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Message-ID: <87r6cny5u5.fsf@saeurebad.de>
Date: Wed, 30 Apr 2008 12:50:26 +0200
From: Johannes Weiner <hannes@...urebad.de>
To: "Yinghai Lu" <yhlu.kernel@...il.com>
Cc: "Ingo Molnar" <mingo@...e.hu>,
"Linus Torvalds" <torvalds@...ux-foundation.org>,
linux-kernel@...r.kernel.org,
"Andrew Morton" <akpm@...ux-foundation.org>,
"Thomas Gleixner" <tglx@...utronix.de>,
"H. Peter Anvin" <hpa@...or.com>, jbarnes@...tuousgeek.org,
"Siddha\, Suresh B" <suresh.b.siddha@...el.com>
Subject: Re: [patch] mm: node-setup agnostic free_bootmem()
Hi,
"Yinghai Lu" <yhlu.kernel@...il.com> writes:
> On Mon, Apr 28, 2008 at 12:11 PM, Yinghai Lu <yhlu.kernel@...il.com> wrote:
>>
>> On Mon, Apr 28, 2008 at 9:54 AM, Johannes Weiner <hannes@...urebad.de> wrote:
>> > Hi Yinghai,
>> >
>> >
>> >
>> > "Yinghai Lu" <yhlu.kernel@...il.com> writes:
>> >
>> > > On Sun, Apr 27, 2008 at 5:40 PM, Ingo Molnar <mingo@...e.hu> wrote:
>> > >>
>> > >> * Johannes Weiner <hannes@...urebad.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@...urebad.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@...urebad.de>
>> > >> CC: Andi Kleen <andi@...stfloor.org>
>> > >> CC: Yinghai Lu <yhlu.kernel@...il.com>
>> > >> CC: Yasunori Goto <y-goto@...fujitsu.com>
>> > >> CC: KAMEZAWA Hiroyuki <kamezawa.hiroyu@...fujitsu.com>
>> > >> CC: Christoph Lameter <clameter@....com>
>> > >> CC: Andrew Morton <akpm@...ux-foundation.org>
>> > >> Signed-off-by: Ingo Molnar <mingo@...e.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@...el.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@...el.com>
> Signed-off-by: Ingo Molnar <mingo@...e.hu>
> Signed-off-by: Thomas Gleixner <tglx@...utronix.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?
Hannes
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