On Mon, Apr 27, 2026 at 05:34:16PM +0200, Sebastian Andrzej Siewior wrote: > On 2026-04-22 14:52:07 [-0400], Aaron Tomlin wrote: > > From: Daniel Wagner <[email protected]> > > > > Introduce blk_mq_{online|possible}_queue_affinity, which returns the > > queue-to-CPU mapping constraints defined by the block layer. This allows > > other subsystems (e.g., IRQ affinity setup) to respect block layer > > requirements. > > > > It is necessary to provide versions for both the online and possible CPU > > masks because some drivers want to spread their I/O queues only across > > online CPUs, while others prefer to use all possible CPUs. And the mask > > used needs to match with the number of queues requested > > (see blk_num_{online|possible}_queues). > > Which driver uses cpu_possible_mask? This mask is assigned at boot time > once the kernel figured how many CPUs are possible based on ACPI or > whatever the system uses. This mask does not change. > > I only see drivers/scsi/lpfc/lpfc_init.c using it. Looking at > cpu_possible_mask might not be the right thing. It is usually the same > thing as "online" except on system where ACPI thinks that something > could be added via hotplug _or_ if the admin shuts down a CPU via > cpuhotplug _or_ boots with less (there a command line option for that). > > In case cpu_possible_mask != cpu_online_mask the intention is to > allocate memory and setup irqs for the offline CPUs? > > > Signed-off-by: Daniel Wagner <[email protected]> > > Reviewed-by: Hannes Reinecke <[email protected]> > > Signed-off-by: Aaron Tomlin <[email protected]> > Hi Sebastian,
In the next iteration, this patch will be dropped. Moving forward, there will be no more consumers of blk_mq_[online|possible]_queue_affinity(). Please see here [1]. [1]: https://lore.kernel.org/lkml/bnklzljfve53m33xdxv4mlu75kqrkpc3xooxgd3pnbvwjst5hr@btomkooj4crh/ -- Aaron Tomlin
signature.asc
Description: PGP signature
