Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760320Ab2EISzf (ORCPT ); Wed, 9 May 2012 14:55:35 -0400 Received: from hqemgate03.nvidia.com ([216.228.121.140]:2498 "EHLO hqemgate03.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758178Ab2EISzd convert rfc822-to-8bit (ORCPT ); Wed, 9 May 2012 14:55:33 -0400 X-PGP-Universal: processed; by hqnvupgp08.nvidia.com on Wed, 09 May 2012 11:55:23 -0700 From: Diwakar Tundlam To: "'Michael Wang'" CC: "'Peter Zijlstra'" , "'Ingo Molnar'" , "'David Rientjes'" , "'linux-kernel@vger.kernel.org'" , Peter De Schrijver Date: Wed, 9 May 2012 11:55:23 -0700 Subject: RE: [PATCH] sched: Make nr_uninterruptible count a signed value Thread-Topic: [PATCH] sched: Make nr_uninterruptible count a signed value Thread-Index: Ac0tuYdOe7FNfMukTkqh327SjjzONAAWxtlQ Message-ID: <1DD7BFEDD3147247B1355BEFEFE46652379C3DF117@HQMAIL04.nvidia.com> References: <1DD7BFEDD3147247B1355BEFEFE46652379C3DF10C@HQMAIL04.nvidia.com> <1336514192.8226.52.camel@twins> <1DD7BFEDD3147247B1355BEFEFE46652379C3DF10D@HQMAIL04.nvidia.com> <1336516020.8226.57.camel@twins> <1336516174.8226.59.camel@twins> <1DD7BFEDD3147247B1355BEFEFE46652379C3DF10E@HQMAIL04.nvidia.com> <4FAA216D.1080909@linux.vnet.ibm.com> In-Reply-To: <4FAA216D.1080909@linux.vnet.ibm.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2335 Lines: 61 >> - P(nr_uninterruptible); >> + P((signed long)nr_uninterruptible); I thought of it too, but it won't compile because the P macro expands to dereferencing rq->nr_uninterruptible, so with your change, it will show up as rq->(signed long)nr_uninterruptible which is a syntax error. --Diwakar. -----Original Message----- From: Michael Wang [mailto:wangyun@linux.vnet.ibm.com] Sent: Wednesday, May 09, 2012 12:49 AM To: Diwakar Tundlam Cc: 'Peter Zijlstra'; 'Ingo Molnar'; 'David Rientjes'; 'linux-kernel@vger.kernel.org'; Peter De Schrijver Subject: Re: [PATCH] sched: Make nr_uninterruptible count a signed value On 05/09/2012 06:46 AM, Diwakar Tundlam wrote: >> No that's right. nr_uninterruptible counts the number of tasks in >> uninterruptible sleep, so deactivate_task puts a task to sleep, so we >> need to increment the number of sleeping tasks, activate_task wakes a >> task up so we need to decrement the number of sleeping tasks. > > Yep, I looked at the code for task_contributes_to_load() and I understand what it is all about. > The ++ and -- are correct, I see it now. > > On the -ve values, strangely inspite of %Ld in the print statement, in my kernel, I see high unsigned values instead of -ve values for nr_uninterruptible. > > But the sum is always 0, though. > > Maybe it is an artifact of 32-bit machine displaying 64-bit print format. > An (unsigned long)(-24) promoted to (signed long long) ends up as 4294967272. > As seen in my output of sched_debug. This may do some help. Regards, Michael Wang --- kernel/sched/debug.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c index 09acaa1..ab9d53f 100644 --- a/kernel/sched/debug.c +++ b/kernel/sched/debug.c @@ -270,7 +270,7 @@ static void print_cpu(struct seq_file *m, int cpu) rq->load.weight); P(nr_switches); P(nr_load_updates); - P(nr_uninterruptible); + P((signed long)nr_uninterruptible); PN(next_balance); P(curr->pid); PN(clock); -- 1.7.4.1 -- 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/