Messages in this thread Patch in this message |  | | Date | Sun, 2 May 2021 09:33:49 +0300 | From | Mike Rapoport <> | Subject | Re: [PATCH v1 6/7] virtio-mem: use page_offline_(start|end) when setting PageOffline() |
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On Thu, Apr 29, 2021 at 02:25:18PM +0200, David Hildenbrand wrote: > Let's properly use page_offline_(start|end) to synchronize setting > PageOffline(), so we won't have valid page access to unplugged memory > regions from /proc/kcore. > > Signed-off-by: David Hildenbrand <david@redhat.com> > --- > drivers/virtio/virtio_mem.c | 2 ++ > mm/util.c | 2 ++ > 2 files changed, 4 insertions(+) > > diff --git a/drivers/virtio/virtio_mem.c b/drivers/virtio/virtio_mem.c > index 10ec60d81e84..dc2a2e2b2ff8 100644 > --- a/drivers/virtio/virtio_mem.c > +++ b/drivers/virtio/virtio_mem.c > @@ -1065,6 +1065,7 @@ static int virtio_mem_memory_notifier_cb(struct notifier_block *nb, > static void virtio_mem_set_fake_offline(unsigned long pfn, > unsigned long nr_pages, bool onlined) > { > + page_offline_begin(); > for (; nr_pages--; pfn++) { > struct page *page = pfn_to_page(pfn); > > @@ -1075,6 +1076,7 @@ static void virtio_mem_set_fake_offline(unsigned long pfn, > ClearPageReserved(page); > } > } > + page_offline_end();
I'm not really familiar with ballooning and memory hotplug, but is it the only place that needs page_offline_{begin,end} ?
> } > > /* > diff --git a/mm/util.c b/mm/util.c > index 95395d4e4209..d0e357bd65e6 100644 > --- a/mm/util.c > +++ b/mm/util.c > @@ -1046,8 +1046,10 @@ void page_offline_begin(void) > { > down_write(&page_offline_rwsem); > } > +EXPORT_SYMBOL(page_offline_begin);
Should have been a part of the previous patch. > void page_offline_end(void) > { > up_write(&page_offline_rwsem); > } > +EXPORT_SYMBOL(page_offline_end);
Ditto
> -- > 2.30.2 >
-- Sincerely yours, Mike.
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