Messages in this thread | | | Date | Tue, 30 Oct 2012 21:38:20 -0700 | From | "H. Peter Anvin" <> | Subject | Re: [PATCH] To crash dump, we need keep other memory type except E820_RAM, because other type come from BIOS or firmware is used by other code(for example: PCI_MMCONFIG). |
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On 10/30/2012 08:39 PM, Zhang, Jun wrote: > Hello, Anvin > Thanks! > > Hello, all > Next is my the latest version, please review it. > Thanks!
You're still starting in the wrong end which is confusing for the reader.
What you probably want to say is something more like:
"We are doing a crash dump, so remove all RAM ranges as they are the ones that need to be dumped. We still need all non-RAM information in order to do I/O."
At that point it should be pretty obvious that the patch is wrong. What if we are *not* doing a crash dump? Just because crash dump is compiled in doesn't mean that that is what we are doing right now.
-hpa
> From 141546c77ff7be523a9e72f5259df4a6827f2c1a Mon Sep 17 00:00:00 2001 > From: jzha144 <jun.zhang@intel.com> > Date: Wed, 31 Oct 2012 08:51:18 +0800 > Subject: [PATCH] If we are doing a crash dump, we still need non-E820_RAM > memory type address information, which come from BIOS or > firmware. for example: PCI_MMCONFIG check this address. > > Signed-off-by: jzha144 <jun.zhang@intel.com> > --- > arch/x86/kernel/e820.c | 9 +++++++++ > 1 files changed, 9 insertions(+), 0 deletions(-) > > diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c > index df06ade..f8672d0 100644 > --- a/arch/x86/kernel/e820.c > +++ b/arch/x86/kernel/e820.c > @@ -851,6 +851,15 @@ static int __init parse_memmap_opt(char *p) > * reset. > */ > saved_max_pfn = e820_end_of_ram_pfn(); > + > + /* > + * If we are doing a crash dump, we still need non-E820_RAM > + * memory type address information. so we only remove > + * E820_RAM type. > + */ > + e820_remove_range(0, ULLONG_MAX, E820_RAM, 1); > + userdef = 1; > + return 0; > #endif > e820.nr_map = 0; > userdef = 1; >
-- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf.
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