diff options
| author | Andrew Morton <akpm@osdl.org> | 2004-03-15 15:15:17 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2004-03-15 15:15:17 -0800 |
| commit | 5bfec9f6eadf728647754ef156aac340de1cc214 (patch) | |
| tree | c5e3ec54060842363715ec580359645312556a56 /include/linux | |
| parent | 952a0ae394f450c878aa2e408c23236896a2efac (diff) | |
[PATCH] Save some memory in mem_map on x86-64
From: Andi Kleen <ak@suse.de>
This patch saves 2MB of memory on a 1GB x86-64 machine, 20MB on a 10GB
machine. It does this by eliminating 8 bytes of useless padding in struct
page.
This resurrects an older patch in a hopefully cleaner form.
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/mm.h | 10 | ||||
| -rw-r--r-- | include/linux/mmzone.h | 2 | ||||
| -rw-r--r-- | include/linux/rmap-locking.h | 4 |
3 files changed, 11 insertions, 5 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h index da8873610af3..aaca9bd6ff8a 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -152,6 +152,12 @@ struct pte_chain; struct mmu_gather; struct inode; +#ifdef ARCH_HAS_ATOMIC_UNSIGNED +typedef unsigned page_flags_t; +#else +typedef unsigned long page_flags_t; +#endif + /* * Each physical page in the system has a struct page associated with * it to keep track of whatever it is we are using the page for at the @@ -168,7 +174,7 @@ struct inode; * TODO: make this structure smaller, it could be as small as 32 bytes. */ struct page { - unsigned long flags; /* atomic flags, some possibly + page_flags_t flags; /* atomic flags, some possibly updated asynchronously */ atomic_t count; /* Usage count, see below. */ struct list_head list; /* ->mapping has some page lists. */ @@ -333,7 +339,7 @@ static inline void put_page(struct page *page) * We'll have up to (MAX_NUMNODES * MAX_NR_ZONES) zones total, * so we use (MAX_NODES_SHIFT + MAX_ZONES_SHIFT) here to get enough bits. */ -#define NODEZONE_SHIFT (BITS_PER_LONG - MAX_NODES_SHIFT - MAX_ZONES_SHIFT) +#define NODEZONE_SHIFT (sizeof(page_flags_t)*8 - MAX_NODES_SHIFT - MAX_ZONES_SHIFT) #define NODEZONE(node, zone) ((node << ZONES_SHIFT) | zone) static inline unsigned long page_zonenum(struct page *page) diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 091159691236..7056b88aad40 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -316,7 +316,7 @@ extern struct pglist_data contig_page_data; #include <asm/mmzone.h> -#if BITS_PER_LONG == 32 +#if BITS_PER_LONG == 32 || defined(ARCH_HAS_ATOMIC_UNSIGNED) /* * with 32 bit page->flags field, we reserve 8 bits for node/zone info. * there are 3 zones (2 bits) and this leaves 8-2=6 bits for nodes. diff --git a/include/linux/rmap-locking.h b/include/linux/rmap-locking.h index d4dd60e34e25..cb30ed470cf6 100644 --- a/include/linux/rmap-locking.h +++ b/include/linux/rmap-locking.h @@ -10,8 +10,8 @@ struct pte_chain; extern kmem_cache_t *pte_chain_cache; -#define pte_chain_lock(page) bit_spin_lock(PG_chainlock, &page->flags) -#define pte_chain_unlock(page) bit_spin_unlock(PG_chainlock, &page->flags) +#define pte_chain_lock(page) bit_spin_lock(PG_chainlock, (unsigned long *)&page->flags) +#define pte_chain_unlock(page) bit_spin_unlock(PG_chainlock, (unsigned long *)&page->flags) struct pte_chain *pte_chain_alloc(int gfp_flags); void __pte_chain_free(struct pte_chain *pte_chain); |