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From:   Huaisheng HS1 Ye <yehs1@lenovo.com>
To:     Michal Hocko <mhocko@kernel.org>
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Subject: RE: [External]  Re: [PATCH 3/3] mm/page_alloc: Fix typo in debug info
 of calculate_node_totalpages
Thread-Topic: [External]  Re: [PATCH 3/3] mm/page_alloc: Fix typo in debug
 info of calculate_node_totalpages
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Date:   Sat, 5 May 2018 02:10:35 +0000
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> On Fri 04-05-18 14:52:09, Huaisheng Ye wrote:
> > realtotalpages is calculated by taking off absent_pages from
> > spanned_pages in every zone.
> > Debug message of calculate_node_totalpages shall accurately
> > indicate that it is real totalpages to avoid ambiguity.
>=20
> Is the printk actually useful? Why don't we simply remove it? You can
> get the information from /proc/zoneinfo so why to litter the dmesg
> output?

Indeed, we can get the amount of pfns as spanned, present and managed
from /proc/zoneinfo after memory initialization has been finished.

But this printk is a relatively meaningful reference within dmesg log.
Especially for people who doesn't have much experience, or someone
has a plan to modify boundary of zones within free_area_init_*.

Sincerely,
Huaisheng Ye
Linux kernel | Lenovo
>=20
> > Signed-off-by: Huaisheng Ye <yehs1@lenovo.com>
> > ---
> >  mm/page_alloc.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> > index 1b39db4..9d57db2 100644
> > --- a/mm/page_alloc.c
> > +++ b/mm/page_alloc.c
> > @@ -5967,7 +5967,7 @@ static void __meminit
> calculate_node_totalpages(struct pglist_data *pgdat,
> >
> >  	pgdat->node_spanned_pages =3D totalpages;
> >  	pgdat->node_present_pages =3D realtotalpages;
> > -	printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id,
> > +	printk(KERN_DEBUG "On node %d realtotalpages: %lu\n",
> pgdat->node_id,
> >  							realtotalpages);
> >  }
> >
> > --
> > 1.8.3.1