[3.13.y.z extended stable] Patch "percpu: free percpu allocation info for uniprocessor system" has been added to staging queue

Kamal Mostafa kamal at canonical.com
Wed Oct 8 22:13:57 UTC 2014

This is a note to let you know that I have just added a patch titled

    percpu: free percpu allocation info for uniprocessor system

to the linux-3.13.y-queue branch of the 3.13.y.z extended stable tree 
which can be found at:


This patch is scheduled to be released in version

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.13.y.z tree, see



>From 4d23024952c944405426229b187b572cdf9d6d7d Mon Sep 17 00:00:00 2001
From: Honggang Li <enjoymindful at gmail.com>
Date: Tue, 12 Aug 2014 21:36:15 +0800
Subject: percpu: free percpu allocation info for uniprocessor system

commit 3189eddbcafcc4d827f7f19facbeddec4424eba8 upstream.

Currently, only SMP system free the percpu allocation info.
Uniprocessor system should free it too. For example, one x86 UML
virtual machine with 256MB memory, UML kernel wastes one page memory.

Signed-off-by: Honggang Li <enjoymindful at gmail.com>
Signed-off-by: Tejun Heo <tj at kernel.org>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
 mm/percpu.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/mm/percpu.c b/mm/percpu.c
index 7d6ce15..02a89cb 100644
--- a/mm/percpu.c
+++ b/mm/percpu.c
@@ -1911,6 +1911,8 @@ void __init setup_per_cpu_areas(void)

 	if (pcpu_setup_first_chunk(ai, fc) < 0)
 		panic("Failed to initialize percpu areas.");
+	pcpu_free_alloc_info(ai);

 #endif	/* CONFIG_SMP */

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