On 17/10/2022 10:06, Johannes Berg wrote:
From: Johannes Berg <johannes.b...@intel.com> Looks like this is needed now, otherwise we get RCU splats from lockdep. But I don't know anything about this code ...
I went through it several times a couple of years ago looking if there is a way to optimize some of the flushes. A lock there will not hurt. I do not think that it would do anything as that bit should be single-threaded (and most invocations are under locks too), but it will not hurt. So if it is needed to make lockdep shut up - let it be.
Signed-off-by: Johannes Berg <johannes.b...@intel.com> --- arch/um/kernel/tlb.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/um/kernel/tlb.c b/arch/um/kernel/tlb.c index ad449173a1a1..3cc6b753e579 100644 --- a/arch/um/kernel/tlb.c +++ b/arch/um/kernel/tlb.c @@ -587,8 +587,10 @@ void flush_tlb_mm(struct mm_struct *mm) struct vm_area_struct *vma; VMA_ITERATOR(vmi, mm, 0);+ rcu_read_lock();for_each_vma(vmi, vma) fix_range(mm, vma->vm_start, vma->vm_end, 0); + rcu_read_unlock(); }void force_flush_all(void)@@ -597,6 +599,8 @@ void force_flush_all(void) struct vm_area_struct *vma; VMA_ITERATOR(vmi, mm, 0);+ rcu_read_lock();for_each_vma(vmi, vma) fix_range(mm, vma->vm_start, vma->vm_end, 1); + rcu_read_unlock(); }
Acked-By: Anton Ivanov <anton.iva...@cambridgegreys.com> -- Anton R. Ivanov Cambridgegreys Limited. Registered in England. Company Number 10273661 https://www.cambridgegreys.com/ _______________________________________________ linux-um mailing list linux-um@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-um
