2020-03-19 13:13:59

by David Hildenbrand

Subject: [PATCH v3 3/8] drivers/base/memory: store mapping between MMOP_* and string in an array

Let's use a simple array which we can reuse soon. While at it, move the
string->mmop conversion out of the device hotplug lock.

Reviewed-by: Wei Yang <[email protected]>
Acked-by: Michal Hocko <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Oscar Salvador <[email protected]>
Cc: "Rafael J. Wysocki" <[email protected]>
Cc: Baoquan He <[email protected]>
Cc: Wei Yang <[email protected]>
Signed-off-by: David Hildenbrand <[email protected]>
---
drivers/base/memory.c | 38 +++++++++++++++++++++++---------------
1 file changed, 23 insertions(+), 15 deletions(-)

diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index e7e77cafef80..8a7f29c0bf97 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -28,6 +28,24 @@

#define MEMORY_CLASS_NAME "memory"

+static const char *const online_type_to_str[] = {
+ [MMOP_OFFLINE] = "offline",
+ [MMOP_ONLINE] = "online",
+ [MMOP_ONLINE_KERNEL] = "online_kernel",
+ [MMOP_ONLINE_MOVABLE] = "online_movable",
+};
+
+static int memhp_online_type_from_str(const char *str)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(online_type_to_str); i++) {
+ if (sysfs_streq(str, online_type_to_str[i]))
+ return i;
+ }
+ return -EINVAL;
+}
+
#define to_memory_block(dev) container_of(dev, struct memory_block, dev)

static int sections_per_block;
@@ -236,26 +254,17 @@ static int memory_subsys_offline(struct device *dev)
static ssize_t state_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
+ const int online_type = memhp_online_type_from_str(buf);
struct memory_block *mem = to_memory_block(dev);
- int ret, online_type;
+ int ret;
+
+ if (online_type < 0)
+ return -EINVAL;

ret = lock_device_hotplug_sysfs();
if (ret)
return ret;

- if (sysfs_streq(buf, "online_kernel"))
- online_type = MMOP_ONLINE_KERNEL;
- else if (sysfs_streq(buf, "online_movable"))
- online_type = MMOP_ONLINE_MOVABLE;
- else if (sysfs_streq(buf, "online"))
- online_type = MMOP_ONLINE;
- else if (sysfs_streq(buf, "offline"))
- online_type = MMOP_OFFLINE;
- else {
- ret = -EINVAL;
- goto err;
- }
-
switch (online_type) {
case MMOP_ONLINE_KERNEL:
case MMOP_ONLINE_MOVABLE:
@@ -271,7 +280,6 @@ static ssize_t state_store(struct device *dev, struct device_attribute *attr,
ret = -EINVAL; /* should never happen */
}

-err:
unlock_device_hotplug();

if (ret < 0)
--
2.24.1

2020-03-19 16:35:14

by Pankaj Gupta

Subject: Re: [PATCH v3 3/8] drivers/base/memory: store mapping between MMOP_* and string in an array

> Let's use a simple array which we can reuse soon. While at it, move the
> string->mmop conversion out of the device hotplug lock.
>
> Reviewed-by: Wei Yang <[email protected]>
> Acked-by: Michal Hocko <[email protected]>
> Cc: Greg Kroah-Hartman <[email protected]>
> Cc: Andrew Morton <[email protected]>
> Cc: Michal Hocko <[email protected]>
> Cc: Oscar Salvador <[email protected]>
> Cc: "Rafael J. Wysocki" <[email protected]>
> Cc: Baoquan He <[email protected]>
> Cc: Wei Yang <[email protected]>
> Signed-off-by: David Hildenbrand <[email protected]>
> ---
> drivers/base/memory.c | 38 +++++++++++++++++++++++---------------
> 1 file changed, 23 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/base/memory.c b/drivers/base/memory.c
> index e7e77cafef80..8a7f29c0bf97 100644
> --- a/drivers/base/memory.c
> +++ b/drivers/base/memory.c
> @@ -28,6 +28,24 @@
>
> #define MEMORY_CLASS_NAME "memory"
>
> +static const char *const online_type_to_str[] = {
> + [MMOP_OFFLINE] = "offline",
> + [MMOP_ONLINE] = "online",
> + [MMOP_ONLINE_KERNEL] = "online_kernel",
> + [MMOP_ONLINE_MOVABLE] = "online_movable",
> +};
> +
> +static int memhp_online_type_from_str(const char *str)
> +{
> + int i;
> +
> + for (i = 0; i < ARRAY_SIZE(online_type_to_str); i++) {
> + if (sysfs_streq(str, online_type_to_str[i]))
> + return i;
> + }
> + return -EINVAL;
> +}
> +
> #define to_memory_block(dev) container_of(dev, struct memory_block, dev)
>
> static int sections_per_block;
> @@ -236,26 +254,17 @@ static int memory_subsys_offline(struct device *dev)
> static ssize_t state_store(struct device *dev, struct device_attribute *attr,
> const char *buf, size_t count)
> {
> + const int online_type = memhp_online_type_from_str(buf);
> struct memory_block *mem = to_memory_block(dev);
> - int ret, online_type;
> + int ret;
> +
> + if (online_type < 0)
> + return -EINVAL;
>
> ret = lock_device_hotplug_sysfs();
> if (ret)
> return ret;
>
> - if (sysfs_streq(buf, "online_kernel"))
> - online_type = MMOP_ONLINE_KERNEL;
> - else if (sysfs_streq(buf, "online_movable"))
> - online_type = MMOP_ONLINE_MOVABLE;
> - else if (sysfs_streq(buf, "online"))
> - online_type = MMOP_ONLINE;
> - else if (sysfs_streq(buf, "offline"))
> - online_type = MMOP_OFFLINE;
> - else {
> - ret = -EINVAL;
> - goto err;
> - }
> -
> switch (online_type) {
> case MMOP_ONLINE_KERNEL:
> case MMOP_ONLINE_MOVABLE:
> @@ -271,7 +280,6 @@ static ssize_t state_store(struct device *dev, struct device_attribute *attr,
> ret = -EINVAL; /* should never happen */
> }
>
> -err:
> unlock_device_hotplug();
>
> if (ret < 0)
> --

Nice cleanup patch.
Acked-by: Pankaj Gupta <[email protected]>

> 2.24.1
>
>

2020-03-20 07:38:44

by Baoquan He

Subject: Re: [PATCH v3 3/8] drivers/base/memory: store mapping between MMOP_* and string in an array

On 03/19/20 at 02:12pm, David Hildenbrand wrote:
> Let's use a simple array which we can reuse soon. While at it, move the
> string->mmop conversion out of the device hotplug lock.
>
> Reviewed-by: Wei Yang <[email protected]>
> Acked-by: Michal Hocko <[email protected]>
> Cc: Greg Kroah-Hartman <[email protected]>
> Cc: Andrew Morton <[email protected]>
> Cc: Michal Hocko <[email protected]>
> Cc: Oscar Salvador <[email protected]>
> Cc: "Rafael J. Wysocki" <[email protected]>
> Cc: Baoquan He <[email protected]>
> Cc: Wei Yang <[email protected]>
> Signed-off-by: David Hildenbrand <[email protected]>
> ---
> drivers/base/memory.c | 38 +++++++++++++++++++++++---------------
> 1 file changed, 23 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/base/memory.c b/drivers/base/memory.c
> index e7e77cafef80..8a7f29c0bf97 100644
> --- a/drivers/base/memory.c
> +++ b/drivers/base/memory.c
> @@ -28,6 +28,24 @@
>
> #define MEMORY_CLASS_NAME "memory"
>
> +static const char *const online_type_to_str[] = {
> + [MMOP_OFFLINE] = "offline",
> + [MMOP_ONLINE] = "online",
> + [MMOP_ONLINE_KERNEL] = "online_kernel",
> + [MMOP_ONLINE_MOVABLE] = "online_movable",
> +};
> +
> +static int memhp_online_type_from_str(const char *str)
> +{
> + int i;

I would change it as:

for (int i = 0; i < ARRAY_SIZE(online_type_to_str); i++) {

> +
> + for (i = 0; i < ARRAY_SIZE(online_type_to_str); i++) {
> + if (sysfs_streq(str, online_type_to_str[i]))
> + return i;
> + }
> + return -EINVAL;
> +}
> +
> #define to_memory_block(dev) container_of(dev, struct memory_block, dev)
>
> static int sections_per_block;
> @@ -236,26 +254,17 @@ static int memory_subsys_offline(struct device *dev)
> static ssize_t state_store(struct device *dev, struct device_attribute *attr,
> const char *buf, size_t count)
> {
> + const int online_type = memhp_online_type_from_str(buf);
> struct memory_block *mem = to_memory_block(dev);
> - int ret, online_type;
> + int ret;
> +
> + if (online_type < 0)
> + return -EINVAL;
>
> ret = lock_device_hotplug_sysfs();
> if (ret)
> return ret;
>
> - if (sysfs_streq(buf, "online_kernel"))
> - online_type = MMOP_ONLINE_KERNEL;
> - else if (sysfs_streq(buf, "online_movable"))
> - online_type = MMOP_ONLINE_MOVABLE;
> - else if (sysfs_streq(buf, "online"))
> - online_type = MMOP_ONLINE;
> - else if (sysfs_streq(buf, "offline"))
> - online_type = MMOP_OFFLINE;
> - else {
> - ret = -EINVAL;
> - goto err;
> - }
> -
> switch (online_type) {
> case MMOP_ONLINE_KERNEL:
> case MMOP_ONLINE_MOVABLE:
> @@ -271,7 +280,6 @@ static ssize_t state_store(struct device *dev, struct device_attribute *attr,
> ret = -EINVAL; /* should never happen */
> }
>
> -err:
> unlock_device_hotplug();
>
> if (ret < 0)
> --
> 2.24.1
>

2020-03-20 09:51:42

by David Hildenbrand

Subject: Re: [PATCH v3 3/8] drivers/base/memory: store mapping between MMOP_* and string in an array

On 20.03.20 08:36, Baoquan He wrote:
> On 03/19/20 at 02:12pm, David Hildenbrand wrote:
>> Let's use a simple array which we can reuse soon. While at it, move the
>> string->mmop conversion out of the device hotplug lock.
>>
>> Reviewed-by: Wei Yang <[email protected]>
>> Acked-by: Michal Hocko <[email protected]>
>> Cc: Greg Kroah-Hartman <[email protected]>
>> Cc: Andrew Morton <[email protected]>
>> Cc: Michal Hocko <[email protected]>
>> Cc: Oscar Salvador <[email protected]>
>> Cc: "Rafael J. Wysocki" <[email protected]>
>> Cc: Baoquan He <[email protected]>
>> Cc: Wei Yang <[email protected]>
>> Signed-off-by: David Hildenbrand <[email protected]>
>> ---
>> drivers/base/memory.c | 38 +++++++++++++++++++++++---------------
>> 1 file changed, 23 insertions(+), 15 deletions(-)
>>
>> diff --git a/drivers/base/memory.c b/drivers/base/memory.c
>> index e7e77cafef80..8a7f29c0bf97 100644
>> --- a/drivers/base/memory.c
>> +++ b/drivers/base/memory.c
>> @@ -28,6 +28,24 @@
>>
>> #define MEMORY_CLASS_NAME "memory"
>>
>> +static const char *const online_type_to_str[] = {
>> + [MMOP_OFFLINE] = "offline",
>> + [MMOP_ONLINE] = "online",
>> + [MMOP_ONLINE_KERNEL] = "online_kernel",
>> + [MMOP_ONLINE_MOVABLE] = "online_movable",
>> +};
>> +
>> +static int memhp_online_type_from_str(const char *str)
>> +{
>> + int i;
>
> I would change it as:
>
> for (int i = 0; i < ARRAY_SIZE(online_type_to_str); i++) {
>

That's not allowed by the C90 standard (and -std=gnu89).

$ gcc main.c -std=gnu89
main.c: In function 'main':
main.c:3:2: error: 'for' loop initial declarations are only allowed in
C99 or C11 mode
3 | for (int i = 0; i < 8; i++) {
| ^~~

One of the reasons why
git grep "for (int "

will result in very little hits (IOW, only 5 in driver code only).

--
Thanks,

David / dhildenb

2020-03-20 10:00:56

by Baoquan He

Subject: Re: [PATCH v3 3/8] drivers/base/memory: store mapping between MMOP_* and string in an array

On 03/20/20 at 10:50am, David Hildenbrand wrote:
> On 20.03.20 08:36, Baoquan He wrote:
> > On 03/19/20 at 02:12pm, David Hildenbrand wrote:
> >> Let's use a simple array which we can reuse soon. While at it, move the
> >> string->mmop conversion out of the device hotplug lock.
> >>
> >> Reviewed-by: Wei Yang <[email protected]>
> >> Acked-by: Michal Hocko <[email protected]>
> >> Cc: Greg Kroah-Hartman <[email protected]>
> >> Cc: Andrew Morton <[email protected]>
> >> Cc: Michal Hocko <[email protected]>
> >> Cc: Oscar Salvador <[email protected]>
> >> Cc: "Rafael J. Wysocki" <[email protected]>
> >> Cc: Baoquan He <[email protected]>
> >> Cc: Wei Yang <[email protected]>
> >> Signed-off-by: David Hildenbrand <[email protected]>
> >> ---
> >> drivers/base/memory.c | 38 +++++++++++++++++++++++---------------
> >> 1 file changed, 23 insertions(+), 15 deletions(-)
> >>
> >> diff --git a/drivers/base/memory.c b/drivers/base/memory.c
> >> index e7e77cafef80..8a7f29c0bf97 100644
> >> --- a/drivers/base/memory.c
> >> +++ b/drivers/base/memory.c
> >> @@ -28,6 +28,24 @@
> >>
> >> #define MEMORY_CLASS_NAME "memory"
> >>
> >> +static const char *const online_type_to_str[] = {
> >> + [MMOP_OFFLINE] = "offline",
> >> + [MMOP_ONLINE] = "online",
> >> + [MMOP_ONLINE_KERNEL] = "online_kernel",
> >> + [MMOP_ONLINE_MOVABLE] = "online_movable",
> >> +};
> >> +
> >> +static int memhp_online_type_from_str(const char *str)
> >> +{
> >> + int i;
> >
> > I would change it as:
> >
> > for (int i = 0; i < ARRAY_SIZE(online_type_to_str); i++) {
> >
>
> That's not allowed by the C90 standard (and -std=gnu89).
>
> $ gcc main.c -std=gnu89
> main.c: In function 'main':
> main.c:3:2: error: 'for' loop initial declarations are only allowed in
> C99 or C11 mode
> 3 | for (int i = 0; i < 8; i++) {
> | ^~~

Good to know, thanks.

>
> One of the reasons why
> git grep "for (int "
>
> will result in very little hits (IOW, only 5 in driver code only).
>
> --
> Thanks,
>
> David / dhildenb