* [PATCH] mm/sparse: clarify pgdat_to_phys
@ 2021-06-30 9:23 Miles Chen
2021-07-02 13:11 ` Mike Rapoport
0 siblings, 1 reply; 3+ messages in thread
From: Miles Chen @ 2021-06-30 9:23 UTC (permalink / raw)
To: Andrew Morton, Mike Rapoport, Mark Rutland
Cc: linux-mm, linux-kernel, linux-mediatek, wsd_upstream, Miles Chen
clarify pgdat_to_phys() by wrapping pgdat_to_phys
with CONFIG_NUMA. (the same config as contig_page_data)
No functional change intended.
Comment from Mark [1]:
"
... and I reckon it'd be clearer and more robust to define
pgdat_to_phys() in the same ifdefs as contig_page_data so
that these, stay in-sync. e.g. have:
| #ifdef CONFIG_NUMA
| #define pgdat_to_phys(x) virt_to_phys(x)
| #else /* CONFIG_NUMA */
|
| extern struct pglist_data contig_page_data;
| ...
| #define pgdat_to_phys(x) __pa_symbol(&contig_page_data)
|
| #endif /* CONIFIG_NUMA */
"
[1] https://lore.kernel.org/linux-arm-kernel/20210615131902.GB47121@C02TD0UTHF1T.local/
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Miles Chen <miles.chen@mediatek.com>
---
mm/sparse.c | 17 +++++++++--------
1 file changed, 9 insertions(+), 8 deletions(-)
diff --git a/mm/sparse.c b/mm/sparse.c
index 7272f7a1449d..62c21ec28e33 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -344,14 +344,15 @@ size_t mem_section_usage_size(void)
return sizeof(struct mem_section_usage) + usemap_size();
}
-static inline phys_addr_t pgdat_to_phys(struct pglist_data *pgdat)
-{
-#ifndef CONFIG_NUMA
- return __pa_symbol(pgdat);
-#else
- return __pa(pgdat);
-#endif
-}
+#ifdef CONFIG_NUMA
+#define pgdat_to_phys(pgdat) __pa(pgdat)
+#else /* CONFIG_NUMA */
+/*
+ * When !CONFIG_NUMA, we only expect pgdat == &contig_page_data,
+ * and use __pa_symbol().
+ */
+#define pgdat_to_phys(pgdat) __pa_symbol(pgdat)
+#endif /* CONFIG_NUMA */
#ifdef CONFIG_MEMORY_HOTREMOVE
static struct mem_section_usage * __init
--
2.18.0
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH] mm/sparse: clarify pgdat_to_phys
2021-06-30 9:23 [PATCH] mm/sparse: clarify pgdat_to_phys Miles Chen
@ 2021-07-02 13:11 ` Mike Rapoport
2021-07-05 9:24 ` Miles Chen
0 siblings, 1 reply; 3+ messages in thread
From: Mike Rapoport @ 2021-07-02 13:11 UTC (permalink / raw)
To: Miles Chen
Cc: Andrew Morton, Mark Rutland, linux-mm, linux-kernel,
linux-mediatek, wsd_upstream
On Wed, Jun 30, 2021 at 05:23:09PM +0800, Miles Chen wrote:
> clarify pgdat_to_phys() by wrapping pgdat_to_phys
> with CONFIG_NUMA. (the same config as contig_page_data)
>
> No functional change intended.
>
> Comment from Mark [1]:
> "
> ... and I reckon it'd be clearer and more robust to define
> pgdat_to_phys() in the same ifdefs as contig_page_data so
> that these, stay in-sync. e.g. have:
>
> | #ifdef CONFIG_NUMA
> | #define pgdat_to_phys(x) virt_to_phys(x)
> | #else /* CONFIG_NUMA */
> |
> | extern struct pglist_data contig_page_data;
> | ...
> | #define pgdat_to_phys(x) __pa_symbol(&contig_page_data)
> |
> | #endif /* CONIFIG_NUMA */
> "
>
> [1] https://lore.kernel.org/linux-arm-kernel/20210615131902.GB47121@C02TD0UTHF1T.local/
>
> Cc: Mark Rutland <mark.rutland@arm.com>
> Signed-off-by: Miles Chen <miles.chen@mediatek.com>
> ---
> mm/sparse.c | 17 +++++++++--------
> 1 file changed, 9 insertions(+), 8 deletions(-)
>
> diff --git a/mm/sparse.c b/mm/sparse.c
> index 7272f7a1449d..62c21ec28e33 100644
> --- a/mm/sparse.c
> +++ b/mm/sparse.c
> @@ -344,14 +344,15 @@ size_t mem_section_usage_size(void)
> return sizeof(struct mem_section_usage) + usemap_size();
> }
>
> -static inline phys_addr_t pgdat_to_phys(struct pglist_data *pgdat)
> -{
> -#ifndef CONFIG_NUMA
> - return __pa_symbol(pgdat);
> -#else
> - return __pa(pgdat);
> -#endif
> -}
> +#ifdef CONFIG_NUMA
> +#define pgdat_to_phys(pgdat) __pa(pgdat)
> +#else /* CONFIG_NUMA */
> +/*
> + * When !CONFIG_NUMA, we only expect pgdat == &contig_page_data,
> + * and use __pa_symbol().
> + */
> +#define pgdat_to_phys(pgdat) __pa_symbol(pgdat)
> +#endif /* CONFIG_NUMA */
I'm not sure a macro is better than a static inline.
Maybe we'd want to warn if pgdat passed to pgtat_to_phys() is not
&contig_page_data, e.g something like
static inline phys_addr_t pgdat_to_phys(struct pglist_data *pgdat)
{
if (!IS_ENABLED(CONFIG_NUMA)) {
if (pgdat == &contig_page_data)
return __pa_symbol(&contig_page_data);
else
pr_warn("Unexpected pglist_data pointer!\n");
}
return __pa(pgdat);
}
> #ifdef CONFIG_MEMORY_HOTREMOVE
> static struct mem_section_usage * __init
> --
> 2.18.0
>
--
Sincerely yours,
Mike.
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH] mm/sparse: clarify pgdat_to_phys
2021-07-02 13:11 ` Mike Rapoport
@ 2021-07-05 9:24 ` Miles Chen
0 siblings, 0 replies; 3+ messages in thread
From: Miles Chen @ 2021-07-05 9:24 UTC (permalink / raw)
To: Mike Rapoport
Cc: Andrew Morton, Mark Rutland, linux-mm, linux-kernel,
linux-mediatek, wsd_upstream
On Fri, 2021-07-02 at 16:11 +0300, Mike Rapoport wrote:
> On Wed, Jun 30, 2021 at 05:23:09PM +0800, Miles Chen wrote:
> > clarify pgdat_to_phys() by wrapping pgdat_to_phys
> > with CONFIG_NUMA. (the same config as contig_page_data)
> >
> > No functional change intended.
> >
> > Comment from Mark [1]:
> > "
> > ... and I reckon it'd be clearer and more robust to define
> > pgdat_to_phys() in the same ifdefs as contig_page_data so
> > that these, stay in-sync. e.g. have:
> >
> > | #ifdef CONFIG_NUMA
> > | #define pgdat_to_phys(x) virt_to_phys(x)
> > | #else /* CONFIG_NUMA */
> > |
> > | extern struct pglist_data contig_page_data;
> > | ...
> > | #define pgdat_to_phys(x) __pa_symbol(&contig_page_data)
> > |
> > | #endif /* CONIFIG_NUMA */
> > "
> >
> > [1] https://lore.kernel.org/linux-arm-kernel/20210615131902.GB47121@C02TD0UTHF1T.local/
> >
> > Cc: Mark Rutland <mark.rutland@arm.com>
> > Signed-off-by: Miles Chen <miles.chen@mediatek.com>
> > ---
> > mm/sparse.c | 17 +++++++++--------
> > 1 file changed, 9 insertions(+), 8 deletions(-)
> >
> > diff --git a/mm/sparse.c b/mm/sparse.c
> > index 7272f7a1449d..62c21ec28e33 100644
> > --- a/mm/sparse.c
> > +++ b/mm/sparse.c
> > @@ -344,14 +344,15 @@ size_t mem_section_usage_size(void)
> > return sizeof(struct mem_section_usage) + usemap_size();
> > }
> >
> > -static inline phys_addr_t pgdat_to_phys(struct pglist_data *pgdat)
> > -{
> > -#ifndef CONFIG_NUMA
> > - return __pa_symbol(pgdat);
> > -#else
> > - return __pa(pgdat);
> > -#endif
> > -}
> > +#ifdef CONFIG_NUMA
> > +#define pgdat_to_phys(pgdat) __pa(pgdat)
> > +#else /* CONFIG_NUMA */
> > +/*
> > + * When !CONFIG_NUMA, we only expect pgdat == &contig_page_data,
> > + * and use __pa_symbol().
> > + */
> > +#define pgdat_to_phys(pgdat) __pa_symbol(pgdat)
> > +#endif /* CONFIG_NUMA */
>
> I'm not sure a macro is better than a static inline.
>
> Maybe we'd want to warn if pgdat passed to pgtat_to_phys() is not
> &contig_page_data, e.g something like
>
> static inline phys_addr_t pgdat_to_phys(struct pglist_data *pgdat)
> {
> if (!IS_ENABLED(CONFIG_NUMA)) {
> if (pgdat == &contig_page_data)
> return __pa_symbol(&contig_page_data);
> else
> pr_warn("Unexpected pglist_data pointer!\n");
> }
>
> return __pa(pgdat);
> }
Sorry for my late response.
Thanks for the guide. It looks better this way.I will submit patch v2.
>
> > #ifdef CONFIG_MEMORY_HOTREMOVE
> > static struct mem_section_usage * __init
> > --
> > 2.18.0
> >
>
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2021-06-30 9:23 [PATCH] mm/sparse: clarify pgdat_to_phys Miles Chen
2021-07-02 13:11 ` Mike Rapoport
2021-07-05 9:24 ` Miles Chen
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