x86_64: Quicklist support for x86_64

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>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: "Luck, Tony" <tony.luck@intel.com>
Acked-by: William Lee Irwin III <wli@holomorphy.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 49 insertions, 24 deletions

diff --git a/include/asm-x86_64/pgalloc.h b/include/asm-x86_64/pgalloc.h
index 8bb564687860..b467be6d367f 100644
--- a/include/asm-x86_64/pgalloc.h
+++ b/include/asm-x86_64/pgalloc.h
@@ -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)))
@@ -20,23 +24,23 @@ static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd, struct page *p
 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)
@@ -57,41 +61,57 @@ static inline void pgd_list_del(pgd_t *pgd)
         spin_unlock(&pgd_lock);
 }
 
-static inline pgd_t *pgd_alloc(struct mm_struct *mm)
+static inline void pgd_ctor(void *x)
 {
         unsigned boundary;
-        pgd_t *pgd = (pgd_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT);
-        if (!pgd)
-                return NULL;
-        pgd_list_add(pgd);
+        pgd_t *pgd = x;
+        struct page *page = virt_to_page(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));
+                init_level4_pgt + boundary,
+                (PTRS_PER_PGD - boundary) * sizeof(pgd_t));
+
+        spin_lock(&pgd_lock);
+        list_add(&page->lru, &pgd_list);
+        spin_unlock(&pgd_lock);
+}
+
+static inline void pgd_dtor(void *x)
+{
+        pgd_t *pgd = x;
+        struct page *page = virt_to_page(pgd);
+
+        spin_lock(&pgd_lock);
+        list_del(&page->lru);
+        spin_unlock(&pgd_lock);
+}
+
+static inline pgd_t *pgd_alloc(struct mm_struct *mm)
+{
+        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);
@@ -103,17 +123,22 @@ static inline struct page *pte_alloc_one(struct mm_struct *mm, unsigned long add
 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);
-} 
+        quicklist_free_page(QUICK_PT, NULL, pte);
+}
 
-#define __pte_free_tlb(tlb,pte) tlb_remove_page((tlb),(pte))
+#define __pte_free_tlb(tlb,pte) quicklist_free_page(QUICK_PT, NULL,(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))
+#define __pmd_free_tlb(tlb,x)   quicklist_free(QUICK_PT, NULL, (x))
+#define __pud_free_tlb(tlb,x)   quicklist_free(QUICK_PT, NULL, (x))
 
+static inline void check_pgt_cache(void)
+{
+        quicklist_trim(QUICK_PGD, pgd_dtor, 25, 16);
+        quicklist_trim(QUICK_PT, NULL, 25, 16);
+}
 #endif /* _X86_64_PGALLOC_H */