[PATCH v2 5/5] perf/x86/intel/bts: Kill a silly warning

From: Alexander Shishkin <alexander.shishkin@linux.intel.com>
To: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@redhat.com>,
	linux-kernel@vger.kernel.org, vince@deater.net,
	eranian@google.com, Arnaldo Carvalho de Melo <acme@infradead.org>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>
Subject: [PATCH v2 5/5] perf/x86/intel/bts: Kill a silly warning
Date: Tue,  6 Sep 2016 16:23:53 +0300	[thread overview]
Message-ID: <20160906132353.19887-6-alexander.shishkin@linux.intel.com> (raw)
In-Reply-To: <20160906132353.19887-1-alexander.shishkin@linux.intel.com>

At the moment, intel_bts will WARN() out if there is more than one
event writing to the same ring buffer, via SET_OUTPUT, and will only
send data from one event to a buffer.

There is no reason to have this warning in, so kill it.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
---
 arch/x86/events/intel/bts.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/arch/x86/events/intel/bts.c b/arch/x86/events/intel/bts.c
index 9233edf993..bdcd651099 100644
--- a/arch/x86/events/intel/bts.c
+++ b/arch/x86/events/intel/bts.c
@@ -378,8 +378,6 @@ bts_buffer_reset(struct bts_buffer *buf, struct perf_output_handle *handle)
 		return 0;
 
 	head = handle->head & ((buf->nr_pages << PAGE_SHIFT) - 1);
-	if (WARN_ON_ONCE(head != local_read(&buf->head)))
-		return -EINVAL;
 
 	phys = &buf->buf[buf->cur_buf];
 	space = phys->offset + phys->displacement + phys->size - head;
-- 
2.9.3
