perf: Remove superfluous allocation error check

If the get_callchain_buffers fails to allocate the buffer it will
decrease the nr_callchain_events right away.

There's no point of checking the allocation error for
nr_callchain_events > 1. Removing that check.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: syzkaller-bugs@googlegroups.com
Cc: x86@kernel.org
Link: http://lkml.kernel.org/r/20180415092352.12403-3-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 2 insertions, 8 deletions

diff --git a/kernel/events/callchain.c b/kernel/events/callchain.c
index 73cc26e321de..c187aa3df3c8 100644
--- a/kernel/events/callchain.c
+++ b/kernel/events/callchain.c
@@ -131,14 +131,8 @@ int get_callchain_buffers(int event_max_stack)
                 goto exit;
         }
 
-        if (count > 1) {
-                /* If the allocation failed, give up */
-                if (!callchain_cpus_entries)
-                        err = -ENOMEM;
-                goto exit;
-        }
-
-        err = alloc_callchain_buffers();
+        if (count == 1)
+                err = alloc_callchain_buffers();
 exit:
         if (err)
                 atomic_dec(&nr_callchain_events);