Le 22/04/2019 à 22:57, Jerome Glisse a écrit :
On Tue, Apr 16, 2019 at 03:45:12PM +0200, Laurent Dufour wrote:
This allows to search for a VMA structure without holding the mmap_sem.
The search is repeated while the mm seqlock is changing and until we found
a valid VMA.
While under the RCU
Le 23/04/2019 à 11:27, Peter Zijlstra a écrit :
On Tue, Apr 16, 2019 at 03:45:12PM +0200, Laurent Dufour wrote:
This allows to search for a VMA structure without holding the mmap_sem.
The search is repeated while the mm seqlock is changing and until we found
a valid VMA.
While under the RCU
On Tue, 23 Apr 2019, Peter Zijlstra wrote:
Also; the initial motivation was prefaulting large VMAs and the
contention on mmap was killing things; but similarly, the contention on
the refcount (I did try that) killed things just the same.
Right, this is just like what can happen with per-vma
On Tue, Apr 16, 2019 at 03:45:12PM +0200, Laurent Dufour wrote:
> This allows to search for a VMA structure without holding the mmap_sem.
>
> The search is repeated while the mm seqlock is changing and until we found
> a valid VMA.
>
> While under the RCU protection, a reference is taken on the
On Tue, Apr 16, 2019 at 03:45:12PM +0200, Laurent Dufour wrote:
> This allows to search for a VMA structure without holding the mmap_sem.
>
> The search is repeated while the mm seqlock is changing and until we found
> a valid VMA.
>
> While under the RCU protection, a reference is taken on the
This allows to search for a VMA structure without holding the mmap_sem.
The search is repeated while the mm seqlock is changing and until we found
a valid VMA.
While under the RCU protection, a reference is taken on the VMA, so the
caller must call put_vma() once it not more need the VMA
