diff options
author | Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> | 2008-11-14 17:47:39 -0500 |
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committer | Ingo Molnar <mingo@elte.hu> | 2008-11-16 09:01:29 +0100 |
commit | c1df1bd2c4d4b20c83755a0f41956b57aec4842a (patch) | |
tree | 08761333b0850c6acfb31d72d7777dccc135ebde /kernel | |
parent | a419246ac7c2d9282dfd843103702895bb3f3fd7 (diff) | |
download | kernel_samsung_espresso10-c1df1bd2c4d4b20c83755a0f41956b57aec4842a.zip kernel_samsung_espresso10-c1df1bd2c4d4b20c83755a0f41956b57aec4842a.tar.gz kernel_samsung_espresso10-c1df1bd2c4d4b20c83755a0f41956b57aec4842a.tar.bz2 |
markers: auto enable tracepoints (new API : trace_mark_tp())
Impact: new API
Add a new API trace_mark_tp(), which declares a marker within a
tracepoint probe. When the marker is activated, the tracepoint is
automatically enabled.
No branch test is used at the marker site, because it would be a
duplicate of the branch already present in the tracepoint.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/marker.c | 53 |
1 files changed, 51 insertions, 2 deletions
diff --git a/kernel/marker.c b/kernel/marker.c index 348e70c..c14ec26 100644 --- a/kernel/marker.c +++ b/kernel/marker.c @@ -479,7 +479,7 @@ static int marker_set_format(struct marker_entry *entry, const char *format) static int set_marker(struct marker_entry *entry, struct marker *elem, int active) { - int ret; + int ret = 0; WARN_ON(strcmp(entry->name, elem->name) != 0); if (entry->format) { @@ -531,9 +531,40 @@ static int set_marker(struct marker_entry *entry, struct marker *elem, */ smp_wmb(); elem->ptype = entry->ptype; + + if (elem->tp_name && (active ^ elem->state)) { + WARN_ON(!elem->tp_cb); + /* + * It is ok to directly call the probe registration because type + * checking has been done in the __trace_mark_tp() macro. + */ + + if (active) { + /* + * try_module_get should always succeed because we hold + * lock_module() to get the tp_cb address. + */ + ret = try_module_get(__module_text_address( + (unsigned long)elem->tp_cb)); + BUG_ON(!ret); + ret = tracepoint_probe_register_noupdate( + elem->tp_name, + elem->tp_cb); + } else { + ret = tracepoint_probe_unregister_noupdate( + elem->tp_name, + elem->tp_cb); + /* + * tracepoint_probe_update_all() must be called + * before the module containing tp_cb is unloaded. + */ + module_put(__module_text_address( + (unsigned long)elem->tp_cb)); + } + } elem->state = active; - return 0; + return ret; } /* @@ -544,7 +575,24 @@ static int set_marker(struct marker_entry *entry, struct marker *elem, */ static void disable_marker(struct marker *elem) { + int ret; + /* leave "call" as is. It is known statically. */ + if (elem->tp_name && elem->state) { + WARN_ON(!elem->tp_cb); + /* + * It is ok to directly call the probe registration because type + * checking has been done in the __trace_mark_tp() macro. + */ + ret = tracepoint_probe_unregister_noupdate(elem->tp_name, + elem->tp_cb); + WARN_ON(ret); + /* + * tracepoint_probe_update_all() must be called + * before the module containing tp_cb is unloaded. + */ + module_put(__module_text_address((unsigned long)elem->tp_cb)); + } elem->state = 0; elem->single.func = __mark_empty_function; /* Update the function before setting the ptype */ @@ -608,6 +656,7 @@ static void marker_update_probes(void) marker_update_probe_range(__start___markers, __stop___markers); /* Markers in modules. */ module_update_markers(); + tracepoint_probe_update_all(); } /** |