Re: [PATCH 6/6] drivers/IB,core: reduce scope of mmap_sem

Davidlohr Bueso
2019-01-21T19:12:16Z

On Mon, 21 Jan 2019, Jason Gunthorpe wrote:

>On Mon, Jan 21, 2019 at 09:42:20AM -0800, Davidlohr Bueso wrote:
>> ib_umem_get() uses gup_longterm() and relies on the lock to
>> stabilze the vma_list, so we cannot really get rid of mmap_sem
>> altogether, but now that the counter is atomic, we can get of
>> some complexity that mmap_sem brings with only pinned_vm.
>>
>> Reviewed-by: Ira Weiny <ira.weiny@intel.com>
>> Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
>> ---
>> drivers/infiniband/core/umem.c | 41 ++---------------------------------------
>> 1 file changed, 2 insertions(+), 39 deletions(-)
>
>I think this addresses my comment..
>
>Considering that it is almost all infiniband, I'd rather it go it go
>through the RDMA tree with an ack from mm people? Please advise..

Yeah also Cc'ing Willy who I forgot to add for v2.

>
>Thanks,
>Jason