Commit 4021a0d5 authored by Chen Wandun's avatar Chen Wandun Committed by Wang Wensheng
Browse files

mm: Add support for limiting the usage of reliable memory in pagecache 

hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I4SK3S


CVE: NA

--------------------------------

Add interface /proc/sys/vm/reliable_pagecache_max_bytes to set the
max size for reliable page cache, the max size cant beyond total
reliable ram.

the whole reliable memory feature depend on kernelcore=mirror,
and which depend on NUMA, so remove redundant code in UMA.

Signed-off-by: default avatarChen Wandun <chenwandun@huawei.com>
Reviewed-by: default avatarKefeng Wang <wangkefeng.wang@huawei.com>
parent 6e6cf0d7

mm/mem_reliable.c

+52 −0
Original line number Diff line number Diff line
@@ -19,6 +19,7 @@ bool shmem_reliable __read_mostly = true; 
bool pagecache_use_reliable_mem __read_mostly = true;

struct percpu_counter pagecache_reliable_pages;

struct percpu_counter anon_reliable_pages;

static unsigned long reliable_pagecache_max_bytes = ULONG_MAX;



bool mem_reliable_counter_initialized(void)

{
@@ -65,12 +66,18 @@ void reliable_lru_add(enum lru_list lru, struct page *page, int val) 


void page_cache_prepare_alloc(gfp_t *gfp)

{

	s64 nr_reliable = 0;



	if (!mem_reliable_is_enabled())

		return;



	if (!pagecache_reliable_is_enabled())

		goto no_reliable;



	nr_reliable = percpu_counter_read_positive(&pagecache_reliable_pages);

	if (nr_reliable > reliable_pagecache_max_bytes >> PAGE_SHIFT)

		goto no_reliable;



	*gfp |= GFP_RELIABLE;

	return;
@@ -171,11 +178,56 @@ void reliable_report_meminfo(struct seq_file *m) 
	}

}



static int reliable_pagecache_max_bytes_write(struct ctl_table *table,

					      int write, void __user *buffer,

					      size_t *length, loff_t *ppos)

{

	unsigned long old_value = reliable_pagecache_max_bytes;

	int ret;



	ret = proc_doulongvec_minmax(table, write, buffer, length, ppos);

	if (!ret && write) {

		if (reliable_pagecache_max_bytes >

		    PAGES_TO_B(total_reliable_pages())) {

			reliable_pagecache_max_bytes = old_value;

			return -EINVAL;

		}

	}



	return ret;

}



static struct ctl_table reliable_ctl_table[] = {

	{

		.procname = "reliable_pagecache_max_bytes",

		.data = &reliable_pagecache_max_bytes,

		.maxlen = sizeof(reliable_pagecache_max_bytes),

		.mode = 0644,

		.proc_handler = reliable_pagecache_max_bytes_write,

	},

	{}

};



static struct ctl_table reliable_dir_table[] = {

	{

		.procname = "vm",

		.maxlen = 0,

		.mode = 0555,

		.child = reliable_ctl_table,

	},

	{}

};



static int __init reliable_sysctl_init(void)

{

	if (!mem_reliable_is_enabled())

		return 0;



	if (!register_sysctl_table(reliable_dir_table)) {

		pr_err("register sysctl failed.");

		return -ENOMEM;

	}



	percpu_counter_init(&pagecache_reliable_pages, 0, GFP_KERNEL);

	percpu_counter_init(&anon_reliable_pages, 0, GFP_KERNEL);