RDMA/umem: Avoid synchronize_srcu in the ODP MR destruction path

synchronize_rcu is slow enough that it should be avoided on the syscall
path when user space is destroying MRs. After all the rework we can now
trivially do this by having call_srcu kfree the per_mm.

Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
This commit is contained in:
Jason Gunthorpe
2018-09-16 20:48:11 +03:00
committed by Doug Ledford
父節點 be7a57b41a
當前提交 56ac9dd917
共有 2 個文件被更改,包括 9 次插入2 次删除

查看文件

@@ -307,6 +307,11 @@ found:
return 0;
}
static void free_per_mm(struct rcu_head *rcu)
{
kfree(container_of(rcu, struct ib_ucontext_per_mm, rcu));
}
void put_per_mm(struct ib_umem_odp *umem_odp)
{
struct ib_ucontext_per_mm *per_mm = umem_odp->per_mm;
@@ -334,9 +339,10 @@ void put_per_mm(struct ib_umem_odp *umem_odp)
per_mm->active = false;
up_write(&per_mm->umem_rwsem);
mmu_notifier_unregister(&per_mm->mn, per_mm->mm);
WARN_ON(!RB_EMPTY_ROOT(&per_mm->umem_tree.rb_root));
mmu_notifier_unregister_no_release(&per_mm->mn, per_mm->mm);
put_pid(per_mm->tgid);
kfree(per_mm);
mmu_notifier_call_srcu(&per_mm->rcu, free_per_mm);
}
struct ib_umem_odp *ib_alloc_odp_umem(struct ib_ucontext_per_mm *per_mm,