This patchset includes zram stats clean up and enhancements.
Sergey Senozhatsky (4):
zram: drop `init_done' struct zram member
zram: do not pass rw argument to __zram_make_request()
zram: rework reported to end-user zram statistics
zram: report failed read and writes stats
drivers/block/zram/zram_drv.c | 210 ++++++++++++++----------------------------
drivers/block/zram/zram_drv.h | 18 ++--
2 files changed, 74 insertions(+), 154 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
1) Introduce ZRAM_ATTR_RO macro to generate zram atomic64_t stats
`show' functions and reduce code duplication.
2) 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.
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 | 163 ++++++++++++------------------------------
drivers/block/zram/zram_drv.h | 17 ++---
2 files changed, 51 insertions(+), 129 deletions(-)
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index b0bcb7e..6eb2155 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;
@@ -52,97 +63,36 @@ static inline struct zram *dev_to_zram(struct device *dev)
return (struct zram *)dev_to_disk(dev)->private_data;
}
-static ssize_t disksize_show(struct device *dev,
- struct device_attribute *attr, char *buf)
-{
- struct zram *zram = dev_to_zram(dev);
-
- return sprintf(buf, "%llu\n", zram->disksize);
-}
-
-static ssize_t initstate_show(struct device *dev,
- struct device_attribute *attr, char *buf)
-{
- 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);
-
- return sprintf(buf, "%u\n", atomic_read(&zram->stats.pages_zero));
-}
-
-static ssize_t orig_data_size_show(struct device *dev,
+static ssize_t memory_used_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
+ u64 val = 0;
struct zram *zram = dev_to_zram(dev);
+ struct zram_meta *meta = zram->meta;
- return sprintf(buf, "%llu\n",
- (u64)(atomic_read(&zram->stats.pages_stored)) << PAGE_SHIFT);
+ down_read(&zram->init_lock);
+ if (init_done(zram))
+ val = zs_get_total_size_bytes(meta->mem_pool);
+ up_read(&zram->init_lock);
+ return sprintf(buf, "%llu\n", val);
}
-static ssize_t compr_data_size_show(struct device *dev,
+static ssize_t disksize_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_size));
+ return sprintf(buf, "%llu\n", zram->disksize);
}
-static ssize_t mem_used_total_show(struct device *dev,
+static ssize_t initstate_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
- u64 val = 0;
+ u32 val = 0;
struct zram *zram = dev_to_zram(dev);
- struct zram_meta *meta = zram->meta;
-
down_read(&zram->init_lock);
- if (init_done(zram))
- val = zs_get_total_size_bytes(meta->mem_pool);
+ val = init_done(zram);
up_read(&zram->init_lock);
-
- return sprintf(buf, "%llu\n", val);
+ return sprintf(buf, "%u\n", val);
}
/* flag operations needs meta->tb_lock */
@@ -293,7 +243,6 @@ 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)) {
/*
@@ -302,21 +251,15 @@ 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.pages_zero);
}
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);
+ atomic64_sub(meta->table[index].size, &zram->stats.compressed_size);
+ atomic64_dec(&zram->stats.pages_stored);
meta->table[index].handle = 0;
meta->table[index].size = 0;
@@ -459,7 +402,7 @@ 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.pages_zero);
ret = 0;
goto out;
}
@@ -478,7 +421,6 @@ 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))
@@ -516,11 +458,8 @@ 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);
- if (clen <= PAGE_SIZE / 2)
- atomic_inc(&zram->stats.good_compress);
-
+ atomic64_add(clen, &zram->stats.compressed_size);
+ atomic64_inc(&zram->stats.pages_stored);
out:
if (locked)
mutex_unlock(&meta->buffer_lock);
@@ -583,23 +522,8 @@ 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");
}
@@ -771,14 +695,15 @@ 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);
+static DEVICE_ATTR(memory_used, S_IRUGO, memory_used_show, NULL);
+
+ZRAM_ATTR_RO(num_reads);
+ZRAM_ATTR_RO(num_writes);
+ZRAM_ATTR_RO(pages_stored);
+ZRAM_ATTR_RO(invalid_io);
+ZRAM_ATTR_RO(notify_free);
+ZRAM_ATTR_RO(pages_zero);
+ZRAM_ATTR_RO(compressed_size);
static struct attribute *zram_disk_attrs[] = {
&dev_attr_disksize.attr,
@@ -786,12 +711,12 @@ static struct attribute *zram_disk_attrs[] = {
&dev_attr_reset.attr,
&dev_attr_num_reads.attr,
&dev_attr_num_writes.attr,
+ &dev_attr_pages_stored.attr,
&dev_attr_invalid_io.attr,
&dev_attr_notify_free.attr,
- &dev_attr_zero_pages.attr,
- &dev_attr_orig_data_size.attr,
- &dev_attr_compr_data_size.attr,
- &dev_attr_mem_used_total.attr,
+ &dev_attr_pages_zero.attr,
+ &dev_attr_compressed_size.attr,
+ &dev_attr_memory_used.attr,
NULL,
};
diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h
index e81e9cd..277023d 100644
--- a/drivers/block/zram/zram_drv.h
+++ b/drivers/block/zram/zram_drv.h
@@ -64,22 +64,19 @@ enum zram_pageflags {
struct table {
unsigned long handle;
u16 size; /* object size (excluding header) */
- u8 count; /* object ref count (not yet used) */
- u8 flags;
+ u16 flags;
} __aligned(4);
struct zram_stats {
- atomic64_t compr_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 num_writes; /* number of writes */
+ atomic64_t num_reads; /* number of reads */
+ atomic64_t pages_stored; /* no. of pages currently stored */
+ atomic64_t compressed_size; /* compressed size of pages stored */
+ atomic64_t pages_zero; /* no. of zero filled pages */
+ atomic64_t failed_reads; /* no. of failed reads */
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 */
- 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
zram accounted but did not report numbers of failed read
and write queries. make these stats available as failed_reads
and failed_writes attrs.
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 6eb2155..ce00d47 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -699,6 +699,8 @@ static DEVICE_ATTR(memory_used, S_IRUGO, memory_used_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(pages_stored);
ZRAM_ATTR_RO(invalid_io);
ZRAM_ATTR_RO(notify_free);
@@ -711,6 +713,8 @@ 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_pages_stored.attr,
&dev_attr_invalid_io.attr,
&dev_attr_notify_free.attr,
--
1.8.5.3.493.gb139ac2
Hello Sergey,
On Wed, Jan 15, 2014 at 01:16:16PM +0300, Sergey Senozhatsky wrote:
> 1) Introduce ZRAM_ATTR_RO macro to generate zram atomic64_t stats
> `show' functions and reduce code duplication.
>
> 2) 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.
>
> Acked-by: Minchan Kim <[email protected]>
I didn't give any Acked in this patch.
If I made you confused, Sorry about that.
This patch did more than thing you mentioned in desription.
1. Introduce macro to remove code duplication
It's really good.
2. Change atomic_t with atomic64_t
At a first look, I didn't want it because lots of custormer for zram
are still 32bit machines so their cost would be increased a bit due to
any locking facility like cmpxchg on some architectures.
Having said that, I will support your cleanup patch now and then
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.
So, please add this comment for future just in case of forgetting.
3. Remove unreported some stat
Looks good to me.
4. Changing name of some stat
I couldn't understand what's the gain because I'm happy with
orig_data_size and compr_data_size now.
5. Removed zram_init_device's warning
Why? This patch doesn't include any justification.
6. Removed unused field of enum zram_pageflags
Looks good to me.
Please, separate it with each patches so let's focus one by one.
> Acked-by: Jerome Marchand <[email protected]>
> Signed-off-by: Sergey Senozhatsky <[email protected]>
> ---
> drivers/block/zram/zram_drv.c | 163 ++++++++++++------------------------------
> drivers/block/zram/zram_drv.h | 17 ++---
> 2 files changed, 51 insertions(+), 129 deletions(-)
>
> diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
> index b0bcb7e..6eb2155 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;
> @@ -52,97 +63,36 @@ static inline struct zram *dev_to_zram(struct device *dev)
> return (struct zram *)dev_to_disk(dev)->private_data;
> }
>
> -static ssize_t disksize_show(struct device *dev,
> - struct device_attribute *attr, char *buf)
> -{
> - struct zram *zram = dev_to_zram(dev);
> -
> - return sprintf(buf, "%llu\n", zram->disksize);
> -}
> -
> -static ssize_t initstate_show(struct device *dev,
> - struct device_attribute *attr, char *buf)
> -{
> - 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);
> -
> - return sprintf(buf, "%u\n", atomic_read(&zram->stats.pages_zero));
> -}
> -
> -static ssize_t orig_data_size_show(struct device *dev,
> +static ssize_t memory_used_show(struct device *dev,
> struct device_attribute *attr, char *buf)
> {
> + u64 val = 0;
> struct zram *zram = dev_to_zram(dev);
> + struct zram_meta *meta = zram->meta;
>
> - return sprintf(buf, "%llu\n",
> - (u64)(atomic_read(&zram->stats.pages_stored)) << PAGE_SHIFT);
> + down_read(&zram->init_lock);
> + if (init_done(zram))
> + val = zs_get_total_size_bytes(meta->mem_pool);
> + up_read(&zram->init_lock);
> + return sprintf(buf, "%llu\n", val);
> }
>
> -static ssize_t compr_data_size_show(struct device *dev,
> +static ssize_t disksize_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_size));
> + return sprintf(buf, "%llu\n", zram->disksize);
> }
>
> -static ssize_t mem_used_total_show(struct device *dev,
> +static ssize_t initstate_show(struct device *dev,
> struct device_attribute *attr, char *buf)
> {
> - u64 val = 0;
> + u32 val = 0;
> struct zram *zram = dev_to_zram(dev);
> - struct zram_meta *meta = zram->meta;
> -
> down_read(&zram->init_lock);
> - if (init_done(zram))
> - val = zs_get_total_size_bytes(meta->mem_pool);
> + val = init_done(zram);
> up_read(&zram->init_lock);
> -
> - return sprintf(buf, "%llu\n", val);
> + return sprintf(buf, "%u\n", val);
> }
>
> /* flag operations needs meta->tb_lock */
> @@ -293,7 +243,6 @@ 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)) {
> /*
> @@ -302,21 +251,15 @@ 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.pages_zero);
> }
> 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);
> + atomic64_sub(meta->table[index].size, &zram->stats.compressed_size);
> + atomic64_dec(&zram->stats.pages_stored);
>
> meta->table[index].handle = 0;
> meta->table[index].size = 0;
> @@ -459,7 +402,7 @@ 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.pages_zero);
> ret = 0;
> goto out;
> }
> @@ -478,7 +421,6 @@ 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))
> @@ -516,11 +458,8 @@ 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);
> - if (clen <= PAGE_SIZE / 2)
> - atomic_inc(&zram->stats.good_compress);
> -
> + atomic64_add(clen, &zram->stats.compressed_size);
> + atomic64_inc(&zram->stats.pages_stored);
> out:
> if (locked)
> mutex_unlock(&meta->buffer_lock);
> @@ -583,23 +522,8 @@ 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");
> }
> @@ -771,14 +695,15 @@ 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);
> +static DEVICE_ATTR(memory_used, S_IRUGO, memory_used_show, NULL);
> +
> +ZRAM_ATTR_RO(num_reads);
> +ZRAM_ATTR_RO(num_writes);
> +ZRAM_ATTR_RO(pages_stored);
> +ZRAM_ATTR_RO(invalid_io);
> +ZRAM_ATTR_RO(notify_free);
> +ZRAM_ATTR_RO(pages_zero);
> +ZRAM_ATTR_RO(compressed_size);
>
> static struct attribute *zram_disk_attrs[] = {
> &dev_attr_disksize.attr,
> @@ -786,12 +711,12 @@ static struct attribute *zram_disk_attrs[] = {
> &dev_attr_reset.attr,
> &dev_attr_num_reads.attr,
> &dev_attr_num_writes.attr,
> + &dev_attr_pages_stored.attr,
> &dev_attr_invalid_io.attr,
> &dev_attr_notify_free.attr,
> - &dev_attr_zero_pages.attr,
> - &dev_attr_orig_data_size.attr,
> - &dev_attr_compr_data_size.attr,
> - &dev_attr_mem_used_total.attr,
> + &dev_attr_pages_zero.attr,
> + &dev_attr_compressed_size.attr,
> + &dev_attr_memory_used.attr,
> NULL,
> };
>
> diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h
> index e81e9cd..277023d 100644
> --- a/drivers/block/zram/zram_drv.h
> +++ b/drivers/block/zram/zram_drv.h
> @@ -64,22 +64,19 @@ enum zram_pageflags {
> struct table {
> unsigned long handle;
> u16 size; /* object size (excluding header) */
> - u8 count; /* object ref count (not yet used) */
> - u8 flags;
> + u16 flags;
> } __aligned(4);
>
> struct zram_stats {
> - atomic64_t compr_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 num_writes; /* number of writes */
> + atomic64_t num_reads; /* number of reads */
> + atomic64_t pages_stored; /* no. of pages currently stored */
> + atomic64_t compressed_size; /* compressed size of pages stored */
> + atomic64_t pages_zero; /* no. of zero filled pages */
> + atomic64_t failed_reads; /* no. of failed reads */
> 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 */
> - 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
>
> --
> 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 Wed, Jan 15, 2014 at 01:16:17PM +0300, Sergey Senozhatsky 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.
>
> Signed-off-by: Sergey Senozhatsky <[email protected]>
Acked-by: Minchan Kim <[email protected]>
--
Kind regards,
Minchan Kim
On (01/16/14 09:56), Minchan Kim wrote:
> Hello Sergey,
>
> On Wed, Jan 15, 2014 at 01:16:16PM +0300, Sergey Senozhatsky wrote:
> > 1) Introduce ZRAM_ATTR_RO macro to generate zram atomic64_t stats
> > `show' functions and reduce code duplication.
> >
> > 2) 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.
> >
> > Acked-by: Minchan Kim <[email protected]>
>
> I didn't give any Acked in this patch.
> If I made you confused, Sorry about that.
>
Hello,
sorry, I misread the situtation.
> This patch did more than thing you mentioned in desription.
>
> 1. Introduce macro to remove code duplication
>
> It's really good.
>
> 2. Change atomic_t with atomic64_t
>
> At a first look, I didn't want it because lots of custormer for zram
> are still 32bit machines so their cost would be increased a bit due to
> any locking facility like cmpxchg on some architectures.
>
> Having said that, I will support your cleanup patch now and then
> 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.
>
> So, please add this comment for future just in case of forgetting.
ok
> 3. Remove unreported some stat
>
> Looks good to me.
>
> 4. Changing name of some stat
>
> I couldn't understand what's the gain because I'm happy with
> orig_data_size and compr_data_size now.
>
well, compressed_size contains regular english words and thus a regular
user can easily understand it. compr_data_size looks like a variable name.
I think I'll drop this at the moment.
> 5. Removed zram_init_device's warning
>
> Why? This patch doesn't include any justification.
>
I think I'll drop this part at the moment. the motivation for this
cleanup was that, imho, such big informative warnings are part of
documentation, not the source code.
-ss
> 6. Removed unused field of enum zram_pageflags
>
> Looks good to me.
>
> Please, separate it with each patches so let's focus one by one.
>
>
> > Acked-by: Jerome Marchand <[email protected]>
> > Signed-off-by: Sergey Senozhatsky <[email protected]>
> > ---
> > drivers/block/zram/zram_drv.c | 163 ++++++++++++------------------------------
> > drivers/block/zram/zram_drv.h | 17 ++---
> > 2 files changed, 51 insertions(+), 129 deletions(-)
> >
> > diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
> > index b0bcb7e..6eb2155 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;
> > @@ -52,97 +63,36 @@ static inline struct zram *dev_to_zram(struct device *dev)
> > return (struct zram *)dev_to_disk(dev)->private_data;
> > }
> >
> > -static ssize_t disksize_show(struct device *dev,
> > - struct device_attribute *attr, char *buf)
> > -{
> > - struct zram *zram = dev_to_zram(dev);
> > -
> > - return sprintf(buf, "%llu\n", zram->disksize);
> > -}
> > -
> > -static ssize_t initstate_show(struct device *dev,
> > - struct device_attribute *attr, char *buf)
> > -{
> > - 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);
> > -
> > - return sprintf(buf, "%u\n", atomic_read(&zram->stats.pages_zero));
> > -}
> > -
> > -static ssize_t orig_data_size_show(struct device *dev,
> > +static ssize_t memory_used_show(struct device *dev,
> > struct device_attribute *attr, char *buf)
> > {
> > + u64 val = 0;
> > struct zram *zram = dev_to_zram(dev);
> > + struct zram_meta *meta = zram->meta;
> >
> > - return sprintf(buf, "%llu\n",
> > - (u64)(atomic_read(&zram->stats.pages_stored)) << PAGE_SHIFT);
> > + down_read(&zram->init_lock);
> > + if (init_done(zram))
> > + val = zs_get_total_size_bytes(meta->mem_pool);
> > + up_read(&zram->init_lock);
> > + return sprintf(buf, "%llu\n", val);
> > }
> >
> > -static ssize_t compr_data_size_show(struct device *dev,
> > +static ssize_t disksize_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_size));
> > + return sprintf(buf, "%llu\n", zram->disksize);
> > }
> >
> > -static ssize_t mem_used_total_show(struct device *dev,
> > +static ssize_t initstate_show(struct device *dev,
> > struct device_attribute *attr, char *buf)
> > {
> > - u64 val = 0;
> > + u32 val = 0;
> > struct zram *zram = dev_to_zram(dev);
> > - struct zram_meta *meta = zram->meta;
> > -
> > down_read(&zram->init_lock);
> > - if (init_done(zram))
> > - val = zs_get_total_size_bytes(meta->mem_pool);
> > + val = init_done(zram);
> > up_read(&zram->init_lock);
> > -
> > - return sprintf(buf, "%llu\n", val);
> > + return sprintf(buf, "%u\n", val);
> > }
> >
> > /* flag operations needs meta->tb_lock */
> > @@ -293,7 +243,6 @@ 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)) {
> > /*
> > @@ -302,21 +251,15 @@ 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.pages_zero);
> > }
> > 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);
> > + atomic64_sub(meta->table[index].size, &zram->stats.compressed_size);
> > + atomic64_dec(&zram->stats.pages_stored);
> >
> > meta->table[index].handle = 0;
> > meta->table[index].size = 0;
> > @@ -459,7 +402,7 @@ 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.pages_zero);
> > ret = 0;
> > goto out;
> > }
> > @@ -478,7 +421,6 @@ 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))
> > @@ -516,11 +458,8 @@ 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);
> > - if (clen <= PAGE_SIZE / 2)
> > - atomic_inc(&zram->stats.good_compress);
> > -
> > + atomic64_add(clen, &zram->stats.compressed_size);
> > + atomic64_inc(&zram->stats.pages_stored);
> > out:
> > if (locked)
> > mutex_unlock(&meta->buffer_lock);
> > @@ -583,23 +522,8 @@ 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");
> > }
> > @@ -771,14 +695,15 @@ 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);
> > +static DEVICE_ATTR(memory_used, S_IRUGO, memory_used_show, NULL);
> > +
> > +ZRAM_ATTR_RO(num_reads);
> > +ZRAM_ATTR_RO(num_writes);
> > +ZRAM_ATTR_RO(pages_stored);
> > +ZRAM_ATTR_RO(invalid_io);
> > +ZRAM_ATTR_RO(notify_free);
> > +ZRAM_ATTR_RO(pages_zero);
> > +ZRAM_ATTR_RO(compressed_size);
> >
> > static struct attribute *zram_disk_attrs[] = {
> > &dev_attr_disksize.attr,
> > @@ -786,12 +711,12 @@ static struct attribute *zram_disk_attrs[] = {
> > &dev_attr_reset.attr,
> > &dev_attr_num_reads.attr,
> > &dev_attr_num_writes.attr,
> > + &dev_attr_pages_stored.attr,
> > &dev_attr_invalid_io.attr,
> > &dev_attr_notify_free.attr,
> > - &dev_attr_zero_pages.attr,
> > - &dev_attr_orig_data_size.attr,
> > - &dev_attr_compr_data_size.attr,
> > - &dev_attr_mem_used_total.attr,
> > + &dev_attr_pages_zero.attr,
> > + &dev_attr_compressed_size.attr,
> > + &dev_attr_memory_used.attr,
> > NULL,
> > };
> >
> > diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h
> > index e81e9cd..277023d 100644
> > --- a/drivers/block/zram/zram_drv.h
> > +++ b/drivers/block/zram/zram_drv.h
> > @@ -64,22 +64,19 @@ enum zram_pageflags {
> > struct table {
> > unsigned long handle;
> > u16 size; /* object size (excluding header) */
> > - u8 count; /* object ref count (not yet used) */
> > - u8 flags;
> > + u16 flags;
> > } __aligned(4);
> >
> > struct zram_stats {
> > - atomic64_t compr_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 num_writes; /* number of writes */
> > + atomic64_t num_reads; /* number of reads */
> > + atomic64_t pages_stored; /* no. of pages currently stored */
> > + atomic64_t compressed_size; /* compressed size of pages stored */
> > + atomic64_t pages_zero; /* no. of zero filled pages */
> > + atomic64_t failed_reads; /* no. of failed reads */
> > 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 */
> > - 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
> >
> > --
> > 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 01/16/2014 09:46 AM, Sergey Senozhatsky wrote:
> On (01/16/14 09:56), Minchan Kim wrote:
>> Hello Sergey,
>>
>> On Wed, Jan 15, 2014 at 01:16:16PM +0300, Sergey Senozhatsky wrote:
>>> 1) Introduce ZRAM_ATTR_RO macro to generate zram atomic64_t stats
>>> `show' functions and reduce code duplication.
>>>
>>> 2) 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.
>>>
>>> Acked-by: Minchan Kim <[email protected]>
>>
>> I didn't give any Acked in this patch.
>> If I made you confused, Sorry about that.
>>
>
> Hello,
>
> sorry, I misread the situtation.
Now that Minchan draw my attention to it: neither did I.
>
>> This patch did more than thing you mentioned in desription.
>>
>> 1. Introduce macro to remove code duplication
>>
>> It's really good.
No argument here.
>>
>> 2. Change atomic_t with atomic64_t
>>
>> At a first look, I didn't want it because lots of custormer for zram
>> are still 32bit machines so their cost would be increased a bit due to
>> any locking facility like cmpxchg on some architectures.
>>
>> Having said that, I will support your cleanup patch now and then
>> 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.
>>
>> So, please add this comment for future just in case of forgetting.
>
> ok
>
>> 3. Remove unreported some stat
>>
>> Looks good to me.
To me too.
>>
>
>> 4. Changing name of some stat
>>
>> I couldn't understand what's the gain because I'm happy with
>> orig_data_size and compr_data_size now.
>>
>
> well, compressed_size contains regular english words and thus a regular
> user can easily understand it. compr_data_size looks like a variable name.
> I think I'll drop this at the moment.
I think that anybody who is going to read this stats will know that zram is
about compression and understand these abbreviations. I also like the fact
that they are both expressed in bytes, unlike the couple pages_store /
compressed_size.
>
>> 5. Removed zram_init_device's warning
>>
>> Why? This patch doesn't include any justification.
>>
>
> I think I'll drop this part at the moment. the motivation for this
> cleanup was that, imho, such big informative warnings are part of
> documentation, not the source code.
Yet you didn't update the documentation.
Jerome
>
> -ss
>
>> 6. Removed unused field of enum zram_pageflags
>>
>> Looks good to me.
>>
>> Please, separate it with each patches so let's focus one by one.
>>
>>
>>> Acked-by: Jerome Marchand <[email protected]>
>>> Signed-off-by: Sergey Senozhatsky <[email protected]>
>>> ---
>>> drivers/block/zram/zram_drv.c | 163 ++++++++++++------------------------------
>>> drivers/block/zram/zram_drv.h | 17 ++---
>>> 2 files changed, 51 insertions(+), 129 deletions(-)
>>>
>>> diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
>>> index b0bcb7e..6eb2155 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;
>>> @@ -52,97 +63,36 @@ static inline struct zram *dev_to_zram(struct device *dev)
>>> return (struct zram *)dev_to_disk(dev)->private_data;
>>> }
>>>
>>> -static ssize_t disksize_show(struct device *dev,
>>> - struct device_attribute *attr, char *buf)
>>> -{
>>> - struct zram *zram = dev_to_zram(dev);
>>> -
>>> - return sprintf(buf, "%llu\n", zram->disksize);
>>> -}
>>> -
>>> -static ssize_t initstate_show(struct device *dev,
>>> - struct device_attribute *attr, char *buf)
>>> -{
>>> - 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);
>>> -
>>> - return sprintf(buf, "%u\n", atomic_read(&zram->stats.pages_zero));
>>> -}
>>> -
>>> -static ssize_t orig_data_size_show(struct device *dev,
>>> +static ssize_t memory_used_show(struct device *dev,
>>> struct device_attribute *attr, char *buf)
>>> {
>>> + u64 val = 0;
>>> struct zram *zram = dev_to_zram(dev);
>>> + struct zram_meta *meta = zram->meta;
>>>
>>> - return sprintf(buf, "%llu\n",
>>> - (u64)(atomic_read(&zram->stats.pages_stored)) << PAGE_SHIFT);
>>> + down_read(&zram->init_lock);
>>> + if (init_done(zram))
>>> + val = zs_get_total_size_bytes(meta->mem_pool);
>>> + up_read(&zram->init_lock);
>>> + return sprintf(buf, "%llu\n", val);
>>> }
>>>
>>> -static ssize_t compr_data_size_show(struct device *dev,
>>> +static ssize_t disksize_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_size));
>>> + return sprintf(buf, "%llu\n", zram->disksize);
>>> }
>>>
>>> -static ssize_t mem_used_total_show(struct device *dev,
>>> +static ssize_t initstate_show(struct device *dev,
>>> struct device_attribute *attr, char *buf)
>>> {
>>> - u64 val = 0;
>>> + u32 val = 0;
>>> struct zram *zram = dev_to_zram(dev);
>>> - struct zram_meta *meta = zram->meta;
>>> -
>>> down_read(&zram->init_lock);
>>> - if (init_done(zram))
>>> - val = zs_get_total_size_bytes(meta->mem_pool);
>>> + val = init_done(zram);
>>> up_read(&zram->init_lock);
>>> -
>>> - return sprintf(buf, "%llu\n", val);
>>> + return sprintf(buf, "%u\n", val);
>>> }
>>>
>>> /* flag operations needs meta->tb_lock */
>>> @@ -293,7 +243,6 @@ 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)) {
>>> /*
>>> @@ -302,21 +251,15 @@ 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.pages_zero);
>>> }
>>> 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);
>>> + atomic64_sub(meta->table[index].size, &zram->stats.compressed_size);
>>> + atomic64_dec(&zram->stats.pages_stored);
>>>
>>> meta->table[index].handle = 0;
>>> meta->table[index].size = 0;
>>> @@ -459,7 +402,7 @@ 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.pages_zero);
>>> ret = 0;
>>> goto out;
>>> }
>>> @@ -478,7 +421,6 @@ 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))
>>> @@ -516,11 +458,8 @@ 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);
>>> - if (clen <= PAGE_SIZE / 2)
>>> - atomic_inc(&zram->stats.good_compress);
>>> -
>>> + atomic64_add(clen, &zram->stats.compressed_size);
>>> + atomic64_inc(&zram->stats.pages_stored);
>>> out:
>>> if (locked)
>>> mutex_unlock(&meta->buffer_lock);
>>> @@ -583,23 +522,8 @@ 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");
>>> }
>>> @@ -771,14 +695,15 @@ 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);
>>> +static DEVICE_ATTR(memory_used, S_IRUGO, memory_used_show, NULL);
>>> +
>>> +ZRAM_ATTR_RO(num_reads);
>>> +ZRAM_ATTR_RO(num_writes);
>>> +ZRAM_ATTR_RO(pages_stored);
>>> +ZRAM_ATTR_RO(invalid_io);
>>> +ZRAM_ATTR_RO(notify_free);
>>> +ZRAM_ATTR_RO(pages_zero);
>>> +ZRAM_ATTR_RO(compressed_size);
>>>
>>> static struct attribute *zram_disk_attrs[] = {
>>> &dev_attr_disksize.attr,
>>> @@ -786,12 +711,12 @@ static struct attribute *zram_disk_attrs[] = {
>>> &dev_attr_reset.attr,
>>> &dev_attr_num_reads.attr,
>>> &dev_attr_num_writes.attr,
>>> + &dev_attr_pages_stored.attr,
>>> &dev_attr_invalid_io.attr,
>>> &dev_attr_notify_free.attr,
>>> - &dev_attr_zero_pages.attr,
>>> - &dev_attr_orig_data_size.attr,
>>> - &dev_attr_compr_data_size.attr,
>>> - &dev_attr_mem_used_total.attr,
>>> + &dev_attr_pages_zero.attr,
>>> + &dev_attr_compressed_size.attr,
>>> + &dev_attr_memory_used.attr,
>>> NULL,
>>> };
>>>
>>> diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h
>>> index e81e9cd..277023d 100644
>>> --- a/drivers/block/zram/zram_drv.h
>>> +++ b/drivers/block/zram/zram_drv.h
>>> @@ -64,22 +64,19 @@ enum zram_pageflags {
>>> struct table {
>>> unsigned long handle;
>>> u16 size; /* object size (excluding header) */
>>> - u8 count; /* object ref count (not yet used) */
>>> - u8 flags;
>>> + u16 flags;
>>> } __aligned(4);
>>>
>>> struct zram_stats {
>>> - atomic64_t compr_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 num_writes; /* number of writes */
>>> + atomic64_t num_reads; /* number of reads */
>>> + atomic64_t pages_stored; /* no. of pages currently stored */
>>> + atomic64_t compressed_size; /* compressed size of pages stored */
>>> + atomic64_t pages_zero; /* no. of zero filled pages */
>>> + atomic64_t failed_reads; /* no. of failed reads */
>>> 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 */
>>> - 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
>>>
>>> --
>>> 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 01/16/2014 01:58 AM, Minchan Kim wrote:
> On Wed, Jan 15, 2014 at 01:16:17PM +0300, Sergey Senozhatsky 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.
>>
>> Signed-off-by: Sergey Senozhatsky <[email protected]>
> Acked-by: Minchan Kim <[email protected]>
>
This of course depends on third patch, but since I have no objection
to the ZRAM_ATTR_RO() macro part:
Acked-by: Jerome Marchand <[email protected]>