On Wed, Jul 02, 2025 at 06:34:00PM +0200, Daniel Wagner wrote: > The io_queue flag informs multiqueue device drivers where to place > hardware queues. Document this new flag in the isolcpus > command-line argument description. > > Signed-off-by: Daniel Wagner <w...@kernel.org> > --- > Documentation/admin-guide/kernel-parameters.txt | 19 ++++++++++++++++++- > 1 file changed, 18 insertions(+), 1 deletion(-) > > diff --git a/Documentation/admin-guide/kernel-parameters.txt > b/Documentation/admin-guide/kernel-parameters.txt > index > f1f2c0874da9ddfc95058c464fdf5dabaf0de713..7594ac5448575cc895ebf7af0fe051d42dc5e0e9 > 100644 > --- a/Documentation/admin-guide/kernel-parameters.txt > +++ b/Documentation/admin-guide/kernel-parameters.txt > @@ -2590,7 +2590,6 @@ > "number of CPUs in system - 1". > > managed_irq > - > Isolate from being targeted by managed interrupts > which have an interrupt mask containing isolated > CPUs. The affinity of managed interrupts is > @@ -2613,6 +2612,24 @@ > housekeeping CPUs has no influence on those > queues. > > + io_queue > + Isolate from I/O queue work caused by multiqueue > + device drivers. Restrict the placement of > + queues to housekeeping CPUs only, ensuring that > + all I/O work is processed by a housekeeping CPU. > + > + Housekeeping CPUs that serve isolated CPUs > + cannot be offlined. > + > + The io_queue configuration takes precedence over > + managed_irq; thus, when io_queue is used, > + managed_irq has no effect. > + > + Note: When an isolated CPU issues an I/O request, > + it is forwarded to a housekeeping CPU. This will > + trigger a software interrupt on the completion > + path. > + > The format of <cpu-list> is described above. > > iucv= [HW,NET] > > -- > 2.50.0 >
Reviewed-by: Aaron Tomlin <atom...@atomlin.com> -- Aaron Tomlin
