David Miller wrote: > You know, for networking over loopback (one of the only real cases > that even matters, if we get a hard interrupt then the return from > that would process any softints), we probably make out just fine > anyways. As long as we hit a local_bh_enable() (and in the return > path from device transmit that's exceedingly likely as all of the > networking locking is BH safe) we'll run the softints from that and > thus long before we get to syscall return.
What about the issue I raised earlier? (I don't think you were copied at that point.) Suppose I have a SCHED_FIFO task spinning on recvmsg() with MSG_DONTWAIT set (and maybe doing other stuff if there are no messages). In this case, schedule() would re-run the spinning task rather than running ksoftirqd. This could prevent any incoming packets from actually being sent up the stack until we get a real hardware interrupt--which could be a whole jiffy if interrupt mitigation is enabled in the net device. (And maybe longer if NOHZ is enabled.) Chris _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
