On Mon, Apr 30, 2018 at 01:10:49PM -0400, Doug Ledford wrote: > On Mon, 2018-04-30 at 08:49 -0600, Jason Gunthorpe wrote: > > On Mon, Apr 23, 2018 at 10:16:18PM +0300, jackm wrote: > > > > > > > TIDs need to be globally unique on the entire machine. > > > Jason, that is not exactly correct. > > > > The expecation for /dev/umad users is that they all receive locally > > unique TID prefixes. The kernel may be OK to keep things port-specific > > but it is slightly breaking the API we are presenting to userspace to > > allow them to alias.. > > > > Jason > > Would people be happier with this commit message then: > > IB/core: Make ib_mad_client_id atomic > > Currently, the kernel protects access to the agent ID allocator on a per > port basis using a spinlock, so it is impossible for two apps/threads on > the same port to get the same TID, but it is entirely possible for two > threads on different ports to end up with the same TID. > > As this can be confusing (regardless of it being legal according to the > IB Spec 1.3, C13-18.1.1, in section 13.4.6.4 - TransactionID usage), > and as the rdma-core user space API for /dev/umad devices implies unique > TIDs even across ports, make the TID an atomic type so that no two > allocations, regardless of port number, will be the same. > > Signed-off-by: Håkon Bugge <haakon.bugge@xxxxxxxxxx> > Reviewed-by: Jack Morgenstein <jackm@xxxxxxxxxxxxxxxxxx> > Reviewed-by: Ira Weiny <ira.weiny@xxxxxxxxx> > Reviewed-by: Zhu Yanjun <yanjun.zhu@xxxxxxxxxx> > Signed-off-by: Doug Ledford <dledford@xxxxxxxxxx> fine for me Jason -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
