From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [PATCH RFC 0/2] add nproc cgroup subsystem Date: Fri, 27 Feb 2015 12:56:19 -0500 Message-ID: <20150227175619.GN3964@htj.duckdns.org> References: <1424660891-12719-1-git-send-email-cyphar@cyphar.com> <20150227114940.GB3964@htj.duckdns.org> <54F09E62.8000007@gmail.com> <20150227170640.GK3964@htj.duckdns.org> <20150227174503.GM3964@htj.duckdns.org> Mime-Version: 1.0 Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; bh=PKda7dLuwxVQdaI0Lvpi/Cb/P1qc0TYxsVB4dTQXRMM=; b=yZbIc5uk/8ERH5o3Hwoa7qBPZzwHK6S1JDH1tPiJrxuXbWrupGIhj7gxYYLrQ8pi2H S7d1eGvACo/JADtU6qkwjp3QlXrOYxtDZypUhPFIf5j/U9YFJ5Lvx74EG1k7p7a5PI8/ iZhkDC8ZouaaighEaT7pxCirLIQWkTcyscfdiNyvdj47dbW6/YXnr5oUk8SXWvLINzaj FiJXyDYXHo0NpJnEUbVlBjRq4uzzB6mzOaySfqndsCh8o7C9EP+/3WpGGuvTsOrTsee6 I6pYhwBKTHm+F0SS4YmaYDL0z/hm3kIwLaFLLWl4czheNY283foMLmwL/iS9X/f1nKEK 1J9Q== Content-Disposition: inline In-Reply-To: <20150227174503.GM3964-piEFEHQLUPpN0TnZuCh8vA@public.gmane.org> Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Tim Hockin Cc: Austin S Hemmelgarn , Aleksa Sarai , Li Zefan , mingo-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, Peter Zijlstra , richard-/L3Ra7n9ekc@public.gmane.org, =?iso-8859-1?Q?Fr=E9d=E9ric?= Weisbecker , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Cgroups On Fri, Feb 27, 2015 at 12:45:03PM -0500, Tejun Heo wrote: > If your complaint is that this is taking too long, I hear you, and > there's a certain amount of validity in arguing that upstreaming a > temporary measure is the better trade-off, but the rationale for nproc > (or nfds, or virtual memory, whatever) has been pretty weak otherwise. Also, note that this is subset of a larger problem. e.g. there's a patchset trying to implement writeback IO control from the filesystem layer. cgroup control of writeback has been a thorny issue for over three years now and the rationale for implementing this reversed controlling scheme is about the same - doing it properly is too difficult, let's bolt something on the top as a practical measure. I think it'd be seriously short-sighted to give in and merge all those. These sorts of shortcuts are crippling in the long term. Again, similarly, proper cgroup writeback support is literally right around the corner. The situation sure can be frustrating if you need something now but we can't make decisions solely on that. This is an a lot longer term project and we better, for once, get things right. Thanks. -- tejun