From c6ded6c52504a3b6d03bb5fd343611bd9b053d84 Mon Sep 17 00:00:00 2001
From: Florian Fischer <florian.fischer@muhq.space>
Date: Mon, 2 Aug 2021 14:00:40 +0200
Subject: [PATCH] pin the thread to CPU 0
---
Makefile | 2 +-
bench.c | 13 +++++++++++++
2 files changed, 14 insertions(+), 1 deletion(-)
diff --git a/Makefile b/Makefile
index 21b4705..9768467 100644
--- a/Makefile
+++ b/Makefile
@@ -5,7 +5,7 @@ OBJ := $(addprefix bench-,$(SYSCALLS))
LDFLAGS := -luring -pthread -lrt
-CFLAGS := -Werror -Wall -g -O3
+CFLAGS := -Werror -Wall -g -O3 -D_GNU_SOURCE
# CFLAGS := -Werror -Wall -g -O0
.PHONY: all clean eval docker-eval check
diff --git a/bench.c b/bench.c
index b7439a6..4199b1e 100644
--- a/bench.c
+++ b/bench.c
@@ -1,9 +1,11 @@
#include <err.h>
#include <fcntl.h>
+#include <sched.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/eventfd.h>
+#include <unistd.h>
#include "stopwatch.h"
@@ -23,11 +25,22 @@ static int create_eventfd() {
return fd;
}
+static void set_cpu_affinity(int cpu) {
+ cpu_set_t set;
+ // NOLINTNEXTLINE(clang-analyzer-security.insecureAPI.DeprecatedOrUnsafeBufferHandling)
+ CPU_ZERO(&set);
+ CPU_SET(cpu, &set);
+ if (sched_setaffinity(getpid(), sizeof(set), &set) == -1)
+ err(EXIT_FAILURE, "sched_setaffinity failed");
+}
+
int main() {
uint64_t cycles_sum = 0;
uint64_t nanos_sum = 0;
uint64_t write_buf = 1;
+ set_cpu_affinity(0);
+
int fd = create_eventfd();
init(fd);
--
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