From: Frederic Weisbecker <fweisbec@gmail.com>
Date: Wed, 9 Sep 2015 22:38:16 +0000 (-0700)
Subject: kmod: remove unecessary explicit wide CPU affinity setting
X-Git-Tag: v4.3-rc1~22^2~32
X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=d097c0240ae8085dd39aa6ca9bd9960969b2b38e;p=linux-block.git

kmod: remove unecessary explicit wide CPU affinity setting

Khelper is affine to all CPUs.  Now since it creates the
call_usermodehelper_exec_[a]sync() kernel threads, those inherit the wide
affinity.

As such explicitly forcing a wide affinity from those kernel threads
is like a no-op.

Just remove it. It's needless and it breaks CPU isolation users who
rely on workqueue affinity tuning.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/kernel/kmod.c b/kernel/kmod.c
index 2d83511e9610..d910b6378fb6 100644
--- a/kernel/kmod.c
+++ b/kernel/kmod.c
@@ -224,9 +224,6 @@ static int call_usermodehelper_exec_async(void *data)
 	flush_signal_handlers(current, 1);
 	spin_unlock_irq(&current->sighand->siglock);
 
-	/* We can run anywhere, unlike our parent keventd(). */
-	set_cpus_allowed_ptr(current, cpu_all_mask);
-
 	/*
 	 * Our parent is keventd, which runs with elevated scheduling priority.
 	 * Avoid propagating that into the userspace child.