From 794ce735ecc954e12a9a901051309772b519c699 Mon Sep 17 00:00:00 2001
From: Michal Hocko <mhocko@suse.com>
Date: Wed, 7 Nov 2018 09:52:56 +0100
Subject: [PATCH 2/5] mm: lower the printk loglevel for __dump_page messages
Git-commit: e0392cf7c53a2c03dbda93de4073c78609b88c51
Patch-mainline: v5.0-rc1
References: generic hotplug debugability

__dump_page messages use KERN_EMERG resp. KERN_ALERT loglevel (this is
the case since 2004). Most callers of this function are really detecting
a critical page state and BUG right after. On the other hand the
function is called also from contexts which just want to inform about
the page state and those would rather not disrupt logs that much (e.g.
some systems route these messages to the normal console).

Reduce the loglevel to KERN_WARNING to make dump_page easier to reuse
for other contexts while those messages will still make it to the kernel
log in most setups. Even if the loglevel setup filters warnings away
those paths that are really critical already print the more targeted
error or panic and that should make it to the kernel log.

Signed-off-by: Michal Hocko <mhocko@suse.com>

---
 mm/debug.c |   18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

--- a/mm/debug.c
+++ b/mm/debug.c
@@ -50,7 +50,7 @@ void __dump_page(struct page *page, cons
 	int mapcount = PageSlab(page) ? 0 : page_mapcount(page);
 	struct address_space *mapping = page_mapping(page);
 
-	pr_emerg("page:%p count:%d mapcount:%d mapping:%p index:%#lx",
+	pr_warn("page:%p count:%d mapcount:%d mapping:%p index:%#lx",
 		  page, page_ref_count(page), mapcount,
 		  page->mapping, page_to_pgoff(page));
 	if (PageCompound(page))
@@ -58,30 +58,30 @@ void __dump_page(struct page *page, cons
 	pr_cont("\n");
 	BUILD_BUG_ON(ARRAY_SIZE(pageflag_names) != __NR_PAGEFLAGS + 1);
 	if (PageAnon(page))
-		pr_emerg("anon ");
+		pr_warn("anon ");
 	else if (PageKsm(page))
-		pr_emerg("ksm ");
+		pr_warn("ksm ");
 	else if (mapping) {
-		pr_emerg("%ps ", mapping->a_ops);
+		pr_warn("%ps ", mapping->a_ops);
 		if (mapping->host->i_dentry.first) {
 			struct dentry *dentry;
 			dentry = container_of(mapping->host->i_dentry.first, struct dentry, d_u.d_alias);
-			pr_emerg("name:\"%pd\" ", dentry);
+			pr_warn("name:\"%pd\" ", dentry);
 		}
 	}
 
-	pr_emerg("flags: %#lx(%pGp)\n", page->flags, &page->flags);
+	pr_warn("flags: %#lx(%pGp)\n", page->flags, &page->flags);
 
-	print_hex_dump(KERN_ALERT, "raw: ", DUMP_PREFIX_NONE, 32,
+	print_hex_dump(KERN_WARNING, "raw: ", DUMP_PREFIX_NONE, 32,
 			sizeof(unsigned long), page,
 			sizeof(struct page), false);
 
 	if (reason)
-		pr_alert("page dumped because: %s\n", reason);
+		pr_warn("page dumped because: %s\n", reason);
 
 #ifdef CONFIG_MEMCG
 	if (page->mem_cgroup)
-		pr_alert("page->mem_cgroup:%p\n", page->mem_cgroup);
+		pr_warn("page->mem_cgroup:%p\n", page->mem_cgroup);
 #endif
 }