Re: [PATCH] mm: rename the oldflags and parameter in memalloc_flags_*()

[Kent Overstreet]

On Wed, Jun 18, 2025 at 04:43:34PM -0700, Andrew Morton wrote:
> On Wed, 18 Jun 2025 15:03:28 +0800 Zhongkun He <hezhongkun.hzk@xxxxxxxxxxxxx> wrote:
> 
> > The variable name oldflags can indeed be misleading, because
> > it does not store the complete original value of flags.
> > Instead, it records which flags from the given set are not
> > currently set. So rename it.
> > 
> 
> Your email client is mangling the patches in strange ways.  Please send
> yourself a patch, figure out why it didn't apply?
> 
> > --- a/include/linux/sched/mm.h
> > +++ b/include/linux/sched/mm.h
> > @@ -322,21 +322,21 @@ static inline void might_alloc(gfp_t gfp_mask)
> >  }
> >  
> >  /**
> > - * memalloc_flags_save - Add a PF_* flag to current->flags, save old value
> > + * memalloc_flags_save - Add a PF_* flag to current->flags, return saved flags mask
> >   *
> >   * This allows PF_* flags to be conveniently added, irrespective of current
> >   * value, and then the old version restored with memalloc_flags_restore().
> >   */
> > -static inline unsigned memalloc_flags_save(unsigned flags)
> > +static inline unsigned int memalloc_flags_save(unsigned int flags_mask)
> >  {
> > -	unsigned oldflags = ~current->flags & flags;
> > -	current->flags |= flags;
> > -	return oldflags;
> > +	unsigned int saved_flags_mask = ~current->flags & flags_mask;
> > +
> > +	current->flags |= flags_mask;
> > +	return saved_flags_mask;
> >  }
> >  
> > -static inline void memalloc_flags_restore(unsigned flags)
> > +static inline void memalloc_flags_restore(unsigned int flags_mask)
> >  {
> > -	current->flags &= ~flags;
> > +	current->flags &= ~flags_mask;
> >  }
> 
> I guess so.  Maybe.  A bit.  Kent, what do you think?

Eesh, seems like pointless verbosity to me. Maybe don't change it if it
doesn't need to be changed?