diff options
Diffstat (limited to 'drivers/scsi/storvsc_drv.c')
| -rw-r--r-- | drivers/scsi/storvsc_drv.c | 96 |
1 files changed, 45 insertions, 51 deletions
diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c index 567f9cd29102..6e4112143c76 100644 --- a/drivers/scsi/storvsc_drv.c +++ b/drivers/scsi/storvsc_drv.c @@ -1406,14 +1406,19 @@ static struct vmbus_channel *get_og_chn(struct storvsc_device *stor_device, } /* - * Our channel array is sparsley populated and we + * Our channel array could be sparsley populated and we * initiated I/O on a processor/hw-q that does not * currently have a designated channel. Fix this. * The strategy is simple: - * I. Ensure NUMA locality - * II. Distribute evenly (best effort) + * I. Prefer the channel associated with the current CPU + * II. Ensure NUMA locality + * III. Distribute evenly (best effort) */ + /* Prefer the channel on the I/O issuing processor/hw-q */ + if (cpumask_test_cpu(q_num, &stor_device->alloced_cpus)) + return stor_device->stor_chns[q_num]; + node_mask = cpumask_of_node(cpu_to_node(q_num)); num_channels = 0; @@ -1469,59 +1474,48 @@ static int storvsc_do_io(struct hv_device *device, /* See storvsc_change_target_cpu(). */ outgoing_channel = READ_ONCE(stor_device->stor_chns[q_num]); if (outgoing_channel != NULL) { - if (outgoing_channel->target_cpu == q_num) { - /* - * Ideally, we want to pick a different channel if - * available on the same NUMA node. - */ - node_mask = cpumask_of_node(cpu_to_node(q_num)); - for_each_cpu_wrap(tgt_cpu, - &stor_device->alloced_cpus, q_num + 1) { - if (!cpumask_test_cpu(tgt_cpu, node_mask)) - continue; - if (tgt_cpu == q_num) - continue; - channel = READ_ONCE( - stor_device->stor_chns[tgt_cpu]); - if (channel == NULL) - continue; - if (hv_get_avail_to_write_percent( - &channel->outbound) - > ring_avail_percent_lowater) { - outgoing_channel = channel; - goto found_channel; - } - } + if (hv_get_avail_to_write_percent(&outgoing_channel->outbound) + > ring_avail_percent_lowater) + goto found_channel; - /* - * All the other channels on the same NUMA node are - * busy. Try to use the channel on the current CPU - */ - if (hv_get_avail_to_write_percent( - &outgoing_channel->outbound) - > ring_avail_percent_lowater) + /* + * Channel is busy, try to find a channel on the same NUMA node + */ + node_mask = cpumask_of_node(cpu_to_node(q_num)); + for_each_cpu_wrap(tgt_cpu, &stor_device->alloced_cpus, + q_num + 1) { + if (!cpumask_test_cpu(tgt_cpu, node_mask)) + continue; + channel = READ_ONCE(stor_device->stor_chns[tgt_cpu]); + if (!channel) + continue; + if (hv_get_avail_to_write_percent(&channel->outbound) + > ring_avail_percent_lowater) { + outgoing_channel = channel; goto found_channel; + } + } - /* - * If we reach here, all the channels on the current - * NUMA node are busy. Try to find a channel in - * other NUMA nodes - */ - for_each_cpu(tgt_cpu, &stor_device->alloced_cpus) { - if (cpumask_test_cpu(tgt_cpu, node_mask)) - continue; - channel = READ_ONCE( - stor_device->stor_chns[tgt_cpu]); - if (channel == NULL) - continue; - if (hv_get_avail_to_write_percent( - &channel->outbound) - > ring_avail_percent_lowater) { - outgoing_channel = channel; - goto found_channel; - } + /* + * If we reach here, all the channels on the current + * NUMA node are busy. Try to find a channel in + * all NUMA nodes + */ + for_each_cpu_wrap(tgt_cpu, &stor_device->alloced_cpus, + q_num + 1) { + channel = READ_ONCE(stor_device->stor_chns[tgt_cpu]); + if (!channel) + continue; + if (hv_get_avail_to_write_percent(&channel->outbound) + > ring_avail_percent_lowater) { + outgoing_channel = channel; + goto found_channel; } } + /* + * If we reach here, all the channels are busy. Use the + * original channel found. + */ } else { spin_lock_irqsave(&stor_device->lock, flags); outgoing_channel = stor_device->stor_chns[q_num]; |