* [RESEND PATCH] mm/sparse: remove duplicated pfn_to_section_nr()
@ 2020-03-16 7:59 qiwuchen55
2020-03-16 8:45 ` Pankaj Gupta
2020-03-21 3:04 ` Andrew Morton
0 siblings, 2 replies; 3+ messages in thread
From: qiwuchen55 @ 2020-03-16 7:59 UTC (permalink / raw)
To: akpm; +Cc: linux-mm, chenqiwu
From: chenqiwu <chenqiwu@xiaomi.com>
Remove duplicated pfn_to_section_nr() in pfn_valid() and pfn_present()
to increase executing efficiency of code.
Signed-off-by: chenqiwu <chenqiwu@xiaomi.com>
---
include/linux/mmzone.h | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 462f687..35763b5 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -1358,10 +1358,11 @@ static inline int pfn_section_valid(struct mem_section *ms, unsigned long pfn)
static inline int pfn_valid(unsigned long pfn)
{
struct mem_section *ms;
+ unsigned long sec_nr = pfn_to_section_nr(pfn);
- if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS)
+ if (sec_nr >= NR_MEM_SECTIONS)
return 0;
- ms = __nr_to_section(pfn_to_section_nr(pfn));
+ ms = __nr_to_section(sec_nr);
if (!valid_section(ms))
return 0;
/*
@@ -1374,9 +1375,11 @@ static inline int pfn_valid(unsigned long pfn)
static inline int pfn_present(unsigned long pfn)
{
- if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS)
+ unsigned long sec_nr = pfn_to_section_nr(pfn);
+
+ if (sec_nr >= NR_MEM_SECTIONS)
return 0;
- return present_section(__nr_to_section(pfn_to_section_nr(pfn)));
+ return present_section(__nr_to_section(sec_nr));
}
static inline unsigned long next_present_section_nr(unsigned long section_nr)
--
1.9.1
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [RESEND PATCH] mm/sparse: remove duplicated pfn_to_section_nr()
2020-03-16 7:59 [RESEND PATCH] mm/sparse: remove duplicated pfn_to_section_nr() qiwuchen55
@ 2020-03-16 8:45 ` Pankaj Gupta
2020-03-21 3:04 ` Andrew Morton
1 sibling, 0 replies; 3+ messages in thread
From: Pankaj Gupta @ 2020-03-16 8:45 UTC (permalink / raw)
To: qiwuchen55; +Cc: Andrew Morton, linux-mm, chenqiwu
> From: chenqiwu <chenqiwu@xiaomi.com>
>
> Remove duplicated pfn_to_section_nr() in pfn_valid() and pfn_present()
> to increase executing efficiency of code.
>
> Signed-off-by: chenqiwu <chenqiwu@xiaomi.com>
> ---
> include/linux/mmzone.h | 11 +++++++----
> 1 file changed, 7 insertions(+), 4 deletions(-)
>
> diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
> index 462f687..35763b5 100644
> --- a/include/linux/mmzone.h
> +++ b/include/linux/mmzone.h
> @@ -1358,10 +1358,11 @@ static inline int pfn_section_valid(struct mem_section *ms, unsigned long pfn)
> static inline int pfn_valid(unsigned long pfn)
> {
> struct mem_section *ms;
> + unsigned long sec_nr = pfn_to_section_nr(pfn);
>
> - if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS)
> + if (sec_nr >= NR_MEM_SECTIONS)
> return 0;
> - ms = __nr_to_section(pfn_to_section_nr(pfn));
> + ms = __nr_to_section(sec_nr);
> if (!valid_section(ms))
> return 0;
> /*
> @@ -1374,9 +1375,11 @@ static inline int pfn_valid(unsigned long pfn)
>
> static inline int pfn_present(unsigned long pfn)
> {
> - if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS)
> + unsigned long sec_nr = pfn_to_section_nr(pfn);
> +
> + if (sec_nr >= NR_MEM_SECTIONS)
> return 0;
> - return present_section(__nr_to_section(pfn_to_section_nr(pfn)));
> + return present_section(__nr_to_section(sec_nr));
> }
>
> static inline unsigned long next_present_section_nr(unsigned long section_nr)
> --
Looks ok.
Acked-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
> 1.9.1
>
>
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [RESEND PATCH] mm/sparse: remove duplicated pfn_to_section_nr()
2020-03-16 7:59 [RESEND PATCH] mm/sparse: remove duplicated pfn_to_section_nr() qiwuchen55
2020-03-16 8:45 ` Pankaj Gupta
@ 2020-03-21 3:04 ` Andrew Morton
1 sibling, 0 replies; 3+ messages in thread
From: Andrew Morton @ 2020-03-21 3:04 UTC (permalink / raw)
To: qiwuchen55; +Cc: linux-mm, chenqiwu
On Mon, 16 Mar 2020 15:59:47 +0800 qiwuchen55@gmail.com wrote:
> From: chenqiwu <chenqiwu@xiaomi.com>
>
> Remove duplicated pfn_to_section_nr() in pfn_valid() and pfn_present()
> to increase executing efficiency of code.
>
> ...
>
> --- a/include/linux/mmzone.h
> +++ b/include/linux/mmzone.h
> @@ -1358,10 +1358,11 @@ static inline int pfn_section_valid(struct mem_section *ms, unsigned long pfn)
> static inline int pfn_valid(unsigned long pfn)
> {
> struct mem_section *ms;
> + unsigned long sec_nr = pfn_to_section_nr(pfn);
>
> - if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS)
> + if (sec_nr >= NR_MEM_SECTIONS)
> return 0;
> - ms = __nr_to_section(pfn_to_section_nr(pfn));
> + ms = __nr_to_section(sec_nr);
> if (!valid_section(ms))
> return 0;
> /*
> @@ -1374,9 +1375,11 @@ static inline int pfn_valid(unsigned long pfn)
>
> static inline int pfn_present(unsigned long pfn)
> {
> - if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS)
> + unsigned long sec_nr = pfn_to_section_nr(pfn);
> +
> + if (sec_nr >= NR_MEM_SECTIONS)
> return 0;
> - return present_section(__nr_to_section(pfn_to_section_nr(pfn)));
> + return present_section(__nr_to_section(sec_nr));
> }
>
The compiler already makes this optimization (pfn_to_section_nr() is
very simple). Generated code appears to be identical.
I guess this patch could be sold as a cleanup, but I don't think it's
worthwhile, really.
^ permalink raw reply [flat|nested] 3+ messages in thread
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2020-03-16 7:59 [RESEND PATCH] mm/sparse: remove duplicated pfn_to_section_nr() qiwuchen55
2020-03-16 8:45 ` Pankaj Gupta
2020-03-21 3:04 ` Andrew Morton
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