Messages in this thread | | | Date | Thu, 3 May 2018 21:12:35 +0300 | From | Leon Romanovsky <> | Subject | Re: [PATCH] IB/umem: use tgid instead of pid in ib_umem structure |
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On Thu, May 03, 2018 at 09:33:10AM -0600, Jason Gunthorpe wrote: > On Thu, May 03, 2018 at 10:04:34PM +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. > > > > Signed-off-by: Lidong Chen <lidongchen@tencent.com> > > --- > > drivers/infiniband/core/umem.c | 12 ++++++------ > > include/rdma/ib_umem.h | 2 +- > > 2 files changed, 7 insertions(+), 7 deletions(-) > > Why are we even using a struct pid for this? Does anyone know? >
Can it be related to "fork" support?
> I'm surprised that struct task isn't held in the struct ib_umem.. >
I think that this code can be removed and all accesses to mm_struct can be done with "current->mm".
Thanks [unhandled content-type:application/pgp-signature] | |