Date: Wed, 7 Nov 2012 13:43:22 +0200
From: "Kirill A. Shutemov" <kirill@shutemov.name>
To: Pekka Enberg <penberg@kernel.org>
Cc: Anton Vorontsov <anton.vorontsov@linaro.org>, Mel Gorman <mgorman@suse.de>,
        Leonid Moiseichuk <leonid.moiseichuk@nokia.com>,
        KOSAKI Motohiro <kosaki.motohiro@gmail.com>,
        Minchan Kim <minchan@kernel.org>,
        Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>,
        John Stultz <john.stultz@linaro.org>, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org, linaro-kernel@lists.linaro.org,
        patches@linaro.org, kernel-team@android.com, linux-man@vger.kernel.org
Subject: Re: [RFC v3 0/3] vmpressure_fd: Linux VM pressure notifications
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On Wed, Nov 07, 2012 at 01:28:12PM +0200, Pekka Enberg wrote:
> On Wed, Nov 7, 2012 at 1:21 PM, Kirill A. Shutemov <kirill@shutemov.name> wrote:
> >> While the new API is very simple, it is still extensible (i.e. versioned).
> >
> > Sorry, I didn't follow previous discussion on this, but could you
> > explain what's wrong with memory notifications from memcg?
> > As I can see you can get pretty similar functionality using memory
> > thresholds on the root cgroup. What's the point?
> 
> Why should you be required to use cgroups to get VM pressure events to
> userspace?

Valid point. But in fact you have it on most systems anyway.

I personally don't like to have a syscall per small feature.
Isn't it better to have a file-based interface which can be used with
normal file syscalls: open()/read()/poll()?

-- 
 Kirill A. Shutemov
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