Messages in this thread | | | Date | Tue, 6 Oct 2015 17:34:23 +0900 | From | Namhyung Kim <> | Subject | Re: [RFC/PATCH 02/38] perf tools: Save mmap_param.len instead of mask |
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Hi Arnaldo,
On Fri, Oct 02, 2015 at 03:44:33PM -0300, Arnaldo Carvalho de Melo wrote: > Em Fri, Oct 02, 2015 at 02:18:43PM +0900, Namhyung Kim escreveu: > > It is more convenient saving mmap length rather than (bit) mask. With > > this patch, we can eliminate dependency to perf_evlist other than > > getting mmap_desc for dealing with mmaps. The mask and length can be > > converted using perf_evlist__mmap_mask/len(). > > > > Cc: Jiri Olsa <jolsa@redhat.com> > > Cc: Adrian Hunter <adrian.hunter@intel.com> > > Signed-off-by: Namhyung Kim <namhyung@kernel.org> > > --- > > tools/perf/util/evlist.c | 31 +++++++++++++++++++++++++------ > > 1 file changed, 25 insertions(+), 6 deletions(-) > > > > diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c > > index c5180a29db1b..e46adcd5b408 100644 > > --- a/tools/perf/util/evlist.c > > +++ b/tools/perf/util/evlist.c > > @@ -29,6 +29,8 @@ > > > > static void perf_evlist__mmap_put(struct perf_evlist *evlist, int idx); > > static void __perf_evlist__munmap(struct perf_evlist *evlist, int idx); > > +static size_t perf_evlist__mmap_mask(size_t len); > > +static size_t perf_evlist__mmap_len(size_t mask); > > Are these "perf_evlist" methods? I don't think so, those are related to > "perf_mmap".
Agreed.
> > > #define FD(e, x, y) (*(int *)xyarray__entry(e->fd, x, y)) > > #define SID(e, x, y) xyarray__entry(e->sample_id, x, y) > > @@ -871,7 +873,9 @@ void __weak auxtrace_mmap_params__set_idx( > > static void __perf_evlist__munmap(struct perf_evlist *evlist, int idx) > > { > > if (evlist->mmap[idx].base != NULL) { > > - munmap(evlist->mmap[idx].base, evlist->mmap_len); > > + size_t mmap_len = perf_evlist__mmap_len(evlist->mmap[idx].mask); > > I.e. here you could have it as: > > size_t mmap_len = perf_mmap__len(evlist->mmap[idx]);
OK.
> > > + > > + munmap(evlist->mmap[idx].base, mmap_len); > > evlist->mmap[idx].base = NULL; > > atomic_set(&evlist->mmap[idx].refcnt, 0); > > } > > @@ -901,8 +905,8 @@ static int perf_evlist__alloc_mmap(struct perf_evlist *evlist) > > } > > > > struct mmap_params { > > - int prot; > > - int mask; > > + int prot; > > + size_t len; > > struct auxtrace_mmap_params auxtrace_mp; > > }; > > > > @@ -924,8 +928,8 @@ static int __perf_evlist__mmap(struct perf_evlist *evlist, int idx, > > */ > > atomic_set(&evlist->mmap[idx].refcnt, 2); > > evlist->mmap[idx].prev = 0; > > - evlist->mmap[idx].mask = mp->mask; > > - evlist->mmap[idx].base = mmap(NULL, evlist->mmap_len, mp->prot, > > + evlist->mmap[idx].mask = perf_evlist__mmap_mask(mp->len); > > Here, since you're not using a perf_mmap instance, but the calculation > is relative to a perf_mmap property, we would use: > > evlist->mmap[idx].mask = __perf_mmap__mask(mp->len);
Will change.
Thanks, Namhyung
> > > > + evlist->mmap[idx].base = mmap(NULL, mp->len, mp->prot, > > MAP_SHARED, fd, 0); > > if (evlist->mmap[idx].base == MAP_FAILED) { > > pr_debug2("failed to mmap perf event ring buffer, error %d\n", > > @@ -1071,6 +1075,21 @@ static size_t perf_evlist__mmap_size(unsigned long pages) > > return (pages + 1) * page_size; > > } > > > > +static size_t perf_evlist__mmap_mask(size_t len) > > +{ > > + BUG_ON(len <= page_size); > > + BUG_ON((len % page_size) != 0); > > + > > + return len - page_size - 1; > > +} > > + > > +static size_t perf_evlist__mmap_len(size_t mask) > > +{ > > + BUG_ON(((mask + 1) % page_size) != 0); > > + > > + return mask + 1 + page_size; > > +} > > + > > static long parse_pages_arg(const char *str, unsigned long min, > > unsigned long max) > > { > > @@ -1176,7 +1195,7 @@ int perf_evlist__mmap_ex(struct perf_evlist *evlist, unsigned int pages, > > evlist->overwrite = overwrite; > > evlist->mmap_len = perf_evlist__mmap_size(pages); > > pr_debug("mmap size %zuB\n", evlist->mmap_len); > > - mp.mask = evlist->mmap_len - page_size - 1; > > + mp.len = evlist->mmap_len; > > > > auxtrace_mmap_params__init(&mp.auxtrace_mp, evlist->mmap_len, > > auxtrace_pages, auxtrace_overwrite); > > -- > > 2.6.0
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