Messages in this thread | | | Date | Thu, 20 Nov 2014 06:08:33 +0100 | From | Juergen Gross <> | Subject | Re: [PATCH V3 0/8] xen: Switch to virtual mapped linear p2m list |
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On 11/19/2014 09:41 PM, Konrad Rzeszutek Wilk wrote: > On Tue, Nov 11, 2014 at 06:43:38AM +0100, Juergen Gross wrote: >> Paravirtualized kernels running on Xen use a three level tree for >> translation of guest specific physical addresses to machine global >> addresses. This p2m tree is used for construction of page table >> entries, so the p2m tree walk is performance critical. >> >> By using a linear virtual mapped p2m list accesses to p2m elements >> can be sped up while even simplifying code. To achieve this goal >> some p2m related initializations have to be performed later in the >> boot process, as the final p2m list can be set up only after basic >> memory management functions are available. >> > > Hey Juergen, > > I finially finished looking at the patchset. Had some comments, > some questions that I hope can make it in the patch so that in > six months or so when somebody looks at the code they can > understand the subtle pieces.
Yep.
OTOH: What was hard to write should be hard to read ;-)
> Looking forward to the v4! (Thought keep in mind that next week > is Thanksgiving week so won't be able to look much after Wednesday)
Let's see how testing is going. Setting up the test system wasn't very smooth due to some unrelated issues.
> >> arch/x86/include/asm/pgtable_types.h | 1 + >> arch/x86/include/asm/xen/page.h | 49 +- >> arch/x86/mm/pageattr.c | 20 + >> arch/x86/xen/mmu.c | 38 +- >> arch/x86/xen/p2m.c | 1315 ++++++++++++++-------------------- >> arch/x86/xen/setup.c | 460 ++++++------ >> arch/x86/xen/xen-ops.h | 6 +- >> 7 files changed, 854 insertions(+), 1035 deletions(-) > > And best of - we are deleting more code!
Indeed. But it's a shame the beautiful ASCII-art in p2m.c is part of the deletions.
Juergen
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