[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>
diff --git a/include/linux/writeback.h b/include/linux/writeback.h
index 0422036..56a23a0 100644
--- a/include/linux/writeback.h
+++ b/include/linux/writeback.h
@@ -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
diff --git a/mm/memory.c b/mm/memory.c
index fa941b1..dd7d7fc 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -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;
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 1c87430..b9f4c6f 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -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