[PATCH 8/8] RSS accounting hooks over the code

Pavel Emelianov xemul at openvz.org
Mon Jun 4 06:46:32 PDT 2007


As described, pages are charged to their first touchers.
The first toucher is determined using pages' _mapcount 
manipulations in rmap calls.

A page is charged in two stages:
1. preparation, in which the resource availability is checked.
   This stage may lead to page reclamation, thus it is performed
   in a "might-sleep" places;
2. the container assignment to page. This is done in an atomic
   code that handles races between multiple touchers.

The uncharge process is tricky. After the _mapcount is changed
and happens to hit zero we cannot trust the page->container 
pointer any longer. So we get the pointer before the decrement.

Includes fixes from Balbir Singh <balbir at in.ibm.com>

Signed-off-by: Pavel Emelianov <xemul at openvz.org>

---

diff -upr linux-2.6.22-rc2-mm1.orig/fs/exec.c linux-2.6.22-rc2-mm1-2/fs/exec.c
--- linux-2.6.22-rc2-mm1.orig/fs/exec.c	2007-05-30 12:32:34.000000000 +0400
+++ linux-2.6.22-rc2-mm1-2/fs/exec.c	2007-06-01 16:35:13.000000000 +0400
@@ -59,6 +59,8 @@
 #include <linux/kmod.h>
 #endif
 
+#include <linux/rss_container.h>
+
 int core_uses_pid;
 char core_pattern[CORENAME_MAX_SIZE] = "core";
 int suid_dumpable = 0;
@@ -314,27 +316,34 @@ void install_arg_page(struct vm_area_str
 	struct mm_struct *mm = vma->vm_mm;
 	pte_t * pte;
 	spinlock_t *ptl;
+	struct page_container *pcont;
 
 	if (unlikely(anon_vma_prepare(vma)))
 		goto out;
 
+	if (container_rss_prepare(page, vma, &pcont))
+		goto out;
+
 	flush_dcache_page(page);
 	pte = get_locked_pte(mm, address, &ptl);
 	if (!pte)
-		goto out;
+		goto out_release;
 	if (!pte_none(*pte)) {
 		pte_unmap_unlock(pte, ptl);
-		goto out;
+		goto out_release;
 	}
 	inc_mm_counter(mm, anon_rss);
 	lru_cache_add_active(page);
 	set_pte_at(mm, address, pte, pte_mkdirty(pte_mkwrite(mk_pte(
 					page, vma->vm_page_prot))));
-	page_add_new_anon_rmap(page, vma, address);
+	page_add_new_anon_rmap(page, vma, address, pcont);
 	pte_unmap_unlock(pte, ptl);
 
 	/* no need for flush_tlb */
 	return;
+
+out_release:
+	container_rss_release(pcont);
 out:
 	__free_page(page);
 	force_sig(SIGKILL, current);
diff -upr linux-2.6.22-rc2-mm1.orig/include/linux/rmap.h linux-2.6.22-rc2-mm1-2/include/linux/rmap.h
--- linux-2.6.22-rc2-mm1.orig/include/linux/rmap.h	2007-05-29 18:01:57.000000000 +0400
+++ linux-2.6.22-rc2-mm1-2/include/linux/rmap.h	2007-06-01 16:35:13.000000000 +0400
@@ -69,9 +69,13 @@ void __anon_vma_link(struct vm_area_stru
 /*
  * rmap interfaces called when adding or removing pte of page
  */
-void page_add_anon_rmap(struct page *, struct vm_area_struct *, unsigned long);
-void page_add_new_anon_rmap(struct page *, struct vm_area_struct *, unsigned long);
-void page_add_file_rmap(struct page *);
+struct page_container;
+
+void page_add_anon_rmap(struct page *, struct vm_area_struct *,
+		unsigned long, struct page_container *);
+void page_add_new_anon_rmap(struct page *, struct vm_area_struct *,
+		unsigned long, struct page_container *);
+void page_add_file_rmap(struct page *, struct page_container *);
 void page_remove_rmap(struct page *, struct vm_area_struct *);
 
 #ifdef CONFIG_DEBUG_VM
diff -upr linux-2.6.22-rc2-mm1.orig/mm/memory.c linux-2.6.22-rc2-mm1-2/mm/memory.c
--- linux-2.6.22-rc2-mm1.orig/mm/memory.c	2007-05-30 12:32:36.000000000 +0400
+++ linux-2.6.22-rc2-mm1-2/mm/memory.c	2007-06-01 16:35:13.000000000 +0400
@@ -60,6 +60,8 @@
 #include <linux/swapops.h>
 #include <linux/elf.h>
 
+#include <linux/rss_container.h>
+
 #ifndef CONFIG_NEED_MULTIPLE_NODES
 /* use the per-pgdat data instead for discontigmem - mbligh */
 unsigned long max_mapnr;
@@ -1155,7 +1157,7 @@ static int zeromap_pte_range(struct mm_s
 			break;
 		}
 		page_cache_get(page);
-		page_add_file_rmap(page);
+		page_add_file_rmap(page, NULL);
 		inc_mm_counter(mm, file_rss);
 		set_pte_at(mm, addr, pte, zero_pte);
 	} while (pte++, addr += PAGE_SIZE, addr != end);
@@ -1263,7 +1265,7 @@ static int insert_page(struct mm_struct 
 	/* Ok, finally just insert the thing.. */
 	get_page(page);
 	inc_mm_counter(mm, file_rss);
-	page_add_file_rmap(page);
+	page_add_file_rmap(page, NULL);
 	set_pte_at(mm, addr, pte, mk_pte(page, prot));
 
 	retval = 0;
@@ -1668,6 +1670,7 @@ static int do_wp_page(struct mm_struct *
 	pte_t entry;
 	int reuse = 0, ret = VM_FAULT_MINOR;
 	struct page *dirty_page = NULL;
+	struct page_container *pcont;
 
 	old_page = vm_normal_page(vma, address, orig_pte);
 	if (!old_page)
@@ -1752,6 +1755,9 @@ gotten:
 		cow_user_page(new_page, old_page, address, vma);
 	}
 
+	if (container_rss_prepare(new_page, vma, &pcont))
+		goto oom;
+
 	/*
 	 * Re-check the pte - we dropped the lock
 	 */
@@ -1779,12 +1785,14 @@ gotten:
 		set_pte_at(mm, address, page_table, entry);
 		update_mmu_cache(vma, address, entry);
 		lru_cache_add_active(new_page);
-		page_add_new_anon_rmap(new_page, vma, address);
+		page_add_new_anon_rmap(new_page, vma, address, pcont);
 
 		/* Free the old page.. */
 		new_page = old_page;
 		ret |= VM_FAULT_WRITE;
-	}
+	} else
+		container_rss_release(pcont);
+
 	if (new_page)
 		page_cache_release(new_page);
 	if (old_page)
@@ -2176,6 +2184,7 @@ static int do_swap_page(struct mm_struct
 	swp_entry_t entry;
 	pte_t pte;
 	int ret = VM_FAULT_MINOR;
+	struct page_container *pcont;
 
 	if (!pte_unmap_same(mm, pmd, page_table, orig_pte))
 		goto out;
@@ -2208,6 +2217,11 @@ static int do_swap_page(struct mm_struct
 		count_vm_event(PGMAJFAULT);
 	}
 
+	if (container_rss_prepare(page, vma, &pcont)) {
+		ret = VM_FAULT_OOM;
+		goto out;
+	}
+
 	delayacct_clear_flag(DELAYACCT_PF_SWAPIN);
 	mark_page_accessed(page);
 	lock_page(page);
@@ -2221,6 +2235,7 @@ static int do_swap_page(struct mm_struct
 
 	if (unlikely(!PageUptodate(page))) {
 		ret = VM_FAULT_SIGBUS;
+		container_rss_release(pcont);
 		goto out_nomap;
 	}
 
@@ -2235,7 +2250,7 @@ static int do_swap_page(struct mm_struct
 
 	flush_icache_page(vma, page);
 	set_pte_at(mm, address, page_table, pte);
-	page_add_anon_rmap(page, vma, address);
+	page_add_anon_rmap(page, vma, address, pcont);
 
 	swap_free(entry);
 	if (vm_swap_full())
@@ -2256,6 +2271,7 @@ unlock:
 out:
 	return ret;
 out_nomap:
+	container_rss_release(pcont);
 	pte_unmap_unlock(page_table, ptl);
 	unlock_page(page);
 	page_cache_release(page);
@@ -2274,6 +2290,7 @@ static int do_anonymous_page(struct mm_s
 	struct page *page;
 	spinlock_t *ptl;
 	pte_t entry;
+	struct page_container *pcont;
 
 	if (write_access) {
 		/* Allocate our own private page. */
@@ -2285,15 +2302,19 @@ static int do_anonymous_page(struct mm_s
 		if (!page)
 			goto oom;
 
+		if (container_rss_prepare(page, vma, &pcont))
+			goto oom_release;
+
 		entry = mk_pte(page, vma->vm_page_prot);
 		entry = maybe_mkwrite(pte_mkdirty(entry), vma);
 
 		page_table = pte_offset_map_lock(mm, pmd, address, &ptl);
 		if (!pte_none(*page_table))
-			goto release;
+			goto release_container;
+
 		inc_mm_counter(mm, anon_rss);
 		lru_cache_add_active(page);
-		page_add_new_anon_rmap(page, vma, address);
+		page_add_new_anon_rmap(page, vma, address, pcont);
 	} else {
 		/* Map the ZERO_PAGE - vm_page_prot is readonly */
 		page = ZERO_PAGE(address);
@@ -2305,7 +2326,7 @@ static int do_anonymous_page(struct mm_s
 		if (!pte_none(*page_table))
 			goto release;
 		inc_mm_counter(mm, file_rss);
-		page_add_file_rmap(page);
+		page_add_file_rmap(page, NULL);
 	}
 
 	set_pte_at(mm, address, page_table, entry);
@@ -2316,9 +2337,14 @@ static int do_anonymous_page(struct mm_s
 unlock:
 	pte_unmap_unlock(page_table, ptl);
 	return VM_FAULT_MINOR;
+release_container:
+	container_rss_release(pcont);
 release:
 	page_cache_release(page);
 	goto unlock;
+
+oom_release:
+	page_cache_release(page);
 oom:
 	return VM_FAULT_OOM;
 }
@@ -2346,6 +2372,7 @@ static int __do_fault(struct mm_struct *
 	int anon = 0;
 	struct page *dirty_page = NULL;
 	struct fault_data fdata;
+	struct page_container *pcont;
 
 	fdata.address = address & PAGE_MASK;
 	fdata.pgoff = pgoff;
@@ -2415,6 +2442,11 @@ static int __do_fault(struct mm_struct *
 
 	}
 
+	if (container_rss_prepare(page, vma, &pcont)) {
+		fdata.type = VM_FAULT_OOM;
+		goto out;
+	}
+
 	page_table = pte_offset_map_lock(mm, pmd, address, &ptl);
 
 	/*
@@ -2437,10 +2469,10 @@ static int __do_fault(struct mm_struct *
 		if (anon) {
                         inc_mm_counter(mm, anon_rss);
                         lru_cache_add_active(page);
-                        page_add_new_anon_rmap(page, vma, address);
+			page_add_new_anon_rmap(page, vma, address, pcont);
 		} else {
 			inc_mm_counter(mm, file_rss);
-			page_add_file_rmap(page);
+			page_add_file_rmap(page, pcont);
 			if (flags & FAULT_FLAG_WRITE) {
 				dirty_page = page;
 				get_page(dirty_page);
@@ -2451,6 +2483,7 @@ static int __do_fault(struct mm_struct *
 		update_mmu_cache(vma, address, entry);
 		lazy_mmu_prot_update(entry);
 	} else {
+		container_rss_release(pcont);
 		if (anon)
 			page_cache_release(page);
 		else
diff -upr linux-2.6.22-rc2-mm1.orig/mm/migrate.c linux-2.6.22-rc2-mm1-2/mm/migrate.c
--- linux-2.6.22-rc2-mm1.orig/mm/migrate.c	2007-05-30 12:32:36.000000000 +0400
+++ linux-2.6.22-rc2-mm1-2/mm/migrate.c	2007-06-01 16:35:13.000000000 +0400
@@ -28,6 +28,7 @@
 #include <linux/mempolicy.h>
 #include <linux/vmalloc.h>
 #include <linux/security.h>
+#include <linux/rss_container.h>
 
 #include "internal.h"
 
@@ -134,6 +135,7 @@ static void remove_migration_pte(struct 
 	pte_t *ptep, pte;
  	spinlock_t *ptl;
 	unsigned long addr = page_address_in_vma(new, vma);
+	struct page_container *pcont;
 
 	if (addr == -EFAULT)
 		return;
@@ -157,6 +159,11 @@ static void remove_migration_pte(struct 
  		return;
  	}
 
+	if (container_rss_prepare(new, vma, &pcont)) {
+		pte_unmap(ptep);
+		return;
+	}
+
  	ptl = pte_lockptr(mm, pmd);
  	spin_lock(ptl);
 	pte = *ptep;
@@ -175,16 +182,19 @@ static void remove_migration_pte(struct 
 	set_pte_at(mm, addr, ptep, pte);
 
 	if (PageAnon(new))
-		page_add_anon_rmap(new, vma, addr);
+		page_add_anon_rmap(new, vma, addr, pcont);
 	else
-		page_add_file_rmap(new);
+		page_add_file_rmap(new, pcont);
 
 	/* No need to invalidate - it was non-present before */
 	update_mmu_cache(vma, addr, pte);
 	lazy_mmu_prot_update(pte);
+	pte_unmap_unlock(ptep, ptl);
+	return;
 
 out:
 	pte_unmap_unlock(ptep, ptl);
+	container_rss_release(pcont);
 }
 
 /*
diff -upr linux-2.6.22-rc2-mm1.orig/mm/page_alloc.c linux-2.6.22-rc2-mm1-2/mm/page_alloc.c
--- linux-2.6.22-rc2-mm1.orig/mm/page_alloc.c	2007-05-30 12:32:36.000000000 +0400
+++ linux-2.6.22-rc2-mm1-2/mm/page_alloc.c	2007-06-01 16:35:15.000000000 +0400
@@ -41,6 +41,7 @@
 #include <linux/pfn.h>
 #include <linux/backing-dev.h>
 #include <linux/fault-inject.h>
+#include <linux/rss_container.h>
 
 #include <asm/tlbflush.h>
 #include <asm/div64.h>
@@ -1042,6 +1043,7 @@ static void fastcall free_hot_cold_page(
 
 	if (!PageHighMem(page))
 		debug_check_no_locks_freed(page_address(page), PAGE_SIZE);
+	set_page_container(page, NULL);
 	arch_free_page(page, 0);
 	kernel_map_pages(page, 1, 0);
 
@@ -2592,6 +2594,7 @@ void __meminit memmap_init_zone(unsigned
 		set_page_links(page, zone, nid, pfn);
 		init_page_count(page);
 		reset_page_mapcount(page);
+		set_page_container(page, NULL);
 		SetPageReserved(page);
 
 		/*
diff -upr linux-2.6.22-rc2-mm1.orig/mm/rmap.c linux-2.6.22-rc2-mm1-2/mm/rmap.c
--- linux-2.6.22-rc2-mm1.orig/mm/rmap.c	2007-05-30 12:32:36.000000000 +0400
+++ linux-2.6.22-rc2-mm1-2/mm/rmap.c	2007-06-01 16:35:15.000000000 +0400
@@ -51,6 +51,8 @@
 
 #include <asm/tlbflush.h>
 
+#include <linux/rss_container.h>
+
 struct kmem_cache *anon_vma_cachep;
 
 static inline void validate_anon_vma(struct vm_area_struct *find_vma)
@@ -563,18 +565,28 @@ static void __page_check_anon_rmap(struc
  * @page:	the page to add the mapping to
  * @vma:	the vm area in which the mapping is added
  * @address:	the user virtual address mapped
+ * @pcont:	the page beancounter to charge page with
  *
  * The caller needs to hold the pte lock and the page must be locked.
  */
 void page_add_anon_rmap(struct page *page,
-	struct vm_area_struct *vma, unsigned long address)
+	struct vm_area_struct *vma, unsigned long address,
+	struct page_container *pcont)
 {
 	VM_BUG_ON(!PageLocked(page));
 	VM_BUG_ON(address < vma->vm_start || address >= vma->vm_end);
-	if (atomic_inc_and_test(&page->_mapcount))
+	if (atomic_inc_and_test(&page->_mapcount)) {
 		__page_set_anon_rmap(page, vma, address);
-	else
+		/* 0 -> 1 state change */
+		container_rss_add(pcont);
+	} else {
 		__page_check_anon_rmap(page, vma, address);
+		/*
+		 * we raced with another touch or just mapped the page
+		 * for the N-th time
+		 */
+		container_rss_release(pcont);
+	}
 }
 
 /*
@@ -582,29 +594,44 @@ void page_add_anon_rmap(struct page *pag
  * @page:	the page to add the mapping to
  * @vma:	the vm area in which the mapping is added
  * @address:	the user virtual address mapped
+ * @pcont:	the page beancounter to charge page with
  *
  * Same as page_add_anon_rmap but must only be called on *new* pages.
  * This means the inc-and-test can be bypassed.
  * Page does not have to be locked.
  */
 void page_add_new_anon_rmap(struct page *page,
-	struct vm_area_struct *vma, unsigned long address)
+	struct vm_area_struct *vma, unsigned long address,
+	struct page_container *pcont)
 {
 	BUG_ON(address < vma->vm_start || address >= vma->vm_end);
 	atomic_set(&page->_mapcount, 0); /* elevate count by 1 (starts at -1) */
+	container_rss_add(pcont);
 	__page_set_anon_rmap(page, vma, address);
 }
 
 /**
  * page_add_file_rmap - add pte mapping to a file page
- * @page: the page to add the mapping to
+ * @page:	the page to add the mapping to
+ * @pcont:	the page beancounter to charge page with
  *
  * The caller needs to hold the pte lock.
  */
-void page_add_file_rmap(struct page *page)
+void page_add_file_rmap(struct page *page, struct page_container *pcont)
 {
-	if (atomic_inc_and_test(&page->_mapcount))
+	if (atomic_inc_and_test(&page->_mapcount)) {
+		if (pcont)
+			/*
+			 * 0 -> 1 state change. add the page
+			 *
+			 * some pages like ZERO_PAGE() or driver specific pages
+			 * are not added to the container as they do not imply
+			 * RSS consumption  --xemul
+			 */
+			container_rss_add(pcont);
 		__inc_zone_page_state(page, NR_FILE_MAPPED);
+	} else if (pcont)
+		container_rss_release(pcont);
 }
 
 #ifdef CONFIG_DEBUG_VM
@@ -635,6 +662,15 @@ void page_dup_rmap(struct page *page, st
  */
 void page_remove_rmap(struct page *page, struct vm_area_struct *vma)
 {
+	struct page_container *pcont;
+
+	/*
+	 * this place is tricky. we get the container pointer *before* the
+	 * mapcount change. this is done so sice we cannot trust this pointer
+	 * *after* mapcount drops to zero - the page can be re-mapped right
+	 * after this so we risk getting the wrong container  --xemul
+	 */
+	pcont = page_container(page);
 	if (atomic_add_negative(-1, &page->_mapcount)) {
 		if (unlikely(page_mapcount(page) < 0)) {
 			printk (KERN_EMERG "Eeek! page_mapcount(page) went negative! (%d)\n", page_mapcount(page));
@@ -652,6 +688,8 @@ void page_remove_rmap(struct page *page,
 			BUG();
 		}
 
+		if (pcont)
+			container_rss_del(pcont);
 		/*
 		 * It would be tidy to reset the PageAnon mapping here,
 		 * but that might overwrite a racing page_add_anon_rmap
diff -upr linux-2.6.22-rc2-mm1.orig/mm/swapfile.c linux-2.6.22-rc2-mm1-2/mm/swapfile.c
--- linux-2.6.22-rc2-mm1.orig/mm/swapfile.c	2007-05-11 16:36:58.000000000 +0400
+++ linux-2.6.22-rc2-mm1-2/mm/swapfile.c	2007-06-01 16:35:13.000000000 +0400
@@ -32,6 +32,8 @@
 #include <asm/tlbflush.h>
 #include <linux/swapops.h>
 
+#include <linux/rss_container.h>
+
 DEFINE_SPINLOCK(swap_lock);
 unsigned int nr_swapfiles;
 long total_swap_pages;
@@ -507,13 +509,14 @@ unsigned int count_swap_pages(int type, 
  * force COW, vm_page_prot omits write permission from any private vma.
  */
 static void unuse_pte(struct vm_area_struct *vma, pte_t *pte,
-		unsigned long addr, swp_entry_t entry, struct page *page)
+		unsigned long addr, swp_entry_t entry, struct page *page,
+		struct page_container *pcont)
 {
 	inc_mm_counter(vma->vm_mm, anon_rss);
 	get_page(page);
 	set_pte_at(vma->vm_mm, addr, pte,
 		   pte_mkold(mk_pte(page, vma->vm_page_prot)));
-	page_add_anon_rmap(page, vma, addr);
+	page_add_anon_rmap(page, vma, addr, pcont);
 	swap_free(entry);
 	/*
 	 * Move the page to the active list so it is not
@@ -530,6 +533,10 @@ static int unuse_pte_range(struct vm_are
 	pte_t *pte;
 	spinlock_t *ptl;
 	int found = 0;
+	struct page_container *pcont;
+
+	if (container_rss_prepare(page, vma, &pcont))
+		return 0;
 
 	pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
 	do {
@@ -538,12 +545,14 @@ static int unuse_pte_range(struct vm_are
 		 * Test inline before going to call unuse_pte.
 		 */
 		if (unlikely(pte_same(*pte, swp_pte))) {
-			unuse_pte(vma, pte++, addr, entry, page);
+			unuse_pte(vma, pte++, addr, entry, page, pcont);
 			found = 1;
 			break;
 		}
 	} while (pte++, addr += PAGE_SIZE, addr != end);
 	pte_unmap_unlock(pte - 1, ptl);
+	if (!found)
+		container_rss_release(pcont);
 	return found;
 }
 


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