On 11/07/18 at 11:18am, Michal Hocko wrote:
> From: Michal Hocko <mhocko@xxxxxxxx>
>
> __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@xxxxxxxx>
> ---
> mm/debug.c | 18 +++++++++---------
> 1 file changed, 9 insertions(+), 9 deletions(-)
>
> diff --git a/mm/debug.c b/mm/debug.c
> index a33177bfc856..d18c5cea3320 100644
> --- a/mm/debug.c
> +++ b/mm/debug.c
> @@ -54,7 +54,7 @@ void __dump_page(struct page *page, const char *reason)
> * dump_page() when detected.
> */
> if (page_poisoned) {
> - pr_emerg("page:%px is uninitialized and poisoned", page);
> + pr_warn("page:%px is uninitialized and poisoned", page);
> goto hex_only;
> }
>
> @@ -65,27 +65,27 @@ void __dump_page(struct page *page, const char *reason)
> */
> mapcount = PageSlab(page) ? 0 : page_mapcount(page);
>
> - pr_emerg("page:%px count:%d mapcount:%d mapping:%px index:%#lx",
> + pr_warn("page:%px count:%d mapcount:%d mapping:%px index:%#lx",
pr_warn("page:%px refcount:%d mapcount:%d mapping:%px index:%#lx",
Better print it as refcount since we have renamed it.
> page, page_ref_count(page), mapcount,
> page->mapping, page_to_pgoff(page));
> if (PageCompound(page))
> pr_cont(" compound_mapcount: %d", compound_mapcount(page));
> pr_cont("\n");
> 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:\"%*s\" ", dentry->d_name.len, dentry->d_name.name);
> + pr_warn("name:\"%*s\" ", dentry->d_name.len, dentry->d_name.name);
> }
> }
> BUILD_BUG_ON(ARRAY_SIZE(pageflag_names) != __NR_PAGEFLAGS + 1);
>
> - pr_emerg("flags: %#lx(%pGp)\n", page->flags, &page->flags);
> + pr_warn("flags: %#lx(%pGp)\n", page->flags, &page->flags);
>
> hex_only:
> print_hex_dump(KERN_ALERT, "raw: ", DUMP_PREFIX_NONE, 32,
> @@ -93,11 +93,11 @@ void __dump_page(struct page *page, const char *reason)
> 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_poisoned && page->mem_cgroup)
> - pr_alert("page->mem_cgroup:%px\n", page->mem_cgroup);
> + pr_warn("page->mem_cgroup:%px\n", page->mem_cgroup);
> #endif
> }
>
> --
> 2.19.1
>
