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From:   Huaisheng HS1 Ye <yehs1@lenovo.com>
To:     Michal Hocko <mhocko@kernel.org>
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        NingTing Cheng <chengnt@lenovo.com>
Subject: RE: [PATCH] include/linux/gfp.h: use unsigned int in gfp_zone
Thread-Topic: [PATCH] include/linux/gfp.h: use unsigned int in gfp_zone
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Date:   Thu, 3 May 2018 14:05:28 +0000
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 > On Thu 03-05-18 11:44:58, Huaisheng Ye wrote:
> > Suggest using unsigned int instead of int for bit within gfp_zone.
> >
> > The value of bit comes from flags, which's type is gfp_t. And it
> > indicates the number of bits in the right shift for GFP_ZONE_TABLE.
> >
> > Signed-off-by: Huaisheng Ye <yehs1@lenovo.com>
>=20
> The patch looks OK but it misses the most important piece of
> information. Why this is worth changing. Does it lead to a better code?
> Silence a warning or...
>=20
Yes, thank you and I will rewrite the commit log later.

Sincerely,
Huaisheng, Ye
> > ---
> >  include/linux/gfp.h | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/include/linux/gfp.h b/include/linux/gfp.h
> > index 1a4582b..21551fc 100644
> > --- a/include/linux/gfp.h
> > +++ b/include/linux/gfp.h
> > @@ -401,7 +401,7 @@ static inline bool gfpflags_allow_blocking(const gf=
p_t
> gfp_flags)
> >  static inline enum zone_type gfp_zone(gfp_t flags)
> >  {
> >  	enum zone_type z;
> > -	int bit =3D (__force int) (flags & GFP_ZONEMASK);
> > +	unsigned int bit =3D (__force unsigned int) (flags & GFP_ZONEMASK);
> >
> >  	z =3D (GFP_ZONE_TABLE >> (bit * GFP_ZONES_SHIFT)) &
> >  					 ((1 << GFP_ZONES_SHIFT) - 1);
> > --
> > 1.8.3.1
> >
>=20
> --
> Michal Hocko
> SUSE Labs