android_kernel_samsung_msm8976/mm/showmem.c
Vinayak Menon 389184e601 mm: showmem: make the notifiers atomic
There are places in kernel like the lowmemorykiller which
invokes show_mem_call_notifiers from an atomic context.
So move from a blocking notifier to atomic. At present
the notifier callbacks does not call sleeping functions,
but it should be made sure, it does not happen in future also.

Change-Id: I9668e67463ab8a6a60be55dbc86b88f45be8b041
Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
2015-06-05 13:54:50 +05:30

54 lines
1.4 KiB
C

/*
* Copyright (c) 2014-2015, The Linux Foundation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
* only version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/kernel.h>
#include <linux/notifier.h>
#include <linux/debugfs.h>
#include <linux/fs.h>
#include <linux/init.h>
ATOMIC_NOTIFIER_HEAD(show_mem_notifier);
int show_mem_notifier_register(struct notifier_block *nb)
{
return atomic_notifier_chain_register(&show_mem_notifier, nb);
}
int show_mem_notifier_unregister(struct notifier_block *nb)
{
return atomic_notifier_chain_unregister(&show_mem_notifier, nb);
}
void show_mem_call_notifiers(void)
{
atomic_notifier_call_chain(&show_mem_notifier, 0, NULL);
}
static int show_mem_notifier_get(void *dat, u64 *val)
{
show_mem_call_notifiers();
*val = 0;
return 0;
}
DEFINE_SIMPLE_ATTRIBUTE(show_mem_notifier_debug_ops, show_mem_notifier_get,
NULL, "%llu\n");
int show_mem_notifier_debugfs_register(void)
{
debugfs_create_file("show_mem_notifier", 0664, NULL, NULL,
&show_mem_notifier_debug_ops);
return 0;
}
late_initcall(show_mem_notifier_debugfs_register);