Re: [PATCH 4/4] cfq-iosched: Allow parent cgroup to preempt its child

[Jan Kara <jack@suse.cz>]

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On Thu 26-11-15 04:24:23, kbuild test robot wrote:
> Hi Jan,
> 
> [auto build test ERROR on block/for-next]
> [also build test ERROR on v4.4-rc2 next-20151124]
> 
> url:    https://github.com/0day-ci/linux/commits/Jan-Kara/SYNC_NOIDLE-preemption-for-ancestor-cgroups/20151125-222645
> base:   https://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux-block.git for-next
> config: i386-allmodconfig (attached as .config)
> reproduce:
>         # save the attached .config to linux build tree
>         make ARCH=i386 
> 
> All errors (new ones prefixed by >>):
> 
> >> ERROR: "cgroup_is_descendant" undefined!

Ah, I didn't notice the function is not exported. Attached patch fixes the
build.

								Honza
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR

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>From 9a489728dbae48311e2ee0fff3c1793dd1e97392 Mon Sep 17 00:00:00 2001
From: Jan Kara <jack@suse.cz>
Date: Thu, 26 Nov 2015 13:29:21 +0100
Subject: [PATCH] cgroup: Export cgroup_is_descendant()

CFQ IO scheduler will use cgroup_is_descendant() to decide whether one
queue can preempt another once.

Signed-off-by: Jan Kara <jack@suse.cz>
---
 kernel/cgroup.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index f1603c153890..6b61f847b040 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -477,6 +477,7 @@ bool cgroup_is_descendant(struct cgroup *cgrp, struct cgroup *ancestor)
 	}
 	return false;
 }
+EXPORT_SYMBOL_GPL(cgroup_is_descendant);
 
 static int notify_on_release(const struct cgroup *cgrp)
 {
-- 
2.1.4