Re: [PATCH] mm: remove some useless comments of node_stat_item

[Matthew Wilcox]

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.