Messages in this thread | | | Date | Tue, 15 Apr 2008 13:03:53 -0700 | From | "Yinghai Lu" <> | Subject | Re: + bootmem-node-setup-agnostic-free_bootmem.patch added to -mm tree |
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On Tue, Apr 15, 2008 at 12:55 PM, Johannes Weiner <hannes@saeurebad.de> wrote: > Hi, > > > > "Yinghai Lu" <yhlu.kernel@gmail.com> writes: > > > On Tue, Apr 15, 2008 at 5:51 AM, Johannes Weiner <hannes@saeurebad.de> wrote: > >> Hi Ingo, > >> > >> > >> > >> Ingo Molnar <mingo@elte.hu> writes: > >> > >> > * akpm@linux-foundation.org <akpm@linux-foundation.org> wrote: > >> > > >> >> Subject: bootmem: node-setup agnostic free_bootmem() > >> >> From: Johannes Weiner <hannes@saeurebad.de> > >> >> > >> >> Make free_bootmem() look up the node holding the specified address > >> >> range which lets it work transparently on single-node and multi-node > >> >> configurations. > >> > > >> > this patch does not fix the bug Yinghai's (now dropped) patches solved: > >> > reserve_early() allocations. So NAK until the full problem has been > >> > sorted out ... > >> > >> Okay, NAK on -mm and -x86 for sure. The patch was meant for mainline > >> where there is no need for free_bootmem() going across nodes, right? > >> > >> But I still object to the way Yinghai implemented it. > >> free_bootmem_core() should not be twisted like this. > >> > >> How about the following (untested, even uncompiled, but you should get > >> the idea) proposal which would replace the patch discussed in this > >> thread: > >> > >> --- tree-linus.orig/mm/bootmem.c > >> +++ tree-linus/mm/bootmem.c > >> @@ -421,7 +421,25 @@ int __init reserve_bootmem(unsigned long > >> > >> > >> void __init free_bootmem(unsigned long addr, unsigned long size) > >> { > >> - free_bootmem_core(NODE_DATA(0)->bdata, addr, size); > >> + bootmem_data_t *bdata; > >> + > >> + list_for_each_entry(bdata, &bdata_list, list) { > >> + unsigned long remainder = 0; > >> > >> + > >> + if (addr < bdata->node_boot_start) > >> + continue; > >> + > >> + if (PFN_DOWN(addr + size) > bdata->node_low_pfn) > >> + remainder = PFN_DOWN(addr + size) - bdata->node_low_pfn; > >> + > >> + size -= PFN_PHYS(remainder); > >> > >> + free_bootmem_core(bdata, addr, size) > >> + > >> + if (!remainder) > >> + break; > >> + > >> + addr = PFN_PHYS(bdata->node_low_pfn + 1); > >> + } > >> > >> } > >> > >> unsigned long __init free_all_bootmem(void) > > > > how about > > 1. bdata is not sorted? > > They are kept in a sorted list. How could they be unsorted? > > > > 2. intel cross node box: node0: 0g-2g, 4g-6g, node1: 2g-4g, 6g-8g. i > > don't think they have two bdata struct for every node. > > How do the bdata structures represent this setup right now? Are you > sure that there is not a node descriptor for every contiguous region?
http://lkml.org/lkml/2008/3/25/233
Subject [patch] srat, x86_64: Add support for nodes spanning other nodes
For example, If the physical address layout on a two node system with 8 GB memory is something like: node 0: 0-2GB, 4-6GB node 1: 2-4GB, 6-8GB
Current kernels fail to boot/detect this NUMA topology.
ACPI SRAT tables can expose such a topology which needs to be supported.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
YH
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