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| author |   Miles Chen <miles.chen@mediatek.com> | 2021-09-02 14:57:13 -0700 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@linux-foundation.org> | 2021-09-03 09:58:14 -0700 |
| commit | bdbda735508ca83341899a77f143e4d5c58007b3 (patch) | |
| tree | 57128ca5fe6b698348ab0383d2ff25aa5a5a0a05 /mm/sparse.c | |
| parent | include/linux/mmzone.h: avoid a warning in sparse memory support (diff) | |
| download | linux-dev-bdbda735508ca83341899a77f143e4d5c58007b3.tar.xz linux-dev-bdbda735508ca83341899a77f143e4d5c58007b3.zip | |
mm/sparse: clarify pgdat_to_phys
Clarify pgdat_to_phys() by testing if
pgdat == &contig_page_data when CONFIG_NUMA=n.
We only expect contig_page_data in such case, so we
use &contig_page_data directly instead of pgdat.
No functional change intended when CONFIG_BUG_VM=n.
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/
Link: https://lkml.kernel.org/r/20210723123342.26406-1-miles.chen@mediatek.com
Signed-off-by: Miles Chen <miles.chen@mediatek.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/sparse.c')
| -rw-r--r-- | mm/sparse.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/mm/sparse.c b/mm/sparse.c index be7936e65b6a..fd29b3abffa0 100644 --- a/mm/sparse.c +++ b/mm/sparse.c @@ -321,7 +321,8 @@ size_t mem_section_usage_size(void) static inline phys_addr_t pgdat_to_phys(struct pglist_data *pgdat) { #ifndef CONFIG_NUMA - return __pa_symbol(pgdat); + VM_BUG_ON(pgdat != &contig_page_data); + return __pa_symbol(&contig_page_data); #else return __pa(pgdat); #endif |