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authorTingwei Zhang <tingwei@codeaurora.org>2020-10-05 10:13:17 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-10-05 12:43:54 +0200
commitb8f8534b10b6ee3cec5e49682d7e0c4796cdccea (patch)
treef8fac11b8074f33f6dae56ba7fbbc12c8f2923a4 /drivers/hwtracing/stm
parente8ecea3017385858be0ba5640b3b364586743c6b (diff)
stm class: ftrace: Use different channel accroding to CPU
To avoid mixup of packets from differnt ftrace packets simultaneously, use different channel for packets from different CPU. Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Tingwei Zhang <tingwei@codeaurora.org> Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Link: https://lore.kernel.org/r/20201005071319.78508-7-alexander.shishkin@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/hwtracing/stm')
-rw-r--r--drivers/hwtracing/stm/ftrace.c5
1 files changed, 4 insertions, 1 deletions
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");