On Sat 07-10-17 20:30:19, Tetsuo Handa wrote: [...] > >From 6a0fd8a5e013ac63a6bcd06bd2ae6fdb25a4f3de Mon Sep 17 00:00:00 2001 > From: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx> > Date: Sat, 7 Oct 2017 19:29:21 +0900 > Subject: [PATCH] virtio: avoid possible OOM lockup at virtballoon_oom_notify() > > In leak_balloon(), mutex_lock(&vb->balloon_lock) is called in order to > serialize against fill_balloon(). But in fill_balloon(), > alloc_page(GFP_HIGHUSER[_MOVABLE] | __GFP_NOMEMALLOC | __GFP_NORETRY) is > called with vb->balloon_lock mutex held. Since GFP_HIGHUSER[_MOVABLE] > implies __GFP_DIRECT_RECLAIM | __GFP_IO | __GFP_FS, despite __GFP_NORETRY > is specified, this allocation attempt might depend on somebody else's > __GFP_DIRECT_RECLAIM memory allocation. How would that dependency look like? Is the holder of the lock doing only __GFP_NORETRY? -- Michal Hocko SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
