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| author |   Parav Pandit <parav@nvidia.com> | 2021-07-21 17:26:45 +0300 |
|---|---|---|
| committer |   Michael S. Tsirkin <mst@redhat.com> | 2021-08-10 11:50:54 -0400 |
| commit | 60f0779862e4ab943810187752c462e85f5fa371 (patch) | |
| tree | 27575f63cc1973c87b8be9a32db44f20ba069df7 /tools/perf/scripts/python/export-to-postgresql.py | |
| parent | Linux 5.14-rc5 (diff) | |
| download | linux-dev-60f0779862e4ab943810187752c462e85f5fa371.tar.xz linux-dev-60f0779862e4ab943810187752c462e85f5fa371.zip | |
virtio: Improve vq->broken access to avoid any compiler optimization
Currently vq->broken field is read by virtqueue_is_broken() in busy
loop in one context by virtnet_send_command().
vq->broken is set to true in other process context by
virtio_break_device(). Reader and writer are accessing it without any
synchronization. This may lead to a compiler optimization which may
result to optimize reading vq->broken only once.
Hence, force reading vq->broken on each invocation of
virtqueue_is_broken() and also force writing it so that such
update is visible to the readers.
It is a theoretical fix that isn't yet encountered in the field.
Signed-off-by: Parav Pandit <parav@nvidia.com>
Link: https://lore.kernel.org/r/20210721142648.1525924-2-parav@nvidia.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'tools/perf/scripts/python/export-to-postgresql.py')
0 files changed, 0 insertions, 0 deletions