[PATCH 4/6] sparc/mm: Do not disable preemption in lazy MMU mode
From: Alexander Gordeev <agordeev@linux.ibm.com>
Date: 2025-06-12 17:36:52
Also in:
linux-mm, linux-s390, lkml, sparclinux, xen-devel
Subsystem:
sparc + ultrasparc (sparc/sparc64), the rest · Maintainers:
"David S. Miller", Andreas Larsson, Linus Torvalds
Commit a1d416bf9faf ("sparc/mm: disable preemption in lazy mmu mode")
is not necessary anymore, since the lazy MMU mode is entered with a
spinlock held and sparc does not support Real-Time. Thus, upon entering
the lazy mode the preemption is already disabled.
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
---
arch/sparc/include/asm/tlbflush_64.h | 2 +-
arch/sparc/mm/tlb.c | 12 ++++++++----
2 files changed, 9 insertions(+), 5 deletions(-)
diff --git a/arch/sparc/include/asm/tlbflush_64.h b/arch/sparc/include/asm/tlbflush_64.h
index 8b8cdaa69272..a6d8068fb211 100644
--- a/arch/sparc/include/asm/tlbflush_64.h
+++ b/arch/sparc/include/asm/tlbflush_64.h@@ -44,7 +44,7 @@ void flush_tlb_kernel_range(unsigned long start, unsigned long end); void flush_tlb_pending(void); void arch_enter_lazy_mmu_mode(void); void arch_leave_lazy_mmu_mode(void); -#define arch_flush_lazy_mmu_mode() do {} while (0) +void arch_flush_lazy_mmu_mode(void); /* Local cpu only. */ void __flush_tlb_all(void);
diff --git a/arch/sparc/mm/tlb.c b/arch/sparc/mm/tlb.c
index a35ddcca5e76..e46dfd5f2583 100644
--- a/arch/sparc/mm/tlb.c
+++ b/arch/sparc/mm/tlb.c@@ -52,10 +52,9 @@ void flush_tlb_pending(void) void arch_enter_lazy_mmu_mode(void) { - struct tlb_batch *tb; + struct tlb_batch *tb = this_cpu_ptr(&tlb_batch); - preempt_disable(); - tb = this_cpu_ptr(&tlb_batch); + VM_WARN_ON_ONCE(preemptible()); tb->active = 1; }
@@ -63,10 +62,15 @@ void arch_leave_lazy_mmu_mode(void) { struct tlb_batch *tb = this_cpu_ptr(&tlb_batch); + VM_WARN_ON_ONCE(preemptible()); if (tb->tlb_nr) flush_tlb_pending(); tb->active = 0; - preempt_enable(); +} + +void arch_flush_lazy_mmu_mode(void) +{ + VM_WARN_ON_ONCE(preemptible()); } static void tlb_batch_add_one(struct mm_struct *mm, unsigned long vaddr,
--
2.48.1