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> + > + /* If the queue has fewer than GVE_RX_BUF_THRESH_DQO descriptors > + * visible to the hardware, the hardware is in danger of starving > + * and cannot trigger interrupts. > + * > + * We use a threshold of 32 because a single maximum-sized RSC > + * packet can consume up to 19 descriptors in the Rx path. Lower > + * thresholds (e.g., 8 or 16) would be unsafe as they could cause > + * the device to drop/stall on a maximum-sized RSC packet. > + * > + * Start the timer to periodically reschedule NAPI and recover. > + */ > + num_bufs_avail_to_hw = > + ((bufq->tail & ~(GVE_RX_BUF_THRESH_DQO - 1)) - > + bufq->head) & bufq->mask; > + > + if (num_bufs_avail_to_hw < GVE_RX_BUF_THRESH_DQO) { nice bit-arith tricks, but perhaps a simpler condiion like: if (num_avail_slots + num_posted < GVE_RX_BUF_THRESH_DQO) would be sufficient? > + mod_timer(&rx->starvation_timer, > + jiffies + msecs_to_jiffies(GVE_RX_NAPI_RESCHED_MS)); > + } > }