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perf evlist: Clarify sterror_mmap variable names

tip:perf/urgent tip-bot for Arnaldo Carvalho de Melo 1 participant 1 message Dec 18, 2014 perf events

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Commit-ID:  e5d4a290da5366c397653c47c3e869a67b1bfa07
Gitweb:     http://git.kernel.org/tip/e5d4a290da5366c397653c47c3e869a67b1bfa07
Author:     Arnaldo Carvalho de Melo <[email protected]>
AuthorDate: Fri, 12 Dec 2014 15:59:51 -0300
Committer:  Arnaldo Carvalho de Melo <[email protected]>
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 <[email protected]>
Cc Borislav Petkov <[email protected]>
Cc David Ahern <[email protected]>
Cc Don Zickus <[email protected]>
Cc Frederic Weisbecker <[email protected]>
Cc Jiri Olsa <[email protected]>
Cc Mike Galbraith <[email protected]>
Cc Namhyung Kim <[email protected]>
Cc Paul Mackerras <[email protected]>
Cc Peter Zijlstra <[email protected]>
Cc Stephane Eranian <[email protected]>
Link http://lkml.kernel.org/n/[email protected] open here
Signed-off-by Arnaldo Carvalho de Melo <[email protected]>
---
 tools/perf/util/evlist.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)
tools/perf/util/evlist.c +3 -3
index de7515d..d661f25 100644
@@ -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);