Commit graph

6 commits

Author SHA1 Message Date
Yong Cong Sin
b55f3c1c4f kernel: remove CONFIG_MP_NUM_CPUS
`CONFIG_MP_NUM_CPUS` has been deprecated for more than 2
releases, it's time to remove it.

Updated all usage of `CONFIG_MP_NUM_CPUS` to
`CONFIG_MP_MAX_NUM_CPUS`

Signed-off-by: Yong Cong Sin <ycsin@meta.com>
Signed-off-by: Yong Cong Sin <yongcong.sin@gmail.com>
2024-09-19 18:28:37 +01:00
Pisit Sawangvonganan
5ed3cd4bc9 kernel: fix typo
Utilize a code spell-checking tool to scan for and correct spelling errors
in all files within the `kernel` directory.

Signed-off-by: Pisit Sawangvonganan <pisit@ndrsolution.com>
2024-07-08 15:51:37 +02:00
Peter Mitsis
ada3c90f8f kernel: Add CONFIG_SCHED_IPI_CASCADE
When this new Kconfig option is enabled, preempted threads on an SMP
system may generate additional IPIs when they are switched out.

Signed-off-by: Peter Mitsis <peter.mitsis@intel.com>
2024-06-21 20:49:11 -04:00
Peter Mitsis
0bcdae2c62 kernel: Add CONFIG_ARCH_HAS_DIRECTED_IPIS
Platforms that support IPIs allow them to be broadcast via the
new arch_sched_broadcast_ipi() routine (replacing arch_sched_ipi()).
Those that also allow IPIs to be directed to specific CPUs may
use arch_sched_directed_ipi() to do so.

As the kernel has the capability to track which CPUs may need an IPI
(see CONFIG_IPI_OPTIMIZE), this commit updates the signalling of
tracked IPIs to use the directed version if supported; otherwise
they continue to use the broadcast version.

Platforms that allow directed IPIs may see a significant reduction
in the number of IPI related ISRs when CONFIG_IPI_OPTIMIZE is
enabled and the number of CPUs increases.  These platforms can be
identified by the Kconfig option CONFIG_ARCH_HAS_DIRECTED_IPIS.

Signed-off-by: Peter Mitsis <peter.mitsis@intel.com>
2024-06-04 22:35:54 -04:00
Peter Mitsis
d8a4c8a90c kernel: Add CONFIG_IPI_OPTIMIZE
The CONFIG_IPI_OPTIMIZE configuration option allows for the flagging
and subsequent signaling of IPIs to be optimized.

It does this by making each bit in the kernel's pending_ipi field
a flag that indicates whether the corresponding CPU might need an IPI
to trigger the scheduling of a new thread on that CPU.

When a new thread is made ready, we compare that thread against each
of the threads currently executing on the other CPUs. If there is a
chance that that thread should preempt the thread on the other CPU
then we flag that an IPI is needed for that CPU. That is, a clear bit
indicates that the CPU absolutely will not need to reschedule, while a
set bit indicates that the target CPU must make that determination for
itself.

Signed-off-by: Peter Mitsis <peter.mitsis@intel.com>
2024-06-04 22:35:54 -04:00
Anas Nashif
6e95bdeca6 kernel: reorg Kconfigs and split them
The kernel kconfig is becoming too big and unmanageable with too many
options scattered across the file. Move some areas out and reorg main
Kconfig slightly.

Signed-off-by: Anas Nashif <anas.nashif@intel.com>
2024-03-06 19:27:28 -05:00