Re: [PATCH] Revert oom rewrite series

From: David Rientjes <rientjes@google.com>
To: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	LKML <linux-kernel@vger.kernel.org>,
	Ying Han <yinghan@google.com>, Bodo Eggert <7eggert@web.de>,
	Mandeep Singh Baines <msb@google.com>,
	"Figo.zhang" <figo1802@gmail.com>
Subject: Re: [PATCH] Revert oom rewrite series
Date: Tue, 30 Nov 2010 12:02:39 -0800 (PST)	[thread overview]
Message-ID: <alpine.DEB.2.00.1011301201060.12979@chino.kir.corp.google.com> (raw)
In-Reply-To: <20101130220510.832E.A69D9226@jp.fujitsu.com>

On Tue, 30 Nov 2010, KOSAKI Motohiro wrote:

> > > > You may remember that the initial version of my rewrite replaced oom_adj 
> > > > entirely with the new oom_score_adj semantics.  Others suggested that it 
> > > > be seperated into a new tunable and the old tunable deprecated for a 
> > > > lengthy period of time.  I accepted that criticism and understood the 
> > > > drawbacks of replacing the tunable immediately and followed those 
> > > > suggestions.  I disagree with you that the deprecation of oom_adj for a 
> > > > period of two years is as dramatic as you imply and I disagree that users 
> > > > are experiencing problems with the linear scale that it now operates on 
> > > > versus the old exponential scale.
> > > 
> > > Yes and No. People wanted to separate AND don't break old one.
> > > 
> > 
> > You're arguing on the behalf of applications that don't exist.
> 
> Why?
> You actually got the bug report.
> 

There have never been any bug reports related to applications using 
oom_score_adj and being impacted with its linear mapping onto oom_adj's 
exponential scale.  That's because no users prior to the rewrite were 
using oom_adj scores that were based on either the expected memory usage 
of the application nor the capacity of the machine.