mm: add cmdline for the reliable memory usage of page cache

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

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

Add cmdline for the reliable memory usage of page cache.
Page cache will not use reliable memory when passing option
"P" to reliable_debug in cmdline.
Signed-off-by: NChen Wandun <chenwandun@huawei.com>
Reviewed-by: NKefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

Documentation/admin-guide/kernel-parameters.txt

@@ -1973,7 +1973,7 @@
 			some extension. These two features are alternatives.
 
 	reliable_debug=	[ARM64]
-			Format: [F][,S]
+			Format: [F][,S][,P]
 			Only works with CONFIG_MEMORY_RELIABLE and
 			"kernelcore=reliable" is configured.
 			F: User tasks with PF_RELIABLE will not allocate
@@ -1981,6 +1981,7 @@
 			from mirrored region failed.
 			Pagecache and tmpfs will follow this rule too.
 			S: The shmem does not use the reliable memory.
+			P: Page cache does not use the reliable memory.
 
 	kgdbdbgp=	[KGDB,HW] kgdb over EHCI usb debug port.
 			Format: <Controller#>[,poll interval]

include/linux/mem_reliable.h

@@ -20,6 +20,7 @@ extern unsigned long task_reliable_limit __read_mostly;
 extern bool reliable_allow_fallback;
 extern bool shmem_reliable;
 extern struct percpu_counter reliable_shmem_used_nr_page;
+extern bool pagecache_use_reliable_mem;
 
 extern void add_reliable_mem_size(long sz);
 extern void mem_reliable_init(bool has_unmirrored_mem,
@@ -85,6 +86,11 @@ static inline bool shmem_reliable_is_enabled(void)
 	return shmem_reliable;
 }
 
+static inline bool pagecache_reliable_is_enabled(void)
+{
+	return pagecache_use_reliable_mem;
+}
+
 static inline void shmem_reliable_page_counter(struct page *page, int nr_page)
 {
 	if (shmem_reliable_is_enabled() && page_reliable(page))
@@ -94,6 +100,7 @@ static inline void shmem_reliable_page_counter(struct page *page, int nr_page)
 #else
 #define reliable_enabled 0
 #define reliable_allow_fb_enabled() false
+#define pagecache_use_reliable_mem 0
 
 static inline bool mem_reliable_is_enabled(void) { return false; }
 static inline void add_reliable_mem_size(long sz) {}
@@ -126,6 +133,7 @@ static inline void shmem_reliable_page_counter(struct page *page, int nr_page)
 {
 }
 
+static inline bool pagecache_reliable_is_enabled(void) { return false; }
 #endif
 
 #endif

include/linux/pagemap.h

@@ -249,7 +249,9 @@ extern struct page *__page_cache_alloc(gfp_t gfp);
 #else
 static inline struct page *__page_cache_alloc(gfp_t gfp)
 {
-	gfp |= ___GFP_RELIABILITY;
+	if (pagecache_reliable_is_enabled())
+		gfp |= ___GFP_RELIABILITY;
+
 	return alloc_pages(gfp, 0);
 }
 #endif

mm/filemap.c

@@ -1042,7 +1042,11 @@ struct page *__page_cache_alloc(gfp_t gfp)
 	int n;
 	struct page *page;
 
-	gfp |= ___GFP_RELIABILITY;
+	if (pagecache_reliable_is_enabled())
+		gfp |= ___GFP_RELIABILITY;
+	else
+		WARN_ON_ONCE(gfp & ___GFP_RELIABILITY);
+
 	if (cpuset_do_page_mem_spread()) {
 		unsigned int cpuset_mems_cookie;
 		do {

mm/mem_reliable.c

@@ -21,6 +21,7 @@ bool reliable_allow_fallback __read_mostly = true;
 bool shmem_reliable __read_mostly = true;
 struct percpu_counter reliable_shmem_used_nr_page __read_mostly;
 
+bool pagecache_use_reliable_mem __read_mostly = true;
 void add_reliable_mem_size(long sz)
 {
 	atomic_long_add(sz, &total_reliable_mem);
@@ -249,6 +250,10 @@ static int __init setup_reliable_debug(char *str)
 			shmem_reliable = false;
 			pr_info("shmem reliable disabled.");
 			break;
+		case 'P':
+			pagecache_use_reliable_mem = false;
+			pr_info("disable page cache use reliable memory\n");
+			break;
 		default:
 			pr_err("reliable_debug option '%c' unknown. skipped\n",
 			       *str);