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SubjectRe: [PATCH 10/21] perf, c2c: Add stats to track data source bits and cpu to node maps
On Tue, Feb 18, 2014 at 02:05:31PM +0100, Jiri Olsa wrote:
> On Mon, Feb 10, 2014 at 12:29:05PM -0500, Don Zickus wrote:
> > This patch adds a bunch of stats that will be used later in post-processing
> > to determine where and with what frequency the HITMs are coming from.
> >
> > Most of the stats are decoded from the data source response. Another
> > piece of the stats is tracking which cpu the record came in on.
> >
> > In order to properly build a cpu map to map where interesting events are coming
> > from, I shamelessly copy-n-pasted the cpu->NUMA node code from builtin-kmem.c.
> >
> > As HITMs are most expensive when going across NUMA nodes, it only made sense
> > to create a quick cpu->NUMA lookup for when processing the records.
> >
> > Credit to Dick Fowles for determining which bits are important and how to
> > properly track them. Ported to perf by me.
> >
> > Original-by: Dick Fowles <rfowles@redhat.com>
> > Signed-off-by: Don Zickus <dzickus@redhat.com>
> > ---
>
> SNIP
>
> > +
> > +static int setup_cpunode_map(void)
> > +{
> > + struct dirent *dent1, *dent2;
> > + DIR *dir1, *dir2;
> > + unsigned int cpu, mem;
> > + char buf[PATH_MAX];
> > +
> > + /* initialize globals */
> > + if (init_cpunode_map())
> > + return -1;
> > +
> > + dir1 = opendir(PATH_SYS_NODE);
> > + if (!dir1)
> > + return 0;
> > +
> > + /* walk tree and setup map */
> > + while ((dent1 = readdir(dir1)) != NULL) {
> > + if (dent1->d_type != DT_DIR ||
> > + sscanf(dent1->d_name, "node%u", &mem) < 1)
> > + continue;
> > +
> > + snprintf(buf, PATH_MAX, "%s/%s", PATH_SYS_NODE, dent1->d_name);
> > + dir2 = opendir(buf);
> > + if (!dir2)
> > + continue;
> > + while ((dent2 = readdir(dir2)) != NULL) {
> > + if (dent2->d_type != DT_LNK ||
> > + sscanf(dent2->d_name, "cpu%u", &cpu) < 1)
> > + continue;
> > + cpunode_map[cpu] = mem;
> > + }
> > + closedir(dir2);
> > + }
> > + closedir(dir1);
> > + return 0;
> > +}
>
>
> There's already setup_cpunode_map interface in builtin-kmem.c
> Please make it global (maybe place in separate object?)
> and use this one.

Heh, where do you think I got this from? :-) Though I did tweak it for my
needs, namely I used 'possible' cpus as opposed to 'online' cpus to deal
with hotplug.

I also ran into a bug here, where this code populating an array based on
what is on the running system, not the system where the data was
collected. Is it possible to have perf-archive add this info?

I try to make this function global on the next version.

Cheers,
Don

>
> jirka


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