mm/sparse: clarify pgdat_to_phys
Subsystems (3)
PATCH 1/1 mm/sparse: clarify pgdat_to_phys
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/[email protected]/
--- mm/sparse.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-)
mm/sparse.c +9 -8
@@ -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
Signature · 1 line
2.18.0
Mike Rapoport
reviewerQuoted 45 lines · Miles Chen
clarify
pgdat_to_phys()by wrappingpgdat_to_physwithCONFIG_NUMA. (the same config ascontig_page_data)No functional change intended.
Comment from Mark [1]:
"
... and I reckon it'd be clearer and more robust to definepgdat_to_phys()in the same ifdefs ascontig_page_dataso 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/[email protected]/
Cc Mark Rutland <[email protected]>Signed-off-by Miles Chen <[email protected]>--- mm/sparse.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-)mm/sparse.c +0
-7@@ -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
mm/sparse.c size_t mem_section_usage_size(void) · line 355
Quoted 10 lines
mm/sparse.c +9
-1-} +#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);
}Quoted 5 lines
mm/sparse.c +0
-0#ifdef CONFIG_MEMORY_HOTREMOVE static struct mem_section_usage * __initSignature · 1 line
2.18.0
Signature · 2 lines
Sincerely yours, Mike.
Quoted 63 lines · Mike Rapoport
Quoted 45 lines · Miles Chen
clarify
pgdat_to_phys()by wrappingpgdat_to_physwithCONFIG_NUMA. (the same config ascontig_page_data)No functional change intended.
Comment from Mark [1]:
"
... and I reckon it'd be clearer and more robust to definepgdat_to_phys()in the same ifdefs ascontig_page_dataso 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/[email protected]/
Cc Mark Rutland <[email protected]>Signed-off-by Miles Chen <[email protected]>--- mm/sparse.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-)mm/sparse.c +0
-7@@ -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 mm/sparse.c size_t mem_section_usage_size(void) · line 355
Quoted 10 lines
mm/sparse.c +9
-1-} +#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 likestatic inline
phys_addr_tpgdat_to_phys(struct pglist_data *pgdat)
Quoted 10 lines
{
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.
Quoted 7 lines
Quoted 6 lines
mm/sparse.c +0
-0#ifdef CONFIG_MEMORY_HOTREMOVE static struct mem_section_usage * __initSignature · 1 line
2.18.0