From 14c26c6a05de138a4fd9a0c05ff8e7435a618324 Mon Sep 17 00:00:00 2001 From: Dave Chinner Date: Tue, 24 Apr 2012 16:33:31 +1000 Subject: xfs: add trace points for log forces 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: Dave Chinner Reviewed-by: Mark Tinguely Signed-off-by: Ben Myers --- fs/xfs/xfs_log.c | 2 ++ fs/xfs/xfs_trace.h | 16 ++++++++++++++++ 2 files changed, 18 insertions(+) diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c index 9b10a15295a..6b965bf450e 100644 --- a/fs/xfs/xfs_log.c +++ b/fs/xfs/xfs_log.c @@ -2941,6 +2941,7 @@ xfs_log_force( { int error; + trace_xfs_log_force(mp, 0); error = _xfs_log_force(mp, flags, NULL); if (error) xfs_warn(mp, "%s: error %d returned.", __func__, error); @@ -3089,6 +3090,7 @@ xfs_log_force_lsn( { int error; + trace_xfs_log_force(mp, lsn); error = _xfs_log_force_lsn(mp, lsn, flags, NULL); if (error) xfs_warn(mp, "%s: error %d returned.", __func__, error); diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h index febff43176f..7cf9d3529e5 100644 --- a/fs/xfs/xfs_trace.h +++ b/fs/xfs/xfs_trace.h @@ -874,6 +874,22 @@ DECLARE_EVENT_CLASS(xfs_log_item_class, __print_flags(__entry->flags, "|", XFS_LI_FLAGS)) ) +TRACE_EVENT(xfs_log_force, + TP_PROTO(struct xfs_mount *mp, xfs_lsn_t lsn), + TP_ARGS(mp, lsn), + TP_STRUCT__entry( + __field(dev_t, dev) + __field(xfs_lsn_t, lsn) + ), + TP_fast_assign( + __entry->dev = mp->m_super->s_dev; + __entry->lsn = lsn; + ), + TP_printk("dev %d:%d lsn 0x%llx", + MAJOR(__entry->dev), MINOR(__entry->dev), + __entry->lsn) +) + #define DEFINE_LOG_ITEM_EVENT(name) \ DEFINE_EVENT(xfs_log_item_class, name, \ TP_PROTO(struct xfs_log_item *lip), \ -- cgit v1.2.3