Re: [PATCH v2] IB/umem: ib_ucontext already have tgid, remove pid from ib_umem structure

858585 jemmy
2018-05-16T07:32:50Z

On Wed, May 16, 2018 at 7:14 AM, Jason Gunthorpe <jgg@ziepe.ca> wrote:
> On Tue, May 08, 2018 at 04:50:16PM +0800, Lidong Chen wrote:
>> The userspace may invoke ibv_reg_mr and ibv_dereg_mr by different threads.
>> If when ibv_dereg_mr invoke and the thread which invoked ibv_reg_mr has
>> exited, get_pid_task will return NULL, ib_umem_release does not decrease
>> mm->pinned_vm. This patch fixes it by use tgid in ib_ucontext struct.
>>
>> Signed-off-by: Lidong Chen <lidongchen@tencent.com>
>> ---
>> [v2]
>> - use ib_ucontext tgid instread of tgid in ib_umem structure
>>
>> drivers/infiniband/core/umem.c | 7 +------
>> include/rdma/ib_umem.h | 1 -
>> 2 files changed, 1 insertion(+), 7 deletions(-)
>
> Applied to for-rc, thanks.
>
> It would be nice to send a cleanup to have all the users of tgid doing
> this pattern
>
> task = get_pid_task(umem->context->tgid, PIDTYPE_PID);
> if (!task)
> goto out;
> mm = get_task_mm(task);
>
> To call some kind of common function like ib_get_mr_mm(), just to make
> it really clear what is happening.

OK, I will submit a patch for this.

>
> Jason