x86 remap allocator in kernel 3.0

Atsushi Kumagai kumagai-atsushi at mxc.nes.nec.co.jp
Mon Jan 16 03:07:47 EST 2012


Hi Petr,

On Fri, 13 Jan 2012 15:39:03 +0100
Petr Tesarik <ptesarik at suse.cz> wrote:

> Dne Pa 13. ledna 2012 04:22:50 tachibana at mxm.nes.nec.co.jp napsal(a):
> > Hi Petr,
> > 
> > On 2012/01/12 11:40:08 +0100, Petr Tesarik <ptesarik at suse.cz> wrote:
> > > Dne ?t 12. ledna 2012 09:16:06 Atsushi Kumagai napsal(a):
> > > > Hello Petr,
> > > > 
> > > > On Tue, 10 Jan 2012 19:14:32 +0100
> > > > 
> > > > Petr Tesarik <ptesarik at suse.cz> wrote:
> > > > > Ken'ichi Ohmichi, please note that makedumpfile is also affected by
> > > > > this deficiency. On my test system, it will fail to produce any
> > > > > output if I set dump level to anything greater than zero:
> > > > > 
> > > > > makedumpfile -c -d 31 -x vmlinux-3.0.13-0.5-pae.debug vmcore kdump.31
> > > > > readmem: Can't convert a physical address(34a012b4) to offset.
> > > > > readmem: type_addr: 0, addr:f4a012b4, size:4
> > > > > get_mm_discontigmem: Can't get node_start_pfn.
> > > > > 
> > > > > makedumpfile Failed.
> > > > > 
> > > > > However, fixing this for makedumpfile is harder, and it will most
> > > > > likely require a few more lines in VMCOREINFO, because debug symbols
> > > > > may not be available at dump time, and I can't see any alternative
> > > > > method to locate the remapped regions.
> > > > 
> > > > Thank you for your indication.
> > > > 
> > > > Could you send me your kernel configuration so that I can reproduce the
> > > > issue ?
> > > 
> > > Attached. The most important settings are:
> > > 
> > > CONFIG_X86_32=y
> > > CONFIG_DISCONTIGMEM_MANUAL=y
> > > 
> > > This also depends on CONFIG_NUMA=y
> > > 
> > > FYI my test system runs 3.0.15 (because that's used for SLES11 SP2), but
> > > the same issue also exists in any later version.
> > > 
> > > Petr Tesarik
> > > SUSE Linux
> > 
> > Thank you for the config. I will fix makedumpfile. However it will take
> > time to solve various issues because I've never run makedumpfile on 3.0.X.
> 
> This patch works for me, at least when using the "-x" command-line switch. To 
> make it perfect, we'll also need an accompanying patch to the kernel to store 
> the appropriate values in VMCOREINFO.
> 
> Signed-off-by: Petr Tesarik <ptesarik at suse.cz>

Thank you for the patch. I will review it.

Thanks
Atsushi Kumagai



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