2013-09-06 13:54:20

by Sergey Senozhatsky

Subject: [PATCH 2/2] staging: zram: remove init_done from zram struct

`zram->init_done != 0' equals to `zram->meta != NULL', so init_done
can be removed.

Signed-off-by: Sergey Senozhatsky <[email protected]>

---

drivers/staging/zram/zram_drv.c | 18 +++++++-----------
drivers/staging/zram/zram_drv.h | 1 -
2 files changed, 7 insertions(+), 12 deletions(-)

diff --git a/drivers/staging/zram/zram_drv.c b/drivers/staging/zram/zram_drv.c
index 17386e2..34b72ea 100644
--- a/drivers/staging/zram/zram_drv.c
+++ b/drivers/staging/zram/zram_drv.c
@@ -60,7 +60,7 @@ 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", zram->meta != NULL);
}

static ssize_t num_reads_show(struct device *dev,
@@ -133,7 +133,7 @@ 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 (meta)
val = zs_get_total_size_bytes(meta->mem_pool);
up_read(&zram->init_lock);

@@ -556,14 +556,12 @@ static void zram_reset_device(struct zram *zram, bool reset_capacity)
flush_work(&zram->free_work);

down_write(&zram->init_lock);
- if (!zram->init_done) {
+ if (!zram->meta) {
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;
@@ -573,7 +571,7 @@ static void zram_reset_device(struct zram *zram, bool reset_capacity)
zs_free(meta->mem_pool, handle);
}

- zram_meta_free(zram->meta);
+ zram_meta_free(meta);
zram->meta = NULL;
/* Reset stats */
memset(&zram->stats, 0, sizeof(zram->stats));
@@ -602,9 +600,7 @@ static void zram_init_device(struct zram *zram, struct zram_meta *meta)

/* zram devices sort of resembles non-rotational disks */
queue_flag_set_unlocked(QUEUE_FLAG_NONROT, zram->disk->queue);
-
zram->meta = meta;
- zram->init_done = 1;

pr_debug("Initialization done!\n");
}
@@ -623,7 +619,7 @@ 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 (zram->meta) {
up_write(&zram->init_lock);
zram_meta_free(meta);
pr_info("Cannot change disksize for initialized device\n");
@@ -731,7 +727,7 @@ 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(!zram->meta))
goto error;

if (!valid_io_request(zram, bio)) {
@@ -880,7 +876,7 @@ 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/staging/zram/zram_drv.h b/drivers/staging/zram/zram_drv.h
index 97a3acf..b1100cf 100644
--- a/drivers/staging/zram/zram_drv.h
+++ b/drivers/staging/zram/zram_drv.h
@@ -110,7 +110,6 @@ struct zram {

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;
/*

2013-09-06 14:16:50

by Denis Kirjanov

Subject: Re: [PATCH 2/2] staging: zram: remove init_done from zram struct

I'm not familiar with the zram code, but looking through the code and
init_done flag it's obvious what is going on rather then looking at
zram->meta field checks.

On 9/6/13, Sergey Senozhatsky <[email protected]> wrote:
> `zram->init_done != 0' equals to `zram->meta != NULL', so init_done
> can be removed.
>
> Signed-off-by: Sergey Senozhatsky <[email protected]>
>
> ---
>
> drivers/staging/zram/zram_drv.c | 18 +++++++-----------
> drivers/staging/zram/zram_drv.h | 1 -
> 2 files changed, 7 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/staging/zram/zram_drv.c
> b/drivers/staging/zram/zram_drv.c
> index 17386e2..34b72ea 100644
> --- a/drivers/staging/zram/zram_drv.c
> +++ b/drivers/staging/zram/zram_drv.c
> @@ -60,7 +60,7 @@ 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", zram->meta != NULL);
> }
>
> static ssize_t num_reads_show(struct device *dev,
> @@ -133,7 +133,7 @@ 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 (meta)
> val = zs_get_total_size_bytes(meta->mem_pool);
> up_read(&zram->init_lock);
>
> @@ -556,14 +556,12 @@ static void zram_reset_device(struct zram *zram, bool
> reset_capacity)
> flush_work(&zram->free_work);
>
> down_write(&zram->init_lock);
> - if (!zram->init_done) {
> + if (!zram->meta) {
> 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;
> @@ -573,7 +571,7 @@ static void zram_reset_device(struct zram *zram, bool
> reset_capacity)
> zs_free(meta->mem_pool, handle);
> }
>
> - zram_meta_free(zram->meta);
> + zram_meta_free(meta);
> zram->meta = NULL;
> /* Reset stats */
> memset(&zram->stats, 0, sizeof(zram->stats));
> @@ -602,9 +600,7 @@ static void zram_init_device(struct zram *zram, struct
> zram_meta *meta)
>
> /* zram devices sort of resembles non-rotational disks */
> queue_flag_set_unlocked(QUEUE_FLAG_NONROT, zram->disk->queue);
> -
> zram->meta = meta;
> - zram->init_done = 1;
>
> pr_debug("Initialization done!\n");
> }
> @@ -623,7 +619,7 @@ 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 (zram->meta) {
> up_write(&zram->init_lock);
> zram_meta_free(meta);
> pr_info("Cannot change disksize for initialized device\n");
> @@ -731,7 +727,7 @@ 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(!zram->meta))
> goto error;
>
> if (!valid_io_request(zram, bio)) {
> @@ -880,7 +876,7 @@ 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/staging/zram/zram_drv.h
> b/drivers/staging/zram/zram_drv.h
> index 97a3acf..b1100cf 100644
> --- a/drivers/staging/zram/zram_drv.h
> +++ b/drivers/staging/zram/zram_drv.h
> @@ -110,7 +110,6 @@ struct zram {
>
> 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;
> /*
>
> _______________________________________________
> devel mailing list
> [email protected]
> http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
>


--
Regards,
Denis

2013-09-06 14:51:48

by Jerome Marchand

Subject: Re: [PATCH 2/2] staging: zram: remove init_done from zram struct

On 09/06/2013 03:52 PM, Sergey Senozhatsky wrote:
> `zram->init_done != 0' equals to `zram->meta != NULL', so init_done
> can be removed.

The name init_done is self explanatory, meta isn't. You could for
instance write a function with an explicit name to test for
initialization.

Jerome

>
> Signed-off-by: Sergey Senozhatsky <[email protected]>
>
> ---
>
> drivers/staging/zram/zram_drv.c | 18 +++++++-----------
> drivers/staging/zram/zram_drv.h | 1 -
> 2 files changed, 7 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/staging/zram/zram_drv.c b/drivers/staging/zram/zram_drv.c
> index 17386e2..34b72ea 100644
> --- a/drivers/staging/zram/zram_drv.c
> +++ b/drivers/staging/zram/zram_drv.c
> @@ -60,7 +60,7 @@ 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", zram->meta != NULL);
> }
>
> static ssize_t num_reads_show(struct device *dev,
> @@ -133,7 +133,7 @@ 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 (meta)
> val = zs_get_total_size_bytes(meta->mem_pool);
> up_read(&zram->init_lock);
>
> @@ -556,14 +556,12 @@ static void zram_reset_device(struct zram *zram, bool reset_capacity)
> flush_work(&zram->free_work);
>
> down_write(&zram->init_lock);
> - if (!zram->init_done) {
> + if (!zram->meta) {
> 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;
> @@ -573,7 +571,7 @@ static void zram_reset_device(struct zram *zram, bool reset_capacity)
> zs_free(meta->mem_pool, handle);
> }
>
> - zram_meta_free(zram->meta);
> + zram_meta_free(meta);
> zram->meta = NULL;
> /* Reset stats */
> memset(&zram->stats, 0, sizeof(zram->stats));
> @@ -602,9 +600,7 @@ static void zram_init_device(struct zram *zram, struct zram_meta *meta)
>
> /* zram devices sort of resembles non-rotational disks */
> queue_flag_set_unlocked(QUEUE_FLAG_NONROT, zram->disk->queue);
> -
> zram->meta = meta;
> - zram->init_done = 1;
>
> pr_debug("Initialization done!\n");
> }
> @@ -623,7 +619,7 @@ 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 (zram->meta) {
> up_write(&zram->init_lock);
> zram_meta_free(meta);
> pr_info("Cannot change disksize for initialized device\n");
> @@ -731,7 +727,7 @@ 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(!zram->meta))
> goto error;
>
> if (!valid_io_request(zram, bio)) {
> @@ -880,7 +876,7 @@ 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/staging/zram/zram_drv.h b/drivers/staging/zram/zram_drv.h
> index 97a3acf..b1100cf 100644
> --- a/drivers/staging/zram/zram_drv.h
> +++ b/drivers/staging/zram/zram_drv.h
> @@ -110,7 +110,6 @@ struct zram {
>
> 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;
> /*
>
> --
> 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/
>

2013-09-06 15:01:10

by Sergey Senozhatsky

Subject: Re: [PATCH 2/2] staging: zram: remove init_done from zram struct

On (09/06/13 16:50), Jerome Marchand wrote:
> On 09/06/2013 03:52 PM, Sergey Senozhatsky wrote:
> > `zram->init_done != 0' equals to `zram->meta != NULL', so init_done
> > can be removed.
>
> The name init_done is self explanatory, meta isn't. You could for
> instance write a function with an explicit name to test for
> initialization.

init_done are pretty useless 4 bytes, they just mimic `!!zram->meta'
value (or `zram->meta != NULL'). well, we can have a macro or inline
function to return `zram->meta != NULL'

-ss

> Jerome
>
> >
> > Signed-off-by: Sergey Senozhatsky <[email protected]>
> >
> > ---
> >
> > drivers/staging/zram/zram_drv.c | 18 +++++++-----------
> > drivers/staging/zram/zram_drv.h | 1 -
> > 2 files changed, 7 insertions(+), 12 deletions(-)
> >
> > diff --git a/drivers/staging/zram/zram_drv.c b/drivers/staging/zram/zram_drv.c
> > index 17386e2..34b72ea 100644
> > --- a/drivers/staging/zram/zram_drv.c
> > +++ b/drivers/staging/zram/zram_drv.c
> > @@ -60,7 +60,7 @@ 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", zram->meta != NULL);
> > }
> >
> > static ssize_t num_reads_show(struct device *dev,
> > @@ -133,7 +133,7 @@ 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 (meta)
> > val = zs_get_total_size_bytes(meta->mem_pool);
> > up_read(&zram->init_lock);
> >
> > @@ -556,14 +556,12 @@ static void zram_reset_device(struct zram *zram, bool reset_capacity)
> > flush_work(&zram->free_work);
> >
> > down_write(&zram->init_lock);
> > - if (!zram->init_done) {
> > + if (!zram->meta) {
> > 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;
> > @@ -573,7 +571,7 @@ static void zram_reset_device(struct zram *zram, bool reset_capacity)
> > zs_free(meta->mem_pool, handle);
> > }
> >
> > - zram_meta_free(zram->meta);
> > + zram_meta_free(meta);
> > zram->meta = NULL;
> > /* Reset stats */
> > memset(&zram->stats, 0, sizeof(zram->stats));
> > @@ -602,9 +600,7 @@ static void zram_init_device(struct zram *zram, struct zram_meta *meta)
> >
> > /* zram devices sort of resembles non-rotational disks */
> > queue_flag_set_unlocked(QUEUE_FLAG_NONROT, zram->disk->queue);
> > -
> > zram->meta = meta;
> > - zram->init_done = 1;
> >
> > pr_debug("Initialization done!\n");
> > }
> > @@ -623,7 +619,7 @@ 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 (zram->meta) {
> > up_write(&zram->init_lock);
> > zram_meta_free(meta);
> > pr_info("Cannot change disksize for initialized device\n");
> > @@ -731,7 +727,7 @@ 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(!zram->meta))
> > goto error;
> >
> > if (!valid_io_request(zram, bio)) {
> > @@ -880,7 +876,7 @@ 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/staging/zram/zram_drv.h b/drivers/staging/zram/zram_drv.h
> > index 97a3acf..b1100cf 100644
> > --- a/drivers/staging/zram/zram_drv.h
> > +++ b/drivers/staging/zram/zram_drv.h
> > @@ -110,7 +110,6 @@ struct zram {
> >
> > 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;
> > /*
> >
> > --
> > 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/
> >
>