On Fri, Nov 09, 2018 at 03:11:31PM -0500, Waiman Long wrote: > The mixing in of a sequence number into the IPC IDs is probably to > avoid ID reuse in userspace as much as possible. With ipcmni_extend > mode, the number of usable sequence numbers is greatly reduced leading > to higher chance of ID reuse. > > To address this issue, we need to conserve the sequence number space > as much as possible. Right now, the sequence number is incremented > for every new ID created. In reality, we only need to increment the > sequence number when one or more IDs have been removed previously to > make sure that those IDs will not be reused when a new one is built. > This is being done irrespective of the ipcmni mode. That's not what I said. Increment the sequence ID when the cursor wraps, not when there's been a deletion.
