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author | Alex Williamson <alex.williamson@redhat.com> | 2015-02-06 14:19:12 -0700 |
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committer | Alex Williamson <alex.williamson@redhat.com> | 2015-02-06 14:19:12 -0700 |
commit | c5e6688752c25434d71920bc969f9fab60353c5e (patch) | |
tree | 176ad1355f26bc2542e320471ab1691400c0974c /Documentation/arm | |
parent | babbf1760970f141eb4021288ce0fb7196bc1a23 (diff) | |
download | linux-c5e6688752c25434d71920bc969f9fab60353c5e.tar.bz2 |
vfio/type1: Add conditional rescheduling
IOMMU operations can be expensive and it's not very difficult for a
user to give us a lot of work to do for a map or unmap operation.
Killing a large VM will vfio assigned devices can result in soft
lockups and IOMMU tracing shows that we can easily spend 80% of our
time with need-resched set. A sprinkling of conf_resched() calls
after map and unmap calls has a very tiny affect on performance
while resulting in traces with <1% of calls overflowing into needs-
resched.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Diffstat (limited to 'Documentation/arm')
0 files changed, 0 insertions, 0 deletions