On Tue, Apr 26, 2011 at 5:28 PM, Minchan Kim <minchan....@gmail.com> wrote: > Please resend this with [2/2] to linux-mm. > > On Tue, Apr 26, 2011 at 5:59 PM, Dave Young <hidave.darks...@gmail.com> wrote: >> When memory pressure is high, virtio ballooning will probably cause oom >> killing. >> Even if alloc_page with GFP_NORETRY itself does not directly trigger oom it >> will make memory becoming low then memory alloc of other processes will >> trigger >> oom killing. It is not desired behaviour. > > I can't understand why it is undesirable. > Why do we have to handle it specially? >
Suppose user run some random memory hogging process while ballooning it will be undesirable. > >> >> Here disable oom killer in fill_balloon to address this issue. >> Add code comment as KOSAKI Motohiro's suggestion. >> >> Signed-off-by: Dave Young <hidave.darks...@gmail.com> >> --- >> drivers/virtio/virtio_balloon.c | 8 ++++++++ >> 1 file changed, 8 insertions(+) >> >> --- linux-2.6.orig/drivers/virtio/virtio_balloon.c 2011-04-26 >> 11:39:14.053118406 +0800 >> +++ linux-2.6/drivers/virtio/virtio_balloon.c 2011-04-26 >> 16:54:56.419741542 +0800 >> @@ -25,6 +25,7 @@ >> #include <linux/freezer.h> >> #include <linux/delay.h> >> #include <linux/slab.h> >> +#include <linux/oom.h> >> >> struct virtio_balloon >> { >> @@ -102,6 +103,12 @@ static void fill_balloon(struct virtio_b >> /* We can only do one array worth at a time. */ >> num = min(num, ARRAY_SIZE(vb->pfns)); >> >> + /* Disable oom killer for indirect oom due to our memory consuming >> + * Currently only hibernation code use oom_killer_disable, > > Hmm, Please look at current mmotm. Now oom_killer_disabled is used by > do_try_to_free_pages in mmotm so it could make unnecessary oom kill. > > BTW, I can't understand why we need to handle virtio by special. > Could you explain it in detail? :) > > > > -- > Kind regards, > Minchan Kim > -- Regards dave -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html