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>
---
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
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