]> git.proxmox.com Git - mirror_ubuntu-disco-kernel.git/commit
IB/hfi1: Rework debugfs to use SRCU
authorMike Marciniszyn <mike.marciniszyn@intel.com>
Wed, 31 Aug 2016 14:24:46 +0000 (07:24 -0700)
committerDoug Ledford <dledford@redhat.com>
Fri, 2 Sep 2016 18:26:55 +0000 (14:26 -0400)
commit16170d9c102764f76c58aad244e947f4e3f44590
tree717586260a4fa59c6fee4fae4400e082207f43cd
parent429b6a721727d49d8565b50a6bc0dc42432383a9
IB/hfi1: Rework debugfs to use SRCU

The debugfs RCU trips many debug kernel warnings because of potential
sleeps with an RCU read lock held. This includes both user copy calls
and slab allocations throughout the file.

This patch switches the RCU to use SRCU for file remove/access
race protection.

In one case, the SRCU is implicit in the use of the raw debugfs file
object and just works.

In the seq_file case, a wrapper around seq_read() and seq_lseek() is
used to enforce the SRCU using the debugfs supplied functions
debugfs_use_file_start() and debugfs_use_file_stop().

The sychronize_rcu() is deleted since the SRCU prevents the remove
access race.

The RCU locking is kept for qp_stats since the QP hash list is
protected using the non-sleepable RCU.

Reviewed-by: Sebastian Sanchez <sebastian.sanchez@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
drivers/infiniband/hw/hfi1/debugfs.c