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Subject[QUICKLIST 3/4] Quicklist support for x86_64
Date
Conver x86_64 to using quicklists

This adds caching of pgds and puds, pmds, pte. That way we can
avoid costly zeroing and initialization of special mappings in the
pgd.

A second quicklist is useful to separate out PGD handling. We can carry
the initialized pgds over to the next process needing them.

Also clean up the pgd_list handling to use regular list macros.
There is no need anymore to avoid the lru field.

Move the add/removal of the pgds to the pgdlist into the
constructor / destructor. That way the implementation is
congruent with i386.

Signed-off-by: Christoph Lameter <clameter@sgi.com>

---
arch/x86_64/Kconfig | 4 ++
arch/x86_64/kernel/process.c | 1
arch/x86_64/kernel/smp.c | 2 -
arch/x86_64/mm/fault.c | 5 +-
include/asm-x86_64/pgalloc.h | 76 +++++++++++++++++++++----------------------
include/asm-x86_64/pgtable.h | 3 -
mm/Kconfig | 5 ++
7 files changed, 52 insertions(+), 44 deletions(-)
Index: linux-2.6.21-rc3-mm2/arch/x86_64/Kconfig
===================================================================
--- linux-2.6.21-rc3-mm2.orig/arch/x86_64/Kconfig 2007-03-12 22:49:20.000000000 -0700
+++ linux-2.6.21-rc3-mm2/arch/x86_64/Kconfig 2007-03-12 22:53:28.000000000 -0700
@@ -56,6 +56,10 @@ config ZONE_DMA
bool
default y

+config NR_QUICK
+ int
+ default 2
+
config ISA
bool

Index: linux-2.6.21-rc3-mm2/include/asm-x86_64/pgalloc.h
===================================================================
--- linux-2.6.21-rc3-mm2.orig/include/asm-x86_64/pgalloc.h 2007-03-12 22:49:20.000000000 -0700
+++ linux-2.6.21-rc3-mm2/include/asm-x86_64/pgalloc.h 2007-03-12 22:53:28.000000000 -0700
@@ -4,6 +4,10 @@
#include <asm/pda.h>
#include <linux/threads.h>
#include <linux/mm.h>
+#include <linux/quicklist.h>
+
+#define QUICK_PGD 0 /* We preserve special mappings over free */
+#define QUICK_PT 1 /* Other page table pages that are zero on free */

#define pmd_populate_kernel(mm, pmd, pte) \
set_pmd(pmd, __pmd(_PAGE_TABLE | __pa(pte)))
@@ -20,86 +24,77 @@ static inline void pmd_populate(struct m
static inline void pmd_free(pmd_t *pmd)
{
BUG_ON((unsigned long)pmd & (PAGE_SIZE-1));
- free_page((unsigned long)pmd);
+ quicklist_free(QUICK_PT, NULL, pmd);
}

static inline pmd_t *pmd_alloc_one (struct mm_struct *mm, unsigned long addr)
{
- return (pmd_t *)get_zeroed_page(GFP_KERNEL|__GFP_REPEAT);
+ return (pmd_t *)quicklist_alloc(QUICK_PT, GFP_KERNEL|__GFP_REPEAT, NULL);
}

static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long addr)
{
- return (pud_t *)get_zeroed_page(GFP_KERNEL|__GFP_REPEAT);
+ return (pud_t *)quicklist_alloc(QUICK_PT, GFP_KERNEL|__GFP_REPEAT, NULL);
}

static inline void pud_free (pud_t *pud)
{
BUG_ON((unsigned long)pud & (PAGE_SIZE-1));
- free_page((unsigned long)pud);
+ quicklist_free(QUICK_PT, NULL, pud);
}

-static inline void pgd_list_add(pgd_t *pgd)
+static inline void pgd_ctor(void *x)
{
+ unsigned boundary;
+ pgd_t *pgd = x;
struct page *page = virt_to_page(pgd);

+ /*
+ * Copy kernel pointers in from init.
+ */
+ boundary = pgd_index(__PAGE_OFFSET);
+ memcpy(pgd + boundary,
+ init_level4_pgt + boundary,
+ (PTRS_PER_PGD - boundary) * sizeof(pgd_t));
+
spin_lock(&pgd_lock);
- page->index = (pgoff_t)pgd_list;
- if (pgd_list)
- pgd_list->private = (unsigned long)&page->index;
- pgd_list = page;
- page->private = (unsigned long)&pgd_list;
+ list_add(&page->lru, &pgd_list);
spin_unlock(&pgd_lock);
}

-static inline void pgd_list_del(pgd_t *pgd)
+static inline void pgd_dtor(void *x)
{
- struct page *next, **pprev, *page = virt_to_page(pgd);
+ pgd_t *pgd = x;
+ struct page *page = virt_to_page(pgd);

spin_lock(&pgd_lock);
- next = (struct page *)page->index;
- pprev = (struct page **)page->private;
- *pprev = next;
- if (next)
- next->private = (unsigned long)pprev;
+ list_del(&page->lru);
spin_unlock(&pgd_lock);
}

+
static inline pgd_t *pgd_alloc(struct mm_struct *mm)
{
- unsigned boundary;
- pgd_t *pgd = (pgd_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT);
- if (!pgd)
- return NULL;
- pgd_list_add(pgd);
- /*
- * Copy kernel pointers in from init.
- * Could keep a freelist or slab cache of those because the kernel
- * part never changes.
- */
- boundary = pgd_index(__PAGE_OFFSET);
- memset(pgd, 0, boundary * sizeof(pgd_t));
- memcpy(pgd + boundary,
- init_level4_pgt + boundary,
- (PTRS_PER_PGD - boundary) * sizeof(pgd_t));
+ pgd_t *pgd = (pgd_t *)quicklist_alloc(QUICK_PGD,
+ GFP_KERNEL|__GFP_REPEAT, pgd_ctor);
+
return pgd;
}

static inline void pgd_free(pgd_t *pgd)
{
BUG_ON((unsigned long)pgd & (PAGE_SIZE-1));
- pgd_list_del(pgd);
- free_page((unsigned long)pgd);
+ quicklist_free(QUICK_PGD, pgd_dtor, pgd);
}

static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
{
- return (pte_t *)get_zeroed_page(GFP_KERNEL|__GFP_REPEAT);
+ return (pte_t *)quicklist_alloc(QUICK_PT, GFP_KERNEL|__GFP_REPEAT, NULL);
}

static inline struct page *pte_alloc_one(struct mm_struct *mm, unsigned long address)
{
- void *p = (void *)get_zeroed_page(GFP_KERNEL|__GFP_REPEAT);
+ void *p = (void *)quicklist_alloc(QUICK_PT, GFP_KERNEL|__GFP_REPEAT, NULL);
if (!p)
return NULL;
return virt_to_page(p);
@@ -111,17 +106,22 @@ static inline struct page *pte_alloc_one
static inline void pte_free_kernel(pte_t *pte)
{
BUG_ON((unsigned long)pte & (PAGE_SIZE-1));
- free_page((unsigned long)pte);
+ quicklist_free(QUICK_PT, NULL, pte);
}

static inline void pte_free(struct page *pte)
{
__free_page(pte);
-}
+}

#define __pte_free_tlb(tlb,pte) tlb_remove_page((tlb),(pte))

#define __pmd_free_tlb(tlb,x) tlb_remove_page((tlb),virt_to_page(x))
#define __pud_free_tlb(tlb,x) tlb_remove_page((tlb),virt_to_page(x))

+static inline void check_pgt_cache(void)
+{
+ quicklist_check(QUICK_PGD, pgd_dtor);
+ quicklist_check(QUICK_PT, NULL);
+}
#endif /* _X86_64_PGALLOC_H */
Index: linux-2.6.21-rc3-mm2/mm/Kconfig
===================================================================
--- linux-2.6.21-rc3-mm2.orig/mm/Kconfig 2007-03-12 22:49:23.000000000 -0700
+++ linux-2.6.21-rc3-mm2/mm/Kconfig 2007-03-12 22:53:28.000000000 -0700
@@ -225,3 +225,8 @@ config QUICKLIST
default y if NR_QUICK != 0


+config QUICKLIST
+ bool
+ default y if NR_QUICK != 0
+
+
Index: linux-2.6.21-rc3-mm2/arch/x86_64/kernel/process.c
===================================================================
--- linux-2.6.21-rc3-mm2.orig/arch/x86_64/kernel/process.c 2007-03-12 22:49:20.000000000 -0700
+++ linux-2.6.21-rc3-mm2/arch/x86_64/kernel/process.c 2007-03-12 22:53:28.000000000 -0700
@@ -207,6 +207,7 @@ void cpu_idle (void)
if (__get_cpu_var(cpu_idle_state))
__get_cpu_var(cpu_idle_state) = 0;

+ check_pgt_cache();
rmb();
idle = pm_idle;
if (!idle)
Index: linux-2.6.21-rc3-mm2/arch/x86_64/kernel/smp.c
===================================================================
--- linux-2.6.21-rc3-mm2.orig/arch/x86_64/kernel/smp.c 2007-03-12 22:49:20.000000000 -0700
+++ linux-2.6.21-rc3-mm2/arch/x86_64/kernel/smp.c 2007-03-12 22:53:28.000000000 -0700
@@ -242,7 +242,7 @@ void flush_tlb_mm (struct mm_struct * mm
}
if (!cpus_empty(cpu_mask))
flush_tlb_others(cpu_mask, mm, FLUSH_ALL);
-
+ check_pgt_cache();
preempt_enable();
}
EXPORT_SYMBOL(flush_tlb_mm);
Index: linux-2.6.21-rc3-mm2/arch/x86_64/mm/fault.c
===================================================================
--- linux-2.6.21-rc3-mm2.orig/arch/x86_64/mm/fault.c 2007-03-12 22:49:20.000000000 -0700
+++ linux-2.6.21-rc3-mm2/arch/x86_64/mm/fault.c 2007-03-12 22:53:28.000000000 -0700
@@ -585,7 +585,7 @@ do_sigbus:
}

DEFINE_SPINLOCK(pgd_lock);
-struct page *pgd_list;
+LIST_HEAD(pgd_list);

void vmalloc_sync_all(void)
{
@@ -605,8 +605,7 @@ void vmalloc_sync_all(void)
if (pgd_none(*pgd_ref))
continue;
spin_lock(&pgd_lock);
- for (page = pgd_list; page;
- page = (struct page *)page->index) {
+ list_for_each_entry(page, &pgd_list, lru) {
pgd_t *pgd;
pgd = (pgd_t *)page_address(page) + pgd_index(address);
if (pgd_none(*pgd))
Index: linux-2.6.21-rc3-mm2/include/asm-x86_64/pgtable.h
===================================================================
--- linux-2.6.21-rc3-mm2.orig/include/asm-x86_64/pgtable.h 2007-03-12 22:49:20.000000000 -0700
+++ linux-2.6.21-rc3-mm2/include/asm-x86_64/pgtable.h 2007-03-12 22:53:28.000000000 -0700
@@ -402,7 +402,7 @@ static inline pte_t pte_modify(pte_t pte
#define __swp_entry_to_pte(x) ((pte_t) { (x).val })

extern spinlock_t pgd_lock;
-extern struct page *pgd_list;
+extern struct list_head pgd_list;
void vmalloc_sync_all(void);

#endif /* !__ASSEMBLY__ */
@@ -419,7 +419,6 @@ extern int kern_addr_valid(unsigned long
#define HAVE_ARCH_UNMAPPED_AREA

#define pgtable_cache_init() do { } while (0)
-#define check_pgt_cache() do { } while (0)

#define PAGE_AGP PAGE_KERNEL_NOCACHE
#define HAVE_PAGE_AGP 1
-
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