1. 16 Feb, 2021 1 commit
    • Christoph Lameter's avatar
      RDMA/ipoib: Remove racy Subnet Manager sendonly join checks · 633d6102
      Christoph Lameter authored
      When a system receives a REREG event from the SM, then the SM information
      in the kernel is marked as invalid and a request is sent to the SM to
      update the information. The SM information is invalid in that time period.
      
      However, receiving a REREG also occurs simultaneously in user space
      applications that are now trying to rejoin the multicast groups. Some of
      those may be sendonly multicast groups which are then failing.
      
      If the SM information is invalid then ib_sa_sendonly_fullmem_support()
      returns false. That is wrong because it just means that we do not know yet
      if the potentially new SM supports sendonly joins.
      
      Sendonly join was introduced in 2015 and all the Subnet managers have
      supported it ever since. So there is no point in checking if a subnet
      manager supports it.
      
      Should an old opensm get a request for a sendonly join then the request
      will fail. The code that is removed here accomodated that situation and
      fell back to a full join.
      
      Falling back to a full join is problematic in itself. The reason to use
      the sendonly join was to reduce the traffic on the Infiniband fabric
      otherwise one could have just stayed with the regular join.  So this patch
      may cause users of very old opensms to discover that lots of traffic
      needlessly crosses their IB fabrics.
      
      Link: https://lore.kernel.org/r/alpine.DEB.2.22.394.2101281845160.13303@www.lameter.comSigned-off-by: default avatarChristoph Lameter <cl@linux.com>
      Signed-off-by: default avatarJason Gunthorpe <jgg@nvidia.com>
      633d6102
  2. 09 Feb, 2021 18 commits
  3. 08 Feb, 2021 13 commits
  4. 05 Feb, 2021 8 commits