From: Alexander Shishkin <alexander.shishkin@linux.intel.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-kernel@vger.kernel.org,
Tingwei Zhang <tingwei@codeaurora.org>,
Steven Rostedt <rostedt@goodmis.org>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>
Subject: [PATCH 6/8] stm class: ftrace: Use different channel accroding to CPU
Date: Mon, 5 Oct 2020 10:13:17 +0300 [thread overview]
Message-ID: <20201005071319.78508-7-alexander.shishkin@linux.intel.com> (raw)
In-Reply-To: <20201005071319.78508-1-alexander.shishkin@linux.intel.com>
From: Tingwei Zhang <tingwei@codeaurora.org>
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>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
---
drivers/hwtracing/stm/ftrace.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/hwtracing/stm/ftrace.c b/drivers/hwtracing/stm/ftrace.c
index c694a6e692d1..3bb606dfa634 100644
--- a/drivers/hwtracing/stm/ftrace.c
+++ b/drivers/hwtracing/stm/ftrace.c
@@ -37,8 +37,10 @@ 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);
+ /* This is called from trace system with preemption disabled */
+ 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)
@@ -63,6 +65,7 @@ static int __init stm_ftrace_init(void)
{
int ret;
+ stm_ftrace.data.nr_chans = roundup_pow_of_two(num_possible_cpus());
ret = stm_source_register_device(NULL, &stm_ftrace.data);
if (ret)
pr_err("Failed to register stm_source - ftrace.\n");
--
2.28.0
next prev parent reply other threads:[~2020-10-05 7:13 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-05 7:13 [PATCH 0/8] stm class/intel_th: Updates for v5.10 Alexander Shishkin
2020-10-05 7:13 ` [PATCH 1/8] stm class: ftrace: Change dependency to TRACING Alexander Shishkin
2020-10-05 7:13 ` [PATCH 2/8] tracing: Add flag to control different traces Alexander Shishkin
2020-10-05 7:13 ` [PATCH 3/8] tracing: Add trace_export support for event trace Alexander Shishkin
2020-10-05 7:13 ` [PATCH 4/8] tracing: Add trace_export support for trace_marker Alexander Shishkin
2020-10-05 7:13 ` [PATCH 5/8] stm class: ftrace: Enable supported trace export flag Alexander Shishkin
2020-10-05 7:13 ` Alexander Shishkin [this message]
2020-10-05 7:13 ` [PATCH 7/8] intel_th: pci: Add Alder Lake-S support Alexander Shishkin
2020-10-05 7:13 ` [PATCH 8/8] intel_th: pci: Add Alder Lake CPU support Alexander Shishkin
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