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

[Baoquan He]

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 <richard.weiyang@xxxxxxxxx>
> >> Acked-by: Michal Hocko <mhocko@xxxxxxxx>
> >> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> >> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> >> Cc: Michal Hocko <mhocko@xxxxxxxxxx>
> >> Cc: Oscar Salvador <osalvador@xxxxxxx>
> >> Cc: "Rafael J. Wysocki" <rafael@xxxxxxxxxx>
> >> Cc: Baoquan He <bhe@xxxxxxxxxx>
> >> Cc: Wei Yang <richard.weiyang@xxxxxxxxx>
> >> Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
> >> ---
> >>  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