On Mon, Sep 23, 2013 at 06:01:30PM +0200, Peter Zijlstra wrote: > On Mon, Sep 23, 2013 at 08:50:59AM -0700, Paul E. McKenney wrote: > > Not a problem, just stuff the idx into some per-task thing. Either > > task_struct or taskinfo will work fine. > > Still not seeing the point of using srcu though.. > > srcu_read_lock() vs synchronize_srcu() is the same but far more > expensive than preempt_disable() vs synchronize_sched(). Heh! You want the old-style SRCU. ;-) > > Or to put it another way, if the underlying slow-path mutex is > > reader-preference, then the whole thing will be reader-preference. > > Right, so 1) we have no such mutex so we're going to have to open-code > that anyway, and 2) like I just explained in the other email, I want the > pending writer case to be _fast_ as well. At some point I suspect that we will want some form of fairness, but in the meantime, good point. Thanx, Paul -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
