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author | David Vrabel <david.vrabel@citrix.com> | 2012-04-26 19:44:06 +0100 |
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committer | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2012-04-27 16:04:21 -0400 |
commit | 7eb7ce4d2e8991aff4ecb71a81949a907ca755ac (patch) | |
tree | f04b92fc472ca0d41ae5eb61daff6748789cd747 /arch/blackfin | |
parent | b930fe5e1f5646e071facda70b25b137ebeae5af (diff) | |
download | linux-3.10-7eb7ce4d2e8991aff4ecb71a81949a907ca755ac.tar.gz linux-3.10-7eb7ce4d2e8991aff4ecb71a81949a907ca755ac.tar.bz2 linux-3.10-7eb7ce4d2e8991aff4ecb71a81949a907ca755ac.zip |
xen: correctly check for pending events when restoring irq flags
In xen_restore_fl_direct(), xen_force_evtchn_callback() was being
called even if no events were pending. This resulted in (depending on
workload) about a 100 times as many xen_version hypercalls as
necessary.
Fix this by correcting the sense of the conditional jump.
This seems to give a significant performance benefit for some
workloads.
There is some subtle tricksy "..since the check here is trying to
check both pending and masked in a single cmpw, but I think this is
correct. It will call check_events now only when the combined
mask+pending word is 0x0001 (aka unmasked, pending)." (Ian)
CC: stable@kernel.org
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Diffstat (limited to 'arch/blackfin')
0 files changed, 0 insertions, 0 deletions