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* [RFC] State of ru_majflt
@ 2003-10-13 16:51 ` Roger Luethi
  0 siblings, 0 replies; 6+ messages in thread
From: Roger Luethi @ 2003-10-13 16:51 UTC (permalink / raw)
  To: linux-kernel, linux-mm

The ru_majflt field of struct rusage doesn't return major page faults --
pages retrieved from cache are counted as well. POSIX and Linux man pages
don't seem to cover that particular field, but the values returned are
neither what BSD (where Linux got its copy of the struct from) does nor
what the field name suggests.

A proper solution would probably have filemap_nopage tell its caller the
correct return code. Is this considered a bug or is it a documentation
issue? How much do we care?

Roger

^ permalink raw reply	[flat|nested] 6+ messages in thread
* [RFC] State of ru_majflt
@ 2003-10-13 16:51 ` Roger Luethi
  0 siblings, 0 replies; 6+ messages in thread
From: Roger Luethi @ 2003-10-13 16:51 UTC (permalink / raw)
  To: linux-kernel, linux-mm

The ru_majflt field of struct rusage doesn't return major page faults --
pages retrieved from cache are counted as well. POSIX and Linux man pages
don't seem to cover that particular field, but the values returned are
neither what BSD (where Linux got its copy of the struct from) does nor
what the field name suggests.

A proper solution would probably have filemap_nopage tell its caller the
correct return code. Is this considered a bug or is it a documentation
issue? How much do we care?

Roger
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
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Don't email: <a href=mailto:"aart@kvack.org"> aart@kvack.org </a>

^ permalink raw reply	[flat|nested] 6+ messages in thread
* Re: [RFC] State of ru_majflt
  2003-10-13 16:51 ` Roger Luethi
@ 2003-10-13 18:51   ` Rik van Riel
  -1 siblings, 0 replies; 6+ messages in thread
From: Rik van Riel @ 2003-10-13 18:51 UTC (permalink / raw)
  To: Roger Luethi; +Cc: linux-kernel, linux-mm

On Mon, 13 Oct 2003, Roger Luethi wrote:

> A proper solution would probably have filemap_nopage tell its caller the
> correct return code.

Agreed.

> Is this considered a bug or is it a documentation issue? How much do we
> care?

It's a bug, but I'm not quite sure how much we care.

Rik
-- 
"Debugging is twice as hard as writing the code in the first place.
Therefore, if you write the code as cleverly as possible, you are,
by definition, not smart enough to debug it." - Brian W. Kernighan

^ permalink raw reply	[flat|nested] 6+ messages in thread
* Re: [RFC] State of ru_majflt
@ 2003-10-13 18:51   ` Rik van Riel
  0 siblings, 0 replies; 6+ messages in thread
From: Rik van Riel @ 2003-10-13 18:51 UTC (permalink / raw)
  To: Roger Luethi; +Cc: linux-kernel, linux-mm

On Mon, 13 Oct 2003, Roger Luethi wrote:

> A proper solution would probably have filemap_nopage tell its caller the
> correct return code.

Agreed.

> Is this considered a bug or is it a documentation issue? How much do we
> care?

It's a bug, but I'm not quite sure how much we care.

Rik
-- 
"Debugging is twice as hard as writing the code in the first place.
Therefore, if you write the code as cleverly as possible, you are,
by definition, not smart enough to debug it." - Brian W. Kernighan
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"aart@kvack.org"> aart@kvack.org </a>

^ permalink raw reply	[flat|nested] 6+ messages in thread
* Re: [RFC] State of ru_majflt
  2003-10-13 16:51 ` Roger Luethi
@ 2003-10-13 23:59   ` William Lee Irwin III
  -1 siblings, 0 replies; 6+ messages in thread
From: William Lee Irwin III @ 2003-10-13 23:59 UTC (permalink / raw)
  To: linux-kernel, linux-mm

On Mon, Oct 13, 2003 at 06:51:04PM +0200, Roger Luethi wrote:
> The ru_majflt field of struct rusage doesn't return major page faults --
> pages retrieved from cache are counted as well. POSIX and Linux man pages
> don't seem to cover that particular field, but the values returned are
> neither what BSD (where Linux got its copy of the struct from) does nor
> what the field name suggests.
> A proper solution would probably have filemap_nopage tell its caller the
> correct return code. Is this considered a bug or is it a documentation
> issue? How much do we care?

Not sure. It does say "FIXME". A quick grep for "nopage" turns up
something like this, which hijacks the currently-unused arguemnt.
Untested (not even compiletested). vs. 2.6.0-test7-bkrecent

I tried to straighten out the do_page_cache_readahead() vs. pgmajfault
business in mm/filemap.c too. I have to wonder if hoisting the increment
to do_no_page() would be in order. do_file_page() probably needs a
similar treatment. filemap_nopage. If anyone calls ->nopage() explicitly
in non-fault c it'll increment pgmajfault when it shouldn't; that would
be automatically resolved by hoisting it into do_no_page().


-- wli


===== Documentation/filesystems/Locking 1.45 vs edited =====
--- 1.45/Documentation/filesystems/Locking	Wed Aug 20 22:31:59 2003
+++ edited/Documentation/filesystems/Locking	Mon Oct 13 15:13:40 2003
@@ -420,7 +420,7 @@
 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 1.38 vs edited =====
--- 1.38/arch/i386/mm/hugetlbpage.c	Tue Sep 23 23:15:29 2003
+++ edited/arch/i386/mm/hugetlbpage.c	Mon Oct 13 15:14:10 2003
@@ -529,7 +529,7 @@
  * 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 1.15 vs edited =====
--- 1.15/arch/ia64/ia32/binfmt_elf32.c	Mon Jul 21 07:39:59 2003
+++ edited/arch/ia64/ia32/binfmt_elf32.c	Mon Oct 13 15:15:42 2003
@@ -60,11 +60,13 @@
 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[(address - vma->vm_start)/PAGE_SIZE];
 
 	get_page(pg);
+	if (type)
+		*type = VM_FAULT_MINOR;
 	return pg;
 }
 
===== arch/ia64/mm/hugetlbpage.c 1.15 vs edited =====
--- 1.15/arch/ia64/mm/hugetlbpage.c	Thu Oct  9 16:09:37 2003
+++ edited/arch/ia64/mm/hugetlbpage.c	Mon Oct 13 15:15:53 2003
@@ -518,7 +518,7 @@
 	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 1.2 vs edited =====
--- 1.2/arch/ppc64/mm/hugetlbpage.c	Sat Sep  6 18:40:37 2003
+++ edited/arch/ppc64/mm/hugetlbpage.c	Mon Oct 13 16:16:04 2003
@@ -914,7 +914,7 @@
  * 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 1.8 vs edited =====
--- 1.8/arch/sparc64/mm/hugetlbpage.c	Tue Aug 26 09:41:27 2003
+++ edited/arch/sparc64/mm/hugetlbpage.c	Mon Oct 13 15:16:38 2003
@@ -433,7 +433,7 @@
 }
 
 static struct page *
-hugetlb_nopage(struct vm_area_struct *vma, unsigned long address, int unused)
+hugetlb_nopage(struct vm_area_struct *vma, unsigned long address, int *unused)
 {
 	BUG();
 	return NULL;
===== drivers/char/agp/alpha-agp.c 1.9 vs edited =====
--- 1.9/drivers/char/agp/alpha-agp.c	Mon Sep 15 17:03:51 2003
+++ edited/drivers/char/agp/alpha-agp.c	Mon Oct 13 15:17:14 2003
@@ -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 @@
 	 */
 	page = virt_to_page(__va(pa));
 	get_page(page);
+	if (type)
+		*type = VM_FAULT_MINOR;
 	return page;
 }
 
===== drivers/char/drm/drmP.h 1.29 vs edited =====
--- 1.29/drivers/char/drm/drmP.h	Thu Sep 25 08:56:58 2003
+++ edited/drivers/char/drm/drmP.h	Mon Oct 13 15:17:38 2003
@@ -760,16 +760,16 @@
 				/* 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 1.25 vs edited =====
--- 1.25/drivers/char/drm/drm_vm.h	Thu Jul 10 23:18:01 2003
+++ edited/drivers/char/drm/drm_vm.h	Mon Oct 13 16:48:08 2003
@@ -76,7 +76,7 @@
  */
 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 @@
 			  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_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 @@
 	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 @@
  */
 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 @@
 			     (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_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 @@
 	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 1.5 vs edited =====
--- 1.5/drivers/ieee1394/dma.c	Thu Jul 24 17:00:00 2003
+++ edited/drivers/ieee1394/dma.c	Mon Oct 13 15:19:12 2003
@@ -187,7 +187,7 @@
 /* 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 @@
 	    (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 1.11 vs edited =====
--- 1.11/drivers/media/video/video-buf.c	Mon Oct  6 08:48:02 2003
+++ edited/drivers/media/video/video-buf.c	Mon Oct 13 15:19:52 2003
@@ -1076,7 +1076,7 @@
  */
 static struct page*
 videobuf_vm_nopage(struct vm_area_struct *vma, unsigned long vaddr,
-		  int write_access)
+		  int *type)
 {
 	struct page *page;
 
@@ -1088,6 +1088,8 @@
 	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 1.69 vs edited =====
--- 1.69/drivers/scsi/sg.c	Sat Sep 20 02:35:07 2003
+++ edited/drivers/scsi/sg.c	Mon Oct 13 15:21:16 2003
@@ -1115,7 +1115,7 @@
 }
 
 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;
@@ -1155,6 +1155,8 @@
 		page = virt_to_page(page_ptr);
 		get_page(page);	/* increment page count */
 	}
+	if (type)
+		*type = VM_FAULT_MINOR;
 	return page;
 }
 
===== fs/ncpfs/mmap.c 1.7 vs edited =====
--- 1.7/fs/ncpfs/mmap.c	Sat Aug 10 20:07:55 2002
+++ edited/fs/ncpfs/mmap.c	Mon Oct 13 16:23:56 2003
@@ -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 @@
 		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 1.133 vs edited =====
--- 1.133/include/linux/mm.h	Sun Oct  5 01:07:49 2003
+++ edited/include/linux/mm.h	Mon Oct 13 16:31:00 2003
@@ -143,7 +143,7 @@
 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);
 };
 
@@ -405,7 +405,7 @@
 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 *);
@@ -563,7 +563,7 @@
 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 1.66 vs edited =====
--- 1.66/kernel/sys.c	Thu Oct  9 15:13:54 2003
+++ edited/kernel/sys.c	Mon Oct 13 16:02:41 2003
@@ -1325,8 +1325,6 @@
  * 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 1.210 vs edited =====
--- 1.210/mm/filemap.c	Tue Oct  7 19:53:43 2003
+++ edited/mm/filemap.c	Mon Oct 13 16:25:46 2003
@@ -984,7 +984,7 @@
  * 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;
@@ -993,7 +993,7 @@
 	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;
@@ -1042,6 +1042,14 @@
 		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);
@@ -1063,6 +1071,8 @@
 	 * Found the page and have a reference on it.
 	 */
 	mark_page_accessed(page);
+	if (type)
+		*type = majmin;
 	return page;
 
 outside_data_content:
@@ -1098,7 +1108,10 @@
 	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 1.139 vs edited =====
--- 1.139/mm/memory.c	Wed Oct  8 08:59:27 2003
+++ edited/mm/memory.c	Mon Oct 13 15:44:10 2003
@@ -1416,7 +1416,7 @@
 	}
 	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)
@@ -1485,14 +1485,12 @@
 		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 1.135 vs edited =====
--- 1.135/mm/shmem.c	Tue Sep  9 23:41:41 2003
+++ edited/mm/shmem.c	Mon Oct 13 16:30:00 2003
@@ -67,7 +67,7 @@
 };
 
 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)
 {
@@ -522,7 +522,7 @@
 			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);
 			}
 		}
 	}
@@ -734,7 +734,7 @@
  * 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);
@@ -743,7 +743,7 @@
 	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;
@@ -780,6 +780,10 @@
 		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) {
@@ -926,6 +930,8 @@
 		} else
 			*pagep = ZERO_PAGE(0);
 	}
+	if (type)
+		*type = majmin;
 	return 0;
 
 failed:
@@ -936,7 +942,7 @@
 	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;
@@ -947,7 +953,7 @@
 	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;
 
@@ -974,7 +980,7 @@
 		/*
 		 * 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) {
@@ -1124,7 +1130,7 @@
 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
@@ -1181,7 +1187,7 @@
 		 * 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;
 
@@ -1264,7 +1270,7 @@
 				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;
@@ -1515,7 +1521,7 @@
 			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);
@@ -1551,7 +1557,7 @@
 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));
@@ -1564,7 +1570,7 @@
 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 1.41 vs edited =====
--- 1.41/sound/core/pcm_native.c	Mon Sep 29 19:28:26 2003
+++ edited/sound/core/pcm_native.c	Mon Oct 13 15:44:41 2003
@@ -2779,7 +2779,7 @@
 	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 @@
 	page = virt_to_page(runtime->status);
 	if (!PageReserved(page))
 		get_page(page);
+	if (type)
+		*type = VM_FAULT_MINOR;
 	return page;
 }
 
===== sound/oss/via82cxxx_audio.c 1.34 vs edited =====
--- 1.34/sound/oss/via82cxxx_audio.c	Sun Oct  5 01:07:55 2003
+++ edited/sound/oss/via82cxxx_audio.c	Mon Oct 13 15:53:34 2003
@@ -2116,7 +2116,7 @@
 
 
 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 @@
 	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 @@
 	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;
 }
 
===== sound/oss/emu10k1/audio.c 1.19 vs edited =====
--- 1.19/sound/oss/emu10k1/audio.c	Tue Aug 26 09:25:41 2003
+++ edited/sound/oss/emu10k1/audio.c	Mon Oct 13 15:52:23 2003
@@ -989,7 +989,7 @@
 	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 @@
 	get_page (dmapage);
 
 	DPD(3, "page: %#lx\n", (unsigned long) dmapage);
+	if (type)
+		*type = VM_FAULT_MINOR;
 	return dmapage;
 }
 

^ permalink raw reply	[flat|nested] 6+ messages in thread
* Re: [RFC] State of ru_majflt
@ 2003-10-13 23:59   ` William Lee Irwin III
  0 siblings, 0 replies; 6+ messages in thread
From: William Lee Irwin III @ 2003-10-13 23:59 UTC (permalink / raw)
  To: linux-kernel, linux-mm

On Mon, Oct 13, 2003 at 06:51:04PM +0200, Roger Luethi wrote:
> The ru_majflt field of struct rusage doesn't return major page faults --
> pages retrieved from cache are counted as well. POSIX and Linux man pages
> don't seem to cover that particular field, but the values returned are
> neither what BSD (where Linux got its copy of the struct from) does nor
> what the field name suggests.
> A proper solution would probably have filemap_nopage tell its caller the
> correct return code. Is this considered a bug or is it a documentation
> issue? How much do we care?

Not sure. It does say "FIXME". A quick grep for "nopage" turns up
something like this, which hijacks the currently-unused arguemnt.
Untested (not even compiletested). vs. 2.6.0-test7-bkrecent

I tried to straighten out the do_page_cache_readahead() vs. pgmajfault
business in mm/filemap.c too. I have to wonder if hoisting the increment
to do_no_page() would be in order. do_file_page() probably needs a
similar treatment. filemap_nopage. If anyone calls ->nopage() explicitly
in non-fault c it'll increment pgmajfault when it shouldn't; that would
be automatically resolved by hoisting it into do_no_page().


-- wli


===== Documentation/filesystems/Locking 1.45 vs edited =====
--- 1.45/Documentation/filesystems/Locking	Wed Aug 20 22:31:59 2003
+++ edited/Documentation/filesystems/Locking	Mon Oct 13 15:13:40 2003
@@ -420,7 +420,7 @@
 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 1.38 vs edited =====
--- 1.38/arch/i386/mm/hugetlbpage.c	Tue Sep 23 23:15:29 2003
+++ edited/arch/i386/mm/hugetlbpage.c	Mon Oct 13 15:14:10 2003
@@ -529,7 +529,7 @@
  * 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 1.15 vs edited =====
--- 1.15/arch/ia64/ia32/binfmt_elf32.c	Mon Jul 21 07:39:59 2003
+++ edited/arch/ia64/ia32/binfmt_elf32.c	Mon Oct 13 15:15:42 2003
@@ -60,11 +60,13 @@
 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[(address - vma->vm_start)/PAGE_SIZE];
 
 	get_page(pg);
+	if (type)
+		*type = VM_FAULT_MINOR;
 	return pg;
 }
 
===== arch/ia64/mm/hugetlbpage.c 1.15 vs edited =====
--- 1.15/arch/ia64/mm/hugetlbpage.c	Thu Oct  9 16:09:37 2003
+++ edited/arch/ia64/mm/hugetlbpage.c	Mon Oct 13 15:15:53 2003
@@ -518,7 +518,7 @@
 	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 1.2 vs edited =====
--- 1.2/arch/ppc64/mm/hugetlbpage.c	Sat Sep  6 18:40:37 2003
+++ edited/arch/ppc64/mm/hugetlbpage.c	Mon Oct 13 16:16:04 2003
@@ -914,7 +914,7 @@
  * 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 1.8 vs edited =====
--- 1.8/arch/sparc64/mm/hugetlbpage.c	Tue Aug 26 09:41:27 2003
+++ edited/arch/sparc64/mm/hugetlbpage.c	Mon Oct 13 15:16:38 2003
@@ -433,7 +433,7 @@
 }
 
 static struct page *
-hugetlb_nopage(struct vm_area_struct *vma, unsigned long address, int unused)
+hugetlb_nopage(struct vm_area_struct *vma, unsigned long address, int *unused)
 {
 	BUG();
 	return NULL;
===== drivers/char/agp/alpha-agp.c 1.9 vs edited =====
--- 1.9/drivers/char/agp/alpha-agp.c	Mon Sep 15 17:03:51 2003
+++ edited/drivers/char/agp/alpha-agp.c	Mon Oct 13 15:17:14 2003
@@ -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 @@
 	 */
 	page = virt_to_page(__va(pa));
 	get_page(page);
+	if (type)
+		*type = VM_FAULT_MINOR;
 	return page;
 }
 
===== drivers/char/drm/drmP.h 1.29 vs edited =====
--- 1.29/drivers/char/drm/drmP.h	Thu Sep 25 08:56:58 2003
+++ edited/drivers/char/drm/drmP.h	Mon Oct 13 15:17:38 2003
@@ -760,16 +760,16 @@
 				/* 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 1.25 vs edited =====
--- 1.25/drivers/char/drm/drm_vm.h	Thu Jul 10 23:18:01 2003
+++ edited/drivers/char/drm/drm_vm.h	Mon Oct 13 16:48:08 2003
@@ -76,7 +76,7 @@
  */
 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 @@
 			  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_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 @@
 	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 @@
  */
 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 @@
 			     (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_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 @@
 	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 1.5 vs edited =====
--- 1.5/drivers/ieee1394/dma.c	Thu Jul 24 17:00:00 2003
+++ edited/drivers/ieee1394/dma.c	Mon Oct 13 15:19:12 2003
@@ -187,7 +187,7 @@
 /* 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 @@
 	    (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 1.11 vs edited =====
--- 1.11/drivers/media/video/video-buf.c	Mon Oct  6 08:48:02 2003
+++ edited/drivers/media/video/video-buf.c	Mon Oct 13 15:19:52 2003
@@ -1076,7 +1076,7 @@
  */
 static struct page*
 videobuf_vm_nopage(struct vm_area_struct *vma, unsigned long vaddr,
-		  int write_access)
+		  int *type)
 {
 	struct page *page;
 
@@ -1088,6 +1088,8 @@
 	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 1.69 vs edited =====
--- 1.69/drivers/scsi/sg.c	Sat Sep 20 02:35:07 2003
+++ edited/drivers/scsi/sg.c	Mon Oct 13 15:21:16 2003
@@ -1115,7 +1115,7 @@
 }
 
 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;
@@ -1155,6 +1155,8 @@
 		page = virt_to_page(page_ptr);
 		get_page(page);	/* increment page count */
 	}
+	if (type)
+		*type = VM_FAULT_MINOR;
 	return page;
 }
 
===== fs/ncpfs/mmap.c 1.7 vs edited =====
--- 1.7/fs/ncpfs/mmap.c	Sat Aug 10 20:07:55 2002
+++ edited/fs/ncpfs/mmap.c	Mon Oct 13 16:23:56 2003
@@ -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 @@
 		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 1.133 vs edited =====
--- 1.133/include/linux/mm.h	Sun Oct  5 01:07:49 2003
+++ edited/include/linux/mm.h	Mon Oct 13 16:31:00 2003
@@ -143,7 +143,7 @@
 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);
 };
 
@@ -405,7 +405,7 @@
 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 *);
@@ -563,7 +563,7 @@
 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 1.66 vs edited =====
--- 1.66/kernel/sys.c	Thu Oct  9 15:13:54 2003
+++ edited/kernel/sys.c	Mon Oct 13 16:02:41 2003
@@ -1325,8 +1325,6 @@
  * 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 1.210 vs edited =====
--- 1.210/mm/filemap.c	Tue Oct  7 19:53:43 2003
+++ edited/mm/filemap.c	Mon Oct 13 16:25:46 2003
@@ -984,7 +984,7 @@
  * 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;
@@ -993,7 +993,7 @@
 	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;
@@ -1042,6 +1042,14 @@
 		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);
@@ -1063,6 +1071,8 @@
 	 * Found the page and have a reference on it.
 	 */
 	mark_page_accessed(page);
+	if (type)
+		*type = majmin;
 	return page;
 
 outside_data_content:
@@ -1098,7 +1108,10 @@
 	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 1.139 vs edited =====
--- 1.139/mm/memory.c	Wed Oct  8 08:59:27 2003
+++ edited/mm/memory.c	Mon Oct 13 15:44:10 2003
@@ -1416,7 +1416,7 @@
 	}
 	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)
@@ -1485,14 +1485,12 @@
 		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 1.135 vs edited =====
--- 1.135/mm/shmem.c	Tue Sep  9 23:41:41 2003
+++ edited/mm/shmem.c	Mon Oct 13 16:30:00 2003
@@ -67,7 +67,7 @@
 };
 
 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)
 {
@@ -522,7 +522,7 @@
 			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);
 			}
 		}
 	}
@@ -734,7 +734,7 @@
  * 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);
@@ -743,7 +743,7 @@
 	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;
@@ -780,6 +780,10 @@
 		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) {
@@ -926,6 +930,8 @@
 		} else
 			*pagep = ZERO_PAGE(0);
 	}
+	if (type)
+		*type = majmin;
 	return 0;
 
 failed:
@@ -936,7 +942,7 @@
 	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;
@@ -947,7 +953,7 @@
 	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;
 
@@ -974,7 +980,7 @@
 		/*
 		 * 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) {
@@ -1124,7 +1130,7 @@
 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
@@ -1181,7 +1187,7 @@
 		 * 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;
 
@@ -1264,7 +1270,7 @@
 				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;
@@ -1515,7 +1521,7 @@
 			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);
@@ -1551,7 +1557,7 @@
 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));
@@ -1564,7 +1570,7 @@
 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 1.41 vs edited =====
--- 1.41/sound/core/pcm_native.c	Mon Sep 29 19:28:26 2003
+++ edited/sound/core/pcm_native.c	Mon Oct 13 15:44:41 2003
@@ -2779,7 +2779,7 @@
 	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 @@
 	page = virt_to_page(runtime->status);
 	if (!PageReserved(page))
 		get_page(page);
+	if (type)
+		*type = VM_FAULT_MINOR;
 	return page;
 }
 
===== sound/oss/via82cxxx_audio.c 1.34 vs edited =====
--- 1.34/sound/oss/via82cxxx_audio.c	Sun Oct  5 01:07:55 2003
+++ edited/sound/oss/via82cxxx_audio.c	Mon Oct 13 15:53:34 2003
@@ -2116,7 +2116,7 @@
 
 
 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 @@
 	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 @@
 	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;
 }
 
===== sound/oss/emu10k1/audio.c 1.19 vs edited =====
--- 1.19/sound/oss/emu10k1/audio.c	Tue Aug 26 09:25:41 2003
+++ edited/sound/oss/emu10k1/audio.c	Mon Oct 13 15:52:23 2003
@@ -989,7 +989,7 @@
 	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 @@
 	get_page (dmapage);
 
 	DPD(3, "page: %#lx\n", (unsigned long) dmapage);
+	if (type)
+		*type = VM_FAULT_MINOR;
 	return dmapage;
 }
 
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^ permalink raw reply	[flat|nested] 6+ messages in thread
end of thread, other threads:[~2003-10-13 23:59 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2003-10-13 16:51 [RFC] State of ru_majflt Roger Luethi
2003-10-13 16:51 ` Roger Luethi
2003-10-13 18:51 ` Rik van Riel
2003-10-13 18:51   ` Rik van Riel
2003-10-13 23:59 ` William Lee Irwin III
2003-10-13 23:59   ` William Lee Irwin III

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