From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx> Subject: mm/debug: improve memcg debugging The memcg_data is only valid on the head page, not the tail pages. Change the format and location of the printout within the dump to match the other parts of struct page better. Link: https://lkml.kernel.org/r/20210114190200.1894484-1-willy@xxxxxxxxxxxxx Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> Reviewed-by: Zi Yan <ziy@xxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/debug.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) --- a/mm/debug.c~mm-debug-improve-memcg-debugging +++ a/mm/debug.c @@ -110,6 +110,11 @@ void __dump_page(struct page *page, cons head_compound_mapcount(head)); } } + +#ifdef CONFIG_MEMCG + if (head->memcg_data) + pr_warn("memcg:%lx\n", head->memcg_data); +#endif if (PageKsm(page)) type = "ksm "; else if (PageAnon(page)) @@ -180,11 +185,6 @@ hex_only: if (reason) pr_warn("page dumped because: %s\n", reason); - -#ifdef CONFIG_MEMCG - if (!page_poisoned && page->memcg_data) - pr_warn("pages's memcg:%lx\n", page->memcg_data); -#endif } void dump_page(struct page *page, const char *reason) _
