Commit 79f52fcb authored by Yang Shi's avatar Yang Shi Committed by Nanyong Sun
Browse files

mm: khugepaged: fix the arguments order in khugepaged_collapse_file trace point 

mainline inclusion
from mainline-v6.12-rc4
commit 37f0b47c5143c2957909ced44fc09ffb118c99f7
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/IAXCD2

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=37f0b47c5143c2957909ced44fc09ffb118c99f7

--------------------------------

The "addr" and "is_shmem" arguments have different order in TP_PROTO and
TP_ARGS.  This resulted in the incorrect trace result:

text-hugepage-644429 [276] 392092.878683: mm_khugepaged_collapse_file:
mm=0xffff20025d52c440, hpage_pfn=0x200678c00, index=512, addr=1, is_shmem=0,
filename=text-hugepage, nr=512, result=failed

The value of "addr" is wrong because it was treated as bool value, the
type of is_shmem.

Fix the order in TP_PROTO to keep "addr" is before "is_shmem" since the
original patch review suggested this order to achieve best packing.

And use "lx" for "addr" instead of "ld" in TP_printk because address is
typically shown in hex.

After the fix, the trace result looks correct:

text-hugepage-7291  [004]   128.627251: mm_khugepaged_collapse_file:
mm=0xffff0001328f9500, hpage_pfn=0x20016ea00, index=512, addr=0x400000,
is_shmem=0, filename=text-hugepage, nr=512, result=failed

Link: https://lkml.kernel.org/r/20241012011702.1084846-1-yang@os.amperecomputing.com


Fixes: 4c9473e8 ("mm/khugepaged: add tracepoint to collapse_file()")
Signed-off-by: default avatarYang Shi <yang@os.amperecomputing.com>
Cc: Gautam Menghani <gautammenghani201@gmail.com>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: <stable@vger.kernel.org>    [6.2+]
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarNanyong Sun <sunnanyong@huawei.com>
parent 0750d45c

include/trace/events/huge_memory.h

+2 −2
Original line number Diff line number Diff line
@@ -208,7 +208,7 @@ TRACE_EVENT(mm_khugepaged_scan_file, 


TRACE_EVENT(mm_khugepaged_collapse_file,

	TP_PROTO(struct mm_struct *mm, struct folio *new_folio, pgoff_t index,

			bool is_shmem, unsigned long addr, struct file *file,

			unsigned long addr, bool is_shmem, struct file *file,

			int nr, int result),

	TP_ARGS(mm, new_folio, index, addr, is_shmem, file, nr, result),

	TP_STRUCT__entry(
@@ -233,7 +233,7 @@ TRACE_EVENT(mm_khugepaged_collapse_file, 
		__entry->result = result;

	),



	TP_printk("mm=%p, hpage_pfn=0x%lx, index=%ld, addr=%ld, is_shmem=%d, filename=%s, nr=%d, result=%s",

	TP_printk("mm=%p, hpage_pfn=0x%lx, index=%ld, addr=%lx, is_shmem=%d, filename=%s, nr=%d, result=%s",

		__entry->mm,

		__entry->hpfn,

		__entry->index,

mm/khugepaged.c

+1 −1
Original line number Diff line number Diff line
@@ -2240,7 +2240,7 @@ static int collapse_file(struct mm_struct *mm, unsigned long addr, 
	folio_put(new_folio);

out:

	VM_BUG_ON(!list_empty(&pagelist));

	trace_mm_khugepaged_collapse_file(mm, new_folio, index, is_shmem, addr, file, HPAGE_PMD_NR, result);

	trace_mm_khugepaged_collapse_file(mm, new_folio, index, addr, is_shmem, file, HPAGE_PMD_NR, result);

	return result;

}