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Date:   Thu, 27 Oct 2022 10:43:09 -0700
From:   Zach O'Keefe <zokeefe@google.com>
To:     Yang Shi <shy828301@gmail.com>
Cc:     Gautam Menghani <gautammenghani201@gmail.com>,
        akpm@linux-foundation.org, rostedt@goodmis.org,
        mhiramat@kernel.org, david@redhat.com, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] mm/khugepaged: Refactor mm_khugepaged_scan_file
 tracepoint to remove filename from function call
Message-ID: <Y1rDLUUVxfRt6mal@google.com>
References: <20221026044524.54793-1-gautammenghani201@gmail.com>
 <CAHbLzkq_6tGYfmd-f8Gg-YSLoLXtdFmpxVCUof90B=YA4X7SAA@mail.gmail.com>
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On Oct 26 11:10, Yang Shi wrote:
> On Tue, Oct 25, 2022 at 9:45 PM Gautam Menghani
> <gautammenghani201@gmail.com> wrote:
> >
> > Refactor the mm_khugepaged_scan_file tracepoint to move filename
> > dereference to the tracepoint definition, for maintaing consistency with
> > other tracepoints[1].
> >
> > [1]:lore.kernel.org/lkml/20221024111621.3ba17e2c@gandalf.local.home/
> >
> > Signed-off-by: Gautam Menghani <gautammenghani201@gmail.com>
> 
> Reviewed-by: Yang Shi <shy828301@gmail.com>
> 

Reviewed-by: Zach O'Keefe <zokeefe@google.com>

> > ---
> >  include/trace/events/huge_memory.h | 8 ++++----
> >  mm/khugepaged.c                    | 3 +--
> >  2 files changed, 5 insertions(+), 6 deletions(-)
> >
> > diff --git a/include/trace/events/huge_memory.h b/include/trace/events/huge_memory.h
> > index 935af4947917..760455dfa860 100644
> > --- a/include/trace/events/huge_memory.h
> > +++ b/include/trace/events/huge_memory.h
> > @@ -171,15 +171,15 @@ TRACE_EVENT(mm_collapse_huge_page_swapin,
> >
> >  TRACE_EVENT(mm_khugepaged_scan_file,
> >
> > -       TP_PROTO(struct mm_struct *mm, struct page *page, const char *filename,
> > +       TP_PROTO(struct mm_struct *mm, struct page *page, struct file *file,
> >                  int present, int swap, int result),
> >
> > -       TP_ARGS(mm, page, filename, present, swap, result),
> > +       TP_ARGS(mm, page, file, present, swap, result),
> >
> >         TP_STRUCT__entry(
> >                 __field(struct mm_struct *, mm)
> >                 __field(unsigned long, pfn)
> > -               __string(filename, filename)
> > +               __string(filename, file->f_path.dentry->d_iname)
> >                 __field(int, present)
> >                 __field(int, swap)
> >                 __field(int, result)
> > @@ -188,7 +188,7 @@ TRACE_EVENT(mm_khugepaged_scan_file,
> >         TP_fast_assign(
> >                 __entry->mm = mm;
> >                 __entry->pfn = page ? page_to_pfn(page) : -1;
> > -               __assign_str(filename, filename);
> > +               __assign_str(filename, file->f_path.dentry->d_iname);
> >                 __entry->present = present;
> >                 __entry->swap = swap;
> >                 __entry->result = result;
> > diff --git a/mm/khugepaged.c b/mm/khugepaged.c
> > index 4734315f7940..9808a899f9f7 100644
> > --- a/mm/khugepaged.c
> > +++ b/mm/khugepaged.c
> > @@ -2157,8 +2157,7 @@ static int hpage_collapse_scan_file(struct mm_struct *mm, unsigned long addr,
> >                 }
> >         }
> >
> > -       trace_mm_khugepaged_scan_file(mm, page, file->f_path.dentry->d_iname,
> > -                                     present, swap, result);
> > +       trace_mm_khugepaged_scan_file(mm, page, file, present, swap, result);
> >         return result;
> >  }
> >  #else
> > --
> > 2.34.1
> >