[Oisf-users] Detect_Thread_Ratio

[Gene Albin]

Ok, so if I'm reading that right (and it's like reading
ancient hieroglyphics to me!) it looks like first we will never have less
than 1 thread, and second we are working with integers so no decimals.  If
that is the case, then does the 'int' function round decimals to the nearest
integer or does it round all down?  I don't see anything there forcing it to
round down so I'd assume it rounds to the nearest.

So my 'homework' answer would be that it uses integers and rounds to the
nearest integer > 0.

How'd I do, teach?

Gene

On Fri, Aug 12, 2011 at 2:59 PM, Will Metcalf <william.metcalf at gmail.com>wrote:

> Since this all sounds a bit like a homework assignment you tell me :D?
>
>   * threads we're not creating the most on CPU0. */
>    if (ncpus > 0)
>        cpu = 1;
>
>    /* always create at least one thread */
>    int thread_max = TmThreadGetNbThreads(DETECT_CPU_SET);
>    if (thread_max == 0)
>        thread_max = ncpus * threading_detect_ratio;
>    if (thread_max < 1)
>        thread_max = 1;
>
>    int thread;
>    for (thread = 0; thread < thread_max; thread++) {
>        snprintf(tname, sizeof(tname), "Detect%"PRIu16, thread+1);
>
>        char *thread_name = SCStrdup(tname);
>        SCLogDebug("Assigning %s affinity to cpu %u", thread_name, cpu);
>
>        ThreadVars *tv_detect_ncpu =
>            TmThreadCreatePacketHandler(thread_name,
>                                        "stream-queue1", "simple",
>                                        "alert-queue1", "simple",
>                                        "1slot");
>        if (tv_detect_ncpu == NULL) {
>            printf("ERROR: TmThreadsCreate failed\n");
>            exit(EXIT_FAILURE);
>        }
>        tm_module = TmModuleGetByName("Detect");
>        if (tm_module == NULL) {
>            printf("ERROR: TmModuleGetByName Detect failed\n");
>            exit(EXIT_FAILURE);
>        }
>        Tm1SlotSetFunc(tv_detect_ncpu, tm_module, (void *)de_ctx);
>
>        TmThreadSetCPU(tv_detect_ncpu, DETECT_CPU_SET);
>
>        char *thread_group_name = SCStrdup("Detect");
>        if (thread_group_name == NULL) {
>            printf("Error allocating memory\n");
>            exit(EXIT_FAILURE);
>        }
>        tv_detect_ncpu->thread_group_name = thread_group_name;
>
>        if (TmThreadSpawn(tv_detect_ncpu) != TM_ECODE_OK) {
>            printf("ERROR: TmThreadSpawn failed\n");
>            exit(EXIT_FAILURE);
>        }
>
>        if ((cpu + 1) == ncpus)
>            cpu = 0;
>        else
>            cpu++;
>     }
>
>
> On Fri, Aug 12, 2011 at 4:38 PM, Gene Albin <gene.albin at gmail.com> wrote:
> > I understand that the detect_thread_ratio in the suricata.yaml file
> > determines the number of threads created by multiplying the ratio number
> by
> > the number of CPU cores.  What does Suricata do when the result is not an
> > integer?  For example .2*48=9.6.  Is this rounded down to the lowest
> > integer?  Does it create 9.6 threads?  Does it round up?
> >
> > Thanks,
> > --
> > Gene Albin
> > gene.albin at gmail.com
> >
> >
> > _______________________________________________
> > Oisf-users mailing list
> > Oisf-users at openinfosecfoundation.org
> > http://lists.openinfosecfoundation.org/mailman/listinfo/oisf-users
> >
> >
>



-- 
Gene Albin
gene.albin at gmail.com
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