Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761668AbYBNQq1 (ORCPT ); Thu, 14 Feb 2008 11:46:27 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759530AbYBNQqO (ORCPT ); Thu, 14 Feb 2008 11:46:14 -0500 Received: from e2.ny.us.ibm.com ([32.97.182.142]:32797 "EHLO e2.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754835AbYBNQqM (ORCPT ); Thu, 14 Feb 2008 11:46:12 -0500 Date: Thu, 14 Feb 2008 22:25:51 +0530 From: Srivatsa Vaddagiri To: Lukas Hejtmanek Cc: mingo@redhat.com, linux-kernel@vger.kernel.org, a.p.zijlstra@chello.nl, dhaval@linux.vnet.ibm.com, aneesh.kumar@in.ibm.com, efault@gmx.de Subject: Re: 2.6.24-git4+ regression Message-ID: <20080214165551.GA21963@linux.vnet.ibm.com> Reply-To: vatsa@linux.vnet.ibm.com References: <20080130135609.GA5100@ics.muni.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080130135609.GA5100@ics.muni.cz> User-Agent: Mutt/1.5.11 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1704 Lines: 56 On Wed, Jan 30, 2008 at 02:56:09PM +0100, Lukas Hejtmanek wrote: > Hello, > > I noticed short thread in LKM regarding "sched: add vslice" causes horrible > interactivity under load. > > I can see similar behavior. If I stress both CPU cores, even typing on > keyboard suffers from huge latencies, I can see letters appearing with delay > (typing into xterm). No swap is used at all, having 1GB free RAM. > > I noticed this bad behavior with 2.6.24-git[46], 2.6.24-rc8-git was OK. Hi Lukas, Can you check if the patch below helps improve interactivity for you? The patch is against 2.6.25-rc1. I would request you to check for difference it makes with CONFIG_FAIR_GROUP_SCHED and CONFIG_FAIR_USER_SCHED turned on. --- kernel/sched.c | 6 +++--- 1 files changed, 3 insertions(+), 3 deletions(-) Index: current/kernel/sched.c =================================================================== --- current.orig/kernel/sched.c +++ current/kernel/sched.c @@ -7431,8 +7431,8 @@ local_load = tg->cfs_rq[i]->load.weight; local_shares = (local_load * total_shares) / total_load; - if (!local_shares) - local_shares = MIN_GROUP_SHARES; + if (!local_load) + local_shares = tg->shares; if (local_shares == tg->se[i]->load.weight) continue; @@ -7710,7 +7710,7 @@ struct rq *rq = cfs_rq->rq; int on_rq; - if (!shares) + if (shares < MIN_GROUP_SHARES) shares = MIN_GROUP_SHARES; on_rq = se->on_rq; -- Regards, vatsa -- 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/