diff options
author | Liming Wang | 2008-12-02 03:33:08 +0100 |
---|---|---|
committer | Ingo Molnar | 2008-12-02 09:23:24 +0100 |
commit | 66eafebc1086014709dc38f52ddcb3d67d9b346c (patch) | |
tree | 10147e635d8d4d15d73cb23baa32a2357570eab0 /kernel/dma-coherent.c | |
parent | Merge branches 'tracing/branch-tracer', 'tracing/ftrace', 'tracing/function-g... (diff) | |
download | kernel-qcow2-linux-66eafebc1086014709dc38f52ddcb3d67d9b346c.tar.gz kernel-qcow2-linux-66eafebc1086014709dc38f52ddcb3d67d9b346c.tar.xz kernel-qcow2-linux-66eafebc1086014709dc38f52ddcb3d67d9b346c.zip |
function trace: fix a bug of single thread function trace
Impact: fix "no output from tracer" bug caused by ftrace_update_pid_func()
When disabling single thread function trace using
"echo -1 > set_ftrace_pid", the normal function trace
has to restore to original function, otherwise the normal
function trace will not work well.
Without this commit, something like below:
$ ps |grep 850
850 root 2556 S -/bin/sh
$ echo 850 > /debug/tracing/set_ftrace_pid
$ echo function > /debug/tracing/current_tracer
$ echo 1 > /debug/tracing/tracing_enabled
$ sleep 1
$ echo 0 > /debug/tracing/tracing_enabled
$ cat /debug/tracing/trace_pipe |wc -l
59704
$ echo -1 > /debug/tracing/set_ftrace_pid
$ echo 1 > /debug/tracing/tracing_enabled
$ sleep 1
$ echo 0 > /debug/tracing/tracing_enabled
$ more /debug/tracing/trace_pipe
<====== nothing output now!
it should output trace record.
Signed-off-by: Liming Wang <liming.wang@windriver.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/dma-coherent.c')
0 files changed, 0 insertions, 0 deletions