From 4c9473e87e75a2a77ccd02e55c91ffe6a52b5df6 Mon Sep 17 00:00:00 2001 From: Gautam Menghani Date: Wed, 26 Oct 2022 10:52:18 +0530 Subject: [PATCH] mm/khugepaged: add tracepoint to collapse_file() "mm_khugepaged_collapse_file" for capturing is_shmem. Currently, is_shmem is not being captured. Capturing is_shmem is useful as it can indicate if tmpfs is being used as a backing store instead of persistent storage. Add the tracepoint in collapse_file() named "mm_khugepaged_collapse_file" for capturing is_shmem. [gautammenghani201@gmail.com: swap is_shmem and addr to save space, per Steven Rostedt] Link: https://lkml.kernel.org/r/20221202201807.182829-1-gautammenghani201@gmail.com Link: https://lkml.kernel.org/r/20221026052218.148234-1-gautammenghani201@gmail.com Signed-off-by: Gautam Menghani Reviewed-by: Steven Rostedt (Google) [tracing] Cc: David Hildenbrand Cc: Masami Hiramatsu (Google) Cc: Yang Shi Cc: Zach O'Keefe Signed-off-by: Andrew Morton --- include/trace/events/huge_memory.h | 38 ++++++++++++++++++++++++++++++ mm/khugepaged.c | 7 +++--- 2 files changed, 42 insertions(+), 3 deletions(-) diff --git a/include/trace/events/huge_memory.h b/include/trace/events/huge_memory.h index 760455dfa860..3e6fb05852f9 100644 --- a/include/trace/events/huge_memory.h +++ b/include/trace/events/huge_memory.h @@ -203,5 +203,43 @@ TRACE_EVENT(mm_khugepaged_scan_file, __print_symbolic(__entry->result, SCAN_STATUS)) ); +TRACE_EVENT(mm_khugepaged_collapse_file, + TP_PROTO(struct mm_struct *mm, struct page *hpage, pgoff_t index, + bool is_shmem, unsigned long addr, struct file *file, + int nr, int result), + TP_ARGS(mm, hpage, index, addr, is_shmem, file, nr, result), + TP_STRUCT__entry( + __field(struct mm_struct *, mm) + __field(unsigned long, hpfn) + __field(pgoff_t, index) + __field(unsigned long, addr) + __field(bool, is_shmem) + __string(filename, file->f_path.dentry->d_iname) + __field(int, nr) + __field(int, result) + ), + + TP_fast_assign( + __entry->mm = mm; + __entry->hpfn = hpage ? page_to_pfn(hpage) : -1; + __entry->index = index; + __entry->addr = addr; + __entry->is_shmem = is_shmem; + __assign_str(filename, file->f_path.dentry->d_iname); + __entry->nr = nr; + __entry->result = result; + ), + + TP_printk("mm=%p, hpage_pfn=0x%lx, index=%ld, addr=%ld, is_shmem=%d, filename=%s, nr=%d, result=%s", + __entry->mm, + __entry->hpfn, + __entry->index, + __entry->addr, + __entry->is_shmem, + __get_str(filename), + __entry->nr, + __print_symbolic(__entry->result, SCAN_STATUS)) +); + #endif /* __HUGE_MEMORY_H */ #include diff --git a/mm/khugepaged.c b/mm/khugepaged.c index 913b0f489352..78ec2771cc65 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -1744,12 +1744,12 @@ static int collapse_file(struct mm_struct *mm, unsigned long addr, { struct address_space *mapping = file->f_mapping; struct page *hpage; - pgoff_t index, end = start + HPAGE_PMD_NR; + pgoff_t index = 0, end = start + HPAGE_PMD_NR; LIST_HEAD(pagelist); XA_STATE_ORDER(xas, &mapping->i_pages, start, HPAGE_PMD_ORDER); int nr_none = 0, result = SCAN_SUCCEED; bool is_shmem = shmem_file(file); - int nr; + int nr = 0; VM_BUG_ON(!IS_ENABLED(CONFIG_READ_ONLY_THP_FOR_FS) && !is_shmem); VM_BUG_ON(start & (HPAGE_PMD_NR - 1)); @@ -2102,7 +2102,8 @@ out: mem_cgroup_uncharge(page_folio(hpage)); put_page(hpage); } - /* TODO: tracepoints */ + + trace_mm_khugepaged_collapse_file(mm, hpage, index, is_shmem, addr, file, nr, result); return result; }