• D
    xfs: add trace points for log forces · 14c26c6a
    Dave Chinner 提交于
    To enable easy tracing of the location of log forces and the
    frequency of them via perf, add a pair of trace points to the log
    force functions.  This will help debug where excessive log forces
    are being issued from by simple perf commands like:
    
    # ~/perf/perf top -e xfs:xfs_log_force -G -U
    
    Which gives this sort of output:
    
    Events: 141  xfs:xfs_log_force
    -  100.00%  [kernel]  [k] xfs_log_force
       - xfs_log_force
            87.04% xfsaild
               kthread
               kernel_thread_helper
          - 12.87% xfs_buf_lock
               _xfs_buf_find
               xfs_buf_get
               xfs_trans_get_buf
               xfs_da_do_buf
               xfs_da_get_buf
               xfs_dir2_data_init
               xfs_dir2_leaf_addname
               xfs_dir_createname
               xfs_create
               xfs_vn_mknod
               xfs_vn_create
               vfs_create
               do_last.isra.41
               path_openat
               do_filp_open
               do_sys_open
               sys_open
               system_call_fastpath
    Signed-off-by: NDave Chinner <dchinner@redhat.com>
    Reviewed-by: NMark Tinguely <tinguely@sgi.com>
    Signed-off-by: NBen Myers <bpm@sig.com>
    14c26c6a
xfs_log.c 99.7 KB