balloons: IRQ CPU affinity controls#722
Open
askervin wants to merge 5 commits into
Open
Conversation
Add pkg/irq for reading interrupts from /proc/interrupts and reading and writing CPU affinities through /proc/irq/NUMBER/smp_affinity_list. Wire the proc root to the plugin host root and mount the host proc filesystem into the balloons daemonset so that affinities of host IRQs can be updated (write access needed). Signed-off-by: Antti Kervinen <antti.kervinen@intel.com>
Add the balloon type options irqClaim and irqMode to the balloons policy configuration. Signed-off-by: Antti Kervinen <antti.kervinen@intel.com>
Set CPU affinities of system IRQs according to the irqClaim and irqMode balloon type options. For each IRQ, the logic is: find balloons that want exactly this IRQ (irqClaim). If nobody, then find balloons that want all IRQs (irqMode: sink). If no volunteers, then list balloons that do not want any IRQs (irqMode: isolate), and set IRQs affinity to all those who do not care. The default is nobody cares (no irq options present), meaning that the balloons policy will not touch IRQ CPU affinities at all, keeping the original behavior. Affinities are updated after balloon changes. Signed-off-by: Antti Kervinen <antti.kervinen@intel.com>
Add an end-to-end test that verifies irqClaim, irqMode sink and irqMode isolate by inspecting /proc/irq affinities on the test VM. Signed-off-by: Antti Kervinen <antti.kervinen@intel.com>
Describe the irqClaim and irqMode balloon type options and their common use cases. Signed-off-by: Antti Kervinen <antti.kervinen@intel.com>
askervin
force-pushed
the
5iH-balloon-irq
branch
from
July 23, 2026 14:19
f80e862 to
a93ae5f
Compare
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Control IRQ CPU affinities using new
irqClaimandirqModeballoon type options.For each IRQ, the logic is:
Combining irqClaim with "irqMode: isolate" in the same balloon type creates balloons that handle only claimed IRQs and no others.