[PATCH] pagefault accounting fix

From: William Lee Irwin III <wli@holomorphy.com>

Our accounting of minor faults versus major faults is currently quite wrong.

To fix it up we need to propagate the actual fault type back to the
higher-level code.  Repurpose the currently-unused third arg to ->nopage
for this.

Documentation/filesystems/Locking

@@ -420,7 +420,7 @@ transfer:	no
 prototypes:
 	void (*open)(struct vm_area_struct*);
 	void (*close)(struct vm_area_struct*);
-	struct page *(*nopage)(struct vm_area_struct*, unsigned long, int);
+	struct page *(*nopage)(struct vm_area_struct*, unsigned long, int *);
 
 locking rules:
 		BKL	mmap_sem

arch/i386/mm/hugetlbpage.c

@@ -534,7 +534,7 @@ int is_hugepage_mem_enough(size_t size)
  * this far.
  */
 static struct page *hugetlb_nopage(struct vm_area_struct *vma,
-				unsigned long address, int unused)
+				unsigned long address, int *unused)
 {
 	BUG();
 	return NULL;

arch/ia64/ia32/binfmt_elf32.c

@@ -60,10 +60,12 @@ extern struct page *ia32_shared_page[];
 extern unsigned long *ia32_gdt;
 
 struct page *
-ia32_install_shared_page (struct vm_area_struct *vma, unsigned long address, int no_share)
+ia32_install_shared_page (struct vm_area_struct *vma, unsigned long address, int *type)
 {
 	struct page *pg = ia32_shared_page[smp_processor_id()];
 	get_page(pg);
+	if (type)
+		*type = VM_FAULT_MINOR;
 	return pg;
 }
 

arch/ia64/mm/hugetlbpage.c

@@ -518,7 +518,7 @@ int is_hugepage_mem_enough(size_t size)
 	return 1;
 }
 
-static struct page *hugetlb_nopage(struct vm_area_struct * area, unsigned long address, int unused)
+static struct page *hugetlb_nopage(struct vm_area_struct * area, unsigned long address, int *unused)
 {
 	BUG();
 	return NULL;

arch/ppc64/mm/hugetlbpage.c

@@ -921,7 +921,7 @@ int is_hugepage_mem_enough(size_t size)
  * this far.
  */
 static struct page *hugetlb_nopage(struct vm_area_struct *vma,
-				unsigned long address, int unused)
+				unsigned long address, int *unused)
 {
 	BUG();
 	return NULL;

arch/sparc64/mm/hugetlbpage.c

@@ -504,7 +504,7 @@ int is_hugepage_mem_enough(size_t size)
  * this far.
  */
 static struct page *hugetlb_nopage(struct vm_area_struct *vma,
-				   unsigned long address, int unused)
+				   unsigned long address, int *unused)
 {
 	BUG();
 	return NULL;

drivers/char/agp/alpha-agp.c

@@ -13,7 +13,7 @@
 
 static struct page *alpha_core_agp_vm_nopage(struct vm_area_struct *vma,
 					     unsigned long address,
-					     int write_access)
+					     int *type)
 {
 	alpha_agp_info *agp = agp_bridge->dev_private_data;
 	dma_addr_t dma_addr;
@@ -30,6 +30,8 @@ static struct page *alpha_core_agp_vm_nopage(struct vm_area_struct *vma,
 	 */
 	page = virt_to_page(__va(pa));
 	get_page(page);
+	if (type)
+		*type = VM_FAULT_MINOR;
 	return page;
 }
 

drivers/char/drm/drmP.h

@@ -760,16 +760,16 @@ extern int	     DRM(fasync)(int fd, struct file *filp, int on);
 				/* Mapping support (drm_vm.h) */
 extern struct page *DRM(vm_nopage)(struct vm_area_struct *vma,
 				   unsigned long address,
-				   int write_access);
+				   int *type);
 extern struct page *DRM(vm_shm_nopage)(struct vm_area_struct *vma,
 				       unsigned long address,
-				       int write_access);
+				       int *type);
 extern struct page *DRM(vm_dma_nopage)(struct vm_area_struct *vma,
 				       unsigned long address,
-				       int write_access);
+				       int *type);
 extern struct page *DRM(vm_sg_nopage)(struct vm_area_struct *vma,
 				      unsigned long address,
-				      int write_access);
+				      int *type);
 extern void	     DRM(vm_open)(struct vm_area_struct *vma);
 extern void	     DRM(vm_close)(struct vm_area_struct *vma);
 extern void	     DRM(vm_shm_close)(struct vm_area_struct *vma);

drivers/char/drm/drm_vm.h

@@ -76,7 +76,7 @@ struct vm_operations_struct   DRM(vm_sg_ops) = {
  */
 struct page *DRM(vm_nopage)(struct vm_area_struct *vma,
 			    unsigned long address,
-			    int write_access)
+			    int *type)
 {
 #if __REALLY_HAVE_AGP
 	drm_file_t *priv  = vma->vm_file->private_data;
@@ -133,6 +133,8 @@ struct page *DRM(vm_nopage)(struct vm_area_struct *vma,
 			  baddr, __va(agpmem->memory->memory[offset]), offset,
 			  atomic_read(&page->count));
 
+		if (type)
+			*type = VM_FAULT_MINOR;
 		return page;
         }
 vm_nopage_error:
@@ -154,7 +156,7 @@ struct page *DRM(vm_nopage)(struct vm_area_struct *vma,
  */
 struct page *DRM(vm_shm_nopage)(struct vm_area_struct *vma,
 				unsigned long address,
-				int write_access)
+				int *type)
 {
 	drm_map_t	 *map	 = (drm_map_t *)vma->vm_private_data;
 	unsigned long	 offset;
@@ -170,6 +172,8 @@ struct page *DRM(vm_shm_nopage)(struct vm_area_struct *vma,
 	if (!page)
 		return NOPAGE_OOM;
 	get_page(page);
+	if (type)
+		*type = VM_FAULT_MINOR;
 
 	DRM_DEBUG("shm_nopage 0x%lx\n", address);
 	return page;
@@ -268,7 +272,7 @@ void DRM(vm_shm_close)(struct vm_area_struct *vma)
  */
 struct page *DRM(vm_dma_nopage)(struct vm_area_struct *vma,
 				unsigned long address,
-				int write_access)
+				int *type)
 {
 	drm_file_t	 *priv	 = vma->vm_file->private_data;
 	drm_device_t	 *dev	 = priv->dev;
@@ -287,6 +291,8 @@ struct page *DRM(vm_dma_nopage)(struct vm_area_struct *vma,
 			     (offset & (~PAGE_MASK))));
 
 	get_page(page);
+	if (type)
+		*type = VM_FAULT_MINOR;
 
 	DRM_DEBUG("dma_nopage 0x%lx (page %lu)\n", address, page_nr);
 	return page;
@@ -304,7 +310,7 @@ struct page *DRM(vm_dma_nopage)(struct vm_area_struct *vma,
  */
 struct page *DRM(vm_sg_nopage)(struct vm_area_struct *vma,
 			       unsigned long address,
-			       int write_access)
+			       int *type)
 {
 	drm_map_t        *map    = (drm_map_t *)vma->vm_private_data;
 	drm_file_t *priv = vma->vm_file->private_data;
@@ -325,6 +331,8 @@ struct page *DRM(vm_sg_nopage)(struct vm_area_struct *vma,
 	page_offset = (offset >> PAGE_SHIFT) + (map_offset >> PAGE_SHIFT);
 	page = entry->pagelist[page_offset];
 	get_page(page);
+	if (type)
+		*type = VM_FAULT_MINOR;
 
 	return page;
 }

drivers/ieee1394/dma.c

@@ -187,7 +187,7 @@ void dma_region_sync(struct dma_region *dma, unsigned long offset, unsigned long
 /* nopage() handler for mmap access */
 
 static struct page*
-dma_region_pagefault(struct vm_area_struct *area, unsigned long address, int write_access)
+dma_region_pagefault(struct vm_area_struct *area, unsigned long address, int *type)
 {
 	unsigned long offset;
 	unsigned long kernel_virt_addr;
@@ -202,6 +202,8 @@ dma_region_pagefault(struct vm_area_struct *area, unsigned long address, int wri
 	    (address > (unsigned long) area->vm_start + (PAGE_SIZE * dma->n_pages)) )
 		goto out;
 
+	if (type)
+		*type = VM_FAULT_MINOR;
 	offset = address - area->vm_start;
 	kernel_virt_addr = (unsigned long) dma->kvirt + offset;
 	ret = vmalloc_to_page((void*) kernel_virt_addr);

drivers/media/video/video-buf.c

@@ -1078,7 +1078,7 @@ videobuf_vm_close(struct vm_area_struct *vma)
  */
 static struct page*
 videobuf_vm_nopage(struct vm_area_struct *vma, unsigned long vaddr,
-		  int write_access)
+		  int *type)
 {
 	struct page *page;
 
@@ -1090,6 +1090,8 @@ videobuf_vm_nopage(struct vm_area_struct *vma, unsigned long vaddr,
 	if (!page)
 		return NOPAGE_OOM;
 	clear_user_page(page_address(page), vaddr, page);
+	if (type)
+		*type = VM_FAULT_MINOR;
 	return page;
 }
 

drivers/scsi/sg.c

@@ -1118,7 +1118,7 @@ sg_rb_correct4mmap(Sg_scatter_hold * rsv_schp, int startFinish)
 }
 
 static struct page *
-sg_vma_nopage(struct vm_area_struct *vma, unsigned long addr, int unused)
+sg_vma_nopage(struct vm_area_struct *vma, unsigned long addr, int *type)
 {
 	Sg_fd *sfp;
 	struct page *page = NOPAGE_SIGBUS;
@@ -1158,6 +1158,8 @@ sg_vma_nopage(struct vm_area_struct *vma, unsigned long addr, int unused)
 		page = virt_to_page(page_ptr);
 		get_page(page);	/* increment page count */
 	}
+	if (type)
+		*type = VM_FAULT_MINOR;
 	return page;
 }
 

fs/ncpfs/mmap.c

@@ -26,7 +26,7 @@
  * Fill in the supplied page for mmap
  */
 static struct page* ncp_file_mmap_nopage(struct vm_area_struct *area,
-				     unsigned long address, int write_access)
+				     unsigned long address, int *type)
 {
 	struct file *file = area->vm_file;
 	struct dentry *dentry = file->f_dentry;
@@ -85,6 +85,15 @@ static struct page* ncp_file_mmap_nopage(struct vm_area_struct *area,
 		memset(pg_addr + already_read, 0, PAGE_SIZE - already_read);
 	flush_dcache_page(page);
 	kunmap(page);
+
+	/*
+	 * If I understand ncp_read_kernel() properly, the above always
+	 * fetches from the network, here the analogue of disk.
+	 * -- wli
+	 */
+	if (type)
+		*type = VM_FAULT_MAJOR;
+	inc_page_state(pgmajfault);
 	return page;
 }
 

include/linux/mm.h

@@ -143,7 +143,7 @@ extern pgprot_t protection_map[16];
 struct vm_operations_struct {
 	void (*open)(struct vm_area_struct * area);
 	void (*close)(struct vm_area_struct * area);
-	struct page * (*nopage)(struct vm_area_struct * area, unsigned long address, int unused);
+	struct page * (*nopage)(struct vm_area_struct * area, unsigned long address, int *type);
 	int (*populate)(struct vm_area_struct * area, unsigned long address, unsigned long len, pgprot_t prot, unsigned long pgoff, int nonblock);
 };
 
@@ -407,7 +407,7 @@ static inline int page_mapped(struct page *page)
 extern void show_free_areas(void);
 
 struct page *shmem_nopage(struct vm_area_struct * vma,
-			unsigned long address, int unused);
+			unsigned long address, int *type);
 struct file *shmem_file_setup(char * name, loff_t size, unsigned long flags);
 void shmem_lock(struct file * file, int lock);
 int shmem_zero_setup(struct vm_area_struct *);
@@ -565,7 +565,7 @@ extern unsigned long page_unuse(struct page *);
 extern void truncate_inode_pages(struct address_space *, loff_t);
 
 /* generic vm_area_ops exported for stackable file systems */
-extern struct page *filemap_nopage(struct vm_area_struct *, unsigned long, int);
+struct page *filemap_nopage(struct vm_area_struct *, unsigned long, int *);
 
 /* mm/page-writeback.c */
 int write_one_page(struct page *page, int wait);

kernel/sys.c

@@ -1323,8 +1323,6 @@ asmlinkage long sys_setrlimit(unsigned int resource, struct rlimit __user *rlim)
  * either stopped or zombied.  In the zombied case the task won't get
  * reaped till shortly after the call to getrusage(), in both cases the
  * task being examined is in a frozen state so the counters won't change.
- *
- * FIXME! Get the fault counts properly!
  */
 int getrusage(struct task_struct *p, int who, struct rusage __user *ru)
 {

mm/filemap.c

@@ -990,7 +990,7 @@ static int page_cache_read(struct file * file, unsigned long offset)
  * it in the page cache, and handles the special cases reasonably without
  * having a lot of duplicated code.
  */
-struct page * filemap_nopage(struct vm_area_struct * area, unsigned long address, int unused)
+struct page * filemap_nopage(struct vm_area_struct * area, unsigned long address, int *type)
 {
 	int error;
 	struct file *file = area->vm_file;
@@ -999,7 +999,7 @@ struct page * filemap_nopage(struct vm_area_struct * area, unsigned long address
 	struct inode *inode = mapping->host;
 	struct page *page;
 	unsigned long size, pgoff, endoff;
-	int did_readaround = 0;
+	int did_readaround = 0, majmin = VM_FAULT_MINOR;
 
 	pgoff = ((address - area->vm_start) >> PAGE_CACHE_SHIFT) + area->vm_pgoff;
 	endoff = ((area->vm_end - area->vm_start) >> PAGE_CACHE_SHIFT) + area->vm_pgoff;
@@ -1048,6 +1048,14 @@ struct page * filemap_nopage(struct vm_area_struct * area, unsigned long address
 		if (ra->mmap_miss > ra->mmap_hit + MMAP_LOTSAMISS)
 			goto no_cached_page;
 
+		/*
+		 * To keep the pgmajfault counter straight, we need to
+		 * check did_readaround, as this is an inner loop.
+		 */
+		if (!did_readaround) {
+			majmin = VM_FAULT_MAJOR;
+			inc_page_state(pgmajfault);
+		}
 		did_readaround = 1;
 		do_page_cache_readahead(mapping, file,
 				pgoff & ~(MMAP_READAROUND-1), MMAP_READAROUND);
@@ -1069,6 +1077,8 @@ struct page * filemap_nopage(struct vm_area_struct * area, unsigned long address
 	 * Found the page and have a reference on it.
 	 */
 	mark_page_accessed(page);
+	if (type)
+		*type = majmin;
 	return page;
 
 outside_data_content:
@@ -1104,7 +1114,10 @@ struct page * filemap_nopage(struct vm_area_struct * area, unsigned long address
 	return NULL;
 
 page_not_uptodate:
-	inc_page_state(pgmajfault);
+	if (!did_readaround) {
+		majmin = VM_FAULT_MAJOR;
+		inc_page_state(pgmajfault);
+	}
 	lock_page(page);
 
 	/* Did it get unhashed while we waited for it? */

mm/memory.c

@@ -1400,7 +1400,7 @@ do_no_page(struct mm_struct *mm, struct vm_area_struct *vma,
 	pte_t entry;
 	struct pte_chain *pte_chain;
 	int sequence = 0;
-	int ret;
+	int ret = VM_FAULT_MINOR;
 
 	if (!vma->vm_ops || !vma->vm_ops->nopage)
 		return do_anonymous_page(mm, vma, page_table,
@@ -1414,7 +1414,7 @@ do_no_page(struct mm_struct *mm, struct vm_area_struct *vma,
 	}
 	smp_rmb();  /* Prevent CPU from reordering lock-free ->nopage() */
 retry:
-	new_page = vma->vm_ops->nopage(vma, address & PAGE_MASK, 0);
+	new_page = vma->vm_ops->nopage(vma, address & PAGE_MASK, &ret);
 
 	/* no page was available -- either SIGBUS or OOM */
 	if (new_page == NOPAGE_SIGBUS)
@@ -1483,14 +1483,12 @@ do_no_page(struct mm_struct *mm, struct vm_area_struct *vma,
 		pte_unmap(page_table);
 		page_cache_release(new_page);
 		spin_unlock(&mm->page_table_lock);
-		ret = VM_FAULT_MINOR;
 		goto out;
 	}
 
 	/* no need to invalidate: a not-present page shouldn't be cached */
 	update_mmu_cache(vma, address, entry);
 	spin_unlock(&mm->page_table_lock);
-	ret = VM_FAULT_MAJOR;
 	goto out;
 oom:
 	ret = VM_FAULT_OOM;

mm/shmem.c

@@ -71,7 +71,7 @@ enum sgp_type {
 };
 
 static int shmem_getpage(struct inode *inode, unsigned long idx,
-			 struct page **pagep, enum sgp_type sgp);
+			 struct page **pagep, enum sgp_type sgp, int *type);
 
 static inline struct page *shmem_dir_alloc(unsigned int gfp_mask)
 {
@@ -540,7 +540,7 @@ static int shmem_notify_change(struct dentry *dentry, struct iattr *attr)
 			if (attr->ia_size & (PAGE_CACHE_SIZE-1)) {
 				(void) shmem_getpage(inode,
 					attr->ia_size>>PAGE_CACHE_SHIFT,
-						&page, SGP_READ);
+						&page, SGP_READ, NULL);
 			}
 			/*
 			 * Reset SHMEM_PAGEIN flag so that shmem_truncate can
@@ -765,7 +765,7 @@ static int shmem_writepage(struct page *page, struct writeback_control *wbc)
  * vm. If we swap it in we mark it dirty since we also free the swap
  * entry since a page cannot live in both the swap and page cache
  */
-static int shmem_getpage(struct inode *inode, unsigned long idx, struct page **pagep, enum sgp_type sgp)
+static int shmem_getpage(struct inode *inode, unsigned long idx, struct page **pagep, enum sgp_type sgp, int *type)
 {
 	struct address_space *mapping = inode->i_mapping;
 	struct shmem_inode_info *info = SHMEM_I(inode);
@@ -774,7 +774,7 @@ static int shmem_getpage(struct inode *inode, unsigned long idx, struct page **p
 	struct page *swappage;
 	swp_entry_t *entry;
 	swp_entry_t swap;
-	int error;
+	int error, majmin = VM_FAULT_MINOR;
 
 	if (idx >= SHMEM_MAX_INDEX)
 		return -EFBIG;
@@ -811,6 +811,10 @@ static int shmem_getpage(struct inode *inode, unsigned long idx, struct page **p
 		if (!swappage) {
 			shmem_swp_unmap(entry);
 			spin_unlock(&info->lock);
+			/* here we actually do the io */
+			if (majmin == VM_FAULT_MINOR && type)
+				inc_page_state(pgmajfault);
+			majmin = VM_FAULT_MAJOR;
 			swapin_readahead(swap);
 			swappage = read_swap_cache_async(swap);
 			if (!swappage) {
@@ -959,6 +963,8 @@ static int shmem_getpage(struct inode *inode, unsigned long idx, struct page **p
 		} else
 			*pagep = ZERO_PAGE(0);
 	}
+	if (type)
+		*type = majmin;
 	return 0;
 
 failed:
@@ -969,7 +975,7 @@ static int shmem_getpage(struct inode *inode, unsigned long idx, struct page **p
 	return error;
 }
 
-struct page *shmem_nopage(struct vm_area_struct *vma, unsigned long address, int unused)
+struct page *shmem_nopage(struct vm_area_struct *vma, unsigned long address, int *type)
 {
 	struct inode *inode = vma->vm_file->f_dentry->d_inode;
 	struct page *page = NULL;
@@ -980,7 +986,7 @@ struct page *shmem_nopage(struct vm_area_struct *vma, unsigned long address, int
 	idx += vma->vm_pgoff;
 	idx >>= PAGE_CACHE_SHIFT - PAGE_SHIFT;
 
-	error = shmem_getpage(inode, idx, &page, SGP_CACHE);
+	error = shmem_getpage(inode, idx, &page, SGP_CACHE, type);
 	if (error)
 		return (error == -ENOMEM)? NOPAGE_OOM: NOPAGE_SIGBUS;
 
@@ -1007,7 +1013,7 @@ static int shmem_populate(struct vm_area_struct *vma,
 		/*
 		 * Will need changing if PAGE_CACHE_SIZE != PAGE_SIZE
 		 */
-		err = shmem_getpage(inode, pgoff, &page, sgp);
+		err = shmem_getpage(inode, pgoff, &page, sgp, NULL);
 		if (err)
 			return err;
 		if (page) {
@@ -1157,7 +1163,7 @@ static int
 shmem_prepare_write(struct file *file, struct page *page, unsigned offset, unsigned to)
 {
 	struct inode *inode = page->mapping->host;
-	return shmem_getpage(inode, page->index, &page, SGP_WRITE);
+	return shmem_getpage(inode, page->index, &page, SGP_WRITE, NULL);
 }
 
 static ssize_t
@@ -1214,7 +1220,7 @@ shmem_file_write(struct file *file, const char __user *buf, size_t count, loff_t
 		 * But it still may be a good idea to prefault below.
 		 */
 
-		err = shmem_getpage(inode, index, &page, SGP_WRITE);
+		err = shmem_getpage(inode, index, &page, SGP_WRITE, NULL);
 		if (err)
 			break;
 
@@ -1296,7 +1302,7 @@ static void do_shmem_file_read(struct file *filp, loff_t *ppos, read_descriptor_
 				break;
 		}
 
-		desc->error = shmem_getpage(inode, index, &page, SGP_READ);
+		desc->error = shmem_getpage(inode, index, &page, SGP_READ, NULL);
 		if (desc->error) {
 			if (desc->error == -EINVAL)
 				desc->error = 0;
@@ -1552,7 +1558,7 @@ static int shmem_symlink(struct inode *dir, struct dentry *dentry, const char *s
 			iput(inode);
 			return -ENOMEM;
 		}
-		error = shmem_getpage(inode, 0, &page, SGP_WRITE);
+		error = shmem_getpage(inode, 0, &page, SGP_WRITE, NULL);
 		if (error) {
 			vm_unacct_memory(VM_ACCT(1));
 			iput(inode);
@@ -1590,7 +1596,7 @@ static int shmem_follow_link_inline(struct dentry *dentry, struct nameidata *nd)
 static int shmem_readlink(struct dentry *dentry, char __user *buffer, int buflen)
 {
 	struct page *page = NULL;
-	int res = shmem_getpage(dentry->d_inode, 0, &page, SGP_READ);
+	int res = shmem_getpage(dentry->d_inode, 0, &page, SGP_READ, NULL);
 	if (res)
 		return res;
 	res = vfs_readlink(dentry, buffer, buflen, kmap(page));
@@ -1603,7 +1609,7 @@ static int shmem_readlink(struct dentry *dentry, char __user *buffer, int buflen
 static int shmem_follow_link(struct dentry *dentry, struct nameidata *nd)
 {
 	struct page *page = NULL;
-	int res = shmem_getpage(dentry->d_inode, 0, &page, SGP_READ);
+	int res = shmem_getpage(dentry->d_inode, 0, &page, SGP_READ, NULL);
 	if (res)
 		return res;
 	res = vfs_follow_link(nd, kmap(page));

sound/core/pcm_native.c

@@ -2779,7 +2779,7 @@ unsigned int snd_pcm_capture_poll(struct file *file, poll_table * wait)
 	return mask;
 }
 
-static struct page * snd_pcm_mmap_status_nopage(struct vm_area_struct *area, unsigned long address, int no_share)
+static struct page * snd_pcm_mmap_status_nopage(struct vm_area_struct *area, unsigned long address, int *type)
 {
 	snd_pcm_substream_t *substream = (snd_pcm_substream_t *)area->vm_private_data;
 	snd_pcm_runtime_t *runtime;
@@ -2791,6 +2791,8 @@ static struct page * snd_pcm_mmap_status_nopage(struct vm_area_struct *area, uns
 	page = virt_to_page(runtime->status);
 	if (!PageReserved(page))
 		get_page(page);
+	if (type)
+		*type = VM_FAULT_MINOR;
 	return page;
 }
 
@@ -2817,7 +2819,7 @@ int snd_pcm_mmap_status(snd_pcm_substream_t *substream, struct file *file,
 	return 0;
 }
 
-static struct page * snd_pcm_mmap_control_nopage(struct vm_area_struct *area, unsigned long address, int no_share)
+static struct page * snd_pcm_mmap_control_nopage(struct vm_area_struct *area, unsigned long address, int *type)
 {
 	snd_pcm_substream_t *substream = (snd_pcm_substream_t *)area->vm_private_data;
 	snd_pcm_runtime_t *runtime;
@@ -2829,6 +2831,8 @@ static struct page * snd_pcm_mmap_control_nopage(struct vm_area_struct *area, un
 	page = virt_to_page(runtime->control);
 	if (!PageReserved(page))
 		get_page(page);
+	if (type)
+		*type = VM_FAULT_MINOR;
 	return page;
 }
 
@@ -2867,7 +2871,7 @@ static void snd_pcm_mmap_data_close(struct vm_area_struct *area)
 	atomic_dec(&substream->runtime->mmap_count);
 }
 
-static struct page * snd_pcm_mmap_data_nopage(struct vm_area_struct *area, unsigned long address, int no_share)
+static struct page * snd_pcm_mmap_data_nopage(struct vm_area_struct *area, unsigned long address, int *type)
 {
 	snd_pcm_substream_t *substream = (snd_pcm_substream_t *)area->vm_private_data;
 	snd_pcm_runtime_t *runtime;
@@ -2895,6 +2899,8 @@ static struct page * snd_pcm_mmap_data_nopage(struct vm_area_struct *area, unsig
 	}
 	if (!PageReserved(page))
 		get_page(page);
+	if (type)
+		*type = VM_FAULT_MINOR;
 	return page;
 }
 

sound/oss/emu10k1/audio.c

@@ -989,7 +989,7 @@ static int emu10k1_audio_ioctl(struct inode *inode, struct file *file, unsigned
 	return 0;
 }
 
-static struct page *emu10k1_mm_nopage (struct vm_area_struct * vma, unsigned long address, int write_access)
+static struct page *emu10k1_mm_nopage (struct vm_area_struct * vma, unsigned long address, int *type)
 {
 	struct emu10k1_wavedevice *wave_dev = vma->vm_private_data;
 	struct woinst *woinst = wave_dev->woinst;
@@ -1032,6 +1032,8 @@ static struct page *emu10k1_mm_nopage (struct vm_area_struct * vma, unsigned lon
 	get_page (dmapage);
 
 	DPD(3, "page: %#lx\n", (unsigned long) dmapage);
+	if (type)
+		*type = VM_FAULT_MINOR;
 	return dmapage;
 }
 

sound/oss/via82cxxx_audio.c

@@ -2116,7 +2116,7 @@ static void via_dsp_cleanup (struct via_info *card)
 
 
 static struct page * via_mm_nopage (struct vm_area_struct * vma,
-				    unsigned long address, int write_access)
+				    unsigned long address, int *type)
 {
 	struct via_info *card = vma->vm_private_data;
 	struct via_channel *chan = &card->ch_out;
@@ -2124,12 +2124,11 @@ static struct page * via_mm_nopage (struct vm_area_struct * vma,
 	unsigned long pgoff;
 	int rd, wr;
 
-	DPRINTK ("ENTER, start %lXh, ofs %lXh, pgoff %ld, addr %lXh, wr %d\n",
+	DPRINTK ("ENTER, start %lXh, ofs %lXh, pgoff %ld, addr %lXh\n",
 		 vma->vm_start,
 		 address - vma->vm_start,
 		 (address - vma->vm_start) >> PAGE_SHIFT,
-		 address,
-		 write_access);
+		 address);
 
         if (address > vma->vm_end) {
 		DPRINTK ("EXIT, returning NOPAGE_SIGBUS\n");
@@ -2167,6 +2166,8 @@ static struct page * via_mm_nopage (struct vm_area_struct * vma,
 	DPRINTK ("EXIT, returning page %p for cpuaddr %lXh\n",
 		 dmapage, (unsigned long) chan->pgtbl[pgoff].cpuaddr);
 	get_page (dmapage);
+	if (type)
+		*type = VM_FAULT_MINOR;
 	return dmapage;
 }