On Tue, 16 Oct 2018 09:46:07 +0300
Ceco <tz.stoyanov@xxxxxxxxx> wrote:
> ping
> Hi Steven, is there a problem with this patch ? Yordan needs these
> changes, he wants to use the new API in KernelShark.
>
> On Fri, Aug 31, 2018 at 9:27 AM Tzvetomir Stoyanov (VMware)
> <tz.stoyanov@xxxxxxxxx> wrote:
> >
> > Added a new API of tracevent library: tep_override_comm()
> > It registers a pid / comm mapping. If a mapping with the same
> > pid already exists, the entry is updated with the new comm.
> >
> > Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@xxxxxxxxx>
> > ---
> > include/traceevent/event-parse.h | 1 +
> > lib/traceevent/event-parse.c | 70 +++++++++++++++++++++++++-------
> > 2 files changed, 56 insertions(+), 15 deletions(-)
> >
> > diff --git a/include/traceevent/event-parse.h b/include/traceevent/event-parse.h
> > index 713a4e4..0dcc024 100644
> > --- a/include/traceevent/event-parse.h
> > +++ b/include/traceevent/event-parse.h
> > @@ -607,6 +607,7 @@ int tep_set_function_resolver(struct tep_handle *pevent,
> > tep_func_resolver_t *func, void *priv);
> > void tep_reset_function_resolver(struct tep_handle *pevent);
> > int tep_register_comm(struct tep_handle *pevent, const char *comm, int pid);
> > +int tep_override_comm(struct tep_handle *pevent, const char *comm, int pid);
> > int tep_register_trace_clock(struct tep_handle *pevent, const char *trace_clock);
> > int tep_register_function(struct tep_handle *pevent, char *name,
> > unsigned long long addr, char *mod);
> > diff --git a/lib/traceevent/event-parse.c b/lib/traceevent/event-parse.c
> > index ce1e202..1954908 100644
> > --- a/lib/traceevent/event-parse.c
> > +++ b/lib/traceevent/event-parse.c
> > @@ -230,11 +230,13 @@ int tep_pid_is_registered(struct tep_handle *pevent, int pid)
> > * we must add this pid. This is much slower than when cmdlines
> > * are added before the array is initialized.
> > */
> > -static int add_new_comm(struct tep_handle *pevent, const char *comm, int pid)
> > +static int add_new_comm(struct tep_handle *pevent,
> > + const char *comm, int pid, bool override)
> > {
> > struct cmdline *cmdlines = pevent->cmdlines;
> > - const struct cmdline *cmdline;
> > + struct cmdline *cmdline;
> > struct cmdline key;
> > + char *new_comm;
> >
> > if (!pid)
> > return 0;
> > @@ -245,8 +247,20 @@ static int add_new_comm(struct tep_handle *pevent, const char *comm, int pid)
> > cmdline = bsearch(&key, pevent->cmdlines, pevent->cmdline_count,
> > sizeof(*pevent->cmdlines), cmdline_cmp);
> > if (cmdline) {
> > - errno = EEXIST;
> > - return -1;
> > + if (!override) {
> > + errno = EEXIST;
> > + return -1;
> > + }
> > + new_comm = strdup(comm);
> > + if(!new_comm) {
> > + errno = ENOMEM;
> > + return -1;
> > + }
> > + if (cmdline->comm)
> > + free(cmdline->comm);
One nit here. free() can take a NULL parameter without issue, so the if
isn't necessary.
free(cmdline->comm);
cmdline->comm = new_comm;
Other than that, the rest looks good.
Want to send a v3 (new thread).
Thanks!
-- Steve
> > + cmdline->comm = new_comm;
> > +
> > + return 0;
> > }
> >
> > cmdlines = realloc(cmdlines, sizeof(*cmdlines) * (pevent->cmdline_count + 1));
> > @@ -273,21 +287,13 @@ static int add_new_comm(struct tep_handle *pevent, const char *comm, int pid)
> > return 0;
> > }
> >
> > -/**
> > - * tep_register_comm - register a pid / comm mapping
> > - * @pevent: handle for the pevent
> > - * @comm: the command line to register
> > - * @pid: the pid to map the command line to
> > - *
> > - * This adds a mapping to search for command line names with
> > - * a given pid. The comm is duplicated.
> > - */
> > -int tep_register_comm(struct tep_handle *pevent, const char *comm, int pid)
> > +static int _tep_register_comm(struct tep_handle *pevent,
> > + const char *comm, int pid, bool override)
> > {
> > struct cmdline_list *item;
> >
> > if (pevent->cmdlines)
> > - return add_new_comm(pevent, comm, pid);
> > + return add_new_comm(pevent, comm, pid, override);
> >
> > item = malloc(sizeof(*item));
> > if (!item)
> > @@ -310,6 +316,40 @@ int tep_register_comm(struct tep_handle *pevent, const char *comm, int pid)
> > return 0;
> > }
> >
> > +/**
> > + * tep_register_comm - register a pid / comm mapping
> > + * @pevent: handle for the pevent
> > + * @comm: the command line to register
> > + * @pid: the pid to map the command line to
> > + *
> > + * This adds a mapping to search for command line names with
> > + * a given pid. The comm is duplicated. If a command with the same pid
> > + * already exist, -1 is returned and errno is set to EEXIST
> > + */
> > +int tep_register_comm(struct tep_handle *pevent, const char *comm, int pid)
> > +{
> > + return _tep_register_comm(pevent, comm, pid, false);
> > +}
> > +
> > +/**
> > + * tep_override_comm - register a pid / comm mapping
> > + * @pevent: handle for the pevent
> > + * @comm: the command line to register
> > + * @pid: the pid to map the command line to
> > + *
> > + * This adds a mapping to search for command line names with
> > + * a given pid. The comm is duplicated. If a command with the same pid
> > + * already exist, the command string is udapted with the new one
> > + */
> > +int tep_override_comm(struct tep_handle *pevent, const char *comm, int pid)
> > +{
> > + if (!pevent->cmdlines && cmdline_init(pevent)) {
> > + errno = ENOMEM;
> > + return -1;
> > + }
> > + return _tep_register_comm(pevent, comm, pid, true);
> > +}
> > +
> > int tep_register_trace_clock(struct tep_handle *pevent, const char *trace_clock)
> > {
> > pevent->trace_clock = strdup(trace_clock);
> > --
> > 2.17.1
> >
|