Messages in this thread |  | | Date | Thu, 13 Mar 2008 15:22:39 -0700 | From | "Yinghai Lu" <> | Subject | Re: [PATCH] mm: fix boundary checking in free_bootmem_core |
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On Thu, Mar 13, 2008 at 2:59 PM, Andi Kleen <ak@suse.de> wrote: > On Thursday 13 March 2008 02:22:40 Andrew Morton wrote: > > On Wed, 12 Mar 2008 18:11:41 -0700 "Yinghai Lu" <yhlu.kernel@gmail.com> wrote: > > > > > > <looks at it> > > > > > > > > Sorry, but I find the changelog very hard to amke sense of. I presently > > > > have: > > > > > > > > > > > > So call it when numa is enabled, we don't know which node have that > > > > range. and make it more robust. > > > > > > > > Try to trim it to get valid sidx, and eidx. > > > > > > > > Could you please expand on this? > > > > > > please check following... > > > > > > > Heaps better, thanks ;) Below is what I now have. > > > > (cc's people) > > > > Guys, could you please review this? Maybe test it a bit? > > > > Thanks. > > > > > > From: "Yinghai Lu" <yhlu.kernel@gmail.com> > > > > With numa enabled, some callers could have a range o fmemory on one node but > > try to free that on other node. This can cause some pages to be freed > > wrongly. > > Concrete examples? > > If that happens it's really just a problem that the bootmem API > is wrong. I was always annoyed by the hardcoded NODE_DATA(0)s in > free_bootmem. > > I would suggest if that happens you just fix free_bootmem to search > for the correct node instead of hardcoding 0 and then eliminate > free_bootmem_node() everywhere and replace it with free_bootmem() > > > > > For example: when we try to allocate 128g boot ram early for gart/swiotlb, and > > free that range later so gart/swiotlb can get some range afterwards. > > I'm confused by the example. AFAIK there is no memory freeing in either > gart nor swiotlb. At least there wasn't until very recently.
For big system when numa=off or disabled, vmemmap will use 3.6g ram when you have 256g. if you don't allocate the PMD continuous.
then i tried to reserve 64M or 128M RAM before that, and free that before gart/switotble try to allloc_bootmem under 4g.
that patch will make the system without ram on node0 not happy. because of free_bootmem is hardcoded to use node0.
> > > > > > With this patch, we don't need to care which node holds the range, just loop > > to call free_bootmem_node for all online nodes. > > > > This patch make free_bootmem_core() more robust by trimming the sidx and eidx > > according the ram range that the node has. > > I think you should just kill free_bootmem_node() and replace it everywhere > with your improved free_bootmem()
using phys_to_nid()? it seems we only have that on x86_64.
also there is assumpation that reserve_bootmem_node, reserver_bootmem can not cross the nodes. I want to remove that constrient too.
YH
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