On Fri, May 30, 2014 at 12:28:30PM -0300, Arnaldo Carvalho de Melo wrote:
> Em Fri, May 30, 2014 at 10:50:25AM -0400, Don Zickus escreveu:
> > Different arches may have different cacheline sizes. Look it up and set
> > a global variable for reference.
>
> [acme@zoo linux]$ strings `which getconf` | grep LINESIZE
> LEVEL1_ICACHE_LINESIZE
> LEVEL1_DCACHE_LINESIZE
> LEVEL2_CACHE_LINESIZE
> LEVEL3_CACHE_LINESIZE
> LEVEL4_CACHE_LINESIZE
> [acme@zoo linux]$
>
> man sysconf
>
> That is what I use in pahole, for instance:
>
> [acme@zoo pahole]$ grep sysconf *.c
> dwarves_fprintf.c: long sys_cacheline_size =
> sysconf(_SC_LEVEL1_DCACHE_LINESIZE);
> [acme@zoo pahole]$
Well that does look easier. I'll hack that up to see if it gives me the
same answer.
Thanks!
Cheers,
Don
>
> - Arnaldo
>
> > Signed-off-by: Don Zickus <dzic...@redhat.com>
> >
> > ---
> > V3: remove unneeded cpumap.h (Namhyung Kim)
> > V2: change to be global and setup in perf.c
> > use filename__read_int for setup
> > ---
> > tools/perf/perf.c | 5 +++++
> > tools/perf/util/cpumap.c | 27 +++++++++++++++++++++++++++
> > tools/perf/util/cpumap.h | 3 +++
> > tools/perf/util/util.c | 1 +
> > tools/perf/util/util.h | 1 +
> > 5 files changed, 37 insertions(+)
> >
> > diff --git a/tools/perf/perf.c b/tools/perf/perf.c
> > index 431798a..dabf08b 100644
> > --- a/tools/perf/perf.c
> > +++ b/tools/perf/perf.c
> > @@ -13,6 +13,7 @@
> > #include "util/quote.h"
> > #include "util/run-command.h"
> > #include "util/parse-events.h"
> > +#include "util/cpumap.h"
> > #include <api/fs/debugfs.h>
> > #include <pthread.h>
> >
> > @@ -459,6 +460,10 @@ int main(int argc, const char **argv)
> > /* The page_size is placed in util object. */
> > page_size = sysconf(_SC_PAGE_SIZE);
> >
> > + /* The cacheline_size is placed in util objet */
> > + if (cpu__setup_cacheline_size() < 0)
> > + goto out;
> > +
> > cmd = perf_extract_argv0_path(argv[0]);
> > if (!cmd)
> > cmd = "perf-help";
> > diff --git a/tools/perf/util/cpumap.c b/tools/perf/util/cpumap.c
> > index c4e55b7..1029982 100644
> > --- a/tools/perf/util/cpumap.c
> > +++ b/tools/perf/util/cpumap.c
> > @@ -477,3 +477,30 @@ int cpu__setup_cpunode_map(void)
> > closedir(dir1);
> > return 0;
> > }
> > +
> > +int cpu__setup_cacheline_size(void)
> > +{
> > + const char *mnt;
> > + char path[PATH_MAX];
> > + int n, size;
> > +
> > +
> > + mnt = sysfs__mountpoint();
> > + if (!mnt)
> > + return -1;
> > +
> > + n = snprintf(path, PATH_MAX,
> > "%s/devices/system/cpu/cpu0/cache/index0/coherency_line_size", mnt);
> > + if (n == PATH_MAX) {
> > + pr_err("sysfs path crossed PATH_MAX(%d) size\n", PATH_MAX);
> > + return -1;
> > + }
> > +
> > + if (filename__read_int(path, &size)) {
> > + pr_err("Can not read cacheline size\n");
> > + return -1;
> > + }
> > +
> > + cacheline_size = size;
> > +
> > + return 0;
> > +}
> > diff --git a/tools/perf/util/cpumap.h b/tools/perf/util/cpumap.h
> > index 61a6548..507d7fd 100644
> > --- a/tools/perf/util/cpumap.h
> > +++ b/tools/perf/util/cpumap.h
> > @@ -5,6 +5,7 @@
> > #include <stdbool.h>
> >
> > #include "perf.h"
> > +#include "util/util.h"
> > #include "util/debug.h"
> >
> > struct cpu_map {
> > @@ -81,4 +82,6 @@ static inline int cpu__get_node(int cpu)
> > return cpunode_map[cpu];
> > }
> >
> > +int cpu__setup_cacheline_size(void);
> > +
> > #endif /* __PERF_CPUMAP_H */
> > diff --git a/tools/perf/util/util.c b/tools/perf/util/util.c
> > index 7fff6be..95aefa7 100644
> > --- a/tools/perf/util/util.c
> > +++ b/tools/perf/util/util.c
> > @@ -17,6 +17,7 @@
> > * XXX We need to find a better place for these things...
> > */
> > unsigned int page_size;
> > +int cacheline_size;
> >
> > bool test_attr__enabled;
> >
> > diff --git a/tools/perf/util/util.h b/tools/perf/util/util.h
> > index b03da44..6686436 100644
> > --- a/tools/perf/util/util.h
> > +++ b/tools/perf/util/util.h
> > @@ -304,6 +304,7 @@ char *rtrim(char *s);
> > void dump_stack(void);
> >
> > extern unsigned int page_size;
> > +extern int cacheline_size;
> >
> > void get_term_dimensions(struct winsize *ws);
> >
> > --
> > 1.7.11.7
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
