| Andrew Morton | 7c3ab73 | 2006-12-10 02:19:19 -0800 | [diff] [blame] | 1 | /* |
| 2 | * task_io_accounting: a structure which is used for recording a single task's |
| 3 | * IO statistics. |
| 4 | * |
| 5 | * Don't include this header file directly - it is designed to be dragged in via |
| 6 | * sched.h. |
| 7 | * |
| 8 | * Blame akpm@osdl.org for all this. |
| 9 | */ |
| 10 | |
| 11 | #ifdef CONFIG_TASK_IO_ACCOUNTING |
| 12 | struct task_io_accounting { |
| 13 | /* |
| 14 | * The number of bytes which this task has caused to be read from |
| 15 | * storage. |
| 16 | */ |
| 17 | u64 read_bytes; |
| 18 | |
| 19 | /* |
| 20 | * The number of bytes which this task has caused, or shall cause to be |
| 21 | * written to disk. |
| 22 | */ |
| 23 | u64 write_bytes; |
| 24 | |
| 25 | /* |
| 26 | * A task can cause "negative" IO too. If this task truncates some |
| 27 | * dirty pagecache, some IO which another task has been accounted for |
| 28 | * (in its write_bytes) will not be happening. We _could_ just |
| 29 | * subtract that from the truncating task's write_bytes, but there is |
| 30 | * information loss in doing that. |
| 31 | */ |
| 32 | u64 cancelled_write_bytes; |
| 33 | }; |
| 34 | #else |
| 35 | struct task_io_accounting { |
| 36 | }; |
| 37 | #endif |