Subject: [PATCH] Affinity of call_usermode_helper fix
From: Rusty Russell <[email-masked]>
To: [email-masked]
Cc: [email-masked]
Date: Fri, 30 Jan 2004 15:52:34 +1100

Vatsa and I noticed this.

call_usermode_helper uses keventd, so the process created inherits its
cpus_allowed mask.  Unset it.

Name: call_usermode_helper Without Being Bound To A Specific CPU
Author: Rusty Russell
Status: Booted on 2.6.2-rc2-bk2

D: call_usermode_helper uses keventd, so the process created inherits
D: its cpus_allowed mask.  Unset it.

diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .6951-linux-2.6.2-rc2-bk2/kernel/kmod.c .6951-linux-2.6.2-rc2-bk2.updated/kernel/kmod.c
--- .6951-linux-2.6.2-rc2-bk2/kernel/kmod.c	2004-01-10 13:59:39.000000000 +1100
+++ .6951-linux-2.6.2-rc2-bk2.updated/kernel/kmod.c	2004-01-29 16:08:31.000000000 +1100
@@ -168,6 +168,8 @@ static int ____call_usermodehelper(void 
 	recalc_sigpending();
 	spin_unlock_irq(&current->sighand->siglock);
 
+	/* We can run anywhere, unlike our parent keventd(). */
+	set_cpus_allowed(current, CPU_MASK_ALL);
 	retval = -EPERM;
 	if (current->fs->root)
 		retval = execve(sub_info->path, sub_info->argv,sub_info->envp);

--
  Anyone who quotes me in their sig is an idiot. -- Rusty Russell.