From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ashok Raj Date: Wed, 28 Apr 2004 14:52:55 +0000 Subject: Re: ia64-cpu-hotplug-cpu_present.patch? Message-Id: <20040428075255.A8859@unix-os.sc.intel.com> List-Id: References: <20040427225741.2fe78d88.pj@sgi.com> In-Reply-To: <20040427225741.2fe78d88.pj@sgi.com>; from pj@sgi.com on Tue, Apr 27, 2004 at 10:57:41PM -0700 MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Paul Jackson Cc: akpm@osdl.org, ashok.raj@intel.com, linux-kernel@vger.kernel.org, linux-ia64@vger.kernel.org On Tue, Apr 27, 2004 at 10:57:41PM -0700, Paul Jackson wrote: Hi Paul, sorry for the trouble. I will try to address them, and will try to resolve the compile problem you are having. > I cannot find any mention of it on lkml or any other email list that > either Google or I track. > > Is there some backdoor path to Andrew's patch directory I don't know of ;)? I sent the patch to linux-ia64, but forgot to copy lkml. No... i did not buy crispy cream for andrew.. although that did cross my mine :-) Some of the points you raise, i will look into, but here is a quick summary fo Paul's top 10 list!. cpu_present is required so that when cpu_up is called in smp_init() we dont call for all possible cpu's but just for cpu's physically present. cpu_possible - indicates cpu may be available, but may not be present in the system. Hence different from phys_cpu_present_mask cpu_possible wont change dynamically but present_map can change depending on the arrival of cpu's in a system. I implemented it for only ia64, and expection is that ACPI or its equilvalent would populate cpu_present_map dynamically. In architectures that dont have cpu_hotplug capability, i have kept cpu_present and possible the same. Once i take a look at the failures, i will send you an updated patch. again really sorry for the inconvenience. Cheers, ashok