mm: remove some useless comments of node_stat_item

  Some comments of node_stat_item are not that helpful and even confusing,
so remove them. No functional change intended.

Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
---
 include/linux/mmzone.h | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)
  

On Thu, Jul 13, 2023 at 07:49:15PM +0800, Miaohe Lin wrote:
> Some comments of node_stat_item are not that helpful and even confusing,
> so remove them. No functional change intended.

No, that's very useful and important.  Why does it confuse you?

>  enum node_stat_item {
>  	NR_LRU_BASE,
>  	NR_INACTIVE_ANON = NR_LRU_BASE, /* must match order of LRU_[IN]ACTIVE */
> -	NR_ACTIVE_ANON,		/*  "     "     "   "       "         */
> -	NR_INACTIVE_FILE,	/*  "     "     "   "       "         */
> -	NR_ACTIVE_FILE,		/*  "     "     "   "       "         */
> -	NR_UNEVICTABLE,		/*  "     "     "   "       "         */
> +	NR_ACTIVE_ANON,
> +	NR_INACTIVE_FILE,
> +	NR_ACTIVE_FILE,
> +	NR_UNEVICTABLE,
>  	NR_SLAB_RECLAIMABLE_B,
>  	NR_SLAB_UNRECLAIMABLE_B,
>  	NR_ISOLATED_ANON,	/* Temporary isolated pages from anon lru */
> -- 
> 2.33.0
> 
>
  

On 2023/7/13 20:10, Matthew Wilcox wrote:
> On Thu, Jul 13, 2023 at 07:49:15PM +0800, Miaohe Lin wrote:
>> Some comments of node_stat_item are not that helpful and even confusing,
>> so remove them. No functional change intended.
> 
> No, that's very useful and important.  Why does it confuse you?

Thanks for your quick respond.

I just can't figure out what these comments want to tell. Could you help explain these?

Thanks.
  

On Thu, Jul 13, 2023 at 08:18:29PM +0800, Miaohe Lin wrote:
> On 2023/7/13 20:10, Matthew Wilcox wrote:
> > On Thu, Jul 13, 2023 at 07:49:15PM +0800, Miaohe Lin wrote:
> >> Some comments of node_stat_item are not that helpful and even confusing,
> >> so remove them. No functional change intended.
> > 
> > No, that's very useful and important.  Why does it confuse you?
> 
> Thanks for your quick respond.
> 
> I just can't figure out what these comments want to tell. Could you help explain these?

Don't snip the thing you want explained to you!

        NR_INACTIVE_ANON = NR_LRU_BASE, /* must match order of LRU_[IN]ACTIVE */
-       NR_ACTIVE_ANON,         /*  "     "     "   "       "         */
-       NR_INACTIVE_FILE,       /*  "     "     "   "       "         */
-       NR_ACTIVE_FILE,         /*  "     "     "   "       "         */
-       NR_UNEVICTABLE,         /*  "     "     "   "       "         */
+	NR_ACTIVE_ANON,
+       NR_INACTIVE_FILE,
+       NR_ACTIVE_FILE,
+	NR_UNEVICTABLE,

What this is communicating to me is that these five items
(NR_INACTIVE_ANON to NR_UNEVICTABLE) must stay in the same order with
LRU_INACTIVE and LRU_ACTIVE.  By removing the ditto-marks from the
subsequent four lines, you've made the comment say that this one line
must stay in the same order as LRU_INACTIVE and LRU_ACTIVE ... which
makes no sense at all.
  

On 2023/7/13 20:31, Matthew Wilcox wrote:
> On Thu, Jul 13, 2023 at 08:18:29PM +0800, Miaohe Lin wrote:
>> On 2023/7/13 20:10, Matthew Wilcox wrote:
>>> On Thu, Jul 13, 2023 at 07:49:15PM +0800, Miaohe Lin wrote:
>>>> Some comments of node_stat_item are not that helpful and even confusing,
>>>> so remove them. No functional change intended.
>>>
>>> No, that's very useful and important.  Why does it confuse you?
>>
>> Thanks for your quick respond.
>>
>> I just can't figure out what these comments want to tell. Could you help explain these?
> 
> Don't snip the thing you want explained to you!
> 
>         NR_INACTIVE_ANON = NR_LRU_BASE, /* must match order of LRU_[IN]ACTIVE */
> -       NR_ACTIVE_ANON,         /*  "     "     "   "       "         */
> -       NR_INACTIVE_FILE,       /*  "     "     "   "       "         */
> -       NR_ACTIVE_FILE,         /*  "     "     "   "       "         */
> -       NR_UNEVICTABLE,         /*  "     "     "   "       "         */
> +	NR_ACTIVE_ANON,
> +       NR_INACTIVE_FILE,
> +       NR_ACTIVE_FILE,
> +	NR_UNEVICTABLE,
> 
> What this is communicating to me is that these five items
> (NR_INACTIVE_ANON to NR_UNEVICTABLE) must stay in the same order with
> LRU_INACTIVE and LRU_ACTIVE.  By removing the ditto-marks from the
> subsequent four lines, you've made the comment say that this one line
> must stay in the same order as LRU_INACTIVE and LRU_ACTIVE ... which
> makes no sense at all.

I see. Many thanks for your kind explanation. :)
  

On 7/13/23 18:01, Matthew Wilcox wrote:
> On Thu, Jul 13, 2023 at 08:18:29PM +0800, Miaohe Lin wrote:
>> On 2023/7/13 20:10, Matthew Wilcox wrote:
>>> On Thu, Jul 13, 2023 at 07:49:15PM +0800, Miaohe Lin wrote:
>>>> Some comments of node_stat_item are not that helpful and even confusing,
>>>> so remove them. No functional change intended.
>>>
>>> No, that's very useful and important.  Why does it confuse you?
>>
>> Thanks for your quick respond.
>>
>> I just can't figure out what these comments want to tell. Could you help explain these?
> 
> Don't snip the thing you want explained to you!
> 
>         NR_INACTIVE_ANON = NR_LRU_BASE, /* must match order of LRU_[IN]ACTIVE */
> -       NR_ACTIVE_ANON,         /*  "     "     "   "       "         */
> -       NR_INACTIVE_FILE,       /*  "     "     "   "       "         */
> -       NR_ACTIVE_FILE,         /*  "     "     "   "       "         */
> -       NR_UNEVICTABLE,         /*  "     "     "   "       "         */
> +	NR_ACTIVE_ANON,
> +       NR_INACTIVE_FILE,
> +       NR_ACTIVE_FILE,
> +	NR_UNEVICTABLE,
> 
> What this is communicating to me is that these five items
> (NR_INACTIVE_ANON to NR_UNEVICTABLE) must stay in the same order with
> LRU_INACTIVE and LRU_ACTIVE.  By removing the ditto-marks from the
> subsequent four lines, you've made the comment say that this one line
> must stay in the same order as LRU_INACTIVE and LRU_ACTIVE ... which
> makes no sense at all.

Just wondering - would it be better to repeat these comments in words for
each line than use "ditto-marks" ?