> From: Yu Zhao <yuzhao@xxxxxxxxxx> > Sent: Tuesday, May 18, 2021 1:18 AM > > On Mon, May 17, 2021 at 5:21 AM Dong Aisheng <aisheng.dong@xxxxxxx> > wrote: > > > > Actually SECTIONS_SHIFT is used in the kernel code, fixed the code > > comments. BTW, also moved the code comment to where it's defined. > > > > Also fixed a checkpatch complain derived from the original code: > > WARNING: please, no space before tabs > > + * SECTIONS_SHIFT ^I^I#bits space required to store a section #$ > > > > Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > > Cc: Yu Zhao <yuzhao@xxxxxxxxxx> > > Cc: Andrey Konovalov <andreyknvl@xxxxxxxxx> > > Cc: Catalin Marinas <catalin.marinas@xxxxxxx> > > Cc: Kees Cook <keescook@xxxxxxxxxxxx> > > Signed-off-by: Dong Aisheng <aisheng.dong@xxxxxxx> > > --- > > include/linux/mmzone.h | 2 -- > > include/linux/page-flags-layout.h | 3 +++ > > 2 files changed, 3 insertions(+), 2 deletions(-) > > > > diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index > > 9cdc88d09f2b..fc23e36cb165 100644 > > --- a/include/linux/mmzone.h > > +++ b/include/linux/mmzone.h > > @@ -1198,8 +1198,6 @@ static inline struct zoneref > > *first_zones_zonelist(struct zonelist *zonelist, #ifdef > > CONFIG_SPARSEMEM > > > > /* > > - * SECTION_SHIFT #bits space required to store a section # > > - * > > * PA_SECTION_SHIFT physical address to/from section > number > > * PFN_SECTION_SHIFT pfn to/from section number > > */ > > diff --git a/include/linux/page-flags-layout.h > > b/include/linux/page-flags-layout.h > > index ef1e3e736e14..aff616855492 100644 > > --- a/include/linux/page-flags-layout.h > > +++ b/include/linux/page-flags-layout.h > > @@ -26,6 +26,9 @@ > > > > #define ZONES_WIDTH ZONES_SHIFT > > > > +/* > > + * SECTIONS_SHIFT #bits space required to store a section # > > + */ > > IMO, we should either make the original comment helpful or just remove it. > Moving it here doesn't improve readability because it's stating the obvious. > Sounds good to me. If not objections, I will remove it in v2 later. Thanks for the suggestion. Regards Aisheng > > #ifdef CONFIG_SPARSEMEM > > #include <asm/sparsemem.h> > > #define SECTIONS_SHIFT (MAX_PHYSMEM_BITS - SECTION_SIZE_BITS) > > -- > > 2.25.1 > >
