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Date: Fri, 19 Feb 2016 11:15:22 +0900
From: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
To: Joonsoo Kim <js1304@gmail.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Michal Nazarewicz <mina86@mina86.com>,
        Minchan Kim <minchan@kernel.org>,
        Mel Gorman <mgorman@techsingularity.net>,
        Vlastimil Babka <vbabka@suse.cz>,
        "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
        Linux Memory Management List <linux-mm@kvack.org>,
        LKML <linux-kernel@vger.kernel.org>, linux-api@vger.kernel.org,
        Joonsoo Kim <iamjoonsoo.kim@lge.com>
Subject: Re: [PATCH 2/2] mm/page_ref: add tracepoint to track down page
 reference manipulation
Message-ID: <20160219021522.GA11625@swordfish>
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On (02/19/16 10:39), Joonsoo Kim wrote:
[..]
> > not sure if it's worth mentioning in the comment, but the other
> > concern here is the performance impact of an extra function call,
> > I believe. otherwise, Joonsoo would just do:
> 
> It's very natural thing so I'm not sure it is worth mentioning.

agree.

> > and in mm/debug_page_ref.c
> >
> > void __page_ref_set(struct page *page, int v)
> > {
> >         if (trace_page_ref_set_enabled())
> >                 trace_page_ref_set(page, v);
> > }
> > EXPORT_SYMBOL(__page_ref_set);
> > EXPORT_TRACEPOINT_SYMBOL(page_ref_set);
> 
> It is what I did in v1.

ah... indeed. well, "That was a year ago, how am I suppose to remember"

	-ss