* Oleg Nesterov <oleg@xxxxxxxxxx> wrote: > On 02/18, Ingo Molnar wrote: > > > > * Oleg Nesterov <oleg@xxxxxxxxxx> wrote: > > > > > Unlike __mod_timer(..., bool pending_only), it preserves the CPU on > > > which the timer is pending. > > > > > > Or, perhaps, we can modify __mod_timer() further, > > > > if then i'd put it into a separate commit. > > > > I think the auto-migration of all the mod_timer() variants is a > > scalability feature: if for example a networking socket's main > > user migrates to another CPU, then the timer 'follows' it - even > > if the timer never actually expires (which is quite common for > > high-speed high-reliability networking transports). > > OK. > > But sometimes it is better (or necessary) to prevent the > migration. Since you already are changed __mod_timer() it > would be ugly to add yet another helper. Perhaps we should > turn "bool pending_only" into "int flags" right now? > > This is minor, and perhaps we will never need the > TIMER_DONT_MIGRATE flag. But if ever need, then we have to > audit all callers. hm, dunno - such unused flags are generally frowned upon, especially if they influence the code flow in a dynamic way. In fact i tried to avoid this flag here too - but __mod_timer() is too small, the flag is used in the middle, and two separate helpers would have made the code look worse. Ingo -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
