Re: [Tarantool-patches] [PATCH v1] test: add ARM at travis-ci

[Serge Petrenko <sergepetrenko@tarantool.org>]

Hi! Thanks for the patch!
Let me add my 5 cents.

> 20 дек. 2019 г., в 09:55, Alexander V. Tikhonov <avtikhon@tarantool.org> написал(а):
> 
> Added ARM architecture for testing release and
> debug Tarantool builds on Travis-ci.
> 
> Close #4270
> ---
> 
> Github: https://github.com/tarantool/tarantool/tree/avtikhon/gh-4270-travis-ci-arm
> Issue: https://github.com/tarantool/tarantool/issues/4270
> 
> .gitlab-ci.yml       | 11 +++++++++++
> .travis.mk           | 12 ++++++++++++
> src/lib/core/fiber.c | 17 ++++++++++++++++-
> 3 files changed, 39 insertions(+), 1 deletion(-)
> 
> diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
> index 3af5a3c8a..1603b65e3 100644
> --- a/.gitlab-ci.yml
> +++ b/.gitlab-ci.yml
> @@ -90,6 +90,17 @@ release_asan_clang8:
>   script:
>     - ${GITLAB_MAKE} test_asan_debian_no_deps
> 
> +release_arm:
> +  stage: test
> +  tags:
> +    - test
> +  variables:
> +    DOCKER_IMAGE: "${CI_REGISTRY}/${CI_PROJECT_PATH}/testing/arm64v8-debian-buster:latest"
> +    DOCKER_OPTIONS: "--network=host"
> +    CMAKE_EXTRA_PARAMS: -DENABLE_BACKTRACE=OFF
> +  script:
> +    - ${GITLAB_MAKE} test_arm_debian_no_deps
> +
> osx_13_release:
>   <<: *release_only_definition
>   <<: *vbox_definition
> diff --git a/.travis.mk b/.travis.mk
> index 42969ff56..1427d5b2f 100644
> --- a/.travis.mk
> +++ b/.travis.mk
> @@ -24,6 +24,7 @@ asan: docker_test_asan_debian
> docker_%:
> 	mkdir -p ~/.cache/ccache
> 	docker run \
> +		${DOCKER_OPTIONS} \
> 		--rm=true --tty=true \
> 		--volume "${PWD}:/tarantool" \
> 		--volume "${HOME}/.cache:/cache" \
> @@ -123,6 +124,17 @@ test_asan_debian_no_deps: build_asan_debian
> 
> test_asan_debian: deps_debian deps_buster_clang_8 test_asan_debian_no_deps
> 
> +#######
> +# ARM #
> +#######
> +
> +qemu_arm_debian:
> +	docker run --rm --privileged multiarch/qemu-user-static --reset -p yes
> +
> +build_arm_debian: qemu_arm_debian docker_build_debian
> +
> +test_arm_debian_no_deps: qemu_arm_debian docker_test_debian_no_deps
> +
> #######
> # OSX #
> #######
> diff --git a/src/lib/core/fiber.c b/src/lib/core/fiber.c
> index 00ae8cded..6ef3c22db 100644
> --- a/src/lib/core/fiber.c
> +++ b/src/lib/core/fiber.c
> @@ -43,7 +43,22 @@
> #include "trigger.h"
> 
> #if ENABLE_FIBER_TOP
> +#if !defined(__arm__) && !defined(__aarch64__) && !defined(__powerpc64__) && !defined(__PPC64__) && \
> +    !defined(__powerpc__)
> #include <x86intrin.h> /* __rdtscp() */
> +#elif defined(__aarch64__)
> +static __inline__ unsigned long long __rdtscp(uint32_t *cpu_id)

Please check src/lib/core/fiber.h
It disables fiber.top for ARM architecture:

```
/*                                                                                  
 * Fiber top doesn't work on ARM processors at the moment,                          
 * because we haven't chosen an alternative to rdtsc.                               
 */                                                                                 
#ifdef __CC_ARM                                                                     
#define ENABLE_FIBER_TOP 0                                                          
#else                                                                               
#define ENABLE_FIBER_TOP 1                                                          
#endif
```

So, it looks like your patch not only adds ARM testing, but also closes a
relevant ticket re fiber.top (https://github.com/tarantool/tarantool/issues/4573)
[Implement fiber.top() for ARM].

Anyway, this is worth a separate patch, and IMO in this patch you should just disable
fiber.top() test on ARM somehow. As I can see you tried to implement it on arm because
otherwise the test would fail.

> +{
> +       // System timer of ARMv8 runs at a different frequency than the CPU's.
> +       // The frequency is fixed, typically in the range 1-50MHz.  It can be
> +       // read at CNTFRQ special register.  We assume the OS has set up
> +       // the virtual timer properly.
> +       if (!cpu_id) { cpu_id = 0; }
> +       int64_t virtual_timer_value;
> +       __asm__ volatile("mrs %0, cntvct_el0" : "=r"(virtual_timer_value));
> +       return virtual_timer_value;
> +}
> +#endif
> 
> static inline void
> clock_stat_add_delta(struct clock_stat *stat, uint64_t clock_delta)
> @@ -109,7 +124,7 @@ cpu_stat_reset(struct cpu_stat *stat)
> static uint64_t
> cpu_stat_on_csw(struct cpu_stat *stat)
> {
> -	uint32_t cpu_id;
> +	uint32_t cpu_id = 0;
> 	uint64_t delta, clock = __rdtscp(&cpu_id);
> 
> 	if (cpu_id == stat->prev_cpu_id) {
> — 
> 2.17.1
> 



--
Serge Petrenko
sergepetrenko@tarantool.org