Re: [Sched-tools] [PATCH v2] rt-app: Add IO-bounded and memory-bounded events.

On 2 July 2015 at 09:16, Pi-Cheng Chen pi-cheng.chen@linaro.org wrote:

Fix sched-tools list

On Thu, Jul 2, 2015 at 3:15 PM, Pi-Cheng Chen pi-cheng.chen@linaro.org wrote:

...

Hi Vincent,

On Fri, May 29, 2015 at 5:19 PM, Vincent Guittot vincent.guittot@linaro.org wrote:

...

Hi Pi-cheng,

On 16 December 2014 at 04:57, pi-cheng.chen pi-cheng.chen@linaro.org wrote:

...

Add 2 new kind of event for running a memory or a io bounded load. "mem" name for a load is memory bounded, and "iorun" name for a load is io bounded. The default file to be written to create the load is /dev/null and the device/file could be specified with "io_device" key in "global" section. The size of per-thread memory buffer to create IO/memory load could also be specified with "mem_buffer_size" in the same section.

E.g. "tasks" : { "thread0" : { "sleep" : 1000, "run" : 100, "mem" : 1000, "sleep" 10000, "iorun" : 1000 } }, "global" : { "io_device" : "/dev/ttyS0", "mem_buffer_size" : 1048576 }

changes v1 to v2: Allocate per-thread memory buffer. Add "mem_buffer_size" in global section to set the size of memory buffer to be allocated. And fix possible buffer overrun when creating IO-bounded load.

Signed-off-by: pi-cheng.chen pi-cheng.chen@linaro.org

src/rt-app.c | 104 +++++++++++++++++++++++++++++++++++++++++++++- src/rt-app_parse_config.c | 27 ++++++++++++ src/rt-app_types.h | 11 +++++ 3 files changed, 140 insertions(+), 2 deletions(-)

diff --git a/src/rt-app.c b/src/rt-app.c index 3cd601d..16bbe48 100644 --- a/src/rt-app.c +++ b/src/rt-app.c @@ -33,7 +33,9 @@ static volatile int continue_running; static pthread_t *threads; static int nthreads; static int p_load; +static int io_fd; rtapp_options_t opts; +static iomem_buf_t *iomem_buf;

You should better create a iomem_buf_t iomem_buf field into the thread struct so you don't have to allocate additionnal array beside

Yes. So the the array to be used could be allocated only when I get a "mem" and "iorun" event during the resources parsing stage, right?

Yes it can be allocated/opened during resources parsing

...

...

...

static ftrace_data_t ft_data = { .debugfs = "/sys/kernel/debug", @@ -110,8 +112,57 @@ static inline loadwait(unsigned long exec) return load_count; }

+static void ioload(unsigned long count, iomem_buf_t *iomem) +{

•   ssize_t ret;
  

•   while (count != 0) {
  

•           unsigned long size;
  

•           if (count > iomem->size)
  

•                   size = iomem->size;
  

•           else
  

•                   size = count;
  

Why can't we loop on the buffer and write more than it's size in the io ?

Sorry. I am not sure what you mean. Would you elaborate?

Sorry, I have done some shortcut while reading your code

...

What I do here is trying to cut the requested IO size into small pieces of chunk which is exactly the per-thread buffer sized to avoid buffer overrun.

It looks a little complicated because I want to start every IO/memory busy loop from the position at which last IO/memory busy loop stopped. I think it would help to trash the cache more. What do you think about it? I remember you suggested to start at the zero position every time as Ivan suggested at last connect, right?

yes, that's probably more simple to use this mechanism: start at the 0 position for each event

Regards, Vincent

...

Thanks for reviewing.

Best Regards, Pi-Cheng

...

...

•           if (size > (iomem->size - iomem->pos))
  

•                   size = iomem->size - iomem->pos;
  

•           ret = write(io_fd, iomem->buf + iomem->pos, size);
  

•           if (ret == -1) {
  

•                   perror("write");
  

•                   return;
  

•           }
  

•           count -= ret;
  

•           iomem->pos += ret;
  

•           if (iomem->pos >= iomem->size)
  

•                   iomem->pos -= iomem->size;
  

•   }
  

+}

+static void memload(unsigned long count, iomem_buf_t *iomem) +{

•   while (count > 0) {
  

•           unsigned long size;
  

•           if (count > iomem->size)
  

•                   size = iomem->size;
  

•           else
  

•                   size = count;
  

same question as for io

...

•           if (size > (iomem->size - iomem->pos))
  

•                   size = iomem->size - iomem->pos;
  

•           memset(iomem->buf + iomem->pos, 0, size);
  

•           count -= size;
  

•           iomem->pos += size;
  

•           if (iomem->pos >= iomem->size)
  

•                   iomem->pos -= iomem->size;
  

•   }
  

+}

static int run_event(event_data_t *event, int dry_run,

•           unsigned long *perf, unsigned long *duration, rtapp_resource_t *resources)
  

•           unsigned long *perf, unsigned long *duration,
  

•           rtapp_resource_t *resources, int ind)
  

{ rtapp_resource_t *rdata = &(resources[event->res]); rtapp_resource_t *ddata = &(resources[event->dep]); @@ -196,6 +247,18 @@ static int run_event(event_data_t *event, int dry_run, pthread_mutex_unlock(&(ddata->res.mtx.obj)); break; }

•   case rtapp_mem:
  

•           {
  

•                   log_debug("mem %d", event->count);
  

•                   memload(event->count, &iomem_buf[ind]);
  

•           }
  

•           break;
  

•   case rtapp_iorun:
  

•           {
  

•                   log_debug("iorun %d", event->count);
  

•                   ioload(event->count, &iomem_buf[ind]);
  

•           }
  

•           break;
    }
  
    return lock;
  

@@ -218,7 +281,8 @@ int run(int ind, event_data_t *events, log_ftrace(ft_data.marker_fd, "[%d] locking %d", ind, events[i].type);

•           lock += run_event(&events[i], !continue_running, &perf, duration, resources);
  

•           lock += run_event(&events[i], !continue_running, &perf,
  

•                                   duration, resources, ind);
    }
  
    return perf;
  

@@ -488,6 +552,35 @@ int main(int argc, char* argv[])

    parse_command_line(argc, argv, &opts);

•   /*
  

•    * allocate per-thread memory buffers for memory-bound and IO-bound
  

•    * busy loops
  

•    */
  

•   iomem_buf = malloc(sizeof(iomem_buf_t) * opts.nthreads);
  

•   if (!iomem_buf) {
  

•           log_error("Cannot allocate memory for IO/memory buffer struct");
  

•           exit(EXIT_FAILURE);
  

•   }
  

•   for (i = 0; i < opts.nthreads; i++) {
  

•           iomem_buf_t *iomem = &iomem_buf[i];
  

•           iomem->size = opts.mem_buffer_size;
  

•           iomem->buf = malloc(iomem->size);
  

•           if (!iomem->buf) {
  

•                   log_error("Cannot allocate memory for memory-bounded"
  

•                                   "and IO-bounded busy loops");
  

•                   exit(EXIT_FAILURE);
  

•           }
  

•           iomem->pos = 0;
  

•   }
  

•   /* open file for IO-bound busy loops */
  

•   io_fd = open(opts.io_device, O_CREAT | O_WRONLY, 0644);
  

•   if (io_fd < 0) {
  

•           log_error("Cannot open io_device file %s", opts.io_device);
  

•           exit(EXIT_FAILURE);
  

•   }
  

•   /* allocated threads */
    nthreads = opts.nthreads;
    threads = malloc(nthreads * sizeof(pthread_t));
  

@@ -713,6 +806,13 @@ int main(int argc, char* argv[]) close(ft_data.trace_fd); close(ft_data.marker_fd); }

•   close(io_fd);
  

•   for (i = 0; i < nthreads; i++)
  

•           free(iomem_buf[i].buf);
  

•   free(iomem_buf);
  

•   exit(EXIT_SUCCESS);
  
  
  

diff --git a/src/rt-app_parse_config.c b/src/rt-app_parse_config.c index e062f79..9bdf38a 100644 --- a/src/rt-app_parse_config.c +++ b/src/rt-app_parse_config.c @@ -27,6 +27,7 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. #define PIN2 PIN" " #define PIN3 PIN2" " #define JSON_FILE_BUF_SIZE 4096 +#define DEFAULT_MEM_BUF_SIZE (4 * 1024 * 1024)

/* redefine foreach as in <json/json_object.h> but to be ANSI

• compatible */

@@ -320,6 +321,22 @@ parse_thread_event_data(char *name, struct json_object *obj, return; }

•   if (!strncmp(name, "mem", strlen("mem")) ||
  

•                   !strncmp(name, "iorun", strlen("iorun"))) {
  

•           if (!json_object_is_type(obj, json_type_int))
  

•                   goto unknown_event;
  

•           data->count = json_object_get_int(obj);
  

•           if (!strncmp(name, "mem", strlen("mem")))
  

•                   data->type = rtapp_mem;
  

•           else
  

•                   data->type = rtapp_iorun;
  

•           log_info(PIN2 "type %d count %d", data->type, data->count);
  

•           return;
  

•   }
  

•   if (!strncmp(name, "lock", strlen("lock")) ||
                    !strncmp(name, "unlock", strlen("unlock"))) {
  
  

@@ -493,6 +510,10 @@ obj_is_event(char *name) return rtapp_suspend; if (!strncmp(name, "resume", strlen("resume"))) return rtapp_resume;

•   if (!strncmp(name, "mem", strlen("mem")))
  

•                   return rtapp_mem;
  

•   if (!strncmp(name, "iorun", strlen("iorun")))
  

•                   return rtapp_iorun;
  
    return 0;
  

} @@ -677,6 +698,8 @@ parse_global(struct json_object *global, rtapp_options_t *opts) opts->logbasename = strdup("rt-app"); opts->ftrace = 0; opts->pi_enabled = 0;

•           opts->io_device = strdup("/dev/null");
  

•           opts->mem_buffer_size = DEFAULT_MEM_BUF_SIZE;
            return;
    }
  
  

@@ -719,6 +742,10 @@ parse_global(struct json_object *global, rtapp_options_t *opts) TRUE, "rt-app"); opts->ftrace = get_bool_value_from(global, "ftrace", TRUE, 0); opts->pi_enabled = get_bool_value_from(global, "pi_enabled", TRUE, 0);

•   opts->io_device = get_string_value_from(global, "io_device", TRUE,
  

•                                           "/dev/null");
  

•   opts->mem_buffer_size = get_int_value_from(global, "mem_buffer_size",
  

•                                                   TRUE, DEFAULT_MEM_BUF_SIZE);
  
  

}

diff --git a/src/rt-app_types.h b/src/rt-app_types.h index cefb3a6..d230d45 100644 --- a/src/rt-app_types.h +++ b/src/rt-app_types.h @@ -65,6 +65,8 @@ typedef enum resource_t rtapp_timer, rtapp_suspend, rtapp_resume,

•   rtapp_mem,
  

•   rtapp_iorun,
  

} resource_t;

struct _rtapp_mutex { @@ -103,6 +105,7 @@ typedef struct _event_data_t { int res; int dep; int duration;

•   int count;
  

} event_data_t;

typedef struct _phase_data_t { @@ -165,6 +168,8 @@ typedef struct _rtapp_options_t {

    int ftrace;
    int die_on_dmiss;

•   char *io_device;
  

•   int mem_buffer_size;
  

} rtapp_options_t;

typedef struct _timing_point_t { @@ -177,4 +182,10 @@ typedef struct _timing_point_t { __u64 rel_start_time; } timing_point_t;

+typedef struct {

•   char *buf;
  

•   int pos;
  

•   int size;
  

+} iomem_buf_t;

#endif // _RTAPP_TYPES_H_

1.9.1