Re: [PATCH v4 1/2] memblock: drop for_each_memblock_type() and open code its users

[Mike Rapoport]

On Tue, Oct 13, 2026 at 03:18:45PM +0000, tarunsahu@xxxxxxxxxx wrote:
> Mike Rapoport <rppt@xxxxxxxxxx> writes:
> 
> > Hi Tarun,
> >
> > Please for the next time add the cover-letter when sending more than one
> > patch.
> 
> Thanks Mike for piking up the patches.
> 
> Sure, I will take care of adding the cover-letter.
> 
> You had some nit change suggestion, Let me know if you want
> me send v5 or it is alright.

I fixed some of it when applying and some right now, no need for v5
 
> ~Tarun
> 
> 
> >
> > On Thu, Oct 08, 2026 at 07:08:27PM +0000, Tarun Sahu wrote:
> >> for_each_memblock_type() always starts the iteration at index 0 and its
> >> body is a trivial 'for' loop, so it hides very little. It also gets in
> >> the way of iterating from an arbitrary index, which the next patch
> >> needs.
> >> 
> >> Remove the macro and open code its three users: memblock_add_range(),
> >> memblock_isolate_range() and memblock_dump(). While at it, move the
> >> region pointer into the loop body scope.
> >> 
> >> No functional change.
> >> 
> >> Reviewed-by: Pratyush Yadav <pratyush@xxxxxxxxxx>
> >> Signed-off-by: Tarun Sahu <tarunsahu@xxxxxxxxxx>
> >> ---
> >>  mm/memblock.c | 17 ++++++-----------
> >>  1 file changed, 6 insertions(+), 11 deletions(-)
> >> 
> >> diff --git a/mm/memblock.c b/mm/memblock.c
> >> index f5aaa38cfa31..59dda7d085f3 100644
> >> --- a/mm/memblock.c
> >> +++ b/mm/memblock.c
> >> @@ -155,11 +155,6 @@ struct memblock_type physmem = {
> >>   */
> >>  static __refdata struct memblock_type *memblock_memory = &memblock.memory;
> >>  
> >> -#define for_each_memblock_type(i, memblock_type, rgn)			\
> >> -	for (i = 0, rgn = &memblock_type->regions[0];			\
> >> -	     i < memblock_type->cnt;					\
> >> -	     i++, rgn = &memblock_type->regions[i])
> >> -
> >>  #define memblock_dbg(fmt, ...)						\
> >>  	do {								\
> >>  		if (memblock_debug)					\
> >> @@ -615,7 +610,6 @@ static int __init_memblock memblock_add_range(struct memblock_type *type,
> >>  	phys_addr_t obase = base;
> >>  	phys_addr_t end = base + memblock_cap_size(base, &size);
> >>  	int idx, nr_new, start_rgn = -1, end_rgn;
> >> -	struct memblock_region *rgn;
> >>  
> >>  	if (!size)
> >>  		return 0;
> >> @@ -651,7 +645,8 @@ static int __init_memblock memblock_add_range(struct memblock_type *type,
> >>  	base = obase;
> >>  	nr_new = 0;
> >>  
> >> -	for_each_memblock_type(idx, type, rgn) {
> >> +	for (idx = 0; idx < type->cnt; idx++) {
> >> +		struct memblock_region *rgn = &type->regions[idx];
> >>  		phys_addr_t rbase = rgn->base;
> >>  		phys_addr_t rend = rbase + rgn->size;
> >>  
> >> @@ -815,7 +810,6 @@ static int __init_memblock memblock_isolate_range(struct memblock_type *type,
> >>  {
> >>  	phys_addr_t end = base + memblock_cap_size(base, &size);
> >>  	int idx;
> >> -	struct memblock_region *rgn;
> >>  
> >>  	*start_rgn = *end_rgn = 0;
> >>  
> >> @@ -827,7 +821,8 @@ static int __init_memblock memblock_isolate_range(struct memblock_type *type,
> >>  		if (memblock_double_array(type, base, size) < 0)
> >>  			return -ENOMEM;
> >>  
> >> -	for_each_memblock_type(idx, type, rgn) {
> >> +	for (idx = 0; idx < type->cnt; idx++) {
> >> +		struct memblock_region *rgn = &type->regions[idx];
> >>  		phys_addr_t rbase = rgn->base;
> >>  		phys_addr_t rend = rbase + rgn->size;
> >>  
> >> @@ -2194,11 +2189,11 @@ static void __init_memblock memblock_dump(struct memblock_type *type)
> >>  	phys_addr_t base, end, size;
> >>  	enum memblock_flags flags;
> >>  	int idx;
> >> -	struct memblock_region *rgn;
> >>  
> >>  	pr_info(" %s.cnt  = 0x%lx\n", type->name, type->cnt);
> >>  
> >> -	for_each_memblock_type(idx, type, rgn) {
> >> +	for (idx = 0; idx < type->cnt; idx++) {
> >> +		struct memblock_region *rgn = &type->regions[idx];
> >>  		char nid_buf[32] = "";
> >>  
> >>  		base = rgn->base;
> >> -- 
> >> 2.56.0.385.gd3acb90ef8-goog
> >> 
> >
> > -- 
> > Sincerely yours,
> > Mike.

-- 
Sincerely yours,
Mike.