LinuxLists.cc - large page patch

2002-08-02 00:36:42

Subject: large page patch

This is a large-page support patch from Rohit Seth, forwarded
with his permission (thanks!).

> Attached is the large_page support for IA-32. For most part there are no
> changes over IA-64 patch. System calls and their semantics remain the
> same. Though there are still some little parts of code that are arch
> specfic (like for IA-64 there is seperate region for large_pages whereas
> on IA-32 it is the same linear address space etc.) I will appreciate if
> you all could provide your input and any issues that you think we need to
> resolve.
>
> Attached is the large_page patch including the following support: 1-
> Private and Shared Anonymous large pages(This is the earlier patch +
> Anonymous share Large_page support). Private Anonymous large_pages stay
> with the particular process and vm segments corresponding to these get
> VM_DONTCOPY attribute. Shared Anonymous pages get shared by children.
> (Children share the same physical large_pages with parent.) Allocation
> and deallocation of this is done using the following two system calls:
>
> sys_get_large_pages (unsigned long addr, unsigned long len, int prot, int flags)
> where prot could be PROT_READ, PROT_WRITE, PROT_EXEC and flags
> is MAP_PRIVATE or MAP_SHARE
> sys_free_large_pages(unsigned long addr)
>
> 2- Shared Large Pages across different processes. Allocation and
> deallocation of large_pages that a process can share and unshare across
> different procecess is using follwoign two systm calls:
>
> sys_share_large_pages(int key, unsigned long addr, unsigned long len, int prot, int flag)
>
> where key is the system wide unique identifier that processes use to share
> pages. This should be non-zero positive number. prot is identical as in
> above cases. flag could be set to IPC_CREAT so that if the segment
> corresponding to key is not already there then it is created (Else -ENOENT
> is returned if there is no existing segment).
>
> sys_unshare_large_pages(unsigned long addr)
>
> is used to unshare the large_pages from process's address space. The
> large_pages are put on lpage_freelist only when the last user has sent the
> request for unsharing it (kind of SHM_DEST attribute).
>
> Most of the support needed for above two cases (Anonymous and Sharing
> across processes) is quite similar in kernel except for binding of
> large_pages to key and temporary inode structure.
>
> 3) Currently the large_page memory is dynamically configurable through
> /proc/sys/kernel/numlargepages User can specify the number (negative
> meaning shrink) that the number of large_page pages need to change. For
> e.g. a value of -2 will reduce the number of large_page pages currently
> configured in system by 2. Note that this change will depend on the
> availability of free large_pages. If none is available then the value
> remains same. (Any cleaner suggestions?)

Some observations which have been made thus far:

- Minimal impact on the VM and MM layers

- Delegates most of it to the arch layer

- Generic code is not tied to pagetables so (for example) PPC could
implement the system calls with BAT registers

- The change to MAX_ORDER is unneeded

- swapping of large pages and making them pagecache-coherent is
unpopular.

- may be better to implement the shm API with fd's, not keys.

- an ia64 implementation is available

diff -Naru linux.org/arch/i386/config.in linux.lp/arch/i386/config.in
--- linux.org/arch/i386/config.in Mon Feb 25 11:37:52 2002
+++ linux.lp/arch/i386/config.in Tue Jul 2 17:49:15 2002
@@ -184,6 +184,8 @@

bool 'Math emulation' CONFIG_MATH_EMULATION
bool 'MTRR (Memory Type Range Register) support' CONFIG_MTRR
+bool 'IA-32 Large Page Support (if available on processor)' CONFIG_LARGE_PAGE
+
bool 'Symmetric multi-processing support' CONFIG_SMP
if [ "$CONFIG_SMP" != "y" ]; then
bool 'Local APIC support on uniprocessors' CONFIG_X86_UP_APIC
@@ -205,7 +207,6 @@

mainmenu_option next_comment
comment 'General setup'
-
bool 'Networking support' CONFIG_NET

# Visual Workstation support is utterly broken.
diff -Naru linux.org/arch/i386/kernel/entry.S linux.lp/arch/i386/kernel/entry.S
--- linux.org/arch/i386/kernel/entry.S Mon Feb 25 11:37:53 2002
+++ linux.lp/arch/i386/kernel/entry.S Tue Jul 2 15:12:23 2002
@@ -634,6 +634,10 @@
.long SYMBOL_NAME(sys_ni_syscall) /* 235 reserved for removexattr */
.long SYMBOL_NAME(sys_ni_syscall) /* reserved for lremovexattr */
.long SYMBOL_NAME(sys_ni_syscall) /* reserved for fremovexattr */
+ .long SYMBOL_NAME(sys_get_large_pages) /* Get large_page pages */
+ .long SYMBOL_NAME(sys_free_large_pages) /* Free large_page pages */
+ .long SYMBOL_NAME(sys_share_large_pages)/* Share large_page pages */
+ .long SYMBOL_NAME(sys_unshare_large_pages)/* UnShare large_page pages */

.rept NR_syscalls-(.-sys_call_table)/4
.long SYMBOL_NAME(sys_ni_syscall)
diff -Naru linux.org/arch/i386/kernel/sys_i386.c linux.lp/arch/i386/kernel/sys_i386.c
--- linux.org/arch/i386/kernel/sys_i386.c Mon Mar 19 12:35:09 2001
+++ linux.lp/arch/i386/kernel/sys_i386.c Wed Jul 3 14:28:16 2002
@@ -254,3 +254,126 @@
return -ERESTARTNOHAND;
}

+#ifdef CONFIG_LARGE_PAGE
+#define LPAGE_ALIGN(x) (((unsigned long)x + (LPAGE_SIZE -1)) & LPAGE_MASK)
+extern long sys_munmap(unsigned long, size_t);
+
+/* get_addr function gets the currently unused virtaul range in
+ * current process's address space. It returns the LARGE_PAGE_SIZE
+ * aligned address (in cases of success). Other kernel generic
+ * routines only could gurantee that allocated address is PAGE_SIZSE aligned.
+ */
+unsigned long
+get_addr(unsigned long addr, unsigned long len)
+{
+ struct vm_area_struct *vma;
+ if (addr) {
+ addr = LPAGE_ALIGN(addr);
+ vma = find_vma(current->mm, addr);
+ if (((TASK_SIZE - len) >= addr) &&
+ (!vma || addr + len <= vma->vm_start))
+ goto found_addr;
+ }
+ addr = LPAGE_ALIGN(TASK_UNMAPPED_BASE);
+ for (vma = find_vma(current->mm, addr); ; vma = vma->vm_next) {
+ if (TASK_SIZE - len < addr)
+ return -ENOMEM;
+ if (!vma || ((addr + len) < vma->vm_start))
+ goto found_addr;
+ addr = vma->vm_end;
+ }
+found_addr:
+ addr = LPAGE_ALIGN(addr);
+ return addr;
+}
+
+asmlinkage unsigned long
+sys_get_large_pages(unsigned long addr, unsigned long len, int prot, int flags)
+{
+ extern int make_lpages_present(unsigned long, unsigned long, int);
+ int temp;
+
+ if (!(cpu_has_pse))
+ return -EINVAL;
+ if (len & (LPAGE_SIZE - 1))
+ return -EINVAL;
+ addr = get_addr(addr, len);
+ if (addr == -ENOMEM)
+ return addr;
+ temp = MAP_SHARED | MAP_ANONYMOUS |MAP_FIXED;
+ addr = do_mmap_pgoff(NULL, addr, len, prot, temp, 0);
+ printk("Returned addr %x\n", addr);
+ if (!(addr & (LPAGE_SIZE -1))) {
+ if (make_lpages_present(addr, (addr+len), flags) < 0) {
+ addr = sys_munmap(addr, len);
+ return -ENOMEM;
+ }
+ }
+ return addr;
+}
+
+asmlinkage unsigned long
+sys_share_large_pages(int key, unsigned long addr, unsigned long len, int prot, int flag)
+{
+ unsigned long raddr;
+ int retval;
+ extern int set_lp_shm_seg(int, unsigned long *, unsigned long, int, int);
+ if (!(cpu_has_pse))
+ return -EINVAL;
+ if (key <= 0)
+ return -EINVAL;
+ if (len & (LPAGE_SIZE - 1))
+ return -EINVAL;
+ raddr = get_addr(addr, len);
+ if (raddr == -ENOMEM)
+ return raddr;
+ retval = set_lp_shm_seg(key, &raddr, len, prot, flag);
+ if (retval < 0)
+ return (unsigned long) retval;
+ return raddr;
+}
+
+asmlinkage int
+sys_free_large_pages(unsigned long addr)
+{
+ struct vm_area_struct *vma;
+ extern int unmap_large_pages(struct vm_area_struct *);
+
+ vma = find_vma(current->mm, addr);
+ if ((!vma) || (!(vma->vm_flags & VM_LARGEPAGE)) ||
+ (vma->vm_start!=addr))
+ return -EINVAL;
+ return unmap_large_pages(vma);
+}
+
+asmlinkage int
+sys_unshare_large_pages(unsigned long addr)
+{
+ return sys_free_large_pages(addr);
+}
+
+#else
+asmlinkage unsigned long
+sys_get_large_pages(unsigned long addr, size_t len, int prot, int flags)
+{
+ return -ENOSYS;
+}
+
+asmlinkage unsigned long
+sys_share_large_apges(int key, unsigned long addr, size_t len, int prot, int flag)
+{
+ return -ENOSYS;
+}
+
+asmlinkage int
+sys_free_large_apges(unsigned long addr)
+{
+ return -ENOSYS;
+}
+
+asmlinkage int
+sys_unshare_large_pages(unsigned long addr)
+{
+ return -ENOSYS;
+}
+#endif
diff -Naru linux.org/arch/i386/mm/Makefile linux.lp/arch/i386/mm/Makefile
--- linux.org/arch/i386/mm/Makefile Fri Dec 29 14:07:20 2000
+++ linux.lp/arch/i386/mm/Makefile Tue Jul 2 16:55:53 2002
@@ -10,5 +10,6 @@
O_TARGET := mm.o

obj-y := init.o fault.o ioremap.o extable.o
+obj-$(CONFIG_LARGE_PAGE) += lpage.o

include $(TOPDIR)/Rules.make
diff -Naru linux.org/arch/i386/mm/init.c linux.lp/arch/i386/mm/init.c
--- linux.org/arch/i386/mm/init.c Fri Dec 21 09:41:53 2001
+++ linux.lp/arch/i386/mm/init.c Tue Jul 2 18:39:13 2002
@@ -447,6 +447,12 @@
return 0;
}

+#ifdef CONFIG_LARGE_PAGE
+long lpagemem = 0;
+int lp_max;
+long lpzone_pages;
+extern struct list_head lpage_freelist;
+#endif
void __init mem_init(void)
{
extern int ppro_with_ram_bug(void);
@@ -532,6 +538,32 @@
zap_low_mappings();
#endif

+#ifdef CONFIG_LARGE_PAGE
+ {
+ long i;
+ long j;
+ struct page *page, *map;
+
+ /*For now reserve quarter for large_pages.*/
+ lpzone_pages = (max_low_pfn >> ((LPAGE_SHIFT - PAGE_SHIFT) + 2)) ;
+ /*Will make this kernel command line. */
+ INIT_LIST_HEAD(&lpage_freelist);
+ for (i=0; i<lpzone_pages; i++) {
+ page = alloc_pages(GFP_ATOMIC, LARGE_PAGE_ORDER);
+ if (page == NULL)
+ break;
+ map = page;
+ for (j=0; j<(LPAGE_SIZE/PAGE_SIZE); j++) {
+ SetPageReserved(map);
+ map++;
+ }
+ list_add(&page->list, &lpage_freelist);
+ }
+ printk("Total Large_page memory pages allocated %ld\n", i);
+ lpzone_pages = lpagemem = i;
+ lp_max = i;
+ }
+#endif
}

/* Put this after the callers, so that it cannot be inlined */
diff -Naru linux.org/arch/i386/mm/lpage.c linux.lp/arch/i386/mm/lpage.c
--- linux.org/arch/i386/mm/lpage.c Wed Dec 31 16:00:00 1969
+++ linux.lp/arch/i386/mm/lpage.c Wed Jul 3 16:09:59 2002
@@ -0,0 +1,475 @@
+/*
+ * IA-32 Large Page Support for Kernel.
+ *
+ * Copyright (C) 2002, Rohit Seth <[email protected]>
+ */
+
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/devfs_fs_kernel.h>
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/file.h>
+#include <linux/swap.h>
+#include <linux/pagemap.h>
+#include <linux/string.h>
+#include <linux/locks.h>
+#include <linux/smp_lock.h>
+#include <linux/slab.h>
+
+#include <asm/uaccess.h>
+#include <asm/mman.h>
+
+static struct vm_operations_struct lp_vm_ops;
+struct list_head lpage_freelist;
+spinlock_t lpage_lock = SPIN_LOCK_UNLOCKED;
+extern long lpagemem;
+
+#define MAX_ID 32
+struct lpkey {
+ struct inode *in;
+ int key;
+} lpk[MAX_ID];
+
+static struct inode *
+find_key_inode(int key)
+{
+ int i;
+
+ for (i=0; i<MAX_ID; i++) {
+ if (lpk[i].key == key)
+ return (lpk[i].in);
+ }
+ return NULL;
+}
+static struct page *
+alloc_large_page(void)
+{
+ struct list_head *curr, *head;
+ struct page *page;
+
+ spin_lock(&lpage_lock);
+
+ head = &lpage_freelist;
+ curr = head->next;
+
+ if (curr == head) {
+ spin_unlock(&lpage_lock);
+ return NULL;
+ }
+ page = list_entry(curr, struct page, list);
+ list_del(curr);
+ lpagemem--;
+ spin_unlock(&lpage_lock);
+ set_page_count(page, 1);
+ memset(page_address(page), 0, LPAGE_SIZE);
+ return page;
+}
+
+static void
+free_large_page(struct page *page)
+{
+ if ((page->mapping != NULL) && (page_count(page) == 2)) {
+ struct inode *inode = page->mapping->host;
+ int i;
+
+ lru_cache_del(page);
+ remove_inode_page(page);
+ set_page_count(page, 1);
+ if ((inode->i_size -= LPAGE_SIZE) == 0) {
+ for (i=0;i<MAX_ID;i++)
+ if (lpk[i].key == inode->i_ino) {
+ lpk[i].key = 0;
+ break;
+ }
+ kfree(inode);
+ }
+ }
+ if (put_page_testzero(page)) {
+ spin_lock(&lpage_lock);
+ list_add(&page->list, &lpage_freelist);
+ lpagemem++;
+ spin_unlock(&lpage_lock);
+ }
+}
+
+static pte_t *
+lp_pte_alloc(struct mm_struct *mm, unsigned long addr)
+{
+ pgd_t *pgd;
+ pmd_t *pmd = NULL;
+
+ pgd = pgd_offset(mm, addr);
+ pmd = pmd_alloc(mm, pgd, addr);
+ return (pte_t *)pmd;
+}
+
+static pte_t *
+lp_pte_offset(struct mm_struct *mm, unsigned long addr)
+{
+ pgd_t *pgd;
+ pmd_t *pmd = NULL;
+
+ pgd =pgd_offset(mm, addr);
+ pmd = pmd_offset(pgd, addr);
+ return (pte_t *)pmd;
+}
+
+#define mk_pte_large(entry) {entry.pte_low |= (_PAGE_PRESENT | _PAGE_PSE);}
+
+static void
+set_lp_pte(struct mm_struct *mm, struct vm_area_struct *vma, struct page *page, pte_t *page_table, int write_access)
+{
+ pte_t entry;
+
+ mm->rss += (LPAGE_SIZE/PAGE_SIZE);
+ if (write_access) {
+ entry = pte_mkwrite(pte_mkdirty(mk_pte(page, vma->vm_page_prot)));
+ } else
+ entry = pte_wrprotect(mk_pte(page, vma->vm_page_prot));
+ entry = pte_mkyoung(entry);
+ mk_pte_large(entry);
+ set_pte(page_table, entry);
+ printk("VIRTUAL_ADDRESS_OF_LPAGE IS %p\n", page->virtual);
+ return;
+}
+
+static int
+anon_get_lpage(struct mm_struct *mm, struct vm_area_struct *vma, int write_access, pte_t *page_table)
+{
+ struct page *page;
+
+ page = alloc_large_page();
+ if (page == NULL)
+ return -1;
+ set_lp_pte(mm, vma, page, page_table, write_access);
+ return 1;
+}
+
+int
+make_lpages_present(unsigned long addr, unsigned long end, int flags)
+{
+ int write;
+ struct mm_struct *mm = current->mm;
+ struct vm_area_struct * vma;
+ pte_t *pte;
+
+ vma = find_vma(mm, addr);
+ if (!vma)
+ goto out_error1;
+
+ write = (vma->vm_flags & VM_WRITE) != 0;
+ if ((vma->vm_end - vma->vm_start) & (LPAGE_SIZE-1))
+ goto out_error1;
+ spin_lock(&mm->page_table_lock);
+ do {
+ pte = lp_pte_alloc(mm, addr);
+ if ((pte) && (pte_none(*pte))) {
+ if (anon_get_lpage(mm, vma,
+ write ? VM_WRITE : VM_READ, pte) == -1)
+ goto out_error;
+ } else
+ goto out_error;
+ addr += LPAGE_SIZE;
+ } while (addr < end);
+ spin_unlock(&mm->page_table_lock);
+ vma->vm_flags |= (VM_LARGEPAGE | VM_RESERVED);
+ if (flags & MAP_PRIVATE )
+ vma->vm_flags |= VM_DONTCOPY;
+ vma->vm_ops = &lp_vm_ops;
+ return 0;
+out_error: /*Error case, remove the partial lp_resources. */
+ if (addr > vma->vm_start) {
+ vma->vm_end = addr ;
+ zap_lp_resources(vma);
+ vma->vm_end = end;
+ }
+ spin_unlock(&mm->page_table_lock);
+out_error1:
+ return -1;
+}
+
+int
+copy_lpage_range(struct mm_struct *dst, struct mm_struct *src, struct vm_area_struct *vma)
+{
+ pte_t *src_pte, *dst_pte, entry;
+ struct page *ptepage;
+ unsigned long addr = vma->vm_start;
+ unsigned long end = vma->vm_end;
+
+ while (addr < end) {
+ dst_pte = lp_pte_alloc(dst, addr);
+ if (!dst_pte)
+ goto nomem;
+ src_pte = lp_pte_offset(src, addr);
+ entry = *src_pte;
+ ptepage = pte_page(entry);
+ get_page(ptepage);
+ set_pte(dst_pte, entry);
+ dst->rss += (LPAGE_SIZE/PAGE_SIZE);
+ addr += LPAGE_SIZE;
+ }
+ return 0;
+
+nomem:
+ return -ENOMEM;
+}
+int
+follow_large_page(struct mm_struct *mm, struct vm_area_struct *vma, struct page **pages, struct vm_area_struct **vmas, unsigned long *st, int *length, int i)
+{
+ pte_t *ptep, pte;
+ unsigned long start = *st;
+ unsigned long pstart;
+ int len = *length;
+ struct page *page;
+
+ do {
+ pstart = start;
+ ptep = lp_pte_offset(mm, start);
+ pte = *ptep;
+
+back1:
+ page = pte_page(pte);
+ if (pages) {
+ page += ((start & ~LPAGE_MASK) >> PAGE_SHIFT);
+ pages[i] = page;
+ page_cache_get(page);
+ }
+ if (vmas)
+ vmas[i] = vma;
+ i++;
+ len--;
+ start += PAGE_SIZE;
+ if (((start & LPAGE_MASK) == pstart) && len && (start < vma->vm_end))
+ goto back1;
+ } while (len && start < vma->vm_end);
+ *length = len;
+ *st = start;
+ return i;
+}
+
+static void
+zap_lp_resources(struct vm_area_struct *mpnt)
+{
+ struct mm_struct *mm = mpnt->vm_mm;
+ unsigned long len, addr, end;
+ pte_t *ptep;
+ struct page *page;
+
+ addr = mpnt->vm_start;
+ end = mpnt->vm_end;
+ len = end - addr;
+ do {
+ ptep = lp_pte_offset(mm, addr);
+ page = pte_page(*ptep);
+ pte_clear(ptep);
+ free_large_page(page);
+ addr += LPAGE_SIZE;
+ } while (addr < end);
+ mm->rss -= (len >> PAGE_SHIFT);
+}
+
+static void
+unlink_vma(struct vm_area_struct *mpnt)
+{
+ struct mm_struct *mm = current->mm;
+ struct vm_area_struct *vma;
+
+ vma = mm->mmap;
+ if (vma == mpnt) {
+ mm->mmap = vma->vm_next;
+ }
+ else {
+ while (vma->vm_next != mpnt) {
+ vma = vma->vm_next;
+ }
+ vma->vm_next = mpnt->vm_next;
+ }
+ rb_erase(&mpnt->vm_rb, &mm->mm_rb);
+ mm->mmap_cache = NULL;
+ mm->map_count--;
+}
+
+int
+unmap_large_pages(struct vm_area_struct *mpnt)
+{
+ struct mm_struct *mm = current->mm;
+
+ unlink_vma(mpnt);
+ spin_lock(&mm->page_table_lock);
+ zap_lp_resources(mpnt);
+ spin_unlock(&mm->page_table_lock);
+ kmem_cache_free(vm_area_cachep, mpnt);
+ return 1;
+}
+
+static struct inode *
+set_new_inode(unsigned long len, int prot, int flag, int key)
+{
+ struct inode *inode;
+ int i;
+
+ for (i=0; i<MAX_ID; i++) {
+ if (lpk[i].key == 0)
+ break;
+ }
+ if (i == MAX_ID)
+ return NULL;
+ inode = kmalloc(sizeof(struct inode), GFP_ATOMIC);
+ if (inode == NULL)
+ return NULL;
+
+ memset(inode, 0, sizeof(struct inode));
+ INIT_LIST_HEAD(&inode->i_hash);
+ inode->i_mapping = &inode->i_data;
+ inode->i_mapping->host = inode;
+ INIT_LIST_HEAD(&inode->i_data.clean_pages);
+ INIT_LIST_HEAD(&inode->i_data.dirty_pages);
+ INIT_LIST_HEAD(&inode->i_data.locked_pages);
+ spin_lock_init(&inode->i_data.i_shared_lock);
+ inode->i_ino = (unsigned long)key;
+
+ lpk[i].key = key;
+ lpk[i].in = inode;
+ inode->i_uid = current->fsuid;
+ inode->i_gid = current->fsgid;
+ inode->i_mode = prot;
+ inode->i_size = len;
+ return inode;
+}
+
+static int
+check_size_prot(struct inode *inode, unsigned long len, int prot, int flag)
+{
+ if (inode->i_uid != current->fsuid)
+ return -1;
+ if (inode->i_gid != current->fsgid)
+ return -1;
+ if (inode->i_mode != prot)
+ return -1;
+ if (inode->i_size != len)
+ return -1;
+ return 0;
+}
+
+int
+set_lp_shm_seg(int key, unsigned long *raddr, unsigned long len, int prot, int flag)
+{
+ struct mm_struct *mm = current->mm;
+ struct vm_area_struct *vma;
+ struct inode *inode;
+ struct address_space *mapping;
+ struct page *page;
+ unsigned long addr = *raddr;
+ int idx;
+ int retval = -ENOMEM;
+
+ if (len & (LPAGE_SIZE -1))
+ return -EINVAL;
+
+ inode = find_key_inode(key);
+ if (inode == NULL) {
+ if (!(flag & IPC_CREAT))
+ return -ENOENT;
+ inode = set_new_inode(len, prot, flag, key);
+ if (inode == NULL)
+ return -ENOMEM;
+ }
+ else
+ if (check_size_prot(inode, len, prot, flag) < 0)
+ return -EINVAL;
+ mapping = inode->i_mapping;
+
+ addr = do_mmap_pgoff(NULL, addr, len, (unsigned long)prot,
+ MAP_FIXED|MAP_PRIVATE | MAP_ANONYMOUS, 0);
+ if (IS_ERR((void *)addr))
+ return -ENOMEM;
+
+ vma = find_vma(mm, addr);
+ if (!vma)
+ return -EINVAL;
+
+ *raddr = addr;
+ spin_lock(&mm->page_table_lock);
+ do {
+ pte_t * pte = lp_pte_alloc(mm, addr);
+ if ((pte) && (pte_none(*pte))) {
+ idx = (addr - vma->vm_start) >> LPAGE_SHIFT;
+ page = find_get_page(mapping, idx);
+ if (page == NULL) {
+ page = alloc_large_page();
+ if (page == NULL)
+ goto out;
+ add_to_page_cache(page, mapping, idx);
+ }
+ set_lp_pte(mm, vma, page, pte, (vma->vm_flags & VM_WRITE));
+ } else
+ goto out;
+ addr += LPAGE_SIZE;
+ } while (addr < vma->vm_end);
+ retval = 0;
+ vma->vm_flags |= (VM_LARGEPAGE | VM_RESERVED);
+ vma->vm_ops = &lp_vm_ops;
+ spin_unlock(&mm->page_table_lock);
+ return retval;
+out:
+ if (addr > vma->vm_start) {
+ raddr = vma->vm_end;
+ vma->vm_end = addr;
+ zap_lp_resources(vma);
+ vma->vm_end = raddr;
+ }
+ spin_unlock(&mm->page_table_lock);
+ return retval;
+}
+
+int
+change_large_page_mem_size(int count)
+{
+ int j;
+ struct page *page, *map;
+ extern long lpzone_pages;
+ extern struct list_head lpage_freelist;
+
+ if (count == 0)
+ return (int)lpzone_pages;
+ if (count > 0) {/*Increase the mem size. */
+ while (count--) {
+ page = alloc_pages(GFP_ATOMIC, LARGE_PAGE_ORDER);
+ if (page == NULL)
+ break;
+ map = page;
+ for (j=0; j<(LPAGE_SIZE/PAGE_SIZE); j++) {
+ SetPageReserved(map);
+ map++;
+ }
+ spin_lock(&lpage_lock);
+ list_add(&page->list, &lpage_freelist);
+ lpagemem++;
+ lpzone_pages++;
+ spin_unlock(&lpage_lock);
+ }
+ return (int)lpzone_pages;
+ }
+ /*Shrink the memory size. */
+ while (count++) {
+ page = alloc_large_page();
+ if (page == NULL)
+ break;
+ spin_lock(&lpage_lock);
+ lpzone_pages--;
+ spin_unlock(&lpage_lock);
+ map = page;
+ for (j=0; j<(LPAGE_SIZE/PAGE_SIZE); j++) {
+ ClearPageReserved(map);
+ map++;
+ }
+ __free_pages(page, LARGE_PAGE_ORDER);
+ }
+ return (int)lpzone_pages;
+}
+static struct vm_operations_struct lp_vm_ops = {
+ close: zap_lp_resources,
+};
diff -Naru linux.org/fs/proc/array.c linux.lp/fs/proc/array.c
--- linux.org/fs/proc/array.c Thu Oct 11 09:00:01 2001
+++ linux.lp/fs/proc/array.c Wed Jul 3 16:59:09 2002
@@ -486,6 +486,17 @@
pgd_t *pgd = pgd_offset(mm, vma->vm_start);
int pages = 0, shared = 0, dirty = 0, total = 0;

+ if (is_vm_large_page(vma)) {
+ int num_pages = ((vma->vm_end - vma->vm_start)/PAGE_SIZE);
+ resident += num_pages;
+ if ((vma->vm_flags & VM_DONTCOPY))
+ share += num_pages;
+ if (vma->vm_flags & VM_WRITE)
+ dt += num_pages;
+ drs += num_pages;
+ vma = vma->vm_next;
+ continue;
+ }
statm_pgd_range(pgd, vma->vm_start, vma->vm_end, &pages, &shared, &dirty, &total);
resident += pages;
share += shared;
diff -Naru linux.org/fs/proc/proc_misc.c linux.lp/fs/proc/proc_misc.c
--- linux.org/fs/proc/proc_misc.c Tue Nov 20 21:29:09 2001
+++ linux.lp/fs/proc/proc_misc.c Wed Jul 3 10:48:21 2002
@@ -151,6 +151,14 @@
B(i.sharedram), B(i.bufferram),
B(pg_size), B(i.totalswap),
B(i.totalswap-i.freeswap), B(i.freeswap));
+#ifdef CONFIG_LARGE_PAGE
+ {
+ extern unsigned long lpagemem, lpzone_pages;
+ len += sprintf(page+len,"Total # of LargePages: %8lu\t\tAvailable: %8lu\n"
+ "LargePageSize: %8lu(0x%xKB)\n",
+ lpzone_pages, lpagemem, LPAGE_SIZE, (LPAGE_SIZE/1024));
+ }
+#endif
/*
* Tagged format, for easy grepping and expansion.
* The above will go away eventually, once the tools
diff -Naru linux.org/include/asm-i386/page.h linux.lp/include/asm-i386/page.h
--- linux.org/include/asm-i386/page.h Mon Feb 25 11:38:12 2002
+++ linux.lp/include/asm-i386/page.h Wed Jul 3 10:49:54 2002
@@ -41,14 +41,22 @@
typedef struct { unsigned long long pmd; } pmd_t;
typedef struct { unsigned long long pgd; } pgd_t;
#define pte_val(x) ((x).pte_low | ((unsigned long long)(x).pte_high << 32))
+#define LPAGE_SHIFT 21
#else
typedef struct { unsigned long pte_low; } pte_t;
typedef struct { unsigned long pmd; } pmd_t;
typedef struct { unsigned long pgd; } pgd_t;
#define pte_val(x) ((x).pte_low)
+#define LPAGE_SHIFT 22
#endif
#define PTE_MASK PAGE_MASK

+#ifdef CONFIG_LARGE_PAGE
+#define LPAGE_SIZE ((1UL) << LPAGE_SHIFT)
+#define LPAGE_MASK (~(LPAGE_SIZE - 1))
+#define LARGE_PAGE_ORDER (LPAGE_SHIFT - PAGE_SHIFT)
+#endif
+
typedef struct { unsigned long pgprot; } pgprot_t;

#define pmd_val(x) ((x).pmd)
diff -Naru linux.org/include/linux/mm.h linux.lp/include/linux/mm.h
--- linux.org/include/linux/mm.h Fri Dec 21 09:42:03 2001
+++ linux.lp/include/linux/mm.h Wed Jul 3 10:49:54 2002
@@ -103,6 +103,7 @@
#define VM_DONTEXPAND 0x00040000 /* Cannot expand with mremap() */
#define VM_RESERVED 0x00080000 /* Don't unmap it from swap_out */

+#define VM_LARGEPAGE 0x00400000 /* Large_Page mapping. */
#define VM_STACK_FLAGS 0x00000177

#define VM_READHINTMASK (VM_SEQ_READ | VM_RAND_READ)
@@ -425,6 +426,16 @@
int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, unsigned long start,
int len, int write, int force, struct page **pages, struct vm_area_struct **vmas);

+#ifdef CONFIG_LARGE_PAGE
+#define is_vm_large_page(vma) (vma->vm_flags & VM_LARGEPAGE)
+extern int copy_large_page(struct mm_struct *, struct mm_struct *, struct vm_area_struct *);
+extern int follow_large_page(struct mm_struct *, struct vm_area_struct *, struct page **, struct vm_area_struct **, unsigned long *, int *, int);
+#else
+#define is_vm_large_page(vma) (0)
+#define follow_large_page(mm, vma, pages, vmas, &start, &len, i) (0)
+#define copy_large_page(dst, src, vma) (0)
+#endif
+
/*
* On a two-level page table, this ends up being trivial. Thus the
* inlining and the symmetry break with pte_alloc() that does all
diff -Naru linux.org/include/linux/mmzone.h linux.lp/include/linux/mmzone.h
--- linux.org/include/linux/mmzone.h Thu Nov 22 11:46:19 2001
+++ linux.lp/include/linux/mmzone.h Wed Jul 3 10:49:54 2002
@@ -13,7 +13,7 @@
*/

#ifndef CONFIG_FORCE_MAX_ZONEORDER
-#define MAX_ORDER 10
+#define MAX_ORDER 15
#else
#define MAX_ORDER CONFIG_FORCE_MAX_ZONEORDER
#endif
diff -Naru linux.org/include/linux/sysctl.h linux.lp/include/linux/sysctl.h
--- linux.org/include/linux/sysctl.h Mon Nov 26 05:29:17 2001
+++ linux.lp/include/linux/sysctl.h Wed Jul 3 10:49:54 2002
@@ -124,6 +124,7 @@
KERN_CORE_USES_PID=52, /* int: use core or core.%pid */
KERN_TAINTED=53, /* int: various kernel tainted flags */
KERN_CADPID=54, /* int: PID of the process to notify on CAD */
+ KERN_LARGE_PAGE_MEM=55, /* Number of large_page pages configured */
};

diff -Naru linux.org/kernel/sysctl.c linux.lp/kernel/sysctl.c
--- linux.org/kernel/sysctl.c Fri Dec 21 09:42:04 2001
+++ linux.lp/kernel/sysctl.c Tue Jul 2 14:07:28 2002
@@ -96,6 +96,10 @@
extern int acct_parm[];
#endif

+#ifdef CONFIG_LARGE_PAGE
+extern int lp_max;
+extern int change_large_page_mem_size(int );
+#endif
extern int pgt_cache_water[];

static int parse_table(int *, int, void *, size_t *, void *, size_t,
@@ -256,6 +260,10 @@
{KERN_S390_USER_DEBUG_LOGGING,"userprocess_debug",
&sysctl_userprocess_debug,sizeof(int),0644,NULL,&proc_dointvec},
#endif
+#ifdef CONFIG_LARGE_PAGE
+ {KERN_LARGE_PAGE_MEM, "numlargepages", &lp_max, sizeof(int), 0644, NULL,
+ &proc_dointvec},
+#endif
{0}
};

@@ -866,6 +874,10 @@
val = -val;
buffer += len;
left -= len;
+#if CONFIG_LARGE_PAGE
+ if (i == &lp_max)
+ val = change_large_page_mem_size(val);
+#endif
switch(op) {
case OP_SET: *i = val; break;
case OP_AND: *i &= val; break;
diff -Naru linux.org/mm/memory.c linux.lp/mm/memory.c
--- linux.org/mm/memory.c Mon Feb 25 11:38:13 2002
+++ linux.lp/mm/memory.c Wed Jul 3 16:14:01 2002
@@ -179,6 +179,9 @@
unsigned long end = vma->vm_end;
unsigned long cow = (vma->vm_flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE;

+ if (is_vm_large_page(vma) )
+ return copy_lpage_range(dst, src, vma);
+
src_pgd = pgd_offset(src, address)-1;
dst_pgd = pgd_offset(dst, address)-1;

@@ -471,6 +474,10 @@
if ( !vma || (pages && vma->vm_flags & VM_IO) || !(flags & vma->vm_flags) )
return i ? : -EFAULT;

+ if (is_vm_large_page(vma)) {
+ i += follow_large_page(mm, vma, pages, vmas, &start, &len, i);
+ continue;
+ }
spin_lock(&mm->page_table_lock);
do {
struct page *map;
@@ -1360,6 +1367,8 @@
{
pgd_t *pgd;
pmd_t *pmd;
+ if (is_vm_large_page(vma) )
+ return -1;

current->state = TASK_RUNNING;
pgd = pgd_offset(mm, address);
diff -Naru linux.org/mm/mmap.c linux.lp/mm/mmap.c
--- linux.org/mm/mmap.c Mon Feb 25 11:38:14 2002
+++ linux.lp/mm/mmap.c Tue Jul 2 14:15:50 2002
@@ -917,6 +917,9 @@
if (mpnt->vm_start >= addr+len)
return 0;

+ if (is_vm_large_page(mpnt)) /*Large pages can not be unmapped like this. */
+ return -EINVAL;
+
/* If we'll make "hole", check the vm areas limit */
if ((mpnt->vm_start < addr && mpnt->vm_end > addr+len)
&& mm->map_count >= MAX_MAP_COUNT)
diff -Naru linux.org/mm/mprotect.c linux.lp/mm/mprotect.c
--- linux.org/mm/mprotect.c Mon Sep 17 15:30:23 2001
+++ linux.lp/mm/mprotect.c Tue Jul 2 14:18:13 2002
@@ -287,6 +287,8 @@
error = -EFAULT;
if (!vma || vma->vm_start > start)
goto out;
+ if (is_vm_large_page(vma))
+ return -EINVAL; /* Cann't change protections on large_page mappings. */

for (nstart = start ; ; ) {
unsigned int newflags;
diff -Naru linux.org/mm/mremap.c linux.lp/mm/mremap.c
--- linux.org/mm/mremap.c Thu Sep 20 20:31:26 2001
+++ linux.lp/mm/mremap.c Tue Jul 2 14:20:05 2002
@@ -267,6 +267,10 @@
vma = find_vma(current->mm, addr);
if (!vma || vma->vm_start > addr)
goto out;
+ if (is_vm_large_page(vma)) {
+ ret = -EINVAL; /* Cann't remap large_page mappings. */
+ goto out;
+ }
/* We can't remap across vm area boundaries */
if (old_len > vma->vm_end - addr)
goto out;

2002-08-02 00:51:31

by David Miller

[permalink] [raw]

Subject: large page patch

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