +858,7 @@ static int create_device(struct zram *zram, int device_id)
goto out_free_disk;
}
- zram->init_done = 0;
+ zram->meta = NULL;
return 0;
out_free_disk:
diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h
index ad8aa35..e81e9cd 100644
--- a/drivers/block/zram/zram_drv.h
+++ b/drivers/block/zram/zram_drv.h
@@ -95,7 +95,6 @@ struct zram {
struct zram_meta *meta;
struct request_queue *queue;
struct gendisk *disk;
- int init_done;
/* Prevent concurrent execution of device init, reset and R/W request */
struct rw_semaphore init_lock;
/*
--
1.8.5.3.493.gb139ac2
Do not pass rw argument down the __zram_make_request() -> zram_bvec_rw()
chain, decode it in zram_bvec_rw() instead. Besides, this is the place
where we distinguish READ and WRITE bio data directions, so account zram
RW stats here, instead of __zram_make_request(). This also allows to account
a real number of zram READ/WRITE operations, not just requests (single RW
request may cause a number of zram RW ops with separate locking,
compression/decompression, etc).
v2: do not check for READA return code. noted by Jerome Marchand.
Acked-by: Minchan Kim <[email protected]>
Acked-by: Jerome Marchand <[email protected]>
Signed-off-by: Sergey Senozhatsky <[email protected]>
---
drivers/block/zram/zram_drv.c | 30 ++++++++++++------------------
1 file changed, 12 insertions(+), 18 deletions(-)
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index c323e05..b0bcb7e 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -533,14 +533,18 @@ out:
}
static int zram_bvec_rw(struct zram *zram, struct bio_vec *bvec, u32 index,
- int offset, struct bio *bio, int rw)
+ int offset, struct bio *bio)
{
int ret;
+ int rw = bio_data_dir(bio);
- if (rw == READ)
+ if (rw == READ) {
+ atomic64_inc(&zram->stats.num_reads);
ret = zram_bvec_read(zram, bvec, index, offset, bio);
- else
+ } else {
+ atomic64_inc(&zram->stats.num_writes);
ret = zram_bvec_write(zram, bvec, index, offset);
+ }
return ret;
}
@@ -670,22 +674,13 @@ out:
return ret;
}
-static void __zram_make_request(struct zram *zram, struct bio *bio, int rw)
+static void __zram_make_request(struct zram *zram, struct bio *bio)
{
int offset;
u32 index;
struct bio_vec bvec;
struct bvec_iter iter;
- switch (rw) {
- case READ:
- atomic64_inc(&zram->stats.num_reads);
- break;
- case WRITE:
- atomic64_inc(&zram->stats.num_writes);
- break;
- }
-
index = bio->bi_iter.bi_sector >> SECTORS_PER_PAGE_SHIFT;
offset = (bio->bi_iter.bi_sector &
(SECTORS_PER_PAGE - 1)) << SECTOR_SHIFT;
@@ -704,16 +699,15 @@ static void __zram_make_request(struct zram *zram, struct bio *bio, int rw)
bv.bv_len = max_transfer_size;
bv.bv_offset = bvec.bv_offset;
- if (zram_bvec_rw(zram, &bv, index, offset, bio, rw) < 0)
+ if (zram_bvec_rw(zram, &bv, index, offset, bio) < 0)
goto out;
bv.bv_len = bvec.bv_len - max_transfer_size;
bv.bv_offset += max_transfer_size;
- if (zram_bvec_rw(zram, &bv, index+1, 0, bio, rw) < 0)
+ if (zram_bvec_rw(zram, &bv, index + 1, 0, bio) < 0)
goto out;
} else
- if (zram_bvec_rw(zram, &bvec, index, offset, bio, rw)
- < 0)
+ if (zram_bvec_rw(zram, &bvec, index, offset, bio) < 0)
goto out;
update_position(&index, &offset, &bvec);
@@ -743,7 +737,7 @@ static void zram_make_request(struct request_queue *queue, struct bio *bio)
goto error;
}
- __zram_make_request(zram, bio, bio_data_dir(bio));
+ __zram_make_request(zram, bio);
up_read(&zram->init_lock);
return;
--
1.8.5.3.493.gb139ac2
Remove `good' and `bad' compressed sub-requests stats. RW request may
cause a number of RW sub-requests. zram used to account `good' compressed
sub-queries (with compressed size less than 50% of original size), `bad'
compressed sub-queries (with compressed size greater that 75% of original
size), leaving sub-requests with compression size between 50% and 75% of
original size not accounted and not reported. zram already accounts each
sub-request's compression size so we can calculate real device compression
ratio.
Signed-off-by: Sergey Senozhatsky <[email protected]>
---
drivers/block/zram/zram_drv.c | 11 -----------
drivers/block/zram/zram_drv.h | 2 --
2 files changed, 13 deletions(-)
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index b0bcb7e..c7c7789 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -293,7 +293,6 @@ static void zram_free_page(struct zram *zram, size_t index)
{
struct zram_meta *meta = zram->meta;
unsigned long handle = meta->table[index].handle;
- u16 size = meta->table[index].size;
if (unlikely(!handle)) {
/*
@@ -307,14 +306,8 @@ static void zram_free_page(struct zram *zram, size_t index)
return;
}
- if (unlikely(size > max_zpage_size))
- atomic_dec(&zram->stats.bad_compress);
-
zs_free(meta->mem_pool, handle);
- if (size <= PAGE_SIZE / 2)
- atomic_dec(&zram->stats.good_compress);
-
atomic64_sub(meta->table[index].size, &zram->stats.compr_size);
atomic_dec(&zram->stats.pages_stored);
@@ -478,7 +471,6 @@ static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index,
}
if (unlikely(clen > max_zpage_size)) {
- atomic_inc(&zram->stats.bad_compress);
clen = PAGE_SIZE;
src = NULL;
if (is_partial_io(bvec))
@@ -518,9 +510,6 @@ static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index,
/* Update stats */
atomic64_add(clen, &zram->stats.compr_size);
atomic_inc(&zram->stats.pages_stored);
- if (clen <= PAGE_SIZE / 2)
- atomic_inc(&zram->stats.good_compress);
-
out:
if (locked)
mutex_unlock(&meta->buffer_lock);
diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h
index e81e9cd..2f173cb 100644
--- a/drivers/block/zram/zram_drv.h
+++ b/drivers/block/zram/zram_drv.h
@@ -78,8 +78,6 @@ struct zram_stats {
atomic64_t notify_free; /* no. of swap slot free notifications */
atomic_t pages_zero; /* no. of zero filled pages */
atomic_t pages_stored; /* no. of pages currently stored */
- atomic_t good_compress; /* % of pages with compression ratio<=50% */
- atomic_t bad_compress; /* % of pages with compression ratio>=75% */
};
struct zram_meta {
--
1.8.5.3.493.gb139ac2
Introduce ZRAM_ATTR_RO macro that generates device_attribute
and default ATTR show() function for existing atomic64_t zram
stats.
Signed-off-by: Sergey Senozhatsky <[email protected]>
---
drivers/block/zram/zram_drv.c | 82 ++++++++++++-------------------------------
1 file changed, 23 insertions(+), 59 deletions(-)
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 0035d39..e7102f1 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -42,6 +42,17 @@ static struct zram *zram_devices;
/* Module params (documentation at end) */
static unsigned int num_devices = 1;
+#define ZRAM_ATTR_RO(name) \
+static ssize_t zram_attr_##name##_show(struct device *d, \
+ struct device_attribute *attr, char *b) \
+{ \
+ struct zram *zram = dev_to_zram(d); \
+ return sprintf(b, "%llu\n", \
+ (u64)atomic64_read(&zram->stats.name)); \
+} \
+static struct device_attribute dev_attr_##name = \
+ __ATTR(name, S_IRUGO, zram_attr_##name##_show, NULL);
+
static inline int init_done(struct zram *zram)
{
return zram->meta != NULL;
@@ -63,53 +74,14 @@ static ssize_t disksize_show(struct device *dev,
static ssize_t initstate_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
+ u32 val;
struct zram *zram = dev_to_zram(dev);
- return sprintf(buf, "%u\n", init_done(zram));
-}
-
-static ssize_t num_reads_show(struct device *dev,
- struct device_attribute *attr, char *buf)
-{
- struct zram *zram = dev_to_zram(dev);
-
- return sprintf(buf, "%llu\n",
- (u64)atomic64_read(&zram->stats.num_reads));
-}
-
-static ssize_t num_writes_show(struct device *dev,
- struct device_attribute *attr, char *buf)
-{
- struct zram *zram = dev_to_zram(dev);
-
- return sprintf(buf, "%llu\n",
- (u64)atomic64_read(&zram->stats.num_writes));
-}
-
-static ssize_t invalid_io_show(struct device *dev,
- struct device_attribute *attr, char *buf)
-{
- struct zram *zram = dev_to_zram(dev);
-
- return sprintf(buf, "%llu\n",
- (u64)atomic64_read(&zram->stats.invalid_io));
-}
-
-static ssize_t notify_free_show(struct device *dev,
- struct device_attribute *attr, char *buf)
-{
- struct zram *zram = dev_to_zram(dev);
-
- return sprintf(buf, "%llu\n",
- (u64)atomic64_read(&zram->stats.notify_free));
-}
-
-static ssize_t zero_pages_show(struct device *dev,
- struct device_attribute *attr, char *buf)
-{
- struct zram *zram = dev_to_zram(dev);
+ down_read(&zram->init_lock);
+ val = init_done(zram);
+ up_read(&zram->init_lock);
- return sprintf(buf, "%llu\n", (u64)atomic64_read(&zram->stats.zero_pages));
+ return sprintf(buf, "%u\n", val);
}
static ssize_t orig_data_size_show(struct device *dev,
@@ -121,15 +93,6 @@ static ssize_t orig_data_size_show(struct device *dev,
(u64)(atomic64_read(&zram->stats.pages_stored)) << PAGE_SHIFT);
}
-static ssize_t compr_data_size_show(struct device *dev,
- struct device_attribute *attr, char *buf)
-{
- struct zram *zram = dev_to_zram(dev);
-
- return sprintf(buf, "%llu\n",
- (u64)atomic64_read(&zram->stats.compr_data_size));
-}
-
static ssize_t mem_used_total_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
@@ -760,15 +723,16 @@ static DEVICE_ATTR(disksize, S_IRUGO | S_IWUSR,
disksize_show, disksize_store);
static DEVICE_ATTR(initstate, S_IRUGO, initstate_show, NULL);
static DEVICE_ATTR(reset, S_IWUSR, NULL, reset_store);
-static DEVICE_ATTR(num_reads, S_IRUGO, num_reads_show, NULL);
-static DEVICE_ATTR(num_writes, S_IRUGO, num_writes_show, NULL);
-static DEVICE_ATTR(invalid_io, S_IRUGO, invalid_io_show, NULL);
-static DEVICE_ATTR(notify_free, S_IRUGO, notify_free_show, NULL);
-static DEVICE_ATTR(zero_pages, S_IRUGO, zero_pages_show, NULL);
static DEVICE_ATTR(orig_data_size, S_IRUGO, orig_data_size_show, NULL);
-static DEVICE_ATTR(compr_data_size, S_IRUGO, compr_data_size_show, NULL);
static DEVICE_ATTR(mem_used_total, S_IRUGO, mem_used_total_show, NULL);
+ZRAM_ATTR_RO(num_reads);
+ZRAM_ATTR_RO(num_writes);
+ZRAM_ATTR_RO(invalid_io);
+ZRAM_ATTR_RO(notify_free);
+ZRAM_ATTR_RO(zero_pages);
+ZRAM_ATTR_RO(compr_data_size);
+
static struct attribute *zram_disk_attrs[] = {
&dev_attr_disksize.attr,
&dev_attr_initstate.attr,
--
1.8.5.3.493.gb139ac2
zram accounted but did not report numbers of failed read
and write queries. make these stats available as failed_reads
and failed_writes attrs.
Acked-by: Minchan Kim <[email protected]>
Acked-by: Jerome Marchand <[email protected]>
Signed-off-by: Sergey Senozhatsky <[email protected]>
---
drivers/block/zram/zram_drv.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index e7102f1..9d67fbf 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -728,6 +728,8 @@ static DEVICE_ATTR(mem_used_total, S_IRUGO, mem_used_total_show, NULL);
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);
@@ -739,6 +741,8 @@ static struct attribute *zram_disk_attrs[] = {
&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_invalid_io.attr,
&dev_attr_notify_free.attr,
&dev_attr_zero_pages.attr,
--
1.8.5.3.493.gb139ac2
struct table `count' member is not used.
Signed-off-by: Sergey Senozhatsky <[email protected]>
---
drivers/block/zram/zram_drv.h | 1 -
1 file changed, 1 deletion(-)
diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h
index 58d4ac5..1d5b1f5 100644
--- a/drivers/block/zram/zram_drv.h
+++ b/drivers/block/zram/zram_drv.h
@@ -64,7 +64,6 @@ enum zram_pageflags {
struct table {
unsigned long handle;
u16 size; /* object size (excluding header) */
- u8 count; /* object ref count (not yet used) */
u8 flags;
} __aligned(4);
--
1.8.5.3.493.gb139ac2
Move zram warning about disksize and size of memory correlation
to zram documentation.
Signed-off-by: Sergey Senozhatsky <[email protected]>
---
Documentation/blockdev/zram.txt | 5 +++++
drivers/block/zram/zram_drv.c | 15 ---------------
2 files changed, 5 insertions(+), 15 deletions(-)
diff --git a/Documentation/blockdev/zram.txt b/Documentation/blockdev/zram.txt
index 2eccddf..393541be 100644
--- a/Documentation/blockdev/zram.txt
+++ b/Documentation/blockdev/zram.txt
@@ -33,6 +33,11 @@ Following shows a typical sequence of steps for using zram.
echo 512M > /sys/block/zram0/disksize
echo 1G > /sys/block/zram0/disksize
+Note:
+There is little point creating a zram of greater than twice the size of memory
+since we expect a 2:1 compression ratio. Note that zram uses about 0.1% of the
+size of the disk when not in use so a huge zram is wasteful.
+
3) Activate:
mkswap /dev/zram0
swapon /dev/zram0
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 9d67fbf..5ec61be 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -535,23 +535,8 @@ static void zram_reset_device(struct zram *zram, bool reset_capacity)
static void zram_init_device(struct zram *zram, struct zram_meta *meta)
{
- if (zram->disksize > 2 * (totalram_pages << PAGE_SHIFT)) {
- pr_info(
- "There is little point creating a zram of greater than "
- "twice the size of memory since we expect a 2:1 compression "
- "ratio. Note that zram uses about 0.1%% of the size of "
- "the disk when not in use so a huge zram is "
- "wasteful.\n"
- "\tMemory Size: %lu kB\n"
- "\tSize you selected: %llu kB\n"
- "Continuing anyway ...\n",
- (totalram_pages << PAGE_SHIFT) >> 10, zram->disksize >> 10
- );
- }
-
/* zram devices sort of resembles non-rotational disks */
queue_flag_set_unlocked(QUEUE_FLAG_NONROT, zram->disk->queue);
-
zram->meta = meta;
pr_debug("Initialization done!\n");
}
--
1.8.5.3.493.gb139ac2
This is a preparation patch for stats code duplication removal.
1) use atomic64_t for `pages_zero' and `pages_stored' zram stats.
2) `compr_size' and `pages_zero' struct zram_stats members did not
follow the existing device attr naming scheme: zram_stats.ATTR has
ATTR_show() function. rename them:
-- compr_size -> compr_data_size
-- pages_zero -> zero_pages
Minchan Kim's note:
If we really have trouble with atomic stat operation, we could
change it with percpu_counter so that it could solve atomic overhead and
unnecessary memory space by introducing unsigned long instead of 64bit
atomic_t.
Signed-off-by: Sergey Senozhatsky <[email protected]>
---
drivers/block/zram/zram_drv.c | 18 +++++++++---------
drivers/block/zram/zram_drv.h | 6 +++---
2 files changed, 12 insertions(+), 12 deletions(-)
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index c7c7789..0035d39 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -109,7 +109,7 @@ static ssize_t zero_pages_show(struct device *dev,
{
struct zram *zram = dev_to_zram(dev);
- return sprintf(buf, "%u\n", atomic_read(&zram->stats.pages_zero));
+ return sprintf(buf, "%llu\n", (u64)atomic64_read(&zram->stats.zero_pages));
}
static ssize_t orig_data_size_show(struct device *dev,
@@ -118,7 +118,7 @@ static ssize_t orig_data_size_show(struct device *dev,
struct zram *zram = dev_to_zram(dev);
return sprintf(buf, "%llu\n",
- (u64)(atomic_read(&zram->stats.pages_stored)) << PAGE_SHIFT);
+ (u64)(atomic64_read(&zram->stats.pages_stored)) << PAGE_SHIFT);
}
static ssize_t compr_data_size_show(struct device *dev,
@@ -127,7 +127,7 @@ static ssize_t compr_data_size_show(struct device *dev,
struct zram *zram = dev_to_zram(dev);
return sprintf(buf, "%llu\n",
- (u64)atomic64_read(&zram->stats.compr_size));
+ (u64)atomic64_read(&zram->stats.compr_data_size));
}
static ssize_t mem_used_total_show(struct device *dev,
@@ -301,15 +301,15 @@ static void zram_free_page(struct zram *zram, size_t index)
*/
if (zram_test_flag(meta, index, ZRAM_ZERO)) {
zram_clear_flag(meta, index, ZRAM_ZERO);
- atomic_dec(&zram->stats.pages_zero);
+ atomic64_dec(&zram->stats.zero_pages);
}
return;
}
zs_free(meta->mem_pool, handle);
- atomic64_sub(meta->table[index].size, &zram->stats.compr_size);
- atomic_dec(&zram->stats.pages_stored);
+ atomic64_sub(meta->table[index].size, &zram->stats.compr_data_size);
+ atomic64_dec(&zram->stats.pages_stored);
meta->table[index].handle = 0;
meta->table[index].size = 0;
@@ -452,7 +452,7 @@ static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index,
zram_set_flag(meta, index, ZRAM_ZERO);
write_unlock(&zram->meta->tb_lock);
- atomic_inc(&zram->stats.pages_zero);
+ atomic64_inc(&zram->stats.zero_pages);
ret = 0;
goto out;
}
@@ -508,8 +508,8 @@ static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index,
write_unlock(&zram->meta->tb_lock);
/* Update stats */
- atomic64_add(clen, &zram->stats.compr_size);
- atomic_inc(&zram->stats.pages_stored);
+ atomic64_add(clen, &zram->stats.compr_data_size);
+ atomic64_inc(&zram->stats.pages_stored);
out:
if (locked)
mutex_unlock(&meta->buffer_lock);
diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h
index 2f173cb..58d4ac5 100644
--- a/drivers/block/zram/zram_drv.h
+++ b/drivers/block/zram/zram_drv.h
@@ -69,15 +69,15 @@ struct table {
} __aligned(4);
struct zram_stats {
- atomic64_t compr_size; /* compressed size of pages stored */
+ atomic64_t compr_data_size; /* compressed size of pages stored */
atomic64_t num_reads; /* failed + successful */
atomic64_t num_writes; /* --do-- */
atomic64_t failed_reads; /* should NEVER! happen */
atomic64_t failed_writes; /* can happen when memory is too low */
atomic64_t invalid_io; /* non-page-aligned I/O requests */
atomic64_t notify_free; /* no. of swap slot free notifications */
- atomic_t pages_zero; /* no. of zero filled pages */
- atomic_t pages_stored; /* no. of pages currently stored */
+ atomic64_t zero_pages; /* no. of zero filled pages */
+ atomic64_t pages_stored; /* no. of pages currently stored */
};
struct zram_meta {
--
1.8.5.3.493.gb139ac2
On 01/16/2014 02:12 PM, Sergey Senozhatsky wrote:
> Remove `good' and `bad' compressed sub-requests stats. RW request may
> cause a number of RW sub-requests. zram used to account `good' compressed
> sub-queries (with compressed size less than 50% of original size), `bad'
> compressed sub-queries (with compressed size greater that 75% of original
> size), leaving sub-requests with compression size between 50% and 75% of
> original size not accounted and not reported. zram already accounts each
> sub-request's compression size so we can calculate real device compression
> ratio.
>
> Signed-off-by: Sergey Senozhatsky <[email protected]>
Acked-by: Jerome Marchand <[email protected]>
> ---
> drivers/block/zram/zram_drv.c | 11 -----------
> drivers/block/zram/zram_drv.h | 2 --
> 2 files changed, 13 deletions(-)
>
> diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
> index b0bcb7e..c7c7789 100644
> --- a/drivers/block/zram/zram_drv.c
> +++ b/drivers/block/zram/zram_drv.c
> @@ -293,7 +293,6 @@ static void zram_free_page(struct zram *zram, size_t index)
> {
> struct zram_meta *meta = zram->meta;
> unsigned long handle = meta->table[index].handle;
> - u16 size = meta->table[index].size;
>
> if (unlikely(!handle)) {
> /*
> @@ -307,14 +306,8 @@ static void zram_free_page(struct zram *zram, size_t index)
> return;
> }
>
> - if (unlikely(size > max_zpage_size))
> - atomic_dec(&zram->stats.bad_compress);
> -
> zs_free(meta->mem_pool, handle);
>
> - if (size <= PAGE_SIZE / 2)
> - atomic_dec(&zram->stats.good_compress);
> -
> atomic64_sub(meta->table[index].size, &zram->stats.compr_size);
> atomic_dec(&zram->stats.pages_stored);
>
> @@ -478,7 +471,6 @@ static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index,
> }
>
> if (unlikely(clen > max_zpage_size)) {
> - atomic_inc(&zram->stats.bad_compress);
> clen = PAGE_SIZE;
> src = NULL;
> if (is_partial_io(bvec))
> @@ -518,9 +510,6 @@ static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index,
> /* Update stats */
> atomic64_add(clen, &zram->stats.compr_size);
> atomic_inc(&zram->stats.pages_stored);
> - if (clen <= PAGE_SIZE / 2)
> - atomic_inc(&zram->stats.good_compress);
> -
> out:
> if (locked)
> mutex_unlock(&meta->buffer_lock);
> diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h
> index e81e9cd..2f173cb 100644
> --- a/drivers/block/zram/zram_drv.h
> +++ b/drivers/block/zram/zram_drv.h
> @@ -78,8 +78,6 @@ struct zram_stats {
> atomic64_t notify_free; /* no. of swap slot free notifications */
> atomic_t pages_zero; /* no. of zero filled pages */
> atomic_t pages_stored; /* no. of pages currently stored */
> - atomic_t good_compress; /* % of pages with compression ratio<=50% */
> - atomic_t bad_compress; /* % of pages with compression ratio>=75% */
> };
>
> struct zram_meta {
>
On 01/16/2014 02:12 PM, Sergey Senozhatsky wrote:
> struct table `count' member is not used.
What was the intended use of this counter anyway?
>
> Signed-off-by: Sergey Senozhatsky <[email protected]>
> ---
> drivers/block/zram/zram_drv.h | 1 -
> 1 file changed, 1 deletion(-)
>
> diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h
> index 58d4ac5..1d5b1f5 100644
> --- a/drivers/block/zram/zram_drv.h
> +++ b/drivers/block/zram/zram_drv.h
> @@ -64,7 +64,6 @@ enum zram_pageflags {
> struct table {
> unsigned long handle;
> u16 size; /* object size (excluding header) */
> - u8 count; /* object ref count (not yet used) */
> u8 flags;
I noticed that your earlier version of this patch changed the
flags size to 16. What has changed?
Jerome
> } __aligned(4);
>
>
On 01/16/2014 02:12 PM, Sergey Senozhatsky wrote:
> This is a preparation patch for stats code duplication removal.
>
> 1) use atomic64_t for `pages_zero' and `pages_stored' zram stats.
> 2) `compr_size' and `pages_zero' struct zram_stats members did not
> follow the existing device attr naming scheme: zram_stats.ATTR has
> ATTR_show() function. rename them:
> -- compr_size -> compr_data_size
> -- pages_zero -> zero_pages
>
> Minchan Kim's note:
> If we really have trouble with atomic stat operation, we could
> change it with percpu_counter so that it could solve atomic overhead and
> unnecessary memory space by introducing unsigned long instead of 64bit
> atomic_t.
>
> Signed-off-by: Sergey Senozhatsky <[email protected]>
Acked-by: Jerome Marchand <[email protected]>
> ---
> drivers/block/zram/zram_drv.c | 18 +++++++++---------
> drivers/block/zram/zram_drv.h | 6 +++---
> 2 files changed, 12 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
> index c7c7789..0035d39 100644
> --- a/drivers/block/zram/zram_drv.c
> +++ b/drivers/block/zram/zram_drv.c
> @@ -109,7 +109,7 @@ static ssize_t zero_pages_show(struct device *dev,
> {
> struct zram *zram = dev_to_zram(dev);
>
> - return sprintf(buf, "%u\n", atomic_read(&zram->stats.pages_zero));
> + return sprintf(buf, "%llu\n", (u64)atomic64_read(&zram->stats.zero_pages));
> }
>
> static ssize_t orig_data_size_show(struct device *dev,
> @@ -118,7 +118,7 @@ static ssize_t orig_data_size_show(struct device *dev,
> struct zram *zram = dev_to_zram(dev);
>
> return sprintf(buf, "%llu\n",
> - (u64)(atomic_read(&zram->stats.pages_stored)) << PAGE_SHIFT);
> + (u64)(atomic64_read(&zram->stats.pages_stored)) << PAGE_SHIFT);
> }
>
> static ssize_t compr_data_size_show(struct device *dev,
> @@ -127,7 +127,7 @@ static ssize_t compr_data_size_show(struct device *dev,
> struct zram *zram = dev_to_zram(dev);
>
> return sprintf(buf, "%llu\n",
> - (u64)atomic64_read(&zram->stats.compr_size));
> + (u64)atomic64_read(&zram->stats.compr_data_size));
> }
>
> static ssize_t mem_used_total_show(struct device *dev,
> @@ -301,15 +301,15 @@ static void zram_free_page(struct zram *zram, size_t index)
> */
> if (zram_test_flag(meta, index, ZRAM_ZERO)) {
> zram_clear_flag(meta, index, ZRAM_ZERO);
> - atomic_dec(&zram->stats.pages_zero);
> + atomic64_dec(&zram->stats.zero_pages);
> }
> return;
> }
>
> zs_free(meta->mem_pool, handle);
>
> - atomic64_sub(meta->table[index].size, &zram->stats.compr_size);
> - atomic_dec(&zram->stats.pages_stored);
> + atomic64_sub(meta->table[index].size, &zram->stats.compr_data_size);
> + atomic64_dec(&zram->stats.pages_stored);
>
> meta->table[index].handle = 0;
> meta->table[index].size = 0;
> @@ -452,7 +452,7 @@ static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index,
> zram_set_flag(meta, index, ZRAM_ZERO);
> write_unlock(&zram->meta->tb_lock);
>
> - atomic_inc(&zram->stats.pages_zero);
> + atomic64_inc(&zram->stats.zero_pages);
> ret = 0;
> goto out;
> }
> @@ -508,8 +508,8 @@ static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index,
> write_unlock(&zram->meta->tb_lock);
>
> /* Update stats */
> - atomic64_add(clen, &zram->stats.compr_size);
> - atomic_inc(&zram->stats.pages_stored);
> + atomic64_add(clen, &zram->stats.compr_data_size);
> + atomic64_inc(&zram->stats.pages_stored);
> out:
> if (locked)
> mutex_unlock(&meta->buffer_lock);
> diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h
> index 2f173cb..58d4ac5 100644
> --- a/drivers/block/zram/zram_drv.h
> +++ b/drivers/block/zram/zram_drv.h
> @@ -69,15 +69,15 @@ struct table {
> } __aligned(4);
>
> struct zram_stats {
> - atomic64_t compr_size; /* compressed size of pages stored */
> + atomic64_t compr_data_size; /* compressed size of pages stored */
> atomic64_t num_reads; /* failed + successful */
> atomic64_t num_writes; /* --do-- */
> atomic64_t failed_reads; /* should NEVER! happen */
> atomic64_t failed_writes; /* can happen when memory is too low */
> atomic64_t invalid_io; /* non-page-aligned I/O requests */
> atomic64_t notify_free; /* no. of swap slot free notifications */
> - atomic_t pages_zero; /* no. of zero filled pages */
> - atomic_t pages_stored; /* no. of pages currently stored */
> + atomic64_t zero_pages; /* no. of zero filled pages */
> + atomic64_t pages_stored; /* no. of pages currently stored */
> };
>
> struct zram_meta {
>
On (01/16/14 14:52), Jerome Marchand wrote:
> On 01/16/2014 02:12 PM, Sergey Senozhatsky wrote:
> > struct table `count' member is not used.
>
> What was the intended use of this counter anyway?
>
> >
> > Signed-off-by: Sergey Senozhatsky <[email protected]>
> > ---
> > drivers/block/zram/zram_drv.h | 1 -
> > 1 file changed, 1 deletion(-)
> >
> > diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h
> > index 58d4ac5..1d5b1f5 100644
> > --- a/drivers/block/zram/zram_drv.h
> > +++ b/drivers/block/zram/zram_drv.h
> > @@ -64,7 +64,6 @@ enum zram_pageflags {
> > struct table {
> > unsigned long handle;
> > u16 size; /* object size (excluding header) */
> > - u8 count; /* object ref count (not yet used) */
> > u8 flags;
>
>
> I noticed that your earlier version of this patch changed the
> flags size to 16. What has changed?
>
nothing really. I was going to extend flags, but changed my plans. so it was
a leftover.
-ss
> Jerome
>
> > } __aligned(4);
> >
> >
>
On Thu, Jan 16, 2014 at 04:12:11PM +0300, Sergey Senozhatsky wrote:
> Remove `good' and `bad' compressed sub-requests stats. RW request may
> cause a number of RW sub-requests. zram used to account `good' compressed
> sub-queries (with compressed size less than 50% of original size), `bad'
> compressed sub-queries (with compressed size greater that 75% of original
> size), leaving sub-requests with compression size between 50% and 75% of
> original size not accounted and not reported. zram already accounts each
> sub-request's compression size so we can calculate real device compression
> ratio.
>
Most important thing is that we have accounted them but have not used
so it doesn't break anything and we could add them again if someone need them
later. :)
> Signed-off-by: Sergey Senozhatsky <[email protected]>
Acked-by: Minchan Kim <[email protected]>
--
Kind regards,
Minchan Kim
On Thu, Jan 16, 2014 at 04:12:12PM +0300, Sergey Senozhatsky wrote:
> This is a preparation patch for stats code duplication removal.
>
> 1) use atomic64_t for `pages_zero' and `pages_stored' zram stats.
> 2) `compr_size' and `pages_zero' struct zram_stats members did not
> follow the existing device attr naming scheme: zram_stats.ATTR has
> ATTR_show() function. rename them:
> -- compr_size -> compr_data_size
> -- pages_zero -> zero_pages
>
> Minchan Kim's note:
> If we really have trouble with atomic stat operation, we could
> change it with percpu_counter so that it could solve atomic overhead and
> unnecessary memory space by introducing unsigned long instead of 64bit
> atomic_t.
>
> Signed-off-by: Sergey Senozhatsky <[email protected]>
Acked-by: Minchan Kim <[email protected]>
--
Kind regards,
Minchan Kim
On Thu, Jan 16, 2014 at 04:12:13PM +0300, Sergey Senozhatsky wrote:
> Introduce ZRAM_ATTR_RO macro that generates device_attribute
> and default ATTR show() function for existing atomic64_t zram
> stats.
>
> Signed-off-by: Sergey Senozhatsky <[email protected]>
Acked-by: Minchan Kim <[email protected]>
--
Kind regards,
Minchan Kim
On Thu, Jan 16, 2014 at 04:12:15PM +0300, Sergey Senozhatsky wrote:
> struct table `count' member is not used.
>
> Signed-off-by: Sergey Senozhatsky <[email protected]>
There is no gain with this patch in memory space ponit of view but it
might reveal the lurking bug.
Acked-by: Minchan Kim <[email protected]>
> ---
> drivers/block/zram/zram_drv.h | 1 -
> 1 file changed, 1 deletion(-)
>
> diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h
> index 58d4ac5..1d5b1f5 100644
> --- a/drivers/block/zram/zram_drv.h
> +++ b/drivers/block/zram/zram_drv.h
> @@ -64,7 +64,6 @@ enum zram_pageflags {
> struct table {
> unsigned long handle;
> u16 size; /* object size (excluding header) */
> - u8 count; /* object ref count (not yet used) */
> u8 flags;
> } __aligned(4);
>
> --
> 1.8.5.3.493.gb139ac2
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/
--
Kind regards,
Minchan Kim
On Thu, Jan 16, 2014 at 04:12:16PM +0300, Sergey Senozhatsky wrote:
> Move zram warning about disksize and size of memory correlation
> to zram documentation.
>
> Signed-off-by: Sergey Senozhatsky <[email protected]>
Acked-by: Minchan Kim <[email protected]>
--
Kind regards,
Minchan Kim
On Thu, Jan 16, 2014 at 04:12:08PM +0300, Sergey Senozhatsky wrote:
> This patchset includes zram stats clean up and enhancements.
>
> Sergey Senozhatsky (8):
> zram: drop `init_done' struct zram member
> zram: do not pass rw argument to __zram_make_request()
> zram: remove good and bad compress stats
> zram: use atomic64_t for all zram stats
> zram: remove zram stats code duplication
> zram: report failed read and write stats
> zram: drop not used table `count' member
> zram: move zram size warning to documentation
>
> Documentation/blockdev/zram.txt | 5 ++
> drivers/block/zram/zram_drv.c | 175 +++++++++++++---------------------------
> drivers/block/zram/zram_drv.h | 10 +--
> 3 files changed, 64 insertions(+), 126 deletions(-)
Great clean up.
Sergey, Thanks!
I am looking forward to your next step!
--
Kind regards,
Minchan Kim
On Fri, Jan 17, 2014 at 04:09:34PM +0900, Minchan Kim wrote:
> On Thu, Jan 16, 2014 at 04:12:08PM +0300, Sergey Senozhatsky wrote:
> > This patchset includes zram stats clean up and enhancements.
> >
> > Sergey Senozhatsky (8):
> > zram: drop `init_done' struct zram member
> > zram: do not pass rw argument to __zram_make_request()
> > zram: remove good and bad compress stats
> > zram: use atomic64_t for all zram stats
> > zram: remove zram stats code duplication
> > zram: report failed read and write stats
> > zram: drop not used table `count' member
> > zram: move zram size warning to documentation
> >
> > Documentation/blockdev/zram.txt | 5 ++
> > drivers/block/zram/zram_drv.c | 175 +++++++++++++---------------------------
> > drivers/block/zram/zram_drv.h | 10 +--
> > 3 files changed, 64 insertions(+), 126 deletions(-)
>
> Great clean up.
>
> Sergey, Thanks!
> I am looking forward to your next step!
Hello Sergey,
I guess Andrew wouldn't pick this patchset until closing merge window
so I picked up in my zram tree so let's do further work based on it.
https://git.kernel.org/cgit/linux/kernel/git/minchan/linux.git/log/?h=zram-next
Thanks.
--
Kind regards,
Minchan Kim
On Thu, 16 Jan 2014 16:12:14 +0300 Sergey Senozhatsky <[email protected]> wrote:
> zram accounted but did not report numbers of failed read
> and write queries. make these stats available as failed_reads
> and failed_writes attrs.
>
> Acked-by: Minchan Kim <[email protected]>
> Acked-by: Jerome Marchand <[email protected]>
> Signed-off-by: Sergey Senozhatsky <[email protected]>
> ---
> drivers/block/zram/zram_drv.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
> index e7102f1..9d67fbf 100644
> --- a/drivers/block/zram/zram_drv.c
> +++ b/drivers/block/zram/zram_drv.c
> @@ -728,6 +728,8 @@ static DEVICE_ATTR(mem_used_total, S_IRUGO, mem_used_total_show, NULL);
>
> 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);
> @@ -739,6 +741,8 @@ static struct attribute *zram_disk_attrs[] = {
> &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_invalid_io.attr,
> &dev_attr_notify_free.attr,
> &dev_attr_zero_pages.attr,
Documentation/blockdev/zram.txt and
Documentation/ABI/testing/sysfs-block-zram need updating...
On (02/04/14 14:18), Andrew Morton wrote:
> Date: Tue, 4 Feb 2014 14:18:49 -0800
> From: Andrew Morton <[email protected]>
> To: Sergey Senozhatsky <[email protected]>
> Cc: Minchan Kim <[email protected]>, Jerome Marchand
> <[email protected]>, Nitin Gupta <[email protected]>,
> [email protected]
> Subject: Re: [PATCHv3 6/8] zram: report failed read and write stats
> X-Mailer: Sylpheed 3.2.0beta5 (GTK+ 2.24.10; x86_64-pc-linux-gnu)
>
> On Thu, 16 Jan 2014 16:12:14 +0300 Sergey Senozhatsky <[email protected]> wrote:
>
> > zram accounted but did not report numbers of failed read
> > and write queries. make these stats available as failed_reads
> > and failed_writes attrs.
> >
> > Acked-by: Minchan Kim <[email protected]>
> > Acked-by: Jerome Marchand <[email protected]>
> > Signed-off-by: Sergey Senozhatsky <[email protected]>
> > ---
> > drivers/block/zram/zram_drv.c | 4 ++++
> > 1 file changed, 4 insertions(+)
> >
> > diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
> > index e7102f1..9d67fbf 100644
> > --- a/drivers/block/zram/zram_drv.c
> > +++ b/drivers/block/zram/zram_drv.c
> > @@ -728,6 +728,8 @@ static DEVICE_ATTR(mem_used_total, S_IRUGO, mem_used_total_show, NULL);
> >
> > 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);
> > @@ -739,6 +741,8 @@ static struct attribute *zram_disk_attrs[] = {
> > &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_invalid_io.attr,
> > &dev_attr_notify_free.attr,
> > &dev_attr_zero_pages.attr,
>
> Documentation/blockdev/zram.txt and
> Documentation/ABI/testing/sysfs-block-zram need updating...
>
Hello,
sure, will update.
-ss