Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1034141AbcJRRuo (ORCPT ); Tue, 18 Oct 2016 13:50:44 -0400 Received: from smtprelay4.synopsys.com ([198.182.47.9]:47116 "EHLO smtprelay.synopsys.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932230AbcJRRud (ORCPT ); Tue, 18 Oct 2016 13:50:33 -0400 Subject: Re: [PATCH] ARC: Adjust cpuinfo for non-continuous cpu ids To: Noam Camus References: <1476798435-8357-1-git-send-email-noamca@mellanox.com> CC: "linux-snps-arc@lists.infradead.org" , "linux-kernel@vger.kernel.org" , Noam Camus From: Vineet Gupta Message-ID: Date: Tue, 18 Oct 2016 10:48:57 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.3.0 MIME-Version: 1.0 In-Reply-To: <1476798435-8357-1-git-send-email-noamca@mellanox.com> Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.10.161.38] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1580 Lines: 48 On 10/18/2016 06:47 AM, Noam Camus wrote: > From: Noam Camus > > num_possible_cpus() returns how many CPUs may be present on system. > However we want the highest possible CPU number. Highest possible number "Detected" at boot ? Can you explain a bit more ! > This may be differ in a sparsed possible CPUs map. > > Signed-off-by: Noam Camus > Acked-by: Vineet Gupta > --- > arch/arc/kernel/setup.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/arch/arc/kernel/setup.c b/arch/arc/kernel/setup.c > index f52a0d0..d13ce84 100644 > --- a/arch/arc/kernel/setup.c > +++ b/arch/arc/kernel/setup.c > @@ -506,7 +506,7 @@ static void *c_start(struct seq_file *m, loff_t *pos) > * way to pass it w/o having to kmalloc/free a 2 byte string. > * Encode cpu-id as 0xFFcccc, which is decoded by show routine. > */ > - return *pos < num_possible_cpus() ? cpu_to_ptr(*pos) : NULL; > + return *pos < nr_cpu_ids ? cpu_to_ptr(*pos) : NULL; My only concern is that for smaller systems - say if I build with NR_CPUS = 4, and there are only 2 cpus present, then /proc/cpuinfo needs to print the fact. And a quick test with ur patch says that is the case - so how does this help you. Do u use nr_cpus cmdline toggle ? [ARCLinux]# cat /proc/cpuinfo IDENTITY : ARCVER [0x51] ARCNUM [0x0] CHIPID [ 0x0] processor [0] : ARC HS38 R2.0 (ARCv2 ISA) ... ... processor [2] : Offline processor [3] : Offline -Vineet > } > > static void *c_next(struct seq_file *m, void *v, loff_t *pos)