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From:   Yafang Shao <laoar.shao@gmail.com>
Date:   Tue, 2 Feb 2021 21:25:40 +0800
Message-ID: <CALOAHbDNH52U1dn+TVe23bUbND9mgLezYWNEcCh7hZyUJdcFiw@mail.gmail.com>
Subject: Re: [PATCH v2 3/3] vsprintf: dump full information of page flags in pGp
To:     Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc:     David Hildenbrand <david@redhat.com>,
        Vlastimil Babka <vbabka@suse.cz>,
        Miaohe Lin <linmiaohe@huawei.com>,
        Christoph Lameter <cl@linux.com>, penberg@kernel.org,
        David Rientjes <rientjes@google.com>, iamjoonsoo.kim@lge.com,
        Andrew Morton <akpm@linux-foundation.org>,
        Petr Mladek <pmladek@suse.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
        Rasmus Villemoes <linux@rasmusvillemoes.dk>,
        Linux MM <linux-mm@kvack.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Joe Perches <joe@perches.com>
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On Tue, Feb 2, 2021 at 12:16 AM Andy Shevchenko
<andriy.shevchenko@linux.intel.com> wrote:
>
> On Mon, Feb 01, 2021 at 09:49:59PM +0800, Yafang Shao wrote:
> > On Mon, Feb 1, 2021 at 9:27 PM Andy Shevchenko
> > <andriy.shevchenko@linux.intel.com> wrote:
> > > On Mon, Feb 01, 2021 at 07:56:10PM +0800, Yafang Shao wrote:
>
> ...
>
> > > > - Before the patch,
> > > > [ 6343.396602] Slab 0x000000004382e02b objects=33 used=3 fp=0x000000009ae06ffc flags=0x17ffffc0010200(slab|head)
> > > >
> > > > - After the patch,
> > > > [ 6871.296131] Slab 0x00000000c0e19a37 objects=33 used=3 fp=0x00000000c4902159 flags=0x17ffffc0010200(Node 0,Zone 2,Lastcpupid 0x1fffff,slab|head)
> > > >
> > > > The Documentation and test cases are also updated.
> > >
> > > Thanks for an update, my comments below.
> > >
> > > ...
> > >
> > > > -     %pGp    referenced|uptodate|lru|active|private
> > > > +     %pGp    Node 0,Zone 2,referenced|uptodate|lru|active|private
> > >
> > > Since of the nature of printf() buffer, I wonder if these should be at the end.
> > > I.o.w. the question is is the added material more important to user to see than
> > > the existed one?
> > >
> >
> > The existing one should be more important than the added one.
> > But the order of output will not match with the value for page->flags.
> > E.g.
> >     flags=0x17ffffc0010200(slab|head,Node 0,Zone 2,Lastcpupid 0x1fffff)
> > It may be strange to compare the value with the string.
>
> More I'm looking at it, more I'm thinking it should have different specifiers
> for each group of desired flags to be printed.
>
> So, you leave %pGp as is and then add another letter to add more details, so
> user will choose what and in which order they want.
>
> For example, let's assume %pGp == %pGpf and P is a new specifier for what you
> are initially adding here:
>
>   %pGpfP => referenced|uptodate|lru|active|private,Node 0,Zone 2
>   %pGpPf => Node 0,Zone 2,referenced|uptodate|lru|active|private
>
> and so on.

Thanks for your suggestion. I will think about it.

-- 
Thanks
Yafang