* Memory leak on UBI volume truncating
@ 2010-01-13 14:28 Marek Skuczynski
2010-01-17 10:37 ` Artem Bityutskiy
0 siblings, 1 reply; 6+ messages in thread
From: Marek Skuczynski @ 2010-01-13 14:28 UTC (permalink / raw)
To: linux-mtd
Hello,
I have prepare a simple volume update stress test (see test code below).
This test has been run for kernel 2.6.23 with some updates from 2.6.28,
and always after a few minutes the OOM killer was launched.
What i found it that each an UBI volume truncate operation with
ubiupdatevol tool
causes memory leak. I think this happens because:
- ubi_start_update() param "bytes" is equal 0
- vol->updating flag is re-set to 0
- vol->upd_buf is allocated regardless of vol->updating flag,
but not released on device close by vol_cdev_release()
I never run the test on a newer kernel version, so I cannot confirm
that this problem still exists.
Please confirm, whether my findings are correct or not, thanks.
Regards,
Marek
int ubi_start_update(struct ubi_device *ubi, struct ubi_volume *vol,
long long bytes)
/* ... */
vol->updating = 1;
if (bytes == 0) {
/* ... */
vol->updating = 0;
}
vol->upd_buf = vmalloc(ubi->leb_size);
/* ... */
}
static int vol_cdev_release(struct inode *inode, struct file *file)
{
/* ... */
if (vol->updating) {
/* ... */
vol->updating = 0;
vfree(vol->upd_buf);
}
/* ... */
}
[--- TEST BODY ----]
while [ true ]
do
echo "Truncating #1"
/tmp/ubiupdatevol /dev/ubi0_3 -t
echo "Writing #1"
cat /dev/zero | /tmp/ubiupdatevol /dev/ubi0_3 -s 4206 -
echo "Truncating #2"
/tmp/ubiupdatevol /dev/ubi0_3 -t
echo "Writing #2"
cat /dev/urandom | /tmp/ubiupdatevol /dev/ubi0_3 -s 4206 -
done
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: Memory leak on UBI volume truncating
2010-01-13 14:28 Memory leak on UBI volume truncating Marek Skuczynski
@ 2010-01-17 10:37 ` Artem Bityutskiy
2010-01-17 10:43 ` Artem Bityutskiy
0 siblings, 1 reply; 6+ messages in thread
From: Artem Bityutskiy @ 2010-01-17 10:37 UTC (permalink / raw)
To: Marek Skuczynski; +Cc: linux-mtd
Hi,
On Wed, 2010-01-13 at 15:28 +0100, Marek Skuczynski wrote:
> Hello,
> I have prepare a simple volume update stress test (see test code below).
> This test has been run for kernel 2.6.23 with some updates from 2.6.28,
> and always after a few minutes the OOM killer was launched.
>
> What i found it that each an UBI volume truncate operation with
> ubiupdatevol tool
> causes memory leak. I think this happens because:
>
> - ubi_start_update() param "bytes" is equal 0
>
> - vol->updating flag is re-set to 0
>
> - vol->upd_buf is allocated regardless of vol->updating flag,
> but not released on device close by vol_cdev_release()
>
> I never run the test on a newer kernel version, so I cannot confirm
> that this problem still exists.
>
> Please confirm, whether my findings are correct or not, thanks.
thanks for this finding. Looks like your analysis is right. Does this
simple patch help?
diff --git a/drivers/mtd/ubi/upd.c b/drivers/mtd/ubi/upd.c
index c1d7b88..9e3cd34 100644
--- a/drivers/mtd/ubi/upd.c
+++ b/drivers/mtd/ubi/upd.c
@@ -155,12 +155,12 @@ int ubi_start_update(struct ubi_device *ubi, struct ubi_volume *vol,
if (err)
return err;
vol->updating = 0;
+ } else {
+ vol->upd_buf = vmalloc(ubi->leb_size);
+ if (!vol->upd_buf)
+ return -ENOMEM;
}
- vol->upd_buf = vmalloc(ubi->leb_size);
- if (!vol->upd_buf)
- return -ENOMEM;
-
vol->upd_ebs = div_u64(bytes + vol->usable_leb_size - 1,
vol->usable_leb_size);
vol->upd_bytes = bytes;
--
Best Regards,
Artem Bityutskiy (Артём Битюцкий)
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: Memory leak on UBI volume truncating
2010-01-17 10:37 ` Artem Bityutskiy
@ 2010-01-17 10:43 ` Artem Bityutskiy
[not found] ` <a328840c1001180034n7fd1c3e9m420afef60f7c97ab@mail.gmail.com>
0 siblings, 1 reply; 6+ messages in thread
From: Artem Bityutskiy @ 2010-01-17 10:43 UTC (permalink / raw)
To: Marek Skuczynski; +Cc: linux-mtd
On Sun, 2010-01-17 at 12:37 +0200, Artem Bityutskiy wrote:
> Hi,
>
> On Wed, 2010-01-13 at 15:28 +0100, Marek Skuczynski wrote:
> > Hello,
> > I have prepare a simple volume update stress test (see test code below).
> > This test has been run for kernel 2.6.23 with some updates from 2.6.28,
> > and always after a few minutes the OOM killer was launched.
> >
> > What i found it that each an UBI volume truncate operation with
> > ubiupdatevol tool
> > causes memory leak. I think this happens because:
> >
> > - ubi_start_update() param "bytes" is equal 0
> >
> > - vol->updating flag is re-set to 0
> >
> > - vol->upd_buf is allocated regardless of vol->updating flag,
> > but not released on device close by vol_cdev_release()
> >
> > I never run the test on a newer kernel version, so I cannot confirm
> > that this problem still exists.
> >
> > Please confirm, whether my findings are correct or not, thanks.
>
> thanks for this finding. Looks like your analysis is right. Does this
> simple patch help?
Actually this even simpler patch should fix the issue. Could you please
test it and let me know if it helps.
diff --git a/drivers/mtd/ubi/upd.c b/drivers/mtd/ubi/upd.c
index c1d7b88..425bf5a 100644
--- a/drivers/mtd/ubi/upd.c
+++ b/drivers/mtd/ubi/upd.c
@@ -155,6 +155,7 @@ int ubi_start_update(struct ubi_device *ubi, struct ubi_volume *vol,
if (err)
return err;
vol->updating = 0;
+ return 0;
}
vol->upd_buf = vmalloc(ubi->leb_size);
--
Best Regards,
Artem Bityutskiy (Артём Битюцкий)
^ permalink raw reply related [flat|nested] 6+ messages in thread
end of thread, other threads:[~2010-01-28 15:08 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
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2010-01-13 14:28 Memory leak on UBI volume truncating Marek Skuczynski
2010-01-17 10:37 ` Artem Bityutskiy
2010-01-17 10:43 ` Artem Bityutskiy
[not found] ` <a328840c1001180034n7fd1c3e9m420afef60f7c97ab@mail.gmail.com>
2010-01-18 8:36 ` Marek Skuczynski
2010-01-18 10:03 ` Artem Bityutskiy
2010-01-28 15:07 ` Artem Bityutskiy
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