+ mm-khugepaged-add-tracepoint-to-hpage_collapse_scan_file.patch added to mm-unstable branch

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: mm/khugepaged: add tracepoint to hpage_collapse_scan_file()
has been added to the -mm mm-unstable branch.  Its filename is
     mm-khugepaged-add-tracepoint-to-hpage_collapse_scan_file.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-khugepaged-add-tracepoint-to-hpage_collapse_scan_file.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: "Zach O'Keefe" <zokeefe@google.com>
Subject: mm/khugepaged: add tracepoint to hpage_collapse_scan_file()
Date: Wed, 7 Sep 2022 07:45:15 -0700

Add huge_memory:trace_mm_khugepaged_scan_file tracepoint to
hpage_collapse_scan_file() analogously to hpage_collapse_scan_pmd().

While this change is targeted at debugging MADV_COLLAPSE pathway, the
"mm_khugepaged" prefix is retained for symmetry with
huge_memory:trace_mm_khugepaged_scan_pmd, which retains it's legacy name
to prevent changing kernel ABI as much as possible.

Link: https://lkml.kernel.org/r/20220907144521.3115321-5-zokeefe@google.com
Signed-off-by: Zach O'Keefe <zokeefe@google.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Chris Kennelly <ckennelly@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: James Houghton <jthoughton@google.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Rongwei Wang <rongwei.wang@linux.alibaba.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 include/trace/events/huge_memory.h |   34 +++++++++++++++++++++++++++
 mm/khugepaged.c                    |    3 +-
 2 files changed, 36 insertions(+), 1 deletion(-)

--- a/include/trace/events/huge_memory.h~mm-khugepaged-add-tracepoint-to-hpage_collapse_scan_file
+++ a/include/trace/events/huge_memory.h
@@ -169,5 +169,39 @@ TRACE_EVENT(mm_collapse_huge_page_swapin
 		__entry->ret)
 );
 
+TRACE_EVENT(mm_khugepaged_scan_file,
+
+	TP_PROTO(struct mm_struct *mm, struct page *page, const char *filename,
+		 int present, int swap, int result),
+
+	TP_ARGS(mm, page, filename, present, swap, result),
+
+	TP_STRUCT__entry(
+		__field(struct mm_struct *, mm)
+		__field(unsigned long, pfn)
+		__string(filename, filename)
+		__field(int, present)
+		__field(int, swap)
+		__field(int, result)
+	),
+
+	TP_fast_assign(
+		__entry->mm = mm;
+		__entry->pfn = page ? page_to_pfn(page) : -1;
+		__assign_str(filename, filename);
+		__entry->present = present;
+		__entry->swap = swap;
+		__entry->result = result;
+	),
+
+	TP_printk("mm=%p, scan_pfn=0x%lx, filename=%s, present=%d, swap=%d, result=%s",
+		__entry->mm,
+		__entry->pfn,
+		__get_str(filename),
+		__entry->present,
+		__entry->swap,
+		__print_symbolic(__entry->result, SCAN_STATUS))
+);
+
 #endif /* __HUGE_MEMORY_H */
 #include <trace/define_trace.h>
--- a/mm/khugepaged.c~mm-khugepaged-add-tracepoint-to-hpage_collapse_scan_file
+++ a/mm/khugepaged.c
@@ -2154,7 +2154,8 @@ static int hpage_collapse_scan_file(stru
 		}
 	}
 
-	/* TODO: tracepoints */
+	trace_mm_khugepaged_scan_file(mm, page, file->f_path.dentry->d_iname,
+				      present, swap, result);
 	return result;
 }
 #else
_

Patches currently in -mm which might be from zokeefe@google.com are

mm-khugepaged-add-struct-collapse_control.patch
mm-khugepaged-add-struct-collapse_control-fix.patch
mm-khugepaged-add-struct-collapse_control-fix-fix-fix.patch
mm-khugepaged-dedup-and-simplify-hugepage-alloc-and-charging.patch
mm-khugepaged-pipe-enum-scan_result-codes-back-to-callers.patch
mm-khugepaged-add-flag-to-predicate-khugepaged-only-behavior.patch
mm-thp-add-flag-to-enforce-sysfs-thp-in-hugepage_vma_check.patch
mm-khugepaged-add-flag-to-predicate-khugepaged-only-behavior-fix.patch
mm-khugepaged-record-scan_pmd_mapped-when-scan_pmd-finds-hugepage.patch
mm-madvise-introduce-madv_collapse-sync-hugepage-collapse.patch
mm-madvise-introduce-madv_collapse-sync-hugepage-collapse-fix-2.patch
mm-madvise-introduce-madv_collapse-sync-hugepage-collapse-fix-3.patch
mm-khugepaged-rename-prefix-of-shared-collapse-functions.patch
mm-madvise-add-madv_collapse-to-process_madvise.patch
mm-madvise-add-madv_collapse-to-process_madvise-fix.patch
selftests-vm-modularize-collapse-selftests.patch
selftests-vm-dedup-hugepage-allocation-logic.patch
selftests-vm-add-madv_collapse-collapse-context-to-selftests.patch
selftests-vm-add-selftest-to-verify-recollapse-of-thps.patch
selftests-vm-add-selftest-to-verify-multi-thp-collapse.patch
mm-shmem-add-flag-to-enforce-shmem-thp-in-hugepage_vma_check.patch
mm-khugepaged-attempt-to-map-file-shmem-backed-pte-mapped-thps-by-pmds.patch
mm-madvise-add-file-and-shmem-support-to-madv_collapse.patch
mm-khugepaged-add-tracepoint-to-hpage_collapse_scan_file.patch
selftests-vm-dedup-thp-helpers.patch
selftests-vm-modularize-thp-collapse-memory-operations.patch
selftests-vm-add-thp-collapse-file-and-tmpfs-testing.patch
selftests-vm-add-thp-collapse-shmem-testing.patch
selftests-vm-add-file-shmem-madv_collapse-selftest-for-cleared-pmd.patch
selftests-vm-add-selftest-for-madv_collapse-of-uffd-minor-memory.patch