From: Mike Rapoport <rppt@kernel.org>
To: David Hildenbrand <david@redhat.com>
Cc: linux-kernel@vger.kernel.org,
Andrew Morton <akpm@linux-foundation.org>,
"Michael S. Tsirkin" <mst@redhat.com>,
Jason Wang <jasowang@redhat.com>,
Alexey Dobriyan <adobriyan@gmail.com>,
"Matthew Wilcox (Oracle)" <willy@infradead.org>,
Oscar Salvador <osalvador@suse.de>,
Michal Hocko <mhocko@suse.com>, Roman Gushchin <guro@fb.com>,
Alex Shi <alex.shi@linux.alibaba.com>,
Steven Price <steven.price@arm.com>,
Mike Kravetz <mike.kravetz@oracle.com>,
Aili Yao <yaoaili@kingsoft.com>, Jiri Bohac <jbohac@suse.cz>,
"K. Y. Srinivasan" <kys@microsoft.com>,
Haiyang Zhang <haiyangz@microsoft.com>,
Stephen Hemminger <sthemmin@microsoft.com>,
Wei Liu <wei.liu@kernel.org>,
Naoya Horiguchi <naoya.horiguchi@nec.com>,
linux-hyperv@vger.kernel.org,
virtualization@lists.linux-foundation.org,
linux-fsdevel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [PATCH v1 6/7] virtio-mem: use page_offline_(start|end) when setting PageOffline()
Date: Sun, 2 May 2021 09:33:49 +0300 [thread overview]
Message-ID: <YI5HzXN7+ZTNXtcI@kernel.org> (raw)
In-Reply-To: <20210429122519.15183-7-david@redhat.com>
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.
next prev parent reply other threads:[~2021-05-02 6:34 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-29 12:25 [PATCH v1 0/7] fs/proc/kcore: don't read offline sections, logically offline pages and hwpoisoned pages David Hildenbrand
2021-04-29 12:25 ` [PATCH v1 1/7] fs/proc/kcore: drop KCORE_REMAP and KCORE_OTHER David Hildenbrand
2021-05-02 6:31 ` Mike Rapoport
2021-04-29 12:25 ` [PATCH v1 2/7] fs/proc/kcore: pfn_is_ram check only applies to KCORE_RAM David Hildenbrand
2021-05-02 6:31 ` Mike Rapoport
2021-04-29 12:25 ` [PATCH v1 3/7] mm: rename and move page_is_poisoned() David Hildenbrand
2021-05-02 6:32 ` Mike Rapoport
2021-05-05 13:13 ` Michal Hocko
2021-05-05 13:17 ` David Hildenbrand
2021-05-05 13:27 ` Michal Hocko
2021-05-05 13:39 ` David Hildenbrand
2021-05-05 13:45 ` Michal Hocko
2021-05-06 1:08 ` Aili Yao
2021-05-06 0:56 ` Aili Yao
2021-05-06 7:06 ` Michal Hocko
2021-05-06 7:28 ` Aili Yao
2021-05-06 7:55 ` Michal Hocko
2021-05-06 8:52 ` Aili Yao
2021-04-29 12:25 ` [PATCH v1 4/7] fs/proc/kcore: don't read offline sections, logically offline pages and hwpoisoned pages David Hildenbrand
2021-05-02 6:32 ` Mike Rapoport
2021-04-29 12:25 ` [PATCH v1 5/7] mm: introduce page_offline_(begin|end|freeze|unfreeze) to synchronize setting PageOffline() David Hildenbrand
2021-05-02 6:33 ` Mike Rapoport
2021-05-03 8:11 ` David Hildenbrand
2021-05-05 13:24 ` Michal Hocko
2021-05-05 15:10 ` David Hildenbrand
2021-05-05 17:41 ` Mike Rapoport
2021-04-29 12:25 ` [PATCH v1 6/7] virtio-mem: use page_offline_(start|end) when " David Hildenbrand
2021-05-02 6:33 ` Mike Rapoport [this message]
2021-05-03 8:16 ` David Hildenbrand
2021-05-03 8:23 ` Michael S. Tsirkin
2021-04-29 12:25 ` [PATCH v1 7/7] fs/proc/kcore: use page_offline_(freeze|unfreeze) David Hildenbrand
2021-05-02 6:34 ` Mike Rapoport
2021-05-03 8:28 ` David Hildenbrand
2021-05-03 9:28 ` Mike Rapoport
2021-05-03 10:13 ` David Hildenbrand
2021-05-03 11:33 ` Mike Rapoport
2021-05-03 11:35 ` David Hildenbrand
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