xfs: event tracing support

Convert the old xfs tracing support that could only be used with the
out of tree kdb and xfsidbg patches to use the generic event tracer.

To use it make sure CONFIG_EVENT_TRACING is enabled and then enable
all xfs trace channels by:

   echo 1 > /sys/kernel/debug/tracing/events/xfs/enable

or alternatively enable single events by just doing the same in one
event subdirectory, e.g.

   echo 1 > /sys/kernel/debug/tracing/events/xfs/xfs_ihold/enable

or set more complex filters, etc. In Documentation/trace/events.txt
all this is desctribed in more detail.  To reads the events do a

   cat /sys/kernel/debug/tracing/trace

Compared to the last posting this patch converts the tracing mostly to
the one tracepoint per callsite model that other users of the new
tracing facility also employ.  This allows a very fine-grained control
of the tracing, a cleaner output of the traces and also enables the
perf tool to use each tracepoint as a virtual performance counter,
     allowing us to e.g. count how often certain workloads git various
     spots in XFS.  Take a look at

    http://lwn.net/Articles/346470/

for some examples.

Also the btree tracing isn't included at all yet, as it will require
additional core tracing features not in mainline yet, I plan to
deliver it later.

And the really nice thing about this patch is that it actually removes
many lines of code while adding this nice functionality:

 fs/xfs/Makefile                |    8
 fs/xfs/linux-2.6/xfs_acl.c     |    1
 fs/xfs/linux-2.6/xfs_aops.c    |   52 -
 fs/xfs/linux-2.6/xfs_aops.h    |    2
 fs/xfs/linux-2.6/xfs_buf.c     |  117 +--
 fs/xfs/linux-2.6/xfs_buf.h     |   33
 fs/xfs/linux-2.6/xfs_fs_subr.c |    3
 fs/xfs/linux-2.6/xfs_ioctl.c   |    1
 fs/xfs/linux-2.6/xfs_ioctl32.c |    1
 fs/xfs/linux-2.6/xfs_iops.c    |    1
 fs/xfs/linux-2.6/xfs_linux.h   |    1
 fs/xfs/linux-2.6/xfs_lrw.c     |   87 --
 fs/xfs/linux-2.6/xfs_lrw.h     |   45 -
 fs/xfs/linux-2.6/xfs_super.c   |  104 ---
 fs/xfs/linux-2.6/xfs_super.h   |    7
 fs/xfs/linux-2.6/xfs_sync.c    |    1
 fs/xfs/linux-2.6/xfs_trace.c   |   75 ++
 fs/xfs/linux-2.6/xfs_trace.h   | 1369 +++++++++++++++++++++++++++++++++++++++++
 fs/xfs/linux-2.6/xfs_vnode.h   |    4
 fs/xfs/quota/xfs_dquot.c       |  110 ---
 fs/xfs/quota/xfs_dquot.h       |   21
 fs/xfs/quota/xfs_qm.c          |   40 -
 fs/xfs/quota/xfs_qm_syscalls.c |    4
 fs/xfs/support/ktrace.c        |  323 ---------
 fs/xfs/support/ktrace.h        |   85 --
 fs/xfs/xfs.h                   |   16
 fs/xfs/xfs_ag.h                |   14
 fs/xfs/xfs_alloc.c             |  230 +-----
 fs/xfs/xfs_alloc.h             |   27
 fs/xfs/xfs_alloc_btree.c       |    1
 fs/xfs/xfs_attr.c              |  107 ---
 fs/xfs/xfs_attr.h              |   10
 fs/xfs/xfs_attr_leaf.c         |   14
 fs/xfs/xfs_attr_sf.h           |   40 -
 fs/xfs/xfs_bmap.c              |  507 +++------------
 fs/xfs/xfs_bmap.h              |   49 -
 fs/xfs/xfs_bmap_btree.c        |    6
 fs/xfs/xfs_btree.c             |    5
 fs/xfs/xfs_btree_trace.h       |   17
 fs/xfs/xfs_buf_item.c          |   87 --
 fs/xfs/xfs_buf_item.h          |   20
 fs/xfs/xfs_da_btree.c          |    3
 fs/xfs/xfs_da_btree.h          |    7
 fs/xfs/xfs_dfrag.c             |    2
 fs/xfs/xfs_dir2.c              |    8
 fs/xfs/xfs_dir2_block.c        |   20
 fs/xfs/xfs_dir2_leaf.c         |   21
 fs/xfs/xfs_dir2_node.c         |   27
 fs/xfs/xfs_dir2_sf.c           |   26
 fs/xfs/xfs_dir2_trace.c        |  216 ------
 fs/xfs/xfs_dir2_trace.h        |   72 --
 fs/xfs/xfs_filestream.c        |    8
 fs/xfs/xfs_fsops.c             |    2
 fs/xfs/xfs_iget.c              |  111 ---
 fs/xfs/xfs_inode.c             |   67 --
 fs/xfs/xfs_inode.h             |   76 --
 fs/xfs/xfs_inode_item.c        |    5
 fs/xfs/xfs_iomap.c             |   85 --
 fs/xfs/xfs_iomap.h             |    8
 fs/xfs/xfs_log.c               |  181 +----
 fs/xfs/xfs_log_priv.h          |   20
 fs/xfs/xfs_log_recover.c       |    1
 fs/xfs/xfs_mount.c             |    2
 fs/xfs/xfs_quota.h             |    8
 fs/xfs/xfs_rename.c            |    1
 fs/xfs/xfs_rtalloc.c           |    1
 fs/xfs/xfs_rw.c                |    3
 fs/xfs/xfs_trans.h             |   47 +
 fs/xfs/xfs_trans_buf.c         |   62 -
 fs/xfs/xfs_vnodeops.c          |    8
 70 files changed, 2151 insertions(+), 2592 deletions(-)

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>

1 files changed, 41 insertions, 76 deletions

diff --git a/fs/xfs/linux-2.6/xfs_buf.c b/fs/xfs/linux-2.6/xfs_buf.c
index 4ddc973aea7a..b4c7d4248aac 100644
--- a/fs/xfs/linux-2.6/xfs_buf.c
+++ b/fs/xfs/linux-2.6/xfs_buf.c
@@ -39,6 +39,7 @@
 #include "xfs_ag.h"
 #include "xfs_dmapi.h"
 #include "xfs_mount.h"
+#include "xfs_trace.h"
 
 static kmem_zone_t *xfs_buf_zone;
 STATIC int xfsbufd(void *);
@@ -53,34 +54,6 @@ static struct workqueue_struct *xfslogd_workqueue;
 struct workqueue_struct *xfsdatad_workqueue;
 struct workqueue_struct *xfsconvertd_workqueue;
 
-#ifdef XFS_BUF_TRACE
-void
-xfs_buf_trace(
-        xfs_buf_t       *bp,
-        char            *id,
-        void            *data,
-        void            *ra)
-{
-        ktrace_enter(xfs_buf_trace_buf,
-                bp, id,
-                (void *)(unsigned long)bp->b_flags,
-                (void *)(unsigned long)bp->b_hold.counter,
-                (void *)(unsigned long)bp->b_sema.count,
-                (void *)current,
-                data, ra,
-                (void *)(unsigned long)((bp->b_file_offset>>32) & 0xffffffff),
-                (void *)(unsigned long)(bp->b_file_offset & 0xffffffff),
-                (void *)(unsigned long)bp->b_buffer_length,
-                NULL, NULL, NULL, NULL, NULL);
-}
-ktrace_t *xfs_buf_trace_buf;
-#define XFS_BUF_TRACE_SIZE      4096
-#define XB_TRACE(bp, id, data)  \
-        xfs_buf_trace(bp, id, (void *)data, (void *)__builtin_return_address(0))
-#else
-#define XB_TRACE(bp, id, data)  do { } while (0)
-#endif
-
 #ifdef XFS_BUF_LOCK_TRACKING
 # define XB_SET_OWNER(bp)       ((bp)->b_last_holder = current->pid)
 # define XB_CLEAR_OWNER(bp)     ((bp)->b_last_holder = -1)
@@ -279,7 +252,8 @@ _xfs_buf_initialize(
         init_waitqueue_head(&bp->b_waiters);
 
         XFS_STATS_INC(xb_create);
-        XB_TRACE(bp, "initialize", target);
+
+        trace_xfs_buf_init(bp, _RET_IP_);
 }
 
 /*
@@ -332,7 +306,7 @@ void
 xfs_buf_free(
         xfs_buf_t               *bp)
 {
-        XB_TRACE(bp, "free", 0);
+        trace_xfs_buf_free(bp, _RET_IP_);
 
         ASSERT(list_empty(&bp->b_hash_list));
 
@@ -445,7 +419,6 @@ _xfs_buf_lookup_pages(
         if (page_count == bp->b_page_count)
                 bp->b_flags |= XBF_DONE;
 
-        XB_TRACE(bp, "lookup_pages", (long)page_count);
         return error;
 }
 
@@ -548,7 +521,6 @@ found:
         if (down_trylock(&bp->b_sema)) {
                 if (!(flags & XBF_TRYLOCK)) {
                         /* wait for buffer ownership */
-                        XB_TRACE(bp, "get_lock", 0);
                         xfs_buf_lock(bp);
                         XFS_STATS_INC(xb_get_locked_waited);
                 } else {
@@ -571,7 +543,8 @@ found:
                 ASSERT((bp->b_flags & _XBF_DELWRI_Q) == 0);
                 bp->b_flags &= XBF_MAPPED;
         }
-        XB_TRACE(bp, "got_lock", 0);
+
+        trace_xfs_buf_find(bp, flags, _RET_IP_);
         XFS_STATS_INC(xb_get_locked);
         return bp;
 }
@@ -627,7 +600,7 @@ xfs_buf_get(
         bp->b_bn = ioff;
         bp->b_count_desired = bp->b_buffer_length;
 
-        XB_TRACE(bp, "get", (unsigned long)flags);
+        trace_xfs_buf_get(bp, flags, _RET_IP_);
         return bp;
 
  no_buffer:
@@ -644,8 +617,6 @@ _xfs_buf_read(
 {
         int                     status;
 
-        XB_TRACE(bp, "_xfs_buf_read", (unsigned long)flags);
-
         ASSERT(!(flags & (XBF_DELWRI|XBF_WRITE)));
         ASSERT(bp->b_bn != XFS_BUF_DADDR_NULL);
 
@@ -673,19 +644,18 @@ xfs_buf_read(
 
         bp = xfs_buf_get(target, ioff, isize, flags);
         if (bp) {
+                trace_xfs_buf_read(bp, flags, _RET_IP_);
+
                 if (!XFS_BUF_ISDONE(bp)) {
-                        XB_TRACE(bp, "read", (unsigned long)flags);
                         XFS_STATS_INC(xb_get_read);
                         _xfs_buf_read(bp, flags);
                 } else if (flags & XBF_ASYNC) {
-                        XB_TRACE(bp, "read_async", (unsigned long)flags);
                         /*
                          * Read ahead call which is already satisfied,
                          * drop the buffer
                          */
                         goto no_buffer;
                 } else {
-                        XB_TRACE(bp, "read_done", (unsigned long)flags);
                         /* We do not want read in the flags */
                         bp->b_flags &= ~XBF_READ;
                 }
@@ -823,7 +793,7 @@ xfs_buf_get_noaddr(
 
         xfs_buf_unlock(bp);
 
-        XB_TRACE(bp, "no_daddr", len);
+        trace_xfs_buf_get_noaddr(bp, _RET_IP_);
         return bp;
 
  fail_free_mem:
@@ -845,8 +815,8 @@ void
 xfs_buf_hold(
         xfs_buf_t               *bp)
 {
+        trace_xfs_buf_hold(bp, _RET_IP_);
         atomic_inc(&bp->b_hold);
-        XB_TRACE(bp, "hold", 0);
 }
 
 /*
@@ -859,7 +829,7 @@ xfs_buf_rele(
 {
         xfs_bufhash_t           *hash = bp->b_hash;
 
-        XB_TRACE(bp, "rele", bp->b_relse);
+        trace_xfs_buf_rele(bp, _RET_IP_);
 
         if (unlikely(!hash)) {
                 ASSERT(!bp->b_relse);
@@ -909,21 +879,19 @@ xfs_buf_cond_lock(
         int                     locked;
 
         locked = down_trylock(&bp->b_sema) == 0;
-        if (locked) {
+        if (locked)
                 XB_SET_OWNER(bp);
-        }
-        XB_TRACE(bp, "cond_lock", (long)locked);
+
+        trace_xfs_buf_cond_lock(bp, _RET_IP_);
         return locked ? 0 : -EBUSY;
 }
 
-#if defined(DEBUG) || defined(XFS_BLI_TRACE)
 int
 xfs_buf_lock_value(
         xfs_buf_t               *bp)
 {
         return bp->b_sema.count;
 }
-#endif
 
 /*
  *      Locks a buffer object.
@@ -935,12 +903,14 @@ void
 xfs_buf_lock(
         xfs_buf_t               *bp)
 {
-        XB_TRACE(bp, "lock", 0);
+        trace_xfs_buf_lock(bp, _RET_IP_);
+
         if (atomic_read(&bp->b_io_remaining))
                 blk_run_address_space(bp->b_target->bt_mapping);
         down(&bp->b_sema);
         XB_SET_OWNER(bp);
-        XB_TRACE(bp, "locked", 0);
+
+        trace_xfs_buf_lock_done(bp, _RET_IP_);
 }
 
 /*
@@ -962,7 +932,8 @@ xfs_buf_unlock(
 
         XB_CLEAR_OWNER(bp);
         up(&bp->b_sema);
-        XB_TRACE(bp, "unlock", 0);
+
+        trace_xfs_buf_unlock(bp, _RET_IP_);
 }
 
 
@@ -974,17 +945,18 @@ void
 xfs_buf_pin(
         xfs_buf_t               *bp)
 {
+        trace_xfs_buf_pin(bp, _RET_IP_);
         atomic_inc(&bp->b_pin_count);
-        XB_TRACE(bp, "pin", (long)bp->b_pin_count.counter);
 }
 
 void
 xfs_buf_unpin(
         xfs_buf_t               *bp)
 {
+        trace_xfs_buf_unpin(bp, _RET_IP_);
+
         if (atomic_dec_and_test(&bp->b_pin_count))
                 wake_up_all(&bp->b_waiters);
-        XB_TRACE(bp, "unpin", (long)bp->b_pin_count.counter);
 }
 
 int
@@ -1035,7 +1007,7 @@ xfs_buf_iodone_work(
          */
         if ((bp->b_error == EOPNOTSUPP) &&
             (bp->b_flags & (XBF_ORDERED|XBF_ASYNC)) == (XBF_ORDERED|XBF_ASYNC)) {
-                XB_TRACE(bp, "ordered_retry", bp->b_iodone);
+                trace_xfs_buf_ordered_retry(bp, _RET_IP_);
                 bp->b_flags &= ~XBF_ORDERED;
                 bp->b_flags |= _XFS_BARRIER_FAILED;
                 xfs_buf_iorequest(bp);
@@ -1050,12 +1022,12 @@ xfs_buf_ioend(
         xfs_buf_t               *bp,
         int                     schedule)
 {
+        trace_xfs_buf_iodone(bp, _RET_IP_);
+
         bp->b_flags &= ~(XBF_READ | XBF_WRITE | XBF_READ_AHEAD);
         if (bp->b_error == 0)
                 bp->b_flags |= XBF_DONE;
 
-        XB_TRACE(bp, "iodone", bp->b_iodone);
-
         if ((bp->b_iodone) || (bp->b_flags & XBF_ASYNC)) {
                 if (schedule) {
                         INIT_WORK(&bp->b_iodone_work, xfs_buf_iodone_work);
@@ -1075,7 +1047,7 @@ xfs_buf_ioerror(
 {
         ASSERT(error >= 0 && error <= 0xffff);
         bp->b_error = (unsigned short)error;
-        XB_TRACE(bp, "ioerror", (unsigned long)error);
+        trace_xfs_buf_ioerror(bp, error, _RET_IP_);
 }
 
 int
@@ -1083,7 +1055,7 @@ xfs_bawrite(
         void                    *mp,
         struct xfs_buf          *bp)
 {
-        XB_TRACE(bp, "bawrite", 0);
+        trace_xfs_buf_bawrite(bp, _RET_IP_);
 
         ASSERT(bp->b_bn != XFS_BUF_DADDR_NULL);
 
@@ -1102,7 +1074,7 @@ xfs_bdwrite(
         void                    *mp,
         struct xfs_buf          *bp)
 {
-        XB_TRACE(bp, "bdwrite", 0);
+        trace_xfs_buf_bdwrite(bp, _RET_IP_);
 
         bp->b_strat = xfs_bdstrat_cb;
         bp->b_mount = mp;
@@ -1253,7 +1225,7 @@ int
 xfs_buf_iorequest(
         xfs_buf_t               *bp)
 {
-        XB_TRACE(bp, "iorequest", 0);
+        trace_xfs_buf_iorequest(bp, _RET_IP_);
 
         if (bp->b_flags & XBF_DELWRI) {
                 xfs_buf_delwri_queue(bp, 1);
@@ -1287,11 +1259,13 @@ int
 xfs_buf_iowait(
         xfs_buf_t               *bp)
 {
-        XB_TRACE(bp, "iowait", 0);
+        trace_xfs_buf_iowait(bp, _RET_IP_);
+
         if (atomic_read(&bp->b_io_remaining))
                 blk_run_address_space(bp->b_target->bt_mapping);
         wait_for_completion(&bp->b_iowait);
-        XB_TRACE(bp, "iowaited", (long)bp->b_error);
+
+        trace_xfs_buf_iowait_done(bp, _RET_IP_);
         return bp->b_error;
 }
 
@@ -1604,7 +1578,8 @@ xfs_buf_delwri_queue(
         struct list_head        *dwq = &bp->b_target->bt_delwrite_queue;
         spinlock_t              *dwlk = &bp->b_target->bt_delwrite_lock;
 
-        XB_TRACE(bp, "delwri_q", (long)unlock);
+        trace_xfs_buf_delwri_queue(bp, _RET_IP_);
+
         ASSERT((bp->b_flags&(XBF_DELWRI|XBF_ASYNC)) == (XBF_DELWRI|XBF_ASYNC));
 
         spin_lock(dwlk);
@@ -1644,7 +1619,7 @@ xfs_buf_delwri_dequeue(
         if (dequeued)
                 xfs_buf_rele(bp);
 
-        XB_TRACE(bp, "delwri_dq", (long)dequeued);
+        trace_xfs_buf_delwri_dequeue(bp, _RET_IP_);
 }
 
 STATIC void
@@ -1692,7 +1667,7 @@ xfs_buf_delwri_split(
         INIT_LIST_HEAD(list);
         spin_lock(dwlk);
         list_for_each_entry_safe(bp, n, dwq, b_list) {
-                XB_TRACE(bp, "walkq1", (long)xfs_buf_ispin(bp));
+                trace_xfs_buf_delwri_split(bp, _RET_IP_);
                 ASSERT(bp->b_flags & XBF_DELWRI);
 
                 if (!xfs_buf_ispin(bp) && !xfs_buf_cond_lock(bp)) {
@@ -1816,14 +1791,10 @@ xfs_flush_buftarg(
 int __init
 xfs_buf_init(void)
 {
-#ifdef XFS_BUF_TRACE
-        xfs_buf_trace_buf = ktrace_alloc(XFS_BUF_TRACE_SIZE, KM_NOFS);
-#endif
-
         xfs_buf_zone = kmem_zone_init_flags(sizeof(xfs_buf_t), "xfs_buf",
                                                 KM_ZONE_HWALIGN, NULL);
         if (!xfs_buf_zone)
-                goto out_free_trace_buf;
+                goto out;
 
         xfslogd_workqueue = create_workqueue("xfslogd");
         if (!xfslogd_workqueue)
@@ -1846,10 +1817,7 @@ xfs_buf_init(void)
         destroy_workqueue(xfslogd_workqueue);
  out_free_buf_zone:
         kmem_zone_destroy(xfs_buf_zone);
- out_free_trace_buf:
-#ifdef XFS_BUF_TRACE
-        ktrace_free(xfs_buf_trace_buf);
-#endif
+ out:
         return -ENOMEM;
 }
 
@@ -1861,9 +1829,6 @@ xfs_buf_terminate(void)
         destroy_workqueue(xfsdatad_workqueue);
         destroy_workqueue(xfslogd_workqueue);
         kmem_zone_destroy(xfs_buf_zone);
-#ifdef XFS_BUF_TRACE
-        ktrace_free(xfs_buf_trace_buf);
-#endif
 }
 
 #ifdef CONFIG_KDB_MODULES