From mboxrd@z Thu Jan 1 00:00:00 1970 From: "KOCHI, Takayoshi" Date: Thu, 18 Oct 2001 22:34:53 +0000 Subject: Re: [Linux-ia64] Kernel Resources & Allocation Order Message-Id: List-Id: References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-ia64@vger.kernel.org Hi, On Thu, 18 Oct 2001 15:24:08 -0500 "Donny Cooper" wrote: > > Do kernel-parameters (such as, mem=X and maxcpus=N) have an allocation order according > to the physical system layout, or > even follow any order at all? Current IA64 Linux implementation uses ACPI MADT order for limiting cpu number and EFI_MEMMAP order for limiting memory. The lowest-numberd cpus (except BSP) or the lowest-mapped memory range is allocated. > For example, if I boot with mem24M and maxcpus=2, will resources > come from the low number DIMM and CPU slots. Or is > SMP completely random, with no guarantee which resources are allocated. ACPI MADT numbering is dependent on firmware implementation (though most platform choose the lowest numberd cpu to come first). Which DIMM is the lowest memory is dependent on hardware (memory-controller or chipset) and firmware (how to program memory controller). > I am aware that you cannot choose which > resources to use, but the documentation I have found on this subject is unclear. Rewriting the resource-limiting (maxcpu, maxmem) code, you can control which part of cpu or memory will be used, but which part of cpu/mem corresponds to which part of physical cpu/mem is different from platform to platform. Regards, -- KOCHI Takayoshi