diff -pruN ../orig-linux-2.6.16.29/arch/i386/mm/pageattr.c ./arch/i386/mm/pageattr.c --- ../orig-linux-2.6.16.29/arch/i386/mm/pageattr.c 2006-09-12 19:02:10.000000000 +0100 +++ ./arch/i386/mm/pageattr.c 2006-09-19 14:05:35.000000000 +0100 @@ -78,7 +78,7 @@ static void set_pmd_pte(pte_t *kpte, uns unsigned long flags; set_pte_atomic(kpte, pte); /* change init_mm */ - if (PTRS_PER_PMD > 1) + if (HAVE_SHARED_KERNEL_PMD) return; spin_lock_irqsave(&pgd_lock, flags); diff -pruN ../orig-linux-2.6.16.29/arch/i386/mm/pgtable.c ./arch/i386/mm/pgtable.c --- ../orig-linux-2.6.16.29/arch/i386/mm/pgtable.c 2006-09-12 19:02:10.000000000 +0100 +++ ./arch/i386/mm/pgtable.c 2006-09-19 14:05:35.000000000 +0100 @@ -215,9 +215,10 @@ void pgd_ctor(void *pgd, kmem_cache_t *c spin_lock_irqsave(&pgd_lock, flags); } - clone_pgd_range((pgd_t *)pgd + USER_PTRS_PER_PGD, - swapper_pg_dir + USER_PTRS_PER_PGD, - KERNEL_PGD_PTRS); + if (PTRS_PER_PMD == 1 || HAVE_SHARED_KERNEL_PMD) + clone_pgd_range((pgd_t *)pgd + USER_PTRS_PER_PGD, + swapper_pg_dir + USER_PTRS_PER_PGD, + KERNEL_PGD_PTRS); if (PTRS_PER_PMD > 1) return; @@ -249,6 +250,30 @@ pgd_t *pgd_alloc(struct mm_struct *mm) goto out_oom; set_pgd(&pgd[i], __pgd(1 + __pa(pmd))); } + + if (!HAVE_SHARED_KERNEL_PMD) { + unsigned long flags; + + for (i = USER_PTRS_PER_PGD; i < PTRS_PER_PGD; i++) { + pmd_t *pmd = kmem_cache_alloc(pmd_cache, GFP_KERNEL); + if (!pmd) + goto out_oom; + set_pgd(&pgd[USER_PTRS_PER_PGD], __pgd(1 + __pa(pmd))); + } + + spin_lock_irqsave(&pgd_lock, flags); + for (i = USER_PTRS_PER_PGD; i < PTRS_PER_PGD; i++) { + unsigned long v = (unsigned long)i << PGDIR_SHIFT; + pgd_t *kpgd = pgd_offset_k(v); + pud_t *kpud = pud_offset(kpgd, v); + pmd_t *kpmd = pmd_offset(kpud, v); + pmd_t *pmd = (void *)__va(pgd_val(pgd[i])-1); + memcpy(pmd, kpmd, PAGE_SIZE); + } + pgd_list_add(pgd); + spin_unlock_irqrestore(&pgd_lock, flags); + } + return pgd; out_oom: @@ -263,9 +288,23 @@ void pgd_free(pgd_t *pgd) int i; /* in the PAE case user pgd entries are overwritten before usage */ - if (PTRS_PER_PMD > 1) - for (i = 0; i < USER_PTRS_PER_PGD; ++i) - kmem_cache_free(pmd_cache, (void *)__va(pgd_val(pgd[i])-1)); + if (PTRS_PER_PMD > 1) { + for (i = 0; i < USER_PTRS_PER_PGD; ++i) { + pmd_t *pmd = (void *)__va(pgd_val(pgd[i])-1); + kmem_cache_free(pmd_cache, pmd); + } + if (!HAVE_SHARED_KERNEL_PMD) { + unsigned long flags; + spin_lock_irqsave(&pgd_lock, flags); + pgd_list_del(pgd); + spin_unlock_irqrestore(&pgd_lock, flags); + for (i = USER_PTRS_PER_PGD; i < PTRS_PER_PGD; i++) { + pmd_t *pmd = (void *)__va(pgd_val(pgd[i])-1); + memset(pmd, 0, PTRS_PER_PMD*sizeof(pmd_t)); + kmem_cache_free(pmd_cache, pmd); + } + } + } /* in the non-PAE case, free_pgtables() clears user pgd entries */ kmem_cache_free(pgd_cache, pgd); } diff -pruN ../orig-linux-2.6.16.29/include/asm-i386/pgtable-2level-defs.h ./include/asm-i386/pgtable-2level-defs.h --- ../orig-linux-2.6.16.29/include/asm-i386/pgtable-2level-defs.h 2006-09-12 19:02:10.000000000 +0100 +++ ./include/asm-i386/pgtable-2level-defs.h 2006-09-19 14:05:35.000000000 +0100 @@ -1,6 +1,8 @@ #ifndef _I386_PGTABLE_2LEVEL_DEFS_H #define _I386_PGTABLE_2LEVEL_DEFS_H +#define HAVE_SHARED_KERNEL_PMD 0 + /* * traditional i386 two-level paging structure: */ diff -pruN ../orig-linux-2.6.16.29/include/asm-i386/pgtable-3level-defs.h ./include/asm-i386/pgtable-3level-defs.h --- ../orig-linux-2.6.16.29/include/asm-i386/pgtable-3level-defs.h 2006-09-12 19:02:10.000000000 +0100 +++ ./include/asm-i386/pgtable-3level-defs.h 2006-09-19 14:05:35.000000000 +0100 @@ -1,6 +1,8 @@ #ifndef _I386_PGTABLE_3LEVEL_DEFS_H #define _I386_PGTABLE_3LEVEL_DEFS_H +#define HAVE_SHARED_KERNEL_PMD 1 + /* * PGDIR_SHIFT determines what a top-level page table entry can map */