2019-10-06 09:00:34

by David Hildenbrand

Subject: [PATCH v6 09/10] mm/memory_hotplug: Drop local variables in shrink_zone_span()

Get rid of the unnecessary local variables.

Cc: Andrew Morton <[email protected]>
Cc: Oscar Salvador <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Pavel Tatashin <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: Wei Yang <[email protected]>
Signed-off-by: David Hildenbrand <[email protected]>
---
mm/memory_hotplug.c | 15 ++++++---------
1 file changed, 6 insertions(+), 9 deletions(-)

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 8dafa1ba8d9f..843481bd507d 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -374,14 +374,11 @@ static unsigned long find_biggest_section_pfn(int nid, struct zone *zone,
static void shrink_zone_span(struct zone *zone, unsigned long start_pfn,
unsigned long end_pfn)
{
- unsigned long zone_start_pfn = zone->zone_start_pfn;
- unsigned long z = zone_end_pfn(zone); /* zone_end_pfn namespace clash */
- unsigned long zone_end_pfn = z;
unsigned long pfn;
int nid = zone_to_nid(zone);

zone_span_writelock(zone);
- if (zone_start_pfn == start_pfn) {
+ if (zone->zone_start_pfn == start_pfn) {
/*
* If the section is smallest section in the zone, it need
* shrink zone->zone_start_pfn and zone->zone_spanned_pages.
@@ -389,25 +386,25 @@ static void shrink_zone_span(struct zone *zone, unsigned long start_pfn,
* for shrinking zone.
*/
pfn = find_smallest_section_pfn(nid, zone, end_pfn,
- zone_end_pfn);
+ zone_end_pfn(zone));
if (pfn) {
+ zone->spanned_pages = zone_end_pfn(zone) - pfn;
zone->zone_start_pfn = pfn;
- zone->spanned_pages = zone_end_pfn - pfn;
} else {
zone->zone_start_pfn = 0;
zone->spanned_pages = 0;
}
- } else if (zone_end_pfn == end_pfn) {
+ } else if (zone_end_pfn(zone) == end_pfn) {
/*
* If the section is biggest section in the zone, it need
* shrink zone->spanned_pages.
* In this case, we find second biggest valid mem_section for
* shrinking zone.
*/
- pfn = find_biggest_section_pfn(nid, zone, zone_start_pfn,
+ pfn = find_biggest_section_pfn(nid, zone, zone->zone_start_pfn,
start_pfn);
if (pfn)
- zone->spanned_pages = pfn - zone_start_pfn + 1;
+ zone->spanned_pages = pfn - zone->zone_start_pfn + 1;
else {
zone->zone_start_pfn = 0;
zone->spanned_pages = 0;
--
2.21.0

2020-02-04 09:28:36

by Oscar Salvador

Subject: Re: [PATCH v6 09/10] mm/memory_hotplug: Drop local variables in shrink_zone_span()

On Sun, Oct 06, 2019 at 10:56:45AM +0200, David Hildenbrand wrote:
> Get rid of the unnecessary local variables.
>
> Cc: Andrew Morton <[email protected]>
> Cc: Oscar Salvador <[email protected]>
> Cc: David Hildenbrand <[email protected]>
> Cc: Michal Hocko <[email protected]>
> Cc: Pavel Tatashin <[email protected]>
> Cc: Dan Williams <[email protected]>
> Cc: Wei Yang <[email protected]>
> Signed-off-by: David Hildenbrand <[email protected]>
> ---
> mm/memory_hotplug.c | 15 ++++++---------
> 1 file changed, 6 insertions(+), 9 deletions(-)
>
> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
> index 8dafa1ba8d9f..843481bd507d 100644
> --- a/mm/memory_hotplug.c
> +++ b/mm/memory_hotplug.c
> @@ -374,14 +374,11 @@ static unsigned long find_biggest_section_pfn(int nid, struct zone *zone,
> static void shrink_zone_span(struct zone *zone, unsigned long start_pfn,
> unsigned long end_pfn)
> {
> - unsigned long zone_start_pfn = zone->zone_start_pfn;
> - unsigned long z = zone_end_pfn(zone); /* zone_end_pfn namespace clash */
> - unsigned long zone_end_pfn = z;
> unsigned long pfn;
> int nid = zone_to_nid(zone);

We could also remove the nid, right?
AFAICS, the nid is only used in find_{smallest/biggest}_section_pfn so we could
place there as well.

Anyway, nothing to nit-pick about:

Reviewed-by: Oscar Salvador <[email protected]>

>
> zone_span_writelock(zone);
> - if (zone_start_pfn == start_pfn) {
> + if (zone->zone_start_pfn == start_pfn) {
> /*
> * If the section is smallest section in the zone, it need
> * shrink zone->zone_start_pfn and zone->zone_spanned_pages.
> @@ -389,25 +386,25 @@ static void shrink_zone_span(struct zone *zone, unsigned long start_pfn,
> * for shrinking zone.
> */
> pfn = find_smallest_section_pfn(nid, zone, end_pfn,
> - zone_end_pfn);
> + zone_end_pfn(zone));
> if (pfn) {
> + zone->spanned_pages = zone_end_pfn(zone) - pfn;
> zone->zone_start_pfn = pfn;
> - zone->spanned_pages = zone_end_pfn - pfn;
> } else {
> zone->zone_start_pfn = 0;
> zone->spanned_pages = 0;
> }
> - } else if (zone_end_pfn == end_pfn) {
> + } else if (zone_end_pfn(zone) == end_pfn) {
> /*
> * If the section is biggest section in the zone, it need
> * shrink zone->spanned_pages.
> * In this case, we find second biggest valid mem_section for
> * shrinking zone.
> */
> - pfn = find_biggest_section_pfn(nid, zone, zone_start_pfn,
> + pfn = find_biggest_section_pfn(nid, zone, zone->zone_start_pfn,
> start_pfn);
> if (pfn)
> - zone->spanned_pages = pfn - zone_start_pfn + 1;
> + zone->spanned_pages = pfn - zone->zone_start_pfn + 1;
> else {
> zone->zone_start_pfn = 0;
> zone->spanned_pages = 0;
> --
> 2.21.0
>

--
Oscar Salvador
SUSE L3

2020-02-04 09:31:44

by David Hildenbrand

Subject: Re: [PATCH v6 09/10] mm/memory_hotplug: Drop local variables in shrink_zone_span()

On 04.02.20 10:26, Oscar Salvador wrote:
> On Sun, Oct 06, 2019 at 10:56:45AM +0200, David Hildenbrand wrote:
>> Get rid of the unnecessary local variables.
>>
>> Cc: Andrew Morton <[email protected]>
>> Cc: Oscar Salvador <[email protected]>
>> Cc: David Hildenbrand <[email protected]>
>> Cc: Michal Hocko <[email protected]>
>> Cc: Pavel Tatashin <[email protected]>
>> Cc: Dan Williams <[email protected]>
>> Cc: Wei Yang <[email protected]>
>> Signed-off-by: David Hildenbrand <[email protected]>
>> ---
>> mm/memory_hotplug.c | 15 ++++++---------
>> 1 file changed, 6 insertions(+), 9 deletions(-)
>>
>> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
>> index 8dafa1ba8d9f..843481bd507d 100644
>> --- a/mm/memory_hotplug.c
>> +++ b/mm/memory_hotplug.c
>> @@ -374,14 +374,11 @@ static unsigned long find_biggest_section_pfn(int nid, struct zone *zone,
>> static void shrink_zone_span(struct zone *zone, unsigned long start_pfn,
>> unsigned long end_pfn)
>> {
>> - unsigned long zone_start_pfn = zone->zone_start_pfn;
>> - unsigned long z = zone_end_pfn(zone); /* zone_end_pfn namespace clash */
>> - unsigned long zone_end_pfn = z;
>> unsigned long pfn;
>> int nid = zone_to_nid(zone);
>
> We could also remove the nid, right?
> AFAICS, the nid is only used in find_{smallest/biggest}_section_pfn so we could
> place there as well.


I remember sending a patch on this (which was acked, but not picked up
yet)...


oh, there it is :)

https://lore.kernel.org/linux-mm/[email protected]/

Thanks!

--
Thanks,

David / dhildenb

2020-02-05 10:09:58

by Wei Yang

Subject: Re: [PATCH v6 09/10] mm/memory_hotplug: Drop local variables in shrink_zone_span()

On Sun, Oct 06, 2019 at 10:56:45AM +0200, David Hildenbrand wrote:
>Get rid of the unnecessary local variables.
>
>Cc: Andrew Morton <[email protected]>
>Cc: Oscar Salvador <[email protected]>
>Cc: David Hildenbrand <[email protected]>
>Cc: Michal Hocko <[email protected]>
>Cc: Pavel Tatashin <[email protected]>
>Cc: Dan Williams <[email protected]>
>Cc: Wei Yang <[email protected]>
>Signed-off-by: David Hildenbrand <[email protected]>

Looks reasonable.

Reviewed-by: Wei Yang <[email protected]>

>---
> mm/memory_hotplug.c | 15 ++++++---------
> 1 file changed, 6 insertions(+), 9 deletions(-)
>
>diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
>index 8dafa1ba8d9f..843481bd507d 100644
>--- a/mm/memory_hotplug.c
>+++ b/mm/memory_hotplug.c
>@@ -374,14 +374,11 @@ static unsigned long find_biggest_section_pfn(int nid, struct zone *zone,
> static void shrink_zone_span(struct zone *zone, unsigned long start_pfn,
> unsigned long end_pfn)
> {
>- unsigned long zone_start_pfn = zone->zone_start_pfn;
>- unsigned long z = zone_end_pfn(zone); /* zone_end_pfn namespace clash */
>- unsigned long zone_end_pfn = z;
> unsigned long pfn;
> int nid = zone_to_nid(zone);
>
> zone_span_writelock(zone);
>- if (zone_start_pfn == start_pfn) {
>+ if (zone->zone_start_pfn == start_pfn) {
> /*
> * If the section is smallest section in the zone, it need
> * shrink zone->zone_start_pfn and zone->zone_spanned_pages.
>@@ -389,25 +386,25 @@ static void shrink_zone_span(struct zone *zone, unsigned long start_pfn,
> * for shrinking zone.
> */
> pfn = find_smallest_section_pfn(nid, zone, end_pfn,
>- zone_end_pfn);
>+ zone_end_pfn(zone));
> if (pfn) {
>+ zone->spanned_pages = zone_end_pfn(zone) - pfn;
> zone->zone_start_pfn = pfn;
>- zone->spanned_pages = zone_end_pfn - pfn;
> } else {
> zone->zone_start_pfn = 0;
> zone->spanned_pages = 0;
> }
>- } else if (zone_end_pfn == end_pfn) {
>+ } else if (zone_end_pfn(zone) == end_pfn) {
> /*
> * If the section is biggest section in the zone, it need
> * shrink zone->spanned_pages.
> * In this case, we find second biggest valid mem_section for
> * shrinking zone.
> */
>- pfn = find_biggest_section_pfn(nid, zone, zone_start_pfn,
>+ pfn = find_biggest_section_pfn(nid, zone, zone->zone_start_pfn,
> start_pfn);
> if (pfn)
>- zone->spanned_pages = pfn - zone_start_pfn + 1;
>+ zone->spanned_pages = pfn - zone->zone_start_pfn + 1;
> else {
> zone->zone_start_pfn = 0;
> zone->spanned_pages = 0;
>--
>2.21.0

--
Wei Yang
Help you, Help me