From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chris Metcalf Subject: [patch] CPU_SET.3: clarify language about "available" cpus Date: Thu, 4 Nov 2010 14:00:43 -0400 Message-ID: <4CD2F4CB.7020807@tilera.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Return-path: Sender: linux-man-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: mtk.manpages-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, linux-man-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-man@vger.kernel.org The CPU_SET.3 man page uses the adjective "available" when explaining what the argument to CPU_SET() means. This is confusing, since "available" isn't well-defined. The kernel has a set of adjectives (possible, present, online, and active) that qualify cpus, but normally none of these are what the cpu_set_t bit index means: it's just "which cpu", using the kernel's internal numbering system, even if that cpu isn't possible or present. This change removes the word "available" and adds a sentence warning that cpu sets may not be contiguous due to dynamic cpu hotplug, etc. --- man3/CPU_SET.3.orig 2010-11-04 13:53:13.714684000 -0400 +++ man3/CPU_SET.3 2010-11-04 13:54:59.972042000 -0400 @@ -124,11 +124,14 @@ argument is specified, it should not produce side effects, since the above macros may evaluate the argument more than once. .PP -The first available CPU on the system corresponds to a +The first CPU on the system corresponds to a .I cpu value of 0, the next CPU corresponds to a .I cpu value of 1, and so on. +No assumptions should be made about particular CPUs being +available, or the set of CPUs being contiguous, since CPUs can +be taken offline dynamically or be otherwise absent. The constant .B CPU_SETSIZE (currently 1024) specifies a value one greater than the maximum CPU -- Chris Metcalf, Tilera Corp. http://www.tilera.com -- To unsubscribe from this list: send the line "unsubscribe linux-man" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html