On Fri, Oct 02, 2015 at 02:18:43PM +0900, Namhyung Kim wrote:
> 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 <jo...@redhat.com>
> Cc: Adrian Hunter <adrian.hun...@intel.com>
> Signed-off-by: Namhyung Kim <namhy...@kernel.org>
after this patch I'm hitting:
[jolsa@krava perf]$ ./perf record kill
kill: not enough arguments
perf: util/evlist.c:1003: perf_evlist__mmap_len: Assertion `!((mask &
page_size) != 0)' failed.
Aborted (core dumped)
[jolsa@krava perf]$
jirka
> ---
> 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);
>
> #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);
> +
> + 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);
> + 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
>
--
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/
