| Message ID | 20190214141335.28144-5-kaslevs@vmware.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Add VM kernel tracing over vsockets and FIFOs | expand |
On Thu, 14 Feb 2019 16:13:28 +0200 Slavomir Kaslev <kaslevs@vmware.com> wrote: > Add BUFFER_FL_GUEST and BUFFER_FL_AGENT flags to differentiate when > trace-record.c is being called to trace guest or the VM tracing agent. > > Also disable functions talking to the local tracefs when called in recording > guest instances context. > > Signed-off-by: Slavomir Kaslev <kaslevs@vmware.com> > --- > tracecmd/include/trace-local.h | 2 ++ > tracecmd/trace-record.c | 55 ++++++++++++++++++++++++++++++++-- > 2 files changed, 55 insertions(+), 2 deletions(-) > > diff --git a/tracecmd/include/trace-local.h b/tracecmd/include/trace-local.h > index a1a06e9..f19c8bb 100644 > --- a/tracecmd/include/trace-local.h > +++ b/tracecmd/include/trace-local.h > @@ -149,6 +149,8 @@ char *strstrip(char *str); > enum buffer_instance_flags { > BUFFER_FL_KEEP = 1 << 0, > BUFFER_FL_PROFILE = 1 << 1, > + BUFFER_FL_GUEST = 1 << 2, > + BUFFER_FL_AGENT = 1 << 3, > }; > > struct func_list { > diff --git a/tracecmd/trace-record.c b/tracecmd/trace-record.c > index 8beefab..107d3d1 100644 > --- a/tracecmd/trace-record.c > +++ b/tracecmd/trace-record.c > @@ -781,6 +781,9 @@ static void __clear_trace(struct buffer_instance *instance) > FILE *fp; > char *path; > > + if (instance->flags & BUFFER_FL_GUEST) > + return; > + > /* reset the trace */ > path = get_instance_file(instance, "trace"); > fp = fopen(path, "w"); > @@ -1264,6 +1267,9 @@ set_plugin_instance(struct buffer_instance *instance, const char *name) > char *path; > char zero = '0'; > > + if (instance->flags & BUFFER_FL_GUEST) > + return; > + > path = get_instance_file(instance, "current_tracer"); > fp = fopen(path, "w"); > if (!fp) { > @@ -1360,6 +1366,9 @@ static void disable_func_stack_trace_instance(struct buffer_instance *instance) > int size; > int ret; > > + if (instance->flags & BUFFER_FL_GUEST) > + return; > + > path = get_instance_file(instance, "current_tracer"); > ret = stat(path, &st); > tracecmd_put_tracing_file(path); I think we should add a: #define is_guest(instance) ((instance)->flags & BUFFER_FL_GUEST) Helper macro here, and all these should be turned into: if (is_guest(instance)) return; Less error prone, and looks cleaner. We could add a is_agent() too in later patches. -- Steve
On Thu, Feb 14, 2019 at 03:05:20PM -0500, Steven Rostedt wrote: > On Thu, 14 Feb 2019 16:13:28 +0200 > Slavomir Kaslev <kaslevs@vmware.com> wrote: > > > Add BUFFER_FL_GUEST and BUFFER_FL_AGENT flags to differentiate when > > trace-record.c is being called to trace guest or the VM tracing agent. > > > > Also disable functions talking to the local tracefs when called in recording > > guest instances context. > > > > Signed-off-by: Slavomir Kaslev <kaslevs@vmware.com> > > --- > > tracecmd/include/trace-local.h | 2 ++ > > tracecmd/trace-record.c | 55 ++++++++++++++++++++++++++++++++-- > > 2 files changed, 55 insertions(+), 2 deletions(-) > > > > diff --git a/tracecmd/include/trace-local.h b/tracecmd/include/trace-local.h > > index a1a06e9..f19c8bb 100644 > > --- a/tracecmd/include/trace-local.h > > +++ b/tracecmd/include/trace-local.h > > @@ -149,6 +149,8 @@ char *strstrip(char *str); > > enum buffer_instance_flags { > > BUFFER_FL_KEEP = 1 << 0, > > BUFFER_FL_PROFILE = 1 << 1, > > + BUFFER_FL_GUEST = 1 << 2, > > + BUFFER_FL_AGENT = 1 << 3, > > }; > > > > struct func_list { > > diff --git a/tracecmd/trace-record.c b/tracecmd/trace-record.c > > index 8beefab..107d3d1 100644 > > --- a/tracecmd/trace-record.c > > +++ b/tracecmd/trace-record.c > > @@ -781,6 +781,9 @@ static void __clear_trace(struct buffer_instance *instance) > > FILE *fp; > > char *path; > > > > + if (instance->flags & BUFFER_FL_GUEST) > > + return; > > + > > /* reset the trace */ > > path = get_instance_file(instance, "trace"); > > fp = fopen(path, "w"); > > @@ -1264,6 +1267,9 @@ set_plugin_instance(struct buffer_instance *instance, const char *name) > > char *path; > > char zero = '0'; > > > > + if (instance->flags & BUFFER_FL_GUEST) > > + return; > > + > > path = get_instance_file(instance, "current_tracer"); > > fp = fopen(path, "w"); > > if (!fp) { > > @@ -1360,6 +1366,9 @@ static void disable_func_stack_trace_instance(struct buffer_instance *instance) > > int size; > > int ret; > > > > + if (instance->flags & BUFFER_FL_GUEST) > > + return; > > + > > path = get_instance_file(instance, "current_tracer"); > > ret = stat(path, &st); > > tracecmd_put_tracing_file(path); > > > I think we should add a: > > #define is_guest(instance) ((instance)->flags & BUFFER_FL_GUEST) > > Helper macro here, and all these should be turned into: > > if (is_guest(instance)) > return; > > Less error prone, and looks cleaner. > > We could add a is_agent() too in later patches. Makes sense. I added both is_agent and is_guest for the next iteration of this patchset.
diff --git a/tracecmd/include/trace-local.h b/tracecmd/include/trace-local.h index a1a06e9..f19c8bb 100644 --- a/tracecmd/include/trace-local.h +++ b/tracecmd/include/trace-local.h @@ -149,6 +149,8 @@ char *strstrip(char *str); enum buffer_instance_flags { BUFFER_FL_KEEP = 1 << 0, BUFFER_FL_PROFILE = 1 << 1, + BUFFER_FL_GUEST = 1 << 2, + BUFFER_FL_AGENT = 1 << 3, }; struct func_list { diff --git a/tracecmd/trace-record.c b/tracecmd/trace-record.c index 8beefab..107d3d1 100644 --- a/tracecmd/trace-record.c +++ b/tracecmd/trace-record.c @@ -781,6 +781,9 @@ static void __clear_trace(struct buffer_instance *instance) FILE *fp; char *path; + if (instance->flags & BUFFER_FL_GUEST) + return; + /* reset the trace */ path = get_instance_file(instance, "trace"); fp = fopen(path, "w"); @@ -1264,6 +1267,9 @@ set_plugin_instance(struct buffer_instance *instance, const char *name) char *path; char zero = '0'; + if (instance->flags & BUFFER_FL_GUEST) + return; + path = get_instance_file(instance, "current_tracer"); fp = fopen(path, "w"); if (!fp) { @@ -1360,6 +1366,9 @@ static void disable_func_stack_trace_instance(struct buffer_instance *instance) int size; int ret; + if (instance->flags & BUFFER_FL_GUEST) + return; + path = get_instance_file(instance, "current_tracer"); ret = stat(path, &st); tracecmd_put_tracing_file(path); @@ -1553,6 +1562,9 @@ reset_events_instance(struct buffer_instance *instance) int i; int ret; + if (instance->flags & BUFFER_FL_GUEST) + return; + if (use_old_event_method()) { /* old way only had top instance */ if (!is_top_instance(instance)) @@ -1904,6 +1916,9 @@ static void write_tracing_on(struct buffer_instance *instance, int on) int ret; int fd; + if (instance->flags & BUFFER_FL_GUEST) + return; + fd = open_tracing_on(instance); if (fd < 0) return; @@ -1923,6 +1938,9 @@ static int read_tracing_on(struct buffer_instance *instance) char buf[10]; int ret; + if (instance->flags & BUFFER_FL_GUEST) + return -1; + fd = open_tracing_on(instance); if (fd < 0) return fd; @@ -2156,6 +2174,9 @@ static void set_mask(struct buffer_instance *instance) int fd; int ret; + if (instance->flags & BUFFER_FL_GUEST) + return; + if (!instance->cpumask) return; @@ -2186,6 +2207,9 @@ static void enable_events(struct buffer_instance *instance) { struct event_list *event; + if (instance->flags & BUFFER_FL_GUEST) + return; + for (event = instance->events; event; event = event->next) { if (!event->neg) update_event(event, event->filter, 0, '1'); @@ -2209,6 +2233,9 @@ static void set_clock(struct buffer_instance *instance) char *content; char *str; + if (instance->flags & BUFFER_FL_GUEST) + return; + if (!instance->clock) return; @@ -2238,6 +2265,9 @@ static void set_max_graph_depth(struct buffer_instance *instance, char *max_grap char *path; int ret; + if (instance->flags & BUFFER_FL_GUEST) + return; + path = get_instance_file(instance, "max_graph_depth"); reset_save_file(path, RESET_DEFAULT_PRIO); tracecmd_put_tracing_file(path); @@ -2463,6 +2493,9 @@ static void expand_event_instance(struct buffer_instance *instance) struct event_list *compressed_list = instance->events; struct event_list *event; + if (instance->flags & BUFFER_FL_GUEST) + return; + reset_event_list(instance); while (compressed_list) { @@ -3336,6 +3369,9 @@ static void set_funcs(struct buffer_instance *instance) int set_notrace = 0; int ret; + if (instance->flags & BUFFER_FL_GUEST) + return; + ret = write_func_file(instance, "set_ftrace_filter", &instance->filter_funcs); if (ret < 0) die("set_ftrace_filter does not exist. Can not filter functions"); @@ -3632,6 +3668,9 @@ static void set_buffer_size_instance(struct buffer_instance *instance) int ret; int fd; + if (instance->flags & BUFFER_FL_GUEST) + return; + if (!buffer_size) return; @@ -3829,6 +3868,9 @@ static void make_instances(void) int ret; for_each_instance(instance) { + if (instance->flags & BUFFER_FL_GUEST) + continue; + path = get_instance_dir(instance); ret = stat(path, &st); if (ret < 0) { @@ -3850,7 +3892,7 @@ void tracecmd_remove_instances(void) for_each_instance(instance) { /* Only delete what we created */ - if (instance->flags & BUFFER_FL_KEEP) + if (instance->flags & (BUFFER_FL_KEEP | BUFFER_FL_GUEST)) continue; if (instance->tracing_on_fd > 0) { close(instance->tracing_on_fd); @@ -3932,7 +3974,7 @@ static void check_function_plugin(void) static int __check_doing_something(struct buffer_instance *instance) { - return (instance->flags & BUFFER_FL_PROFILE) || + return (instance->flags & (BUFFER_FL_PROFILE | BUFFER_FL_GUEST)) || instance->plugin || instance->events; } @@ -3954,6 +3996,9 @@ update_plugin_instance(struct buffer_instance *instance, { const char *plugin = instance->plugin; + if (instance->flags & BUFFER_FL_GUEST) + return; + if (!plugin) return; @@ -4053,6 +4098,9 @@ static void record_stats(void) int cpu; for_all_instances(instance) { + if (instance->flags & BUFFER_FL_GUEST) + continue; + s_save = instance->s_save; s_print = instance->s_print; for (cpu = 0; cpu < instance->cpu_count; cpu++) { @@ -4079,6 +4127,9 @@ static void destroy_stats(void) int cpu; for_all_instances(instance) { + if (instance->flags & BUFFER_FL_GUEST) + continue; + for (cpu = 0; cpu < instance->cpu_count; cpu++) { trace_seq_destroy(&instance->s_save[cpu]); trace_seq_destroy(&instance->s_print[cpu]);
Add BUFFER_FL_GUEST and BUFFER_FL_AGENT flags to differentiate when trace-record.c is being called to trace guest or the VM tracing agent. Also disable functions talking to the local tracefs when called in recording guest instances context. Signed-off-by: Slavomir Kaslev <kaslevs@vmware.com> --- tracecmd/include/trace-local.h | 2 ++ tracecmd/trace-record.c | 55 ++++++++++++++++++++++++++++++++-- 2 files changed, 55 insertions(+), 2 deletions(-)