From 5c6a865a091868afb740cc346c5b79030d8e81a0 Mon Sep 17 00:00:00 2001
From: Daniel Borkmann <dborkman@redhat.com>
Date: Fri, 11 Jan 2013 15:41:29 +0100
Subject: [PATCH] trafgen: fix CPU IRQ pinning range with --cpu arg

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
---
 src/trafgen.c |  2 +-
 src/xutils.c  | 23 +++++++++++++++--------
 src/xutils.h  |  3 ++-
 3 files changed, 18 insertions(+), 10 deletions(-)

diff --git a/src/trafgen.c b/src/trafgen.c
index 66702e3b..69d8b460 100644
--- a/src/trafgen.c
+++ b/src/trafgen.c
@@ -1136,7 +1136,7 @@ int main(int argc, char **argv)
 	}
 
 	irq = device_irq_number(ctx.device);
-	device_reset_irq_affinity(irq);
+	device_set_irq_affinity_list(irq, 0, ctx.cpus - 1);
 
 	if (ctx.num > 0 && ctx.num <= ctx.cpus)
 		ctx.cpus = 1;
diff --git a/src/xutils.c b/src/xutils.c
index f1761c2e..45b74b22 100644
--- a/src/xutils.c
+++ b/src/xutils.c
@@ -639,17 +639,24 @@ int device_irq_number(const char *ifname)
 	return irq;
 }
 
-void device_reset_irq_affinity(int irq)
+int device_set_irq_affinity_list(int irq, unsigned long from, unsigned long to)
 {
-	int ret;
-	char cmd[256];
+	int ret, fd;
+	char file[256], list[64];
 
-	slprintf(cmd, sizeof(cmd),
-		 "cat /proc/irq/default_smp_affinity >/proc/irq/%d/smp_affinity", irq);
+	slprintf(file, sizeof(file), "/proc/irq/%d/smp_affinity_list", irq);
+	slprintf(list, sizeof(list), "%lu-%lu\n", from, to);
 
-	ret = system(cmd);
-	if (ret < 0)
-		panic("Cannot execute system(2)!\n");
+	fd = open(file, O_WRONLY);
+	if (fd < 0) {
+		whine("Cannot open file %s!\n", file);
+		return -ENOENT;
+	}
+
+	ret = write(fd, list, strlen(list));
+
+	close(fd);
+	return ret;
 }
 
 int device_bind_irq_to_cpu(int irq, int cpu)
diff --git a/src/xutils.h b/src/xutils.h
index 86623c3c..536fe7f3 100644
--- a/src/xutils.h
+++ b/src/xutils.h
@@ -50,7 +50,8 @@ extern int device_mtu(const char *ifname);
 extern int device_address(const char *ifname, int af,
 			  struct sockaddr_storage *ss);
 extern int device_irq_number(const char *ifname);
-extern void device_reset_irq_affinity(int irq);
+extern int device_set_irq_affinity_list(int irq, unsigned long from,
+					unsigned long to);
 extern int device_bind_irq_to_cpu(int irq, int cpu);
 extern void sock_print_net_stats(int sock, unsigned long skipped);
 extern int device_ifindex(const char *ifname);
-- 
2.11.4.GIT