Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754158Ab0KIX4F (ORCPT ); Tue, 9 Nov 2010 18:56:05 -0500 Received: from smtp-out.google.com ([74.125.121.35]:22905 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752442Ab0KIX4B (ORCPT ); Tue, 9 Nov 2010 18:56:01 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=google.com; s=beta; h=date:from:x-x-sender:to:cc:subject:in-reply-to:message-id :references:user-agent:mime-version:content-type; b=os7EFg7yKTPlh76e+fdf8L5ePP3cNK/34r/RLVkai10yOwcOqjfnvcvTqYAFml77If p1S2RGjmPvXXkYw4OJ4w== Date: Tue, 9 Nov 2010 15:55:53 -0800 (PST) From: David Rientjes X-X-Sender: rientjes@chino.kir.corp.google.com To: Alan Cox cc: KOSAKI Motohiro , Andrew Morton , Linus Torvalds , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [patch] oom: document obsolete oom_adj tunable In-Reply-To: Message-ID: References: <20101101030353.607A.A69D9226@jp.fujitsu.com> <20101109105801.BC30.A69D9226@jp.fujitsu.com> <20101109233541.13be4cd5@lxorguk.ukuu.org.uk> User-Agent: Alpine 2.00 (DEB 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2131 Lines: 46 /proc/pid/oom_adj was deprecated in August 2010 with the introduction of the new oom killer heuristic. This patch copies the Documentation/feature-removal-schedule.txt entry for this tunable to the Documentation/ABI/obsolete directory so nobody misses it. Reported-by: Alan Cox Signed-off-by: David Rientjes --- Documentation/ABI/obsolete/proc-pid-oom_adj | 22 ++++++++++++++++++++++ 1 files changed, 22 insertions(+), 0 deletions(-) create mode 100644 Documentation/ABI/obsolete/proc-pid-oom_adj diff --git a/Documentation/ABI/obsolete/proc-pid-oom_adj b/Documentation/ABI/obsolete/proc-pid-oom_adj new file mode 100644 --- /dev/null +++ b/Documentation/ABI/obsolete/proc-pid-oom_adj @@ -0,0 +1,22 @@ +What: /proc//oom_adj +When: August 2012 +Why: /proc//oom_adj allows userspace to influence the oom killer's + badness heuristic used to determine which task to kill when the kernel + is out of memory. + + The badness heuristic has since been rewritten since the introduction of + this tunable such that its meaning is deprecated. The value was + implemented as a bitshift on a score generated by the badness() + function that did not have any precise units of measure. With the + rewrite, the score is given as a proportion of available memory to the + task allocating pages, so using a bitshift which grows the score + exponentially is, thus, impossible to tune with fine granularity. + + A much more powerful interface, /proc//oom_score_adj, was + introduced with the oom killer rewrite that allows users to increase or + decrease the badness() score linearly. This interface will replace + /proc//oom_adj. + + A warning will be emitted to the kernel log if an application uses this + deprecated interface. After it is printed once, future warnings will be + suppressed until the kernel is rebooted. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/