[PATCH v5 12/18] arm64: sched/preempt: Enable HAS_SEPARATE_PREEMPT_RESCHED_BITS
Boqun Feng <[email protected]>
| Newsgroups | org.kernel.vger.rust-for-linux,org.kernel.vger.linux-kernel |
|---|---|
| Message-ID | <[email protected]> |
Arm64 already uses 64-bit preempt count and the need reschedule bit is maintained in a separate 32-bit word from the preempt count. Therefore preempt count has enough bits to represent 16 levels of NMI nesting, hence enable it for arm64. This saves a per-CPU variable and additional instructions in the NMI path. Signed-off-by: Boqun Feng <[email protected]> --- arch/arm64/Kconfig | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index b3afe0688919..349c3533cd1e 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -247,6 +247,7 @@ config ARM64 select PCI_SYSCALL if PCI select POWER_RESET select POWER_SUPPLY + select HAS_SEPARATE_PREEMPT_RESCHED_BITS select SPARSE_IRQ select SWIOTLB select SYSCTL_EXCEPTION_TRACE -- 2.50.1 (Apple Git-155)