[v9] eal: add build-time option to omit trace
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Commit Message
Some applications want to omit the trace feature.
Either to reduce the memory footprint, to reduce the exposed attack
surface, or for other reasons.
This patch adds an option in rte_config.h to include or omit trace in the
build. Trace is included by default.
Omitting trace works by omitting all trace points.
For API and ABI compatibility, the trace feature itself remains.
Furthermore, a public function to determine if trace is build time enabled
is added; mainly for the benefit of the dpdk-test application.
Signed-off-by: Morten Brørup <mb@smartsharesystems.com>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
Acked-by: Jerin Jacob <jerinj@marvell.com>
---
v9:
* Assume library and application are built with same rte_config.h.
* Renamed internal function __rte_trace_point_generic_is_enabled() to
rte_trace_feature_is_enabled(), which is public. (Jerin Jacob)
* Removed changes that became superfluous with the above change.
v8:
* Added Stephen's Ack to v4, forgot to carry over.
v7:
* Updated version.map to not export __rte_trace_feature_is_enabled for
Windows target.
v6:
* Removed test_trace_perf.c changes; they don't compile for Windows
target, and are superfluous.
v5:
* Added public function rte_trace_feature_is_enabled(), to test if trace
is build time enabled in both the DPDK and the application. Use in test
application instead of private function. (Jerin Jacob)
v4:
* Added check for generic trace enabled when registering trace points, in
RTE_INIT. (Jerin Jacob)
* Test application uses function instead of macro to check if generic
trace is enabled. (Jerin Jacob)
* Performance test application uses function to check if generic trace is
enabled.
v3:
* Simpler version with much fewer ifdefs. (Jerin Jacob)
v2:
* Added/modified macros required for building applications with trace
omitted.
---
app/test/test_trace.c | 4 ++++
config/rte_config.h | 1 +
lib/eal/include/rte_trace.h | 19 +++++++++++++++++++
lib/eal/include/rte_trace_point.h | 3 +++
lib/eal/include/rte_trace_point_register.h | 2 ++
5 files changed, 29 insertions(+)
Comments
> From: Morten Brørup [mailto:mb@smartsharesystems.com]
> Sent: Monday, 7 October 2024 13.46
>
> Some applications want to omit the trace feature.
> Either to reduce the memory footprint, to reduce the exposed attack
> surface, or for other reasons.
>
> This patch adds an option in rte_config.h to include or omit trace in
> the
> build. Trace is included by default.
>
> Omitting trace works by omitting all trace points.
> For API and ABI compatibility, the trace feature itself remains.
>
> Furthermore, a public function to determine if trace is build time
> enabled
> is added; mainly for the benefit of the dpdk-test application.
>
> Signed-off-by: Morten Brørup <mb@smartsharesystems.com>
> Acked-by: Stephen Hemminger <stephen@networkplumber.org>
> Acked-by: Jerin Jacob <jerinj@marvell.com>
> ---
Both trace_autotest and trace_perf_autotest have been tested (in a Linux environment) to behave as expected, both with and without RTE_TRACE defined.
Tested-by: Morten Brørup <mb@smartsharesystems.com>
On Mon, Oct 7, 2024 at 1:46 PM Morten Brørup <mb@smartsharesystems.com> wrote:
>
> Some applications want to omit the trace feature.
> Either to reduce the memory footprint, to reduce the exposed attack
> surface, or for other reasons.
>
> This patch adds an option in rte_config.h to include or omit trace in the
> build. Trace is included by default.
>
> Omitting trace works by omitting all trace points.
> For API and ABI compatibility, the trace feature itself remains.
>
> Furthermore, a public function to determine if trace is build time enabled
> is added; mainly for the benefit of the dpdk-test application.
>
> Signed-off-by: Morten Brørup <mb@smartsharesystems.com>
> Acked-by: Stephen Hemminger <stephen@networkplumber.org>
> Acked-by: Jerin Jacob <jerinj@marvell.com>
Series applied.
Thanks Morten.
@@ -245,6 +245,10 @@ static struct unit_test_suite trace_tests = {
static int
test_trace(void)
{
+ if (!rte_trace_feature_is_enabled()) {
+ printf("Trace omitted at build-time, skipping test\n");
+ return TEST_SKIPPED;
+ }
return unit_test_suite_runner(&trace_tests);
}
@@ -49,6 +49,7 @@
#define RTE_MAX_TAILQ 32
#define RTE_LOG_DP_LEVEL RTE_LOG_INFO
#define RTE_MAX_VFIO_CONTAINERS 64
+#define RTE_TRACE 1
/* bsd module defines */
#define RTE_CONTIGMEM_MAX_NUM_BUFS 64
@@ -35,6 +35,25 @@ extern "C" {
__rte_experimental
bool rte_trace_is_enabled(void);
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change, or be removed, without prior notice
+ *
+ * Test if trace feature is enabled at compile time.
+ *
+ * @return
+ * true if trace feature is enabled, false otherwise.
+ */
+static __rte_always_inline
+bool rte_trace_feature_is_enabled(void)
+{
+#ifdef RTE_TRACE
+ return true;
+#else
+ return false;
+#endif
+}
+
/**
* Enumerate trace mode operation.
*/
@@ -30,6 +30,7 @@ extern "C" {
#include <rte_per_lcore.h>
#include <rte_stdatomic.h>
#include <rte_string_fns.h>
+#include <rte_trace.h>
#include <rte_uuid.h>
/** The tracepoint object. */
@@ -359,6 +360,8 @@ __rte_trace_point_emit_ev_header(void *mem, uint64_t in)
#define __rte_trace_point_emit_header_generic(t) \
void *mem; \
do { \
+ if (!rte_trace_feature_is_enabled()) \
+ return; \
const uint64_t val = rte_atomic_load_explicit(t, rte_memory_order_acquire); \
if (likely(!(val & __RTE_TRACE_FIELD_ENABLE_MASK))) \
return; \
@@ -23,6 +23,8 @@ rte_trace_point_t __rte_section("__rte_trace_point") __##trace; \
static const char __##trace##_name[] = RTE_STR(name); \
RTE_INIT(trace##_init) \
{ \
+ if (!rte_trace_feature_is_enabled()) \
+ return; \
__rte_trace_point_register(&__##trace, __##trace##_name, \
(void (*)(void)) trace); \
}