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From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
To: Paul Mackerras via Linuxppc-dev <linuxppc-dev@lists.ozlabs.org>,
	linuxppc-dev@lists.ozlabs.org
Subject: Re: [RFC PATCH 0/9] powerpc/mm: Restructure Linux PTE on Book3S/64 to radix format
Date: Sun, 21 Feb 2016 13:11:17 +0530	[thread overview]
Message-ID: <87povq7boi.fsf@linux.vnet.ibm.com> (raw)
In-Reply-To: <87ziuvcun9.fsf@linux.vnet.ibm.com>

"Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> writes:

> Paul Mackerras <paulus@samba.org> writes:
>
>> This patch series modifies the Linux PTE format used on 64-bit Book3S
>> processors (i.e. POWER server processors) to make the bits line up
>> with the PTE format used in the radix trees defined in PowerISA v3.0.
>> This will reduce the amount of further change required to make a
>> kernel that can run with either a radix MMU or a hashed page table
>> (HPT) MMU.
>>
>> This also changes the upper levels of the tree to use real addresses
>> rather than kernel virtual addresses - that is, we no longer have the
>> 0xc000... at the top of each PGD/PUD/PMD entry.  I made this change
>> for all 64-bit machines, both embedded and server.
>>
>> The patch series is against v4.5-rc4 plus Aneesh's "powerpc/mm/hash:
>> Clear the invalid slot information correctly" patch.
>>
>> I have compiled this for all the defconfigs in the tree, without
>> error.  I have tested this, with the fixes branch of the powerpc tree
>> merged in, both running bare-metal on a POWER8 and in a KVM guest on
>> that POWER8 system.  In the guest I tested both 4k and 64k configs,
>> with THP enabled; in the host I tested with 64k page size and THP
>> enabled.  All these tests ran fine, including running a KVM guest on
>> the bare-metal system.  So far I have done kernel compiles in a loop
>> as the test, but I plan to run LTP and possibly some other tests.
>>
>> Comments welcome.
>
> I was expecting some complex changes in asm and other part of the code. That
> is one of the reason I was holding of a series like this till I get the
> radix merged. I should have really tried the radix/hash linux page table 
> consolidation to see the impact.

One of the details that i hit last time with _PAGE_PTE was the usage of
@h symbol in asm code. I did a quick look and I guess we are ok. But it
will be good to double check. pmdp_splitting_flush (which got removed)
had usages like %4@h etc

-aneesh

  parent reply	other threads:[~2016-02-21  7:41 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-02-20  6:12 [RFC PATCH 0/9] powerpc/mm: Restructure Linux PTE on Book3S/64 to radix format Paul Mackerras
2016-02-20  6:12 ` [RFC PATCH 1/9] powerpc/mm/book3s-64: Clean up some obsolete or misleading comments Paul Mackerras
2016-02-20  6:12 ` [RFC PATCH 2/9] powerpc/mm/book3s-64: Free up 7 high-order bits in the Linux PTE Paul Mackerras
2016-02-20 16:16   ` Aneesh Kumar K.V
2016-02-21 22:43     ` Paul Mackerras
2016-02-20  6:12 ` [RFC PATCH 3/9] powerpc/mm/64: Use physical addresses in upper page table tree levels Paul Mackerras
2016-02-20 16:35   ` Aneesh Kumar K.V
2016-02-21 22:45     ` Paul Mackerras
2016-02-20  6:12 ` [RFC PATCH 4/9] powerpc/mm/book3s-64: Move _PAGE_PRESENT to the most significant bit Paul Mackerras
2016-02-20  8:33   ` kbuild test robot
2016-02-20 16:41   ` Aneesh Kumar K.V
2016-02-21 22:40     ` Paul Mackerras
2016-02-20  6:12 ` [RFC PATCH 5/9] powerpc/mm/book3s-64: Move _PAGE_PTE to 2nd " Paul Mackerras
2016-02-20  6:12 ` [RFC PATCH 6/9] powerpc/mm/book3s-64: Move HPTE-related bits in PTE to upper end Paul Mackerras
2016-02-20  6:12 ` [RFC PATCH 7/9] powerpc/mm/book3s-64: Shuffle read, write, execute and user bits in PTE Paul Mackerras
2016-02-21  7:30   ` Aneesh Kumar K.V
2016-02-21 22:36     ` Paul Mackerras
2016-02-22  0:27       ` Michael Ellerman
2016-02-20  6:12 ` [RFC PATCH 8/9] powerpc/mm/book3s-64: Move software-used " Paul Mackerras
2016-02-20  6:12 ` [RFC PATCH 9/9] powerpc/mm/book3s-64: Expand the real page number field of the Linux PTE Paul Mackerras
2016-02-20 14:40 ` [RFC PATCH 0/9] powerpc/mm: Restructure Linux PTE on Book3S/64 to radix format Aneesh Kumar K.V
2016-02-20 15:32   ` Aneesh Kumar K.V
2016-02-21  7:41   ` Aneesh Kumar K.V [this message]
2016-02-21 22:31     ` Paul Mackerras
2016-02-22  0:30   ` Michael Ellerman

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