From: Chen Wandun <chenwandun@huawei.com> 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: Chen Wandun <chenwandun@huawei.com> Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com> --- mm/mem_reliable.c | 51 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 51 insertions(+) diff --git a/mm/mem_reliable.c b/mm/mem_reliable.c index 4d49da71809b..b81e1147088d 100644 --- a/mm/mem_reliable.c +++ b/mm/mem_reliable.c @@ -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 +178,55 @@ void reliable_report_meminfo(struct seq_file *m) } } +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); -- 2.20.1