Messages in this thread | | | Date | Wed, 30 Apr 2008 13:30:27 -0700 | From | "Yinghai Lu" <> | Subject | Re: [patch] mm: node-setup agnostic free_bootmem() |
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On Wed, Apr 30, 2008 at 10:52 AM, Johannes Weiner <hannes@saeurebad.de> wrote: > > Hi, > > "Yinghai Lu" <yhlu.kernel@gmail.com> writes: > > > On Wed, Apr 30, 2008 at 3:50 AM, Johannes Weiner <hannes@saeurebad.de> wrote: > >> > >> Hi, > >> > >> "Yinghai Lu" <yhlu.kernel@gmail.com> writes: > >> > >> > On Mon, Apr 28, 2008 at 12:11 PM, Yinghai Lu <yhlu.kernel@gmail.com> wrote: > >> >> > >> >> On Mon, Apr 28, 2008 at 9:54 AM, Johannes Weiner <hannes@saeurebad.de> wrote: > >> >> > Hi Yinghai, > >> >> > > >> >> > > >> >> > > >> >> > "Yinghai Lu" <yhlu.kernel@gmail.com> writes: > >> >> > > >> >> > > On Sun, Apr 27, 2008 at 5:40 PM, Ingo Molnar <mingo@elte.hu> wrote: > >> >> > >> > >> >> > >> * Johannes Weiner <hannes@saeurebad.de> wrote: > >> >> > >> > >> >> > >> > > so i very much agree that your changes are cleaner, i just wanted to > >> >> > >> > > have one that has all the fixes included. > >> >> > >> > > >> >> > >> > I had planned this to be another patch because there are more then one > >> >> > >> > boundary check I wanted to tighten. I can merge them though if you > >> >> > >> > like. > >> >> > >> > >> >> > >> no, better to have them in separate patches. > >> >> > >> > >> >> > >> > > Would you like to post a patch against current -git or should i > >> >> > >> > > extract the cleaner reserve_bootmem() from your previous patch? > >> >> > >> > > >> >> > >> > I just moved and have only sporadic internet access and free time > >> >> > >> > slots available. Would be nice if you could do it! > >> >> > >> > >> >> > >> sure, find the merged patch below, against latest -git, boot-tested on > >> >> > >> x86. Is this what you had in mind? > >> >> > >> > >> >> > >> Ingo > >> >> > >> > >> >> > >> ----------------> > >> >> > >> Subject: mm: node-setup agnostic free_bootmem() > >> >> > >> From: Johannes Weiner <hannes@saeurebad.de> > >> >> > >> Date: Wed, 16 Apr 2008 13:36:31 +0200 > >> >> > >> > >> >> > >> Make free_bootmem() look up the node holding the specified address > >> >> > >> range which lets it work transparently on single-node and multi-node > >> >> > >> configurations. > >> >> > >> > >> >> > >> If the address range exceeds the node range, it well be marked free > >> >> > >> across node boundaries, too. > >> >> > >> > >> >> > >> Signed-off-by: Johannes Weiner <hannes@saeurebad.de> > >> >> > >> CC: Andi Kleen <andi@firstfloor.org> > >> >> > >> CC: Yinghai Lu <yhlu.kernel@gmail.com> > >> >> > >> CC: Yasunori Goto <y-goto@jp.fujitsu.com> > >> >> > >> CC: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> > >> >> > >> CC: Christoph Lameter <clameter@sgi.com> > >> >> > >> CC: Andrew Morton <akpm@linux-foundation.org> > >> >> > >> Signed-off-by: Ingo Molnar <mingo@elte.hu> > >> >> > >> --- > >> >> > >> mm/bootmem.c | 27 +++++++++++++++++++++++++-- > >> >> > >> 1 file changed, 25 insertions(+), 2 deletions(-) > >> >> > >> > >> >> > >> Index: linux-x86.q/mm/bootmem.c > >> >> > >> =================================================================== > >> >> > >> --- linux-x86.q.orig/mm/bootmem.c > >> >> > >> +++ linux-x86.q/mm/bootmem.c > >> >> > >> @@ -493,8 +493,31 @@ int __init reserve_bootmem(unsigned long > >> >> > >> void __init free_bootmem(unsigned long addr, unsigned long size) > >> >> > >> { > >> >> > >> bootmem_data_t *bdata; > >> >> > >> - list_for_each_entry(bdata, &bdata_list, list) > >> >> > >> - free_bootmem_core(bdata, addr, size); > >> >> > >> + unsigned long pos = addr; > >> >> > >> + unsigned long partsize = size; > >> >> > >> + > >> >> > >> + list_for_each_entry(bdata, &bdata_list, list) { > >> >> > >> + unsigned long remainder = 0; > >> >> > >> + > >> >> > >> + if (pos < bdata->node_boot_start) > >> >> > >> + continue; > >> >> > >> + > >> >> > >> + if (PFN_DOWN(pos + partsize) > bdata->node_low_pfn) { > >> >> > >> + remainder = PFN_DOWN(pos + partsize) - bdata->node_low_pfn; > >> >> > >> + partsize -= remainder; > >> >> > >> + } > >> >> > >> + > >> >> > >> + free_bootmem_core(bdata, pos, partsize); > >> >> > >> + > >> >> > >> + if (!remainder) > >> >> > >> + return; > >> >> > >> + > >> >> > >> + pos = PFN_PHYS(bdata->node_low_pfn + 1); > >> >> > >> + } > >> >> > >> + printk(KERN_ERR "free_bootmem: request: addr=%lx, size=%lx, " > >> >> > >> + "state: pos=%lx, partsize=%lx\n", addr, size, > >> >> > >> + pos, partsize); > >> >> > >> + BUG(); > >> >> > >> } > >> >> > >> > >> >> > >> unsigned long __init free_all_bootmem(void) > >> >> > >> > >> >> > > > >> >> > > it will not work with cross nodes. > >> >> > > > >> >> > > for example: node 0: 0-2g, 4-6g, node1: 2-4g, 6-8g. > >> >> > > and if ramdisk sit cross 2G boundary. you will only free the range > >> >> > > before 2g. > >> >> > > >> >> > Yes, you stated that several times but this is not a technical argument: > >> >> > These setups are afaik not yet supported by the kernel at all. And you > >> >> > could not explain the node layout with the patch that implements support > >> >> > for these configurations. > >> >> > >> >> I looked at Suresh's patch, and it still only has one bdata for one node. > >> > > >> > Suresh's patch already in the Linus tree. > >> > commit 6ec6e0d9f2fd7cb6ca6bc3bfab5ae7b5cdd8c36f > >> > Author: Suresh Siddha <suresh.b.siddha@intel.com> > >> > Date: Tue Mar 25 10:14:35 2008 -0700 > >> > > >> > srat, x86: 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> > >> > Signed-off-by: Ingo Molnar <mingo@elte.hu> > >> > Signed-off-by: Thomas Gleixner <tglx@linutronix.de> > >> > >> Okay, so we have one bdata for node 0 and one for node 1. Does that mean > >> that both have overlapping pfn ranges? > >> > >> [1 ||||| ] > >> [2 ||||| ] > >> > >> Like this? How are the ||||| represented in the bootmem maps of each bdata? > > > > Yes. > > Okay. So they share the same PFNs. Now imagine the following scenario: > > node0: 0-2GB, 4-6GB > node1: 2-4GB, 6-8GB > > /* Marks the range on node0 and node1 */ > free_bootmem(1.5G, 2G); > > /* Frees all bootmem on both nodes */ > free_all_bootmem_node(NODE_DATA(0)); > free_all_bootmem_node(NODE_DATA(1)); > > Aren't the same page descriptors send to __free_bootmem_pages() twice?
yeah, there is some problem.... may need to ask every node took another node_bootmem_not_use_map ...to record the holes.
YH
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