From mboxrd@z Thu Jan 1 00:00:00 1970 From: alexander.shishkin@linux.intel.com (Alexander Shishkin) Date: Tue, 07 Jun 2016 13:00:21 +0300 Subject: [RFC PATCH 3/4] trace: Duplicate the output of the function trace logs to STM In-Reply-To: <1464779939-24986-4-git-send-email-zhang.chunyan@linaro.org> References: <1464779939-24986-1-git-send-email-zhang.chunyan@linaro.org> <1464779939-24986-4-git-send-email-zhang.chunyan@linaro.org> Message-ID: <87lh2hqpxm.fsf@ashishki-desk.ger.corp.intel.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Chunyan Zhang writes: > This patch adds an output from Ftrace to STM. But does it? > That being said, > Function trace messages would also be duplicated to STM buffer when > being stored into ring buffer. Not sure what you mean here. What's "STM buffer"? > > Signed-off-by: Chunyan Zhang > --- > kernel/trace/trace.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c > index 8a4bd6b..d613053 100644 > --- a/kernel/trace/trace.c > +++ b/kernel/trace/trace.c > @@ -44,6 +44,7 @@ > > #include "trace.h" > #include "trace_output.h" > +#include "trace_output_stm.h" > > /* > * On boot up, the ring buffer is set to the minimum size, so that > @@ -1884,8 +1885,10 @@ trace_function(struct trace_array *tr, > entry->ip = ip; > entry->parent_ip = parent_ip; > > - if (!call_filter_check_discard(call, entry, buffer, event)) > + if (!call_filter_check_discard(call, entry, buffer, event)) { > __buffer_unlock_commit(buffer, event); > + ftrace_stm_func(ip, parent_ip); > + } So this logs instruction pointers, not the actual events. Not much is duplicated like the message suggests, but it also doesn't seem very useful. Regards, -- Alex