From: Tzvetomir Stoyanov <tz.stoyanov@gmail.com> To: Steven Rostedt <rostedt@goodmis.org> Cc: linux-trace-devel@vger.kernel.org Subject: Re: [PATCH v18 04/18] trace-cmd: Add new library APIs for ftrace instances. Date: Mon, 6 Jan 2020 16:47:00 +0200 Message-ID: <CAPpZLN5Jk-N-CnKrepL+8F1tHUFPHqDZcmiS=eaMO_0Tw0kV3w@mail.gmail.com> (raw) In-Reply-To: <20191220220332.517cb36f@rorschach.local.home> On Sat, Dec 21, 2019 at 5:03 AM Steven Rostedt <rostedt@goodmis.org> wrote: > > On Fri, 13 Dec 2019 17:30:15 +0200 > "Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com> wrote: > > > +/** > > + * tracecmd_get_instance_file - return the path to a instance file > > + * @instance: buffer instance for the file, can be NULL for the top instance > > + * @file: name of file to return > > + * > > + * Returns the path name of the @file for the given @instance > > + * > > + * Must use tracecmd_put_tracing_file() to free the returned string > > + */ > > +char * > > +tracecmd_get_instance_file(struct tracecmd_instance *instance, const char *file) > > +{ > > + char *path; > > + char *buf; > > + int ret; > > + > > + if (instance && instance->name) { > > + ret = asprintf(&buf, "instances/%s/%s", instance->name, file); > > + if (ret < 0) > > + die("Failed to allocate name for %s/%s", instance->name, file); > > + path = tracecmd_get_tracing_file(buf); > > + free(buf); > > + } else > > + path = tracecmd_get_tracing_file(file); > > + > > + return path; > > +} > > + > > +/** > > + * tracecmd_get_instance_file - return the path to a instance file > > + * @instance: buffer instance for the file, can be NULL for the top instance > > + * @file: name of file to return > > + * > > + * Returns the path name of the @file for the given @instance > > + * > > + * Must use tracecmd_put_tracing_file() to free the returned string > > The above is a cut and paste of tracecmd_get_instance_file, not of the > instance_dir. > > > + */ > > +char *tracecmd_get_instance_dir(struct tracecmd_instance *instance) > > +{ > > + char *buf; > > + char *path; > > + int ret; > > + > > + if (instance->name) { > > + ret = asprintf(&buf, "instances/%s", instance->name); > > + if (ret < 0) > > + die("Failed to allocate for instance %s", instance->name); > > + path = tracecmd_get_tracing_file(buf); > > + free(buf); > > + } else > > + path = tracecmd_find_tracing_dir(); > > + > > + return path; > > +} > > + > > +/** > > + * tracecmd_write_instance_file - Write in trace file of specific instance > > + * @instance: buffer instance for the file, can be NULL for the top instance > > + * @file: name of the file > > + * @str: Nul terminated string, that will be written in the file > > + * @type: Nul terminated string, describing the current write operation > > + * Used for logging purposes > > + * > > + * Returns the number of written bytes, or -1 in case of an error > > + */ > > +int tracecmd_write_instance_file(struct tracecmd_instance *instance, > > + const char *file, const char *str, > > + const char *type) > > I think we should get rid of the type and move the logic that needs it > to the callers. > > > > +{ > > + struct stat st; > > + char *path; > > + int ret; > > + > > + path = tracecmd_get_instance_file(instance, file); > > + ret = stat(path, &st); > > + if (ret == 0) > > + ret = tracecmd_write_file(path, str, type); > > + tracecmd_put_tracing_file(path); > > + > > + return ret; > > +} > > + > > [..] > > > +/* > > + * tracecmd_write_file - Write in trace file > > + * @file: Full name of the trace file. > > + * @str: Null terminated string, that will be written in the file. > > + * @type: Null terminated string, describing the current write operation. > > + * Used for logging purposes. > > + * > > + * Returns the number of written bytes, or -1 in case of an error > > + */ > > +int tracecmd_write_file(const char *file, const char *str, const char *type) > > +{ > > + char buf[BUFSIZ]; > > + int ret; > > + int fd; > > + > > + fd = open(file, O_WRONLY | O_TRUNC); > > + if (fd < 0) > > + die("opening to '%s'", file); > > + ret = write(fd, str, strlen(str)); > > + close(fd); > > + if (ret < 0 && type) { > > + /* write failed */ > > + fd = open(file, O_RDONLY); > > + if (fd < 0) > > + die("writing to '%s'", file); > > + /* the filter has the error */ > > + while ((ret = read(fd, buf, BUFSIZ)) > 0) > > + fprintf(stderr, "%.*s", ret, buf); > > + die("Failed %s of %s\n", type, file); > > Yeah, the above needs to be moved to the upper layers. It even has a > comment about "the filter has the error". That's reference to the > filter file of trace events, which is the only file that really does > that. > > -- Steve > These new instance APIs are going to be part of the new libtracefs, I'll remove this patch from the series, when the libtracefs code is merged. > > + close(fd); > > + } > > + return ret; > > +} > > -- Tzvetomir (Ceco) Stoyanov VMware Open Source Technology Center
next prev parent reply index Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-12-13 15:30 [PATCH v18 00/18]Timestamp synchronization of host - guest tracing session Tzvetomir Stoyanov (VMware) 2019-12-13 15:30 ` [PATCH v18 01/18] trace-cmd: Implement new lib API: tracecmd_local_events_system() Tzvetomir Stoyanov (VMware) 2019-12-13 15:30 ` [PATCH v18 02/18] trace-cmd: Add support for negative time offsets in trace.dat file Tzvetomir Stoyanov (VMware) 2019-12-13 15:30 ` [PATCH v18 03/18] trace-cmd: Add implementations of htonll() and ntohll() Tzvetomir Stoyanov (VMware) 2019-12-21 2:34 ` Steven Rostedt 2019-12-13 15:30 ` [PATCH v18 04/18] trace-cmd: Add new library APIs for ftrace instances Tzvetomir Stoyanov (VMware) 2019-12-21 3:03 ` Steven Rostedt 2020-01-06 14:47 ` Tzvetomir Stoyanov [this message] 2019-12-13 15:30 ` [PATCH v18 05/18] trace-cmd: Add new library API for local CPU count Tzvetomir Stoyanov (VMware) 2019-12-13 15:30 ` [PATCH v18 06/18] trace-cmd: Add new library API for reading ftrace buffers Tzvetomir Stoyanov (VMware) 2019-12-13 15:30 ` [PATCH v18 07/18] trace-cmd: Find and store pids of tasks, which run virtual CPUs of given VM Tzvetomir Stoyanov (VMware) 2019-12-13 15:30 ` [PATCH v18 08/18] trace-cmd: Implement new API tracecmd_add_option_v() Tzvetomir Stoyanov (VMware) 2019-12-13 15:30 ` [PATCH v18 09/18] trace-cmd: Add new API to generate a unique ID of the tracing session Tzvetomir Stoyanov (VMware) 2019-12-13 15:30 ` [PATCH v18 10/18] trace-cmd: Store the session tracing ID in the trace.dat file Tzvetomir Stoyanov (VMware) 2019-12-20 20:04 ` Steven Rostedt 2020-01-06 14:33 ` Tzvetomir Stoyanov 2019-12-13 15:30 ` [PATCH v18 11/18] trace-cmd: Exchange tracing IDs between host and guest Tzvetomir Stoyanov (VMware) 2019-12-13 15:30 ` [PATCH v18 12/18] trace-cmd: Implement new option in trace.dat file: TRACECMD_OPTION_TIME_SHIFT Tzvetomir Stoyanov (VMware) 2019-12-21 3:19 ` Steven Rostedt 2019-12-13 15:30 ` [PATCH v18 13/18] trace-cmd: Add guest information in host's trace.dat file Tzvetomir Stoyanov (VMware) 2019-12-20 20:52 ` Steven Rostedt 2020-01-06 14:43 ` Tzvetomir Stoyanov 2020-01-06 14:55 ` Steven Rostedt 2019-12-13 15:30 ` [PATCH v18 14/18] trace-cmd: Add host trace clock as guest trace argument Tzvetomir Stoyanov (VMware) 2019-12-13 15:30 ` [PATCH v18 15/18] trace-cmd: Refactor few trace-cmd internal functions Tzvetomir Stoyanov (VMware) 2019-12-13 15:30 ` [PATCH v18 16/18] trace-cmd: Basic infrastructure for host - guest timestamp synchronization Tzvetomir Stoyanov (VMware) 2019-12-21 4:48 ` Steven Rostedt 2020-01-31 9:53 ` Tzvetomir Stoyanov 2020-01-31 14:49 ` Steven Rostedt 2019-12-13 15:30 ` [PATCH v18 17/18] trace-cmd: [POC] PTP-like algorithm " Tzvetomir Stoyanov (VMware) 2019-12-13 15:30 ` [PATCH v18 18/18] trace-cmd: Debug scripts for " Tzvetomir Stoyanov (VMware)
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