On Fri, May 10, 2024 at 08:17:54AM -0700, Darrick J. Wong wrote:
> On Fri, May 10, 2024 at 12:33:39PM +0800, Zorro Lang wrote:
> > To avoid the dependence of debugfs, tracefs is mounted on another
> > place -- /sys/kernel/tracing now. But for the compatibility, the
> > /sys/kernel/debug/tracing is still there. So change _require_ftrace
> > helper, try to use the new /sys/kernel/tracing path at first, or
> > fallback to the old one if it's not supported.
> >
> > xfs/499 uses ftrace, so call _require_ftrace in it.
> >
> > Signed-off-by: Zorro Lang <zlang@xxxxxxxxxx>
> > ---
> > common/tracing | 13 +++++++++----
> > tests/xfs/499 | 6 +++---
> > 2 files changed, 12 insertions(+), 7 deletions(-)
> >
> > diff --git a/common/tracing b/common/tracing
> > index b3051c27..8613d044 100644
> > --- a/common/tracing
> > +++ b/common/tracing
> > @@ -4,11 +4,16 @@
> > #
> > # Routines for dealing with ftrace (or any other tracing).
> >
> > -FTRACE_INSTANCES_DIR="/sys/kernel/debug/tracing/instances/"
> > -
> > _require_ftrace() {
> > - test -d "$FTRACE_INSTANCES_DIR" || \
> > - _notrun "kernel does not support ftrace"
> > + if [ -d /sys/kernel/tracing/instances/ ];then
> > + FTRACE_ROOT="/sys/kernel/tracing"
> > + FTRACE_INSTANCES_DIR="/sys/kernel/tracing/instances"
>
> To answer my own question, this new path has been in Debian since at
> least 2021.
Oh, I thought the /sys/kernel/tracing was created in linux v4.1 :
cc31004a4aa7 ("tracefs: Add directory /sys/kernel/tracing")
But might be used in different distro widely later.
>
> > + elif [ -d /sys/kernel/debug/tracing/instances/ ];then
> > + FTRACE_ROOT="/sys/kernel/debug/tracing"
> > + FTRACE_INSTANCES_DIR="/sys/kernel/debug/tracing/instances"
> > + else
> > + _notrun "The ftrace is not supported, or tracefs is not mounted"
> > + fi
> > }
> >
> > _ftrace_cleanup() {
> > diff --git a/tests/xfs/499 b/tests/xfs/499
> > index 9672f95d..883415dc 100755
> > --- a/tests/xfs/499
> > +++ b/tests/xfs/499
> > @@ -14,18 +14,18 @@ _begin_fstest auto quick
> > _register_cleanup "_cleanup" BUS
> >
> > # Import common functions.
> > +. ./common/tracing
>
> You could probably get rid of the "Import common functions" comment.
Sure, will change that when I merge it.
>
> This looks good!
> Reviewed-by: Darrick J. Wong <djwong@xxxxxxxxxx>
Thanks,
Zorro
>
> --D
>
> >
> > # real QA test starts here
> > _supported_fs xfs
> > +_require_ftrace
> > _require_command "$CC_PROG" "cc"
> >
> > cprog=$tmp.ftrace.c
> > oprog=$tmp.ftrace
> > sedprog=$tmp.ftrace.sed
> >
> > -ftrace_dir=$DEBUGFS_MNT/tracing/events/xfs
> > -
> > -test -d $ftrace_dir || _notrun "ftrace not enabled"
> > +ftrace_dir=$FTRACE_ROOT/events/xfs
> >
> > # The second argument to __print_symbolic is stringified in the tracepoint's
> > # fmt file, so we look for "{ NUM, STRING }" and try to separate each of them
> > --
> > 2.44.0
> >
> >
>
