==> Regarding Re: [PATCH 1/2] e1000: fix netpoll with NAPI; Mitch Williams <[EMAIL PROTECTED]> adds:
mitch.a.williams> On Wed, 2006-06-07 at 11:44 -0700, Jeff Moyer wrote: >> That patch locks around the tx clean routine. As such, it doesn't >> prevent the problem. mitch.a.williams> The call to netif_rx_schedule_prep provides locking mitch.a.williams> because it sets the __LINK_STATE_RX_SCHED bit atomically. mitch.a.williams> The spinlock around e1000_clean_tx_irq is to protect it mitch.a.williams> from other calls to the transmit routine, not NAPI. Yes, but what prevents recursion in the poll routine? Consider that the poll routine could end up triggerring a printk (think iptables, here). In that case, you end up calling into netpoll, and if the tx ring is full, we call the poll_controller routine. We've now recursed. The poll lock was originally introduced to prevent recursion, not concurrent access. -Jeff - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
