# HG changeset patch
# User kfraser@xxxxxxxxxxxxxxxxxxxxx
# Date 1168597734 0
# Node ID 648e58e31c26c200e17c77c44e9658385f65db04
# Parent 7c5c72a0283f433949d9da82ae197da4f27861eb
linux/i386: allow CONFIG_HIGHPTE on i386
While, as discussed, the performance impact of this option is
certainly higher than on native Linux, the option should not be
entirely disallowed if people want to sacrifice performance for less
lowmem pressure.
Signed-off-by: Jan Beulich <jbeulich@xxxxxxxxxx>
---
linux-2.6-xen-sparse/arch/i386/Kconfig | 2
linux-2.6-xen-sparse/arch/i386/mm/highmem-xen.c | 1
linux-2.6-xen-sparse/arch/i386/mm/pgtable-xen.c | 30 ++++++++---
linux-2.6-xen-sparse/include/asm-i386/mach-xen/asm/pgalloc.h | 2
4 files changed, 27 insertions(+), 8 deletions(-)
diff -r 7c5c72a0283f -r 648e58e31c26 linux-2.6-xen-sparse/arch/i386/Kconfig
--- a/linux-2.6-xen-sparse/arch/i386/Kconfig Fri Jan 12 10:22:36 2007 +0000
+++ b/linux-2.6-xen-sparse/arch/i386/Kconfig Fri Jan 12 10:28:54 2007 +0000
@@ -594,7 +594,7 @@ config HAVE_ARCH_EARLY_PFN_TO_NID
config HIGHPTE
bool "Allocate 3rd-level pagetables from highmem"
- depends on (HIGHMEM4G || HIGHMEM64G) && !X86_XEN
+ depends on HIGHMEM4G || HIGHMEM64G
help
The VM uses one page table entry for each page of physical memory.
For systems with a lot of RAM, this can be wasteful of precious
diff -r 7c5c72a0283f -r 648e58e31c26
linux-2.6-xen-sparse/arch/i386/mm/highmem-xen.c
--- a/linux-2.6-xen-sparse/arch/i386/mm/highmem-xen.c Fri Jan 12 10:22:36
2007 +0000
+++ b/linux-2.6-xen-sparse/arch/i386/mm/highmem-xen.c Fri Jan 12 10:28:54
2007 +0000
@@ -129,5 +129,6 @@ EXPORT_SYMBOL(kmap);
EXPORT_SYMBOL(kmap);
EXPORT_SYMBOL(kunmap);
EXPORT_SYMBOL(kmap_atomic);
+EXPORT_SYMBOL(kmap_atomic_pte);
EXPORT_SYMBOL(kunmap_atomic);
EXPORT_SYMBOL(kmap_atomic_to_page);
diff -r 7c5c72a0283f -r 648e58e31c26
linux-2.6-xen-sparse/arch/i386/mm/pgtable-xen.c
--- a/linux-2.6-xen-sparse/arch/i386/mm/pgtable-xen.c Fri Jan 12 10:22:36
2007 +0000
+++ b/linux-2.6-xen-sparse/arch/i386/mm/pgtable-xen.c Fri Jan 12 10:28:54
2007 +0000
@@ -238,23 +238,41 @@ struct page *pte_alloc_one(struct mm_str
#ifdef CONFIG_HIGHPTE
pte = alloc_pages(GFP_KERNEL|__GFP_HIGHMEM|__GFP_REPEAT|__GFP_ZERO, 0);
+ if (pte && PageHighMem(pte)) {
+ struct mmuext_op op;
+
+ kmap_flush_unused();
+ op.cmd = MMUEXT_PIN_L1_TABLE;
+ op.arg1.mfn = pfn_to_mfn(page_to_pfn(pte));
+ BUG_ON(HYPERVISOR_mmuext_op(&op, 1, NULL, DOMID_SELF) < 0);
+ }
#else
pte = alloc_pages(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO, 0);
+#endif
if (pte) {
SetPageForeign(pte, pte_free);
set_page_count(pte, 1);
}
-#endif
return pte;
}
void pte_free(struct page *pte)
{
- unsigned long va = (unsigned long)__va(page_to_pfn(pte)<<PAGE_SHIFT);
-
- if (!pte_write(*virt_to_ptep(va)))
- BUG_ON(HYPERVISOR_update_va_mapping(
- va, pfn_pte(page_to_pfn(pte), PAGE_KERNEL), 0));
+ unsigned long pfn = page_to_pfn(pte);
+
+ if (!PageHighMem(pte)) {
+ unsigned long va = (unsigned long)__va(pfn << PAGE_SHIFT);
+
+ if (!pte_write(*virt_to_ptep(va)))
+ BUG_ON(HYPERVISOR_update_va_mapping(
+ va, pfn_pte(pfn, PAGE_KERNEL), 0));
+ } else {
+ struct mmuext_op op;
+
+ op.cmd = MMUEXT_UNPIN_TABLE;
+ op.arg1.mfn = pfn_to_mfn(pfn);
+ BUG_ON(HYPERVISOR_mmuext_op(&op, 1, NULL, DOMID_SELF) < 0);
+ }
ClearPageForeign(pte);
set_page_count(pte, 1);
diff -r 7c5c72a0283f -r 648e58e31c26
linux-2.6-xen-sparse/include/asm-i386/mach-xen/asm/pgalloc.h
--- a/linux-2.6-xen-sparse/include/asm-i386/mach-xen/asm/pgalloc.h Fri Jan
12 10:22:36 2007 +0000
+++ b/linux-2.6-xen-sparse/include/asm-i386/mach-xen/asm/pgalloc.h Fri Jan
12 10:28:54 2007 +0000
@@ -42,7 +42,7 @@ static inline void pte_free_kernel(pte_t
static inline void pte_free_kernel(pte_t *pte)
{
free_page((unsigned long)pte);
- make_page_writable(pte, XENFEAT_writable_page_tables);
+ make_lowmem_page_writable(pte, XENFEAT_writable_page_tables);
}
extern void pte_free(struct page *pte);
_______________________________________________
Xen-changelog mailing list
Xen-changelog@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-changelog
|
Home