X-Git-Url: http://git.onelab.eu/?p=linux-2.6.git;a=blobdiff_plain;f=include%2Flinux%2Ftask_io_accounting.h;fp=include%2Flinux%2Ftask_io_accounting.h;h=44d00e9cceea551256df7428be8856e719d04ef1;hp=0000000000000000000000000000000000000000;hb=76828883507a47dae78837ab5dec5a5b4513c667;hpb=64ba3f394c830ec48a1c31b53dcae312c56f1604

diff --git a/include/linux/task_io_accounting.h b/include/linux/task_io_accounting.h
new file mode 100644
index 000000000..44d00e9cc
--- /dev/null
+++ b/include/linux/task_io_accounting.h
@@ -0,0 +1,37 @@
+/*
+ * task_io_accounting: a structure which is used for recording a single task's
+ * IO statistics.
+ *
+ * Don't include this header file directly - it is designed to be dragged in via
+ * sched.h.
+ *
+ * Blame akpm@osdl.org for all this.
+ */
+
+#ifdef CONFIG_TASK_IO_ACCOUNTING
+struct task_io_accounting {
+	/*
+	 * The number of bytes which this task has caused to be read from
+	 * storage.
+	 */
+	u64 read_bytes;
+
+	/*
+	 * The number of bytes which this task has caused, or shall cause to be
+	 * written to disk.
+	 */
+	u64 write_bytes;
+
+	/*
+	 * A task can cause "negative" IO too.  If this task truncates some
+	 * dirty pagecache, some IO which another task has been accounted for
+	 * (in its write_bytes) will not be happening.  We _could_ just
+	 * subtract that from the truncating task's write_bytes, but there is
+	 * information loss in doing that.
+	 */
+	u64 cancelled_write_bytes;
+};
+#else
+struct task_io_accounting {
+};
+#endif