Once stop_machine() is gone from the CPU offline path, we won't be able
to depend on disabling preemption to prevent CPUs from going offline
from under us.
Use the get/put_online_cpus_atomic() APIs to prevent CPUs from going
offline, while invoking from atomic context.
Cc: Richard Henderson <rth@xxxxxxxxxxx>
Cc: Ivan Kokshaysky <ink@xxxxxxxxxxxxxxxxxxxx>
Cc: Matt Turner <mattst88@xxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: linux-alpha@xxxxxxxxxxxxxxx
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@xxxxxxxxxxxxxxxxxx>
---
arch/alpha/kernel/smp.c | 19 +++++++++----------
1 file changed, 9 insertions(+), 10 deletions(-)
diff --git a/arch/alpha/kernel/smp.c b/arch/alpha/kernel/smp.c
index 7b60834..e147268 100644
--- a/arch/alpha/kernel/smp.c
+++ b/arch/alpha/kernel/smp.c
@@ -497,7 +497,6 @@ smp_cpus_done(unsigned int max_cpus)
((bogosum + 2500) / (5000/HZ)) % 100);
}
-
void
smp_percpu_timer_interrupt(struct pt_regs *regs)
{
@@ -681,7 +680,7 @@ ipi_flush_tlb_mm(void *x)
void
flush_tlb_mm(struct mm_struct *mm)
{
- preempt_disable();
+ get_online_cpus_atomic();
if (mm == current->active_mm) {
flush_tlb_current(mm);
@@ -693,7 +692,7 @@ flush_tlb_mm(struct mm_struct *mm)
if (mm->context[cpu])
mm->context[cpu] = 0;
}
- preempt_enable();
+ put_online_cpus_atomic();
return;
}
}
@@ -702,7 +701,7 @@ flush_tlb_mm(struct mm_struct *mm)
printk(KERN_CRIT "flush_tlb_mm: timed out\n");
}
- preempt_enable();
+ put_online_cpus_atomic();
}
EXPORT_SYMBOL(flush_tlb_mm);
@@ -730,7 +729,7 @@ flush_tlb_page(struct vm_area_struct *vma, unsigned long addr)
struct flush_tlb_page_struct data;
struct mm_struct *mm = vma->vm_mm;
- preempt_disable();
+ get_online_cpus_atomic();
if (mm == current->active_mm) {
flush_tlb_current_page(mm, vma, addr);
@@ -742,7 +741,7 @@ flush_tlb_page(struct vm_area_struct *vma, unsigned long addr)
if (mm->context[cpu])
mm->context[cpu] = 0;
}
- preempt_enable();
+ put_online_cpus_atomic();
return;
}
}
@@ -755,7 +754,7 @@ flush_tlb_page(struct vm_area_struct *vma, unsigned long addr)
printk(KERN_CRIT "flush_tlb_page: timed out\n");
}
- preempt_enable();
+ put_online_cpus_atomic();
}
EXPORT_SYMBOL(flush_tlb_page);
@@ -786,7 +785,7 @@ flush_icache_user_range(struct vm_area_struct *vma, struct page *page,
if ((vma->vm_flags & VM_EXEC) == 0)
return;
- preempt_disable();
+ get_online_cpus_atomic();
if (mm == current->active_mm) {
__load_new_mm_context(mm);
@@ -798,7 +797,7 @@ flush_icache_user_range(struct vm_area_struct *vma, struct page *page,
if (mm->context[cpu])
mm->context[cpu] = 0;
}
- preempt_enable();
+ put_online_cpus_atomic();
return;
}
}
@@ -807,5 +806,5 @@ flush_icache_user_range(struct vm_area_struct *vma, struct page *page,
printk(KERN_CRIT "flush_icache_page: timed out\n");
}
- preempt_enable();
+ put_online_cpus_atomic();
}
--
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