[PATCH] mm: balance dirty pages

Now that we can detect writers of shared mappings, throttle them. Avoids OOM by surprise. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] mm: balance dirty pages
Now that we can detect writers of shared mappings, throttle them. Avoids OOM by surprise. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Peter Zijlstra · Linus Torvalds
1 parent d08b3851da
Showing 3 changed files with 14 additions and 2 deletions Side-by-side Diff
include/linux/writeback.h
mm/memory.c
mm/page-writeback.c
@@ -116,6 +116,7 @@
 			loff_t pos, loff_t count);
 int sync_page_range_nolock(struct inode *inode, struct address_space *mapping,
 			   loff_t pos, loff_t count);
+void set_page_dirty_balance(struct page *page);
  
 /* pdflush.c */
 extern int nr_pdflush_threads;	/* Global so it can be exported to sysctl
@@ -49,6 +49,7 @@
 #include <linux/module.h>
 #include <linux/delayacct.h>
 #include <linux/init.h>
+#include <linux/writeback.h>
  
 #include <asm/pgalloc.h>
 #include <asm/uaccess.h>
@@ -1571,7 +1572,7 @@
 unlock:
 	pte_unmap_unlock(page_table, ptl);
 	if (dirty_page) {
-		set_page_dirty(dirty_page);
+		set_page_dirty_balance(dirty_page);
 		put_page(dirty_page);
 	}
 	return ret;
@@ -2218,7 +2219,7 @@
 unlock:
 	pte_unmap_unlock(page_table, ptl);
 	if (dirty_page) {
-		set_page_dirty(dirty_page);
+		set_page_dirty_balance(dirty_page);
 		put_page(dirty_page);
 	}
 	return ret;
@@ -244,6 +244,16 @@
 		pdflush_operation(background_writeout, 0);
 }
  
+void set_page_dirty_balance(struct page *page)
+{
+	if (set_page_dirty(page)) {
+		struct address_space *mapping = page_mapping(page);
+
+		if (mapping)
+			balance_dirty_pages_ratelimited(mapping);
+	}
+}
+
 /**
  * balance_dirty_pages_ratelimited_nr - balance dirty memory state
  * @mapping: address_space which was dirtied
...	...	@@ -116,6 +116,7 @@
116	116	loff_t pos, loff_t count);
117	117	int sync_page_range_nolock(struct inode inode, struct address_space mapping,
118	118	loff_t pos, loff_t count);
	119	+void set_page_dirty_balance(struct page *page);
119	120
120	121	/* pdflush.c */
121	122	extern int nr_pdflush_threads; /* Global so it can be exported to sysctl
...	...	@@ -49,6 +49,7 @@
49	49	#include <linux/module.h>
50	50	#include <linux/delayacct.h>
51	51	#include <linux/init.h>
	52	+#include <linux/writeback.h>
52	53
53	54	#include <asm/pgalloc.h>
54	55	#include <asm/uaccess.h>
...	...	@@ -1571,7 +1572,7 @@
1571	1572	unlock:
1572	1573	pte_unmap_unlock(page_table, ptl);
1573	1574	if (dirty_page) {
1574		- set_page_dirty(dirty_page);
	1575	+ set_page_dirty_balance(dirty_page);
1575	1576	put_page(dirty_page);
1576	1577	}
1577	1578	return ret;
...	...	@@ -2218,7 +2219,7 @@
2218	2219	unlock:
2219	2220	pte_unmap_unlock(page_table, ptl);
2220	2221	if (dirty_page) {
2221		- set_page_dirty(dirty_page);
	2222	+ set_page_dirty_balance(dirty_page);
2222	2223	put_page(dirty_page);
2223	2224	}
2224	2225	return ret;
...	...	@@ -244,6 +244,16 @@
244	244	pdflush_operation(background_writeout, 0);
245	245	}
246	246
	247	+void set_page_dirty_balance(struct page *page)
	248	+{
	249	+ if (set_page_dirty(page)) {
	250	+ struct address_space *mapping = page_mapping(page);
	251	+
	252	+ if (mapping)
	253	+ balance_dirty_pages_ratelimited(mapping);
	254	+ }
	255	+}
	256	+
247	257	/**
248	258	* balance_dirty_pages_ratelimited_nr - balance dirty memory state
249	259	* @mapping: address_space which was dirtied