[tip:perf/urgent] perf evlist: Clarify sterror_mmap variable names

tip-bot for Arnaldo Carvalho de Melo
2014-12-18T06:29:14Z

Commit-ID: e5d4a290da5366c397653c47c3e869a67b1bfa07
Gitweb: http://git.kernel.org/tip/e5d4a290da5366c397653c47c3e869a67b1bfa07
Author: Arnaldo Carvalho de Melo <acme@redhat.com>
AuthorDate: Fri, 12 Dec 2014 15:59:51 -0300
Committer: Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Tue, 16 Dec 2014 13:38:26 -0300

perf evlist: Clarify sterror_mmap variable names

Prep patch for doing further checks like when the number of pages that
is being attempted is actually below /proc/sys/kernel/perf_event_mlock_kb but
the operation fails because the user doesn't have CAP_IPC_LOCK.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-wetzlux7mzvofu5cuji5i71i@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/perf/util/evlist.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index de7515d..d661f25 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -1487,16 +1487,16 @@ int perf_evlist__strerror_open(struct perf_evlist *evlist __maybe_unused,
int perf_evlist__strerror_mmap(struct perf_evlist *evlist, int err, char *buf, size_t size)
{
char sbuf[STRERR_BUFSIZE], *emsg = strerror_r(err, sbuf, sizeof(sbuf));
- int value;
+ int pages_attempted = evlist->mmap_len / 1024, pages_max_per_user;

switch (err) {
case EPERM:
- sysctl__read_int("kernel/perf_event_mlock_kb", &value);
+ sysctl__read_int("kernel/perf_event_mlock_kb", &pages_max_per_user);
scnprintf(buf, size, "Error:\t%s.\n"
"Hint:\tCheck /proc/sys/kernel/perf_event_mlock_kb (%d kB) setting.\n"
"Hint:\tTried using %zd kB.\n"
"Hint:\tTry using a smaller -m/--mmap-pages value.",
- emsg, value, evlist->mmap_len / 1024);
+ emsg, pages_max_per_user, pages_attempted);
break;
default:
scnprintf(buf, size, "%s", emsg);