tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
tools/counter: Create Counter tools
This creates an example Counter program under tools/counter/*
to exemplify the Counter character device interface.
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Link: https://lore.kernel.org/r/7c0f975ba098952122302d258ec9ffdef04befaf.1632884256.git.vilhelm.gray@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
authored by
William Breathitt Gray
and committed by
Jonathan Cameron
08609989
a8a28737
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MAINTAINERS
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MAINTAINERS
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tools/Makefile
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tools/Makefile
···
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@echo ' acpi - ACPI tools'
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@echo ' bpf - misc BPF tools'
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@echo ' cgroup - cgroup tools'
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@echo ' counter - counter tools'
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@echo ' cpupower - a tool for all things x86 CPU power'
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@echo ' debugging - tools for debugging'
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@echo ' firewire - the userspace part of nosy, an IEEE-1394 traffic sniffer'
···
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cpupower: FORCE
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$(call descend,power/$@)
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cgroup firewire hv guest bootconfig spi usb virtio vm bpf iio gpio objtool leds wmi pci firmware debugging tracing: FORCE
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cgroup counter firewire hv guest bootconfig spi usb virtio vm bpf iio gpio objtool leds wmi pci firmware debugging tracing: FORCE
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$(call descend,$@)
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bpf/%: FORCE
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kvm_stat: FORCE
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$(call descend,kvm/$@)
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all: acpi cgroup cpupower gpio hv firewire liblockdep \
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all: acpi cgroup counter cpupower gpio hv firewire liblockdep \
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perf selftests bootconfig spi turbostat usb \
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virtio vm bpf x86_energy_perf_policy \
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tmon freefall iio objtool kvm_stat wmi \
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cpupower_install:
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$(call descend,power/$(@:_install=),install)
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cgroup_install firewire_install gpio_install hv_install iio_install perf_install bootconfig_install spi_install usb_install virtio_install vm_install bpf_install objtool_install wmi_install pci_install debugging_install tracing_install:
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cgroup_install counter_install firewire_install gpio_install hv_install iio_install perf_install bootconfig_install spi_install usb_install virtio_install vm_install bpf_install objtool_install wmi_install pci_install debugging_install tracing_install:
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$(call descend,$(@:_install=),install)
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liblockdep_install:
···
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kvm_stat_install:
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$(call descend,kvm/$(@:_install=),install)
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install: acpi_install cgroup_install cpupower_install gpio_install \
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install: acpi_install cgroup_install counter_install cpupower_install gpio_install \
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hv_install firewire_install iio_install liblockdep_install \
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perf_install selftests_install turbostat_install usb_install \
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virtio_install vm_install bpf_install x86_energy_perf_policy_install \
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cpupower_clean:
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$(call descend,power/cpupower,clean)
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cgroup_clean hv_clean firewire_clean bootconfig_clean spi_clean usb_clean virtio_clean vm_clean wmi_clean bpf_clean iio_clean gpio_clean objtool_clean leds_clean pci_clean firmware_clean debugging_clean tracing_clean:
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cgroup_clean counter_clean hv_clean firewire_clean bootconfig_clean spi_clean usb_clean virtio_clean vm_clean wmi_clean bpf_clean iio_clean gpio_clean objtool_clean leds_clean pci_clean firmware_clean debugging_clean tracing_clean:
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$(call descend,$(@:_clean=),clean)
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liblockdep_clean:
···
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build_clean:
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$(call descend,build,clean)
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clean: acpi_clean cgroup_clean cpupower_clean hv_clean firewire_clean \
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clean: acpi_clean cgroup_clean counter_clean cpupower_clean hv_clean firewire_clean \
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perf_clean selftests_clean turbostat_clean bootconfig_clean spi_clean usb_clean virtio_clean \
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vm_clean bpf_clean iio_clean x86_energy_perf_policy_clean tmon_clean \
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freefall_clean build_clean libbpf_clean libsubcmd_clean liblockdep_clean \
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tools/counter/Build
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tools/counter/Build
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counter_example-y += counter_example.o
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tools/counter/Makefile
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tools/counter/Makefile
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# SPDX-License-Identifier: GPL-2.0
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include ../scripts/Makefile.include
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bindir ?= /usr/bin
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ifeq ($(srctree),)
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srctree := $(patsubst %/,%,$(dir $(CURDIR)))
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srctree := $(patsubst %/,%,$(dir $(srctree)))
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endif
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# Do not use make's built-in rules
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# (this improves performance and avoids hard-to-debug behaviour);
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MAKEFLAGS += -r
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override CFLAGS += -O2 -Wall -g -D_GNU_SOURCE -I$(OUTPUT)include
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ALL_TARGETS := counter_example
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ALL_PROGRAMS := $(patsubst %,$(OUTPUT)%,$(ALL_TARGETS))
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all: $(ALL_PROGRAMS)
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export srctree OUTPUT CC LD CFLAGS
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include $(srctree)/tools/build/Makefile.include
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#
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# We need the following to be outside of kernel tree
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#
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$(OUTPUT)include/linux/counter.h: ../../include/uapi/linux/counter.h
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mkdir -p $(OUTPUT)include/linux 2>&1 || true
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ln -sf $(CURDIR)/../../include/uapi/linux/counter.h $@
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prepare: $(OUTPUT)include/linux/counter.h
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COUNTER_EXAMPLE := $(OUTPUT)counter_example.o
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$(COUNTER_EXAMPLE): prepare FORCE
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$(Q)$(MAKE) $(build)=counter_example
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$(OUTPUT)counter_example: $(COUNTER_EXAMPLE)
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$(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) $< -o $@
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clean:
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rm -f $(ALL_PROGRAMS)
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rm -rf $(OUTPUT)include/linux/counter.h
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find $(if $(OUTPUT),$(OUTPUT),.) -name '*.o' -delete -o -name '\.*.d' -delete
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install: $(ALL_PROGRAMS)
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install -d -m 755 $(DESTDIR)$(bindir); \
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for program in $(ALL_PROGRAMS); do \
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install $$program $(DESTDIR)$(bindir); \
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done
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FORCE:
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.PHONY: all install clean FORCE prepare
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tools/counter/counter_example.c
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tools/counter/counter_example.c
···
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// SPDX-License-Identifier: GPL-2.0-only
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/* Counter - example userspace application
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*
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* The userspace application opens /dev/counter0, configures the
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* COUNTER_EVENT_INDEX event channel 0 to gather Count 0 count and Count
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* 1 count, and prints out the data as it becomes available on the
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* character device node.
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*
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* Copyright (C) 2021 William Breathitt Gray
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*/
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#include <errno.h>
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#include <fcntl.h>
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#include <linux/counter.h>
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#include <stdio.h>
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#include <string.h>
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#include <sys/ioctl.h>
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#include <unistd.h>
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static struct counter_watch watches[2] = {
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{
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/* Component data: Count 0 count */
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.component.type = COUNTER_COMPONENT_COUNT,
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.component.scope = COUNTER_SCOPE_COUNT,
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.component.parent = 0,
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/* Event type: Index */
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.event = COUNTER_EVENT_INDEX,
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/* Device event channel 0 */
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.channel = 0,
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},
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{
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/* Component data: Count 1 count */
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.component.type = COUNTER_COMPONENT_COUNT,
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.component.scope = COUNTER_SCOPE_COUNT,
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.component.parent = 1,
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/* Event type: Index */
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.event = COUNTER_EVENT_INDEX,
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/* Device event channel 0 */
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.channel = 0,
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},
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};
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int main(void)
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{
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int fd;
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int ret;
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int i;
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struct counter_event event_data[2];
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fd = open("/dev/counter0", O_RDWR);
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if (fd == -1) {
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perror("Unable to open /dev/counter0");
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return 1;
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}
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for (i = 0; i < 2; i++) {
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ret = ioctl(fd, COUNTER_ADD_WATCH_IOCTL, watches + i);
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if (ret == -1) {
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fprintf(stderr, "Error adding watches[%d]: %s\n", i,
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strerror(errno));
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return 1;
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}
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}
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ret = ioctl(fd, COUNTER_ENABLE_EVENTS_IOCTL);
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if (ret == -1) {
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perror("Error enabling events");
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return 1;
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}
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for (;;) {
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ret = read(fd, event_data, sizeof(event_data));
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if (ret == -1) {
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perror("Failed to read event data");
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return 1;
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}
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if (ret != sizeof(event_data)) {
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fprintf(stderr, "Failed to read event data\n");
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return -EIO;
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}
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printf("Timestamp 0: %llu\tCount 0: %llu\n"
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"Error Message 0: %s\n"
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"Timestamp 1: %llu\tCount 1: %llu\n"
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"Error Message 1: %s\n",
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event_data[0].timestamp, event_data[0].value,
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strerror(event_data[0].status),
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event_data[1].timestamp, event_data[1].value,
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strerror(event_data[1].status));
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}
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return 0;
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}