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From:   Tingwei Zhang <tingwei@codeaurora.org>
To:     Steven Rostedt <rostedt@goodmis.org>,
        Ingo Molnar <mingo@redhat.com>
Cc:     Tingwei Zhang <tingwei@codeaurora.org>, tsoni@codeaurora.org,
        Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>,
        Mao Jinlong <jinlmao@codeaurora.org>,
        linux-kernel@vger.kernel.org
Subject: [PATCH 4/4] stm class: ftrace: use different channel accroding to CPU
Date:   Mon, 20 Jul 2020 10:21:17 +0800
Message-Id: <20200720022117.9375-5-tingwei@codeaurora.org>
In-Reply-To: <20200720022117.9375-1-tingwei@codeaurora.org>
References: <20200720022117.9375-1-tingwei@codeaurora.org>
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To avoid mixup of packets from differnt ftrace packets simultaneously,
use different channel for packets from different CPU.

Signed-off-by: Tingwei Zhang <tingwei@codeaurora.org>
---
 drivers/hwtracing/stm/ftrace.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/hwtracing/stm/ftrace.c b/drivers/hwtracing/stm/ftrace.c
index ce868e095410..6c3bce11c8d3 100644
--- a/drivers/hwtracing/stm/ftrace.c
+++ b/drivers/hwtracing/stm/ftrace.c
@@ -10,7 +10,7 @@
 #include <linux/stm.h>
 #include <linux/trace.h>
 
-#define STM_FTRACE_NR_CHANNELS 1
+#define STM_FTRACE_NR_CHANNELS NR_CPUS
 #define STM_FTRACE_CHAN 0
 
 static int stm_ftrace_link(struct stm_source_data *data);
@@ -37,8 +37,9 @@ static void notrace
 stm_ftrace_write(struct trace_export *export, const void *buf, unsigned int len)
 {
 	struct stm_ftrace *stm = container_of(export, struct stm_ftrace, ftrace);
+	unsigned int cpu = smp_processor_id();
 
-	stm_source_write(&stm->data, STM_FTRACE_CHAN, buf, len);
+	stm_source_write(&stm->data, STM_FTRACE_CHAN + cpu, buf, len);
 }
 
 static int stm_ftrace_link(struct stm_source_data *data)
-- 
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