- Ursprüngliche Mail -
> Von: "Johannes Berg"
>> -mmap_read_lock(mm);
>> +/* We use a RCU lock instead of a mm lock, because
>> + * this can be invoked out of critical/atomic sections
>> + * and that does not agree with the sleepable semantics
>> + * of the standard sem
On Fri, Sept 22, 2023 at 06:56, anton.iva...@cambridgegreys.com wrote:
>
> From: Anton Ivanov anton.iva...@cambridgegreys.com
>
>
> 1. Preemption requires saving/restoring FPU state. This patch
> adds support for it using GCC intrinsics as well as appropriate
> storage space in the thread struct
On 22/09/2023 12:22, Johannes Berg wrote:
4. UML TLB flush is also invoked during a fork. This happens
with interrupts and preempt disabled which disagrees with the
standard mm locking via rwsem. The mm lock for this code path
had to be replaced with an rcu.
For the record, even if I figure
>
> 4. UML TLB flush is also invoked during a fork. This happens
> with interrupts and preempt disabled which disagrees with the
> standard mm locking via rwsem. The mm lock for this code path
> had to be replaced with an rcu.
For the record, even if I figured out this gets rid of the complaints,
On 22/09/2023 11:56, anton.iva...@cambridgegreys.com wrote:
From: Anton Ivanov
1. Preemption requires saving/restoring FPU state. This patch
adds support for it using GCC intrinsics as well as appropriate
storage space in the thread structure.
2. irq critical sections need preempt_disable()
From: Anton Ivanov
1. Preemption requires saving/restoring FPU state. This patch
adds support for it using GCC intrinsics as well as appropriate
storage space in the thread structure.
2. irq critical sections need preempt_disable()/preempt_enable().
3. TLB critical sections need preempt_disable
