@@ -325,7 +325,7 @@ try_again:
}
perf_evlist__channel_reset(evlist);
- if (perf_evlist__mmap_ex(evlist, opts->mmap_pages, false,
+ if (perf_evlist__mmap_ex(evlist, opts->mmap_pages,
opts->auxtrace_mmap_pages,
opts->auxtrace_snapshot_mode) < 0) {
if (errno == EPERM) {
@@ -789,6 +789,7 @@ union perf_event *perf_evlist__mmap_read_ex(struct perf_evlist *evlist,
struct perf_mmap *md = &evlist->mmap[idx];
u64 head, old;
int err = perf_evlist__channel_idx(evlist, &channel, &idx);
+ bool rdonly;
if (err || !perf_evlist__channel_is_enabled(evlist, channel)) {
pr_err("ERROR: invalid mmap index: channel %d, idx: %d\n",
@@ -805,8 +806,8 @@ union perf_event *perf_evlist__mmap_read_ex(struct perf_evlist *evlist,
head = perf_mmap__read_head(md);
- return __perf_evlist__mmap_read(md, evlist->overwrite, head,
- old, &md->prev);
+ rdonly = perf_evlist__channel_check(evlist, channel, RDONLY);
+ return __perf_evlist__mmap_read(md, rdonly, old, head, &md->prev);
}
union perf_event *
@@ -894,7 +895,7 @@ void perf_evlist__mmap_consume_ex(struct perf_evlist *evlist,
return;
}
- if (!evlist->overwrite) {
+ if (!perf_evlist__channel_check(evlist, channel, RDONLY)) {
u64 old = md->prev;
perf_mmap__write_tail(md, old);
@@ -987,7 +988,6 @@ static int perf_evlist__alloc_mmap(struct perf_evlist *evlist)
}
struct mmap_params {
- int prot;
int mask;
struct auxtrace_mmap_params auxtrace_mp;
};
@@ -995,6 +995,15 @@ struct mmap_params {
static int __perf_evlist__mmap(struct perf_evlist *evlist, int idx,
struct mmap_params *mp, int fd)
{
+ int channel = perf_evlist__idx_channel(evlist, idx);
+ int prot = PROT_READ;
+
+ if (channel < 0)
+ return -1;
+
+ if (!perf_evlist__channel_check(evlist, channel, RDONLY))
+ prot |= PROT_WRITE;
+
/*
* The last one will be done at perf_evlist__mmap_consume(), so that we
* make sure we don't prevent tools from consuming every last event in
@@ -1011,7 +1020,7 @@ 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].base = mmap(NULL, evlist->mmap_len, prot,
MAP_SHARED, fd, 0);
if (evlist->mmap[idx].base == MAP_FAILED) {
pr_debug2("failed to mmap perf event ring buffer, error %d\n",
@@ -1030,7 +1039,11 @@ static int __perf_evlist__mmap(struct perf_evlist *evlist, int idx,
static unsigned long
perf_evlist__channel_for_evsel(struct perf_evsel *evsel __maybe_unused)
{
- return 0;
+ unsigned long flag = 0;
+
+ if (evsel->overwrite)
+ flag |= PERF_EVLIST__CHANNEL_RDONLY;
+ return flag;
}
static int
@@ -1286,11 +1299,10 @@ int perf_evlist__parse_mmap_pages(const struct option *opt, const char *str,
* perf_evlist__mmap_ex - Create mmaps to receive events.
* @evlist: list of events
* @pages: map length in pages
- * @overwrite: overwrite older events?
* @auxtrace_pages - auxtrace map length in pages
* @auxtrace_overwrite - overwrite older auxtrace data?
*
- * If @overwrite is %false the user needs to signal event consumption using
+ * For writable channel, the user needs to signal event consumption using
* perf_mmap__write_tail(). Using perf_evlist__mmap_read() does this
* automatically.
*
@@ -1300,16 +1312,13 @@ int perf_evlist__parse_mmap_pages(const struct option *opt, const char *str,
* Return: %0 on success, negative error code otherwise.
*/
int perf_evlist__mmap_ex(struct perf_evlist *evlist, unsigned int pages,
- bool overwrite, unsigned int auxtrace_pages,
- bool auxtrace_overwrite)
+ unsigned int auxtrace_pages, bool auxtrace_overwrite)
{
int err;
struct perf_evsel *evsel;
const struct cpu_map *cpus = evlist->cpus;
const struct thread_map *threads = evlist->threads;
- struct mmap_params mp = {
- .prot = PROT_READ | (overwrite ? 0 : PROT_WRITE),
- };
+ struct mmap_params mp;
err = perf_evlist__channel_complete(evlist);
if (err)
@@ -1321,7 +1330,6 @@ int perf_evlist__mmap_ex(struct perf_evlist *evlist, unsigned int pages,
if (evlist->pollfd.entries == NULL && perf_evlist__alloc_pollfd(evlist) < 0)
return -ENOMEM;
- 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;
@@ -1345,8 +1353,13 @@ int perf_evlist__mmap_ex(struct perf_evlist *evlist, unsigned int pages,
int perf_evlist__mmap(struct perf_evlist *evlist, unsigned int pages,
bool overwrite)
{
+ struct perf_evsel *evsel;
+
perf_evlist__channel_reset(evlist);
- return perf_evlist__mmap_ex(evlist, pages, overwrite, 0, false);
+ evlist__for_each(evlist, evsel)
+ evsel->overwrite = overwrite;
+
+ return perf_evlist__mmap_ex(evlist, pages, 0, false);
}
int perf_evlist__create_maps(struct perf_evlist *evlist, struct target *target)
@@ -20,9 +20,10 @@ struct record_opts;
#define PERF_EVLIST__HLIST_BITS 8
#define PERF_EVLIST__HLIST_SIZE (1 << PERF_EVLIST__HLIST_BITS)
-#define PERF_EVLIST__NR_CHANNELS 2
+#define PERF_EVLIST__NR_CHANNELS 3
enum perf_evlist_mmap_flag {
PERF_EVLIST__CHANNEL_ENABLED = 1,
+ PERF_EVLIST__CHANNEL_RDONLY = 2,
};
/**
@@ -45,7 +46,6 @@ struct perf_evlist {
int nr_entries;
int nr_groups;
int nr_mmaps;
- bool overwrite;
bool enabled;
bool has_user_cpus;
size_t mmap_len;
@@ -223,8 +223,7 @@ int perf_evlist__parse_mmap_pages(const struct option *opt,
unsigned long perf_event_mlock_kb_in_pages(void);
int perf_evlist__mmap_ex(struct perf_evlist *evlist, unsigned int pages,
- bool overwrite, unsigned int auxtrace_pages,
- bool auxtrace_overwrite);
+ unsigned int auxtrace_pages, bool auxtrace_overwrite);
int perf_evlist__mmap(struct perf_evlist *evlist, unsigned int pages,
bool overwrite);
void perf_evlist__munmap(struct perf_evlist *evlist);
@@ -112,6 +112,7 @@ struct perf_evsel {
bool tracking;
bool per_pkg;
bool precise_max;
+ bool overwrite;
/* parse modifier helper */
int exclude_GH;
int nr_members;