Commit 4c60d499 authored by Randy Dunlap's avatar Randy Dunlap Committed by Jonathan Corbet
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Documentation: KVM: make corrections to halt-polling.rst 



Module parameters are in sysfs, not debugfs, so change that.

Remove superfluous "that" following "Note:".
Hyphenate "system-wide" values.
Hyphenate "trade-off".

Don't treat "denial of service" as a verb.

Signed-off-by: default avatarRandy Dunlap <rdunlap@infradead.org>
Cc: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: kvm@vger.kernel.org
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Signed-off-by: default avatarJonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20230612030810.23376-2-rdunlap@infradead.org
parent 1954d515

Documentation/virt/kvm/halt-polling.rst

+5 −5
Original line number Diff line number Diff line
@@ -112,11 +112,11 @@ powerpc kvm-hv case. 
|			| function.		    |			      |

+-----------------------+---------------------------+-------------------------+



These module parameters can be set from the debugfs files in:

These module parameters can be set from the sysfs files in:



	/sys/module/kvm/parameters/



Note: that these module parameters are system wide values and are not able to

Note: these module parameters are system-wide values and are not able to

      be tuned on a per vm basis.



Any changes to these parameters will be picked up by new and existing vCPUs the
@@ -142,12 +142,12 @@ Further Notes 
  global max polling interval (halt_poll_ns) then the host will always poll for the

  entire block time and thus cpu utilisation will go to 100%.



- Halt polling essentially presents a trade off between power usage and latency and

- Halt polling essentially presents a trade-off between power usage and latency and

  the module parameters should be used to tune the affinity for this. Idle cpu time is

  essentially converted to host kernel time with the aim of decreasing latency when

  entering the guest.



- Halt polling will only be conducted by the host when no other tasks are runnable on

  that cpu, otherwise the polling will cease immediately and schedule will be invoked to

  allow that other task to run. Thus this doesn't allow a guest to denial of service the

  cpu.
 
  allow that other task to run. Thus this doesn't allow a guest to cause denial of service

  of the cpu.