Re: [PATCH v3 2/3] perf test: Remove x86 rdpmc test

[Arnaldo Carvalho de Melo]

Em Tue, Jul 19, 2022 at 03:39:45PM -0700, Ian Rogers escreveu:
> This test has been superseded by test_stat_user_read in:
> tools/lib/perf/tests/test-evsel.c
> The updated test doesn't divide-by-0 when running time of a counter is
> 0. It also supports ARM64.

Thanks, applied.

- Arnaldo

 
> Acked-by: Rob Herring <robh@xxxxxxxxxx>
> Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
> ---
>  tools/perf/arch/x86/tests/Build        |   1 -
>  tools/perf/arch/x86/tests/arch-tests.c |   2 -
>  tools/perf/arch/x86/tests/rdpmc.c      | 182 -------------------------
>  3 files changed, 185 deletions(-)
>  delete mode 100644 tools/perf/arch/x86/tests/rdpmc.c
> 
> diff --git a/tools/perf/arch/x86/tests/Build b/tools/perf/arch/x86/tests/Build
> index 28d793390198..70b5bcbc15df 100644
> --- a/tools/perf/arch/x86/tests/Build
> +++ b/tools/perf/arch/x86/tests/Build
> @@ -2,7 +2,6 @@ perf-$(CONFIG_DWARF_UNWIND) += regs_load.o
>  perf-$(CONFIG_DWARF_UNWIND) += dwarf-unwind.o
>  
>  perf-y += arch-tests.o
> -perf-y += rdpmc.o
>  perf-y += sample-parsing.o
>  perf-$(CONFIG_AUXTRACE) += insn-x86.o intel-pt-pkt-decoder-test.o
>  perf-$(CONFIG_X86_64) += bp-modify.o
> diff --git a/tools/perf/arch/x86/tests/arch-tests.c b/tools/perf/arch/x86/tests/arch-tests.c
> index 64fb73d14d2f..04018b8aa85b 100644
> --- a/tools/perf/arch/x86/tests/arch-tests.c
> +++ b/tools/perf/arch/x86/tests/arch-tests.c
> @@ -3,7 +3,6 @@
>  #include "tests/tests.h"
>  #include "arch-tests.h"
>  
> -DEFINE_SUITE("x86 rdpmc", rdpmc);
>  #ifdef HAVE_AUXTRACE_SUPPORT
>  DEFINE_SUITE("x86 instruction decoder - new instructions", insn_x86);
>  DEFINE_SUITE("Intel PT packet decoder", intel_pt_pkt_decoder);
> @@ -14,7 +13,6 @@ DEFINE_SUITE("x86 bp modify", bp_modify);
>  DEFINE_SUITE("x86 Sample parsing", x86_sample_parsing);
>  
>  struct test_suite *arch_tests[] = {
> -	&suite__rdpmc,
>  #ifdef HAVE_DWARF_UNWIND_SUPPORT
>  	&suite__dwarf_unwind,
>  #endif
> diff --git a/tools/perf/arch/x86/tests/rdpmc.c b/tools/perf/arch/x86/tests/rdpmc.c
> deleted file mode 100644
> index 498413ad9c97..000000000000
> --- a/tools/perf/arch/x86/tests/rdpmc.c
> +++ /dev/null
> @@ -1,182 +0,0 @@
> -// SPDX-License-Identifier: GPL-2.0
> -#include <errno.h>
> -#include <unistd.h>
> -#include <stdlib.h>
> -#include <signal.h>
> -#include <sys/mman.h>
> -#include <sys/types.h>
> -#include <sys/wait.h>
> -#include <linux/string.h>
> -#include <linux/types.h>
> -#include "perf-sys.h"
> -#include "debug.h"
> -#include "tests/tests.h"
> -#include "cloexec.h"
> -#include "event.h"
> -#include <internal/lib.h> // page_size
> -#include "arch-tests.h"
> -
> -static u64 rdpmc(unsigned int counter)
> -{
> -	unsigned int low, high;
> -
> -	asm volatile("rdpmc" : "=a" (low), "=d" (high) : "c" (counter));
> -
> -	return low | ((u64)high) << 32;
> -}
> -
> -static u64 rdtsc(void)
> -{
> -	unsigned int low, high;
> -
> -	asm volatile("rdtsc" : "=a" (low), "=d" (high));
> -
> -	return low | ((u64)high) << 32;
> -}
> -
> -static u64 mmap_read_self(void *addr)
> -{
> -	struct perf_event_mmap_page *pc = addr;
> -	u32 seq, idx, time_mult = 0, time_shift = 0;
> -	u64 count, cyc = 0, time_offset = 0, enabled, running, delta;
> -
> -	do {
> -		seq = pc->lock;
> -		barrier();
> -
> -		enabled = pc->time_enabled;
> -		running = pc->time_running;
> -
> -		if (enabled != running) {
> -			cyc = rdtsc();
> -			time_mult = pc->time_mult;
> -			time_shift = pc->time_shift;
> -			time_offset = pc->time_offset;
> -		}
> -
> -		idx = pc->index;
> -		count = pc->offset;
> -		if (idx)
> -			count += rdpmc(idx - 1);
> -
> -		barrier();
> -	} while (pc->lock != seq);
> -
> -	if (enabled != running) {
> -		u64 quot, rem;
> -
> -		quot = (cyc >> time_shift);
> -		rem = cyc & (((u64)1 << time_shift) - 1);
> -		delta = time_offset + quot * time_mult +
> -			((rem * time_mult) >> time_shift);
> -
> -		enabled += delta;
> -		if (idx)
> -			running += delta;
> -
> -		quot = count / running;
> -		rem = count % running;
> -		count = quot * enabled + (rem * enabled) / running;
> -	}
> -
> -	return count;
> -}
> -
> -/*
> - * If the RDPMC instruction faults then signal this back to the test parent task:
> - */
> -static void segfault_handler(int sig __maybe_unused,
> -			     siginfo_t *info __maybe_unused,
> -			     void *uc __maybe_unused)
> -{
> -	exit(-1);
> -}
> -
> -static int __test__rdpmc(void)
> -{
> -	volatile int tmp = 0;
> -	u64 i, loops = 1000;
> -	int n;
> -	int fd;
> -	void *addr;
> -	struct perf_event_attr attr = {
> -		.type = PERF_TYPE_HARDWARE,
> -		.config = PERF_COUNT_HW_INSTRUCTIONS,
> -		.exclude_kernel = 1,
> -	};
> -	u64 delta_sum = 0;
> -        struct sigaction sa;
> -	char sbuf[STRERR_BUFSIZE];
> -
> -	sigfillset(&sa.sa_mask);
> -	sa.sa_sigaction = segfault_handler;
> -	sa.sa_flags = 0;
> -	sigaction(SIGSEGV, &sa, NULL);
> -
> -	fd = sys_perf_event_open(&attr, 0, -1, -1,
> -				 perf_event_open_cloexec_flag());
> -	if (fd < 0) {
> -		pr_err("Error: sys_perf_event_open() syscall returned "
> -		       "with %d (%s)\n", fd,
> -		       str_error_r(errno, sbuf, sizeof(sbuf)));
> -		return -1;
> -	}
> -
> -	addr = mmap(NULL, page_size, PROT_READ, MAP_SHARED, fd, 0);
> -	if (addr == (void *)(-1)) {
> -		pr_err("Error: mmap() syscall returned with (%s)\n",
> -		       str_error_r(errno, sbuf, sizeof(sbuf)));
> -		goto out_close;
> -	}
> -
> -	for (n = 0; n < 6; n++) {
> -		u64 stamp, now, delta;
> -
> -		stamp = mmap_read_self(addr);
> -
> -		for (i = 0; i < loops; i++)
> -			tmp++;
> -
> -		now = mmap_read_self(addr);
> -		loops *= 10;
> -
> -		delta = now - stamp;
> -		pr_debug("%14d: %14Lu\n", n, (long long)delta);
> -
> -		delta_sum += delta;
> -	}
> -
> -	munmap(addr, page_size);
> -	pr_debug("   ");
> -out_close:
> -	close(fd);
> -
> -	if (!delta_sum)
> -		return -1;
> -
> -	return 0;
> -}
> -
> -int test__rdpmc(struct test_suite *test __maybe_unused, int subtest __maybe_unused)
> -{
> -	int status = 0;
> -	int wret = 0;
> -	int ret;
> -	int pid;
> -
> -	pid = fork();
> -	if (pid < 0)
> -		return -1;
> -
> -	if (!pid) {
> -		ret = __test__rdpmc();
> -
> -		exit(ret);
> -	}
> -
> -	wret = waitpid(pid, &status, 0);
> -	if (wret < 0 || status)
> -		return -1;
> -
> -	return 0;
> -}
> -- 
> 2.37.0.170.g444d1eabd0-goog

-- 

- Arnaldo