From: Waiman Long <longman@redhat.com> mainline inclusion from mainline-v5.18-rc1 commit 865ed6a3278654ce4a55eb74c5283eeb82ad4699 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I9GSSR Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- The page_owner information currently includes the pid of the calling task. That is useful as long as the task is still running. Otherwise, the number is meaningless. To have more information about the allocating tasks that had exited by the time the page_owner information is retrieved, we need to store the command name of the task. Add a new comm field into page_owner structure to store the command name and display it when the page_owner information is retrieved. Link: https://lkml.kernel.org/r/20220202203036.744010-5-longman@redhat.com Signed-off-by: Waiman Long <longman@redhat.com> Acked-by: Rafael Aquini <aquini@redhat.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Mike Rapoport <rppt@kernel.org> Cc: Petr Mladek <pmladek@suse.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Steven Rostedt (Google) <rostedt@goodmis.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Conflicts: mm/page_owner.c [context conflicts] Signed-off-by: Jinjiang Tu <tujinjiang@huawei.com> --- mm/page_owner.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/mm/page_owner.c b/mm/page_owner.c index 08f8a861b25c..0b4b5b204257 100644 --- a/mm/page_owner.c +++ b/mm/page_owner.c @@ -29,6 +29,7 @@ struct page_owner { depot_stack_handle_t free_handle; u64 ts_nsec; u64 free_ts_nsec; + char comm[TASK_COMM_LEN]; pid_t pid; }; @@ -172,6 +173,8 @@ static inline void __set_page_owner_handle(struct page *page, page_owner->last_migrate_reason = -1; page_owner->pid = current->pid; page_owner->ts_nsec = local_clock(); + strlcpy(page_owner->comm, current->comm, + sizeof(page_owner->comm)); __set_bit(PAGE_EXT_OWNER, &page_ext->flags); __set_bit(PAGE_EXT_OWNER_ALLOCATED, &page_ext->flags); @@ -239,6 +242,7 @@ void __copy_page_owner(struct page *oldpage, struct page *newpage) new_page_owner->pid = old_page_owner->pid; new_page_owner->ts_nsec = old_page_owner->ts_nsec; new_page_owner->free_ts_nsec = old_page_owner->ts_nsec; + strcpy(new_page_owner->comm, old_page_owner->comm); /* * We don't clear the bit on the oldpage as it's going to be freed @@ -391,10 +395,11 @@ print_page_owner(char __user *buf, size_t count, unsigned long pfn, return -ENOMEM; ret = scnprintf(kbuf, count, - "Page allocated via order %u, mask %#x(%pGg), pid %d, ts %llu ns, free_ts %llu ns\n", + "Page allocated via order %u, mask %#x(%pGg), pid %d (%s), ts %llu ns, free_ts %llu ns\n", page_owner->order, page_owner->gfp_mask, &page_owner->gfp_mask, page_owner->pid, - page_owner->ts_nsec, page_owner->free_ts_nsec); + page_owner->comm, page_owner->ts_nsec, + page_owner->free_ts_nsec); /* Print information relevant to grouping pages by mobility */ pageblock_mt = get_pageblock_migratetype(page); @@ -464,9 +469,10 @@ void __dump_page_owner(struct page *page) else pr_alert("page_owner tracks the page as freed\n"); - pr_alert("page last allocated via order %u, migratetype %s, gfp_mask %#x(%pGg), pid %d, ts %llu, free_ts %llu\n", + pr_alert("page last allocated via order %u, migratetype %s, gfp_mask %#x(%pGg), pid %d (%s), ts %llu, free_ts %llu\n", page_owner->order, migratetype_names[mt], gfp_mask, &gfp_mask, - page_owner->pid, page_owner->ts_nsec, page_owner->free_ts_nsec); + page_owner->pid, page_owner->comm, page_owner->ts_nsec, + page_owner->free_ts_nsec); handle = READ_ONCE(page_owner->handle); if (!handle) { -- 2.25.1