Messages in this thread | | | Date | Mon, 15 Jul 2013 15:44:51 +0200 | From | Michael Holzheu <> | Subject | Re: [PATCH v6 3/5] vmcore: Introduce remap_oldmem_pfn_range() |
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On Tue, 2 Jul 2013 11:42:14 -0400 Vivek Goyal <vgoyal@redhat.com> wrote:
> On Mon, Jul 01, 2013 at 09:32:37PM +0200, Michael Holzheu wrote: > > For zfcpdump we can't map the HSA storage because it is only available > > via a read interface. Therefore, for the new vmcore mmap feature we have > > introduce a new mechanism to create mappings on demand. > > > > This patch introduces a new architecture function remap_oldmem_pfn_range() > > that should be used to create mappings with remap_pfn_range() for oldmem > > areas that can be directly mapped. For zfcpdump this is everything besides > > of the HSA memory. For the areas that are not mapped by remap_oldmem_pfn_range() > > a generic vmcore a new generic vmcore fault handler mmap_vmcore_fault() > > is called. > > > > This handler works as follows: > > > > * Get already available or new page from page cache (find_or_create_page) > > * Check if /proc/vmcore page is filled with data (PageUptodate) > > * If yes: > > Return that page > > * If no: > > Fill page using __vmcore_read(), set PageUptodate, and return page > > > > Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> > > In general vmcore related changes look fine to me. I am not very familiar > with the logic of finding pages in page cache and using page uptodate > flag. > > Hatayama, can you please review it. > > Acked-by: Vivek Goyal <vgoyal@redhat.com>
Hello Vivek and Andrew,
We just realized that Hatayama's mmap patches went into v3.11-rc1. This currently breaks s390 kdump because of the following two issues:
1) The copy_oldmem_page() is now used for copying to vmalloc memory 2) The mmap() implementation is not compatible with the current s390 crashkernel swap: See: http://marc.info/?l=kexec&m=136940802511603&w=2
The "kdump: Introduce ELF header in new memory feature" patch series will fix both issues for s390.
There is the one small open discussion left:
http://www.mail-archive.com/linux-kernel@vger.kernel.org/msg464856.html
But once we have finished that, would it be possible to get the patches in 3.11?
Michael
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