Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754551AbXLASno (ORCPT ); Sat, 1 Dec 2007 13:43:44 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752609AbXLASna (ORCPT ); Sat, 1 Dec 2007 13:43:30 -0500 Received: from smtp-out.google.com ([216.239.33.17]:30352 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752388AbXLASna (ORCPT ); Sat, 1 Dec 2007 13:43:30 -0500 DomainKey-Signature: a=rsa-sha1; s=beta; d=google.com; c=nofws; q=dns; h=received:date:from:x-x-sender:to:cc:subject:in-reply-to: message-id:references:mime-version:content-type; b=cyE2AezvVUo7nxZNYhCwU6SXQ/iOZnvaUyplH0ng3p8HSJ2h+OdMifTdtmtmlVMCn E3HsMKRHj+l261eZSKUGw== Date: Sat, 1 Dec 2007 10:42:57 -0800 (PST) From: David Rientjes X-X-Sender: rientjes@chino.kir.corp.google.com To: Ingo Molnar cc: linux-kernel@vger.kernel.org, Andrew Morton , Arjan van de Ven , Thomas Gleixner Subject: Re: [feature] automatically detect hung TASK_UNINTERRUPTIBLE tasks In-Reply-To: <20071201092037.GA32544@elte.hu> Message-ID: References: <20071201092037.GA32544@elte.hu> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1133 Lines: 27 On Sat, 1 Dec 2007, Ingo Molnar wrote: > this patch extends the soft-lockup detector to automatically > detect hung TASK_UNINTERRUPTIBLE tasks. Such hung tasks are > printed the following way: > Wouldn't a natural extension of this feature be to mark these hung TASK_UNINTERRUPTIBLE tasks with a new thread flag such as TIF_HUNG for the purposes of the OOM killer? Right now, the OOM killer will become a no-op when any candidate task that it scans through is found to have the TIF_MEMDIE flag when selecting a task to kill. So any hung task in this state could cause the OOM killer to infinitely loop. If lockdep could set_tsk_thread_flag(g, TIF_HUNG), this could be detected in the OOM killer and not only could we prevent the infinite looping but we could also clear TIF_MEMDIE and reduce the increased timeslice that the OOM killer gives to the tasks it kills. David -- 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/