Commit 4c9473e8 authored by Gautam Menghani's avatar Gautam Menghani Committed by Andrew Morton
Browse files

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: default avatarGautam Menghani <gautammenghani201@gmail.com>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>	[tracing]
Cc: David Hildenbrand <david@redhat.com>
Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Zach O'Keefe <zokeefe@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent f7355e99

include/trace/events/huge_memory.h

+38 −0
Original line number Diff line number Diff line
@@ -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 <trace/define_trace.h>

mm/khugepaged.c

+4 −3
Original line number Diff line number Diff line
@@ -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 @@ static int collapse_file(struct mm_struct *mm, unsigned long addr, 
		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;

}