diff options
| author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2013-02-23 04:34:32 +0400 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-02-24 05:50:17 +0400 |
| commit | 75980e97daccfc6babbac7e180ff118537955f5d (patch) | |
| tree | b5721bae11eab21a8ee7c2ba4c7f153a59766dd6 /include/linux/mm.h | |
| parent | bbeae5b05ef6e40bf54db05ceb8635824153b9e2 (diff) | |
| download | linux-75980e97daccfc6babbac7e180ff118537955f5d.tar.xz | |
mm: fold page->_last_nid into page->flags where possible
page->_last_nid fits into page->flags on 64-bit. The unlikely 32-bit
NUMA configuration with NUMA Balancing will still need an extra page
field. As Peter notes "Completely dropping 32bit support for
CONFIG_NUMA_BALANCING would simplify things, but it would also remove
the warning if we grow enough 64bit only page-flags to push the last-cpu
out."
[mgorman@suse.de: minor modifications]
Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Simon Jeons <simon.jeons@gmail.com>
Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/mm.h')
| -rw-r--r-- | include/linux/mm.h | 33 |
1 files changed, 32 insertions, 1 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h index c2d7d5993b14..473abbda942e 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -581,10 +581,11 @@ static inline pte_t maybe_mkwrite(pte_t pte, struct vm_area_struct *vma) * sets it, so none of the operations on it need to be atomic. */ -/* Page flags: | [SECTION] | [NODE] | ZONE | ... | FLAGS | */ +/* Page flags: | [SECTION] | [NODE] | ZONE | [LAST_NID] | ... | FLAGS | */ #define SECTIONS_PGOFF ((sizeof(unsigned long)*8) - SECTIONS_WIDTH) #define NODES_PGOFF (SECTIONS_PGOFF - NODES_WIDTH) #define ZONES_PGOFF (NODES_PGOFF - ZONES_WIDTH) +#define LAST_NID_PGOFF (ZONES_PGOFF - LAST_NID_WIDTH) /* * Define the bit shifts to access each section. For non-existent @@ -594,6 +595,7 @@ static inline pte_t maybe_mkwrite(pte_t pte, struct vm_area_struct *vma) #define SECTIONS_PGSHIFT (SECTIONS_PGOFF * (SECTIONS_WIDTH != 0)) #define NODES_PGSHIFT (NODES_PGOFF * (NODES_WIDTH != 0)) #define ZONES_PGSHIFT (ZONES_PGOFF * (ZONES_WIDTH != 0)) +#define LAST_NID_PGSHIFT (LAST_NID_PGOFF * (LAST_NID_WIDTH != 0)) /* NODE:ZONE or SECTION:ZONE is used to ID a zone for the buddy allocator */ #ifdef NODE_NOT_IN_PAGE_FLAGS @@ -615,6 +617,7 @@ static inline pte_t maybe_mkwrite(pte_t pte, struct vm_area_struct *vma) #define ZONES_MASK ((1UL << ZONES_WIDTH) - 1) #define NODES_MASK ((1UL << NODES_WIDTH) - 1) #define SECTIONS_MASK ((1UL << SECTIONS_WIDTH) - 1) +#define LAST_NID_MASK ((1UL << LAST_NID_WIDTH) - 1) #define ZONEID_MASK ((1UL << ZONEID_SHIFT) - 1) static inline enum zone_type page_zonenum(const struct page *page) @@ -654,6 +657,7 @@ static inline int page_to_nid(const struct page *page) #endif #ifdef CONFIG_NUMA_BALANCING +#ifdef LAST_NID_NOT_IN_PAGE_FLAGS static inline int page_xchg_last_nid(struct page *page, int nid) { return xchg(&page->_last_nid, nid); @@ -668,6 +672,33 @@ static inline void reset_page_last_nid(struct page *page) page->_last_nid = -1; } #else +static inline int page_last_nid(struct page *page) +{ + return (page->flags >> LAST_NID_PGSHIFT) & LAST_NID_MASK; +} + +static inline int page_xchg_last_nid(struct page *page, int nid) +{ + unsigned long old_flags, flags; + int last_nid; + + do { + old_flags = flags = page->flags; + last_nid = page_last_nid(page); + + flags &= ~(LAST_NID_MASK << LAST_NID_PGSHIFT); + flags |= (nid & LAST_NID_MASK) << LAST_NID_PGSHIFT; + } while (unlikely(cmpxchg(&page->flags, old_flags, flags) != old_flags)); + + return last_nid; +} + +static inline void reset_page_last_nid(struct page *page) +{ + page_xchg_last_nid(page, (1 << LAST_NID_SHIFT) - 1); +} +#endif /* LAST_NID_NOT_IN_PAGE_FLAGS */ +#else static inline int page_xchg_last_nid(struct page *page, int nid) { return page_to_nid(page); |