[PATCH 4/7] nandsim: Don't use PF_MEMALLOC

From: KOSAKI Motohiro
Date: Tue Nov 17 2009 - 02:19:40 EST



Non MM subsystem must not use PF_MEMALLOC. Memory reclaim need few
memory, anyone must not prevent it. Otherwise the system cause
mysterious hang-up and/or OOM Killer invokation.

Cc: David Woodhouse <David.Woodhouse@xxxxxxxxx>
Cc: Artem Bityutskiy <Artem.Bityutskiy@xxxxxxxxx>
Cc: linux-mtd@xxxxxxxxxxxxxxxxxxx
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
---
drivers/mtd/nand/nandsim.c | 22 ++--------------------
1 files changed, 2 insertions(+), 20 deletions(-)

diff --git a/drivers/mtd/nand/nandsim.c b/drivers/mtd/nand/nandsim.c
index cd0711b..97a8bbb 100644
--- a/drivers/mtd/nand/nandsim.c
+++ b/drivers/mtd/nand/nandsim.c
@@ -1322,34 +1322,18 @@ static int get_pages(struct nandsim *ns, struct file *file, size_t count, loff_t
return 0;
}

-static int set_memalloc(void)
-{
- if (current->flags & PF_MEMALLOC)
- return 0;
- current->flags |= PF_MEMALLOC;
- return 1;
-}
-
-static void clear_memalloc(int memalloc)
-{
- if (memalloc)
- current->flags &= ~PF_MEMALLOC;
-}
-
static ssize_t read_file(struct nandsim *ns, struct file *file, void *buf, size_t count, loff_t *pos)
{
mm_segment_t old_fs;
ssize_t tx;
- int err, memalloc;
+ int err;

err = get_pages(ns, file, count, *pos);
if (err)
return err;
old_fs = get_fs();
set_fs(get_ds());
- memalloc = set_memalloc();
tx = vfs_read(file, (char __user *)buf, count, pos);
- clear_memalloc(memalloc);
set_fs(old_fs);
put_pages(ns);
return tx;
@@ -1359,16 +1343,14 @@ static ssize_t write_file(struct nandsim *ns, struct file *file, void *buf, size
{
mm_segment_t old_fs;
ssize_t tx;
- int err, memalloc;
+ int err;

err = get_pages(ns, file, count, *pos);
if (err)
return err;
old_fs = get_fs();
set_fs(get_ds());
- memalloc = set_memalloc();
tx = vfs_write(file, (char __user *)buf, count, pos);
- clear_memalloc(memalloc);
set_fs(old_fs);
put_pages(ns);
return tx;
--
1.6.2.5



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