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| author | Vitaly Kuznetsov <vkuznets@redhat.com> | 2018-03-05 06:17:21 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-03-06 18:57:17 +0100 |
| commit | bba072d1627222325e79b7b8e6c0847e4a32d96c (patch) | |
| tree | ad0180b4990be6a6003075e0c08e1004df681542 /Documentation/ABI/stable | |
| parent | hv_balloon: simplify hv_online_page()/hv_page_online_one() (diff) | |
| download | linux-bba072d1627222325e79b7b8e6c0847e4a32d96c.tar.xz linux-bba072d1627222325e79b7b8e6c0847e4a32d96c.zip | |
hv_balloon: fix bugs in num_pages_onlined accounting
Our num_pages_onlined accounting is buggy:
1) In case we're offlining a memory block which was present at boot (e.g.
when there was no hotplug at all) we subtract 32k from 0 and as
num_pages_onlined is unsigned get a very big positive number.
2) Commit 6df8d9aaf3af ("Drivers: hv: balloon: Correctly update onlined
page count") made num_pages_onlined counter accurate on onlining but
totally incorrect on offlining for partly populated regions: no matter
how many pages were onlined and what was actually added to
num_pages_onlined counter we always subtract the full region (32k) so
again, num_pages_onlined can wrap around zero. By onlining/offlining
the same partly populated region multiple times we can make the
situation worse.
Solve these issues by doing accurate accounting on offlining: walk HAS
list, check for covered range and gaps.
Fixes: 6df8d9aaf3af ("Drivers: hv: balloon: Correctly update onlined page count")
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'Documentation/ABI/stable')
0 files changed, 0 insertions, 0 deletions