Reduce the default VMbus channel ring buffer size for storvsc SCSI devices from 1 Mbyte to 128 Kbytes. Measurements show that ring buffer sizes above 128 Kbytes do not increase performance even at very high IOPS rates, so don't waste the memory. Also remove the dependence on PAGE_SIZE, since the ring buffer size should not change on architectures where PAGE_SIZE is not 4 Kbytes.
Unified · Split
| @@ -385,7 +385,7 @@ enum storvsc_request_type { · 384 unmodified lines | |||
| 385 | * This is the end of Protocol specific defines. | 385 | * This is the end of Protocol specific defines. |
| 386 | */ | 386 | */ |
| 387 | 387 | ||
| 388 | static int storvsc_ringbuffer_size = (256 * PAGE_SIZE); | 388 | static int storvsc_ringbuffer_size = (128 * 1024); |
| 389 | static u32 max_outstanding_req_per_channel; | 389 | static u32 max_outstanding_req_per_channel; |
| 390 | 390 | ||
| 391 | static int storvsc_vcpus_per_sub_channel = 4; | 391 | static int storvsc_vcpus_per_sub_channel = 4; |