[PATCH v2 0/2] tracing: allow disabling compilation of specific trace systems
Currently, enabling CONFIG_TRACING on a system comes as all-or-nothing: either tracepoints for all subsystems are compiled (with CONFIG_TRACING) or none of them do (without it). This caused me an unacceptable performance penalty (obviously SOME penalty was expected, but not one so severe) which made me revert the changes in configuration. The first patch in this series modifies the files that actually define the tracepoint to look for a preprocessor macro NOTRACE and define nops (as if CONFIG_TRACING was not set) instead of them. The second patch provides an example of how I see this working, with the gpio subsystem as the example for absolutely no reason. If this idea is deemed worth the time by the community, I'll create patches for the other subsystems. Changelog: v2: - A comment in tracepoint.h explaining NOTRACE and its use - Avoid duplication of the test for both NOTRACE and a config option by defining TRACEPOINTS_ENABLED when both are present and using that to check whether or not to define tracepoints Tal Shorer (2): tracing: allow disabling compilation of specific trace systems tracing: gpio: add Kconfig option for enabling/disabling trace events drivers/gpio/Kconfig | 7 +++ include/linux/tracepoint.h | 6 +++--- include/trace/define_trace.h | 2 +- include/trace/events/gpio.h | 4 4 files changed, 15 insertions(+), 4 deletions(-) -- 2.4.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH v2 0/2] tracing: allow disabling compilation of specific trace systems
Currently, enabling CONFIG_TRACING on a system comes as all-or-nothing: either tracepoints for all subsystems are compiled (with CONFIG_TRACING) or none of them do (without it). This caused me an unacceptable performance penalty (obviously SOME penalty was expected, but not one so severe) which made me revert the changes in configuration. The first patch in this series modifies the files that actually define the tracepoint to look for a preprocessor macro NOTRACE and define nops (as if CONFIG_TRACING was not set) instead of them. The second patch provides an example of how I see this working, with the gpio subsystem as the example for absolutely no reason. If this idea is deemed worth the time by the community, I'll create patches for the other subsystems. Changelog: v2: - A comment in tracepoint.h explaining NOTRACE and its use - Avoid duplication of the test for both NOTRACE and a config option by defining TRACEPOINTS_ENABLED when both are present and using that to check whether or not to define tracepoints Tal Shorer (2): tracing: allow disabling compilation of specific trace systems tracing: gpio: add Kconfig option for enabling/disabling trace events drivers/gpio/Kconfig | 7 +++ include/linux/tracepoint.h | 6 +++--- include/trace/define_trace.h | 2 +- include/trace/events/gpio.h | 4 4 files changed, 15 insertions(+), 4 deletions(-) -- 2.4.3 -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
