+ /*
+ * whenever a process try to read/write the file, the
+ * jobid of the process will be saved here, and it'll
+ * be packed into the write PRC when flush later.
+ *
+ * so the read/write statistics for jobid will not be
+ * accurate if the file is shared by different jobs.
+ */
+ char f_jobid[JOBSTATS_JOBID_SIZE];