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Date: Tue, 2 Jul 2013 21:47:03 +0200
From: Pavel Machek <pavel@ucw.cz>
To: Luiz Capitulino <lcapitulino@redhat.com>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, mhocko@suse.cz,
        minchan@kernel.org, anton@enomsg.org, akpm@linux-foundation.org
Subject: Re: [PATCH] vmpressure: implement strict mode
Message-ID: <20130702194703.GA19373@amd.pavel.ucw.cz>
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 <20130701085103.GA19798@amd.pavel.ucw.cz>
 <20130702110628.5dbb75e0@redhat.com>
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On Tue 2013-07-02 11:06:28, Luiz Capitulino wrote:
> On Mon, 1 Jul 2013 10:51:03 +0200
> Pavel Machek <pavel@ucw.cz> wrote:
> 
> > Hi!
> > 
> > > diff --git a/Documentation/cgroups/memory.txt b/Documentation/cgroups/memory.txt
> > > index ddf4f93..3c589cf 100644
> > > --- a/Documentation/cgroups/memory.txt
> > > +++ b/Documentation/cgroups/memory.txt
> > > @@ -807,12 +807,14 @@ register a notification, an application must:
> > >  
> > >  - create an eventfd using eventfd(2);
> > >  - open memory.pressure_level;
> > > -- write string like "<event_fd> <fd of memory.pressure_level> <level>"
> > > +- write string like "<event_fd> <fd of memory.pressure_level> <level> [strict]"
> > >    to cgroup.event_control.
> > >  
> > 
> > This is.. pretty strange interface. Would it be cleaner to do ioctl()?
> > New syscall?
> 
> Are you referring to my new mode or to the whole thing?

Well. The interface was already very strange and you made it even
worse.

For example... How is the string terminated? \0? \n? Not at all? Needs
to be written in single write? How many spaces are allowed? Can I put
there \t? How many leading zeros? How do you know that you can stop
looking for "strict" string?

Dunno. Passing fd by writting it out in ascii is strange. (And writing
fd in ascii to the same fd is ... very strange.)

									Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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