Messages in this thread Patch in this message | | | Date | Fri, 30 May 2014 12:28:30 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [PATCH 6/7 V2] perf: Add support to dynamically get cacheline size |
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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]$
- Arnaldo > Signed-off-by: Don Zickus <dzickus@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
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