From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
To: David Gibson <dwg@au1.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org, paulus@samba.org, linux-mm@kvack.org
Subject: Re: [PATCH -V5 17/25] powerpc/THP: Implement transparent hugepages for ppc64
Date: Fri, 12 Apr 2013 10:36:58 +0530 [thread overview]
Message-ID: <8761zsmj65.fsf@linux.vnet.ibm.com> (raw)
In-Reply-To: <20130412005135.GA5065@truffula.fritz.box>
David Gibson <dwg@au1.ibm.com> writes:
> On Thu, Apr 11, 2013 at 01:10:29PM +0530, Aneesh Kumar K.V wrote:
>> David Gibson <dwg@au1.ibm.com> writes:
>>
>> > On Thu, Apr 04, 2013 at 11:27:55AM +0530, Aneesh Kumar K.V wrote:
>> >> From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
>> >>
>> >> We now have pmd entries covering to 16MB range. To implement THP on powerpc,
>> >> we double the size of PMD. The second half is used to deposit the pgtable (PTE page).
>> >> We also use the depoisted PTE page for tracking the HPTE information. The information
>> >> include [ secondary group | 3 bit hidx | valid ]. We use one byte per each HPTE entry.
>> >> With 16MB hugepage and 64K HPTE we need 256 entries and with 4K HPTE we need
>> >> 4096 entries. Both will fit in a 4K PTE page.
>> >>
>> >> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
>> >> ---
>> >> arch/powerpc/include/asm/page.h | 2 +-
>> >> arch/powerpc/include/asm/pgtable-ppc64-64k.h | 3 +-
>> >> arch/powerpc/include/asm/pgtable-ppc64.h | 2 +-
>> >> arch/powerpc/include/asm/pgtable.h | 240 ++++++++++++++++++++
>> >> arch/powerpc/mm/pgtable.c | 314 ++++++++++++++++++++++++++
>> >> arch/powerpc/mm/pgtable_64.c | 13 ++
>> >> arch/powerpc/platforms/Kconfig.cputype | 1 +
>> >> 7 files changed, 572 insertions(+), 3 deletions(-)
>> >>
>> >> diff --git a/arch/powerpc/include/asm/page.h b/arch/powerpc/include/asm/page.h
>> >> index 38e7ff6..b927447 100644
>> >> --- a/arch/powerpc/include/asm/page.h
>> >> +++ b/arch/powerpc/include/asm/page.h
>> >> @@ -40,7 +40,7 @@
>> >> #ifdef CONFIG_HUGETLB_PAGE
>> >> extern unsigned int HPAGE_SHIFT;
>> >> #else
>> >> -#define HPAGE_SHIFT PAGE_SHIFT
>> >> +#define HPAGE_SHIFT PMD_SHIFT
>> >
>> > That looks like it could break everything except the 64k page size
>> > 64-bit base.
>>
>> How about
>
> It seems very dubious to me to have transparent hugepages enabled
> without explicit hugepages in the first place.
>
IMHO once we have THP, we will not be using explicit hugepages unless we
want 16GB pages.
-aneesh
WARNING: multiple messages have this Message-ID (diff)
From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
To: David Gibson <dwg@au1.ibm.com>
Cc: paulus@samba.org, linuxppc-dev@lists.ozlabs.org, linux-mm@kvack.org
Subject: Re: [PATCH -V5 17/25] powerpc/THP: Implement transparent hugepages for ppc64
Date: Fri, 12 Apr 2013 10:36:58 +0530 [thread overview]
Message-ID: <8761zsmj65.fsf@linux.vnet.ibm.com> (raw)
In-Reply-To: <20130412005135.GA5065@truffula.fritz.box>
David Gibson <dwg@au1.ibm.com> writes:
> On Thu, Apr 11, 2013 at 01:10:29PM +0530, Aneesh Kumar K.V wrote:
>> David Gibson <dwg@au1.ibm.com> writes:
>>
>> > On Thu, Apr 04, 2013 at 11:27:55AM +0530, Aneesh Kumar K.V wrote:
>> >> From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
>> >>
>> >> We now have pmd entries covering to 16MB range. To implement THP on powerpc,
>> >> we double the size of PMD. The second half is used to deposit the pgtable (PTE page).
>> >> We also use the depoisted PTE page for tracking the HPTE information. The information
>> >> include [ secondary group | 3 bit hidx | valid ]. We use one byte per each HPTE entry.
>> >> With 16MB hugepage and 64K HPTE we need 256 entries and with 4K HPTE we need
>> >> 4096 entries. Both will fit in a 4K PTE page.
>> >>
>> >> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
>> >> ---
>> >> arch/powerpc/include/asm/page.h | 2 +-
>> >> arch/powerpc/include/asm/pgtable-ppc64-64k.h | 3 +-
>> >> arch/powerpc/include/asm/pgtable-ppc64.h | 2 +-
>> >> arch/powerpc/include/asm/pgtable.h | 240 ++++++++++++++++++++
>> >> arch/powerpc/mm/pgtable.c | 314 ++++++++++++++++++++++++++
>> >> arch/powerpc/mm/pgtable_64.c | 13 ++
>> >> arch/powerpc/platforms/Kconfig.cputype | 1 +
>> >> 7 files changed, 572 insertions(+), 3 deletions(-)
>> >>
>> >> diff --git a/arch/powerpc/include/asm/page.h b/arch/powerpc/include/asm/page.h
>> >> index 38e7ff6..b927447 100644
>> >> --- a/arch/powerpc/include/asm/page.h
>> >> +++ b/arch/powerpc/include/asm/page.h
>> >> @@ -40,7 +40,7 @@
>> >> #ifdef CONFIG_HUGETLB_PAGE
>> >> extern unsigned int HPAGE_SHIFT;
>> >> #else
>> >> -#define HPAGE_SHIFT PAGE_SHIFT
>> >> +#define HPAGE_SHIFT PMD_SHIFT
>> >
>> > That looks like it could break everything except the 64k page size
>> > 64-bit base.
>>
>> How about
>
> It seems very dubious to me to have transparent hugepages enabled
> without explicit hugepages in the first place.
>
IMHO once we have THP, we will not be using explicit hugepages unless we
want 16GB pages.
-aneesh
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2013-04-12 5:07 UTC|newest]
Thread overview: 146+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-04-04 5:57 [PATCH -V5 00/25] THP support for PPC64 Aneesh Kumar K.V
2013-04-04 5:57 ` Aneesh Kumar K.V
2013-04-04 5:57 ` [PATCH -V5 01/25] powerpc: Use signed formatting when printing error Aneesh Kumar K.V
2013-04-04 5:57 ` Aneesh Kumar K.V
2013-04-04 5:57 ` [PATCH -V5 02/25] powerpc: Save DAR and DSISR in pt_regs on MCE Aneesh Kumar K.V
2013-04-04 5:57 ` Aneesh Kumar K.V
2013-04-04 5:57 ` [PATCH -V5 03/25] powerpc: Don't hard code the size of pte page Aneesh Kumar K.V
2013-04-04 5:57 ` Aneesh Kumar K.V
2013-04-04 5:57 ` [PATCH -V5 04/25] powerpc: Reduce the PTE_INDEX_SIZE Aneesh Kumar K.V
2013-04-04 5:57 ` Aneesh Kumar K.V
2013-04-11 7:10 ` David Gibson
2013-04-11 7:10 ` David Gibson
2013-04-04 5:57 ` [PATCH -V5 05/25] powerpc: Move the pte free routines from common header Aneesh Kumar K.V
2013-04-04 5:57 ` Aneesh Kumar K.V
2013-04-04 5:57 ` [PATCH -V5 06/25] powerpc: Reduce PTE table memory wastage Aneesh Kumar K.V
2013-04-04 5:57 ` Aneesh Kumar K.V
2013-04-10 4:46 ` David Gibson
2013-04-10 4:46 ` David Gibson
2013-04-10 6:29 ` Aneesh Kumar K.V
2013-04-10 6:29 ` Aneesh Kumar K.V
2013-04-10 7:04 ` David Gibson
2013-04-10 7:04 ` David Gibson
2013-04-10 7:53 ` Aneesh Kumar K.V
2013-04-10 7:53 ` Aneesh Kumar K.V
2013-04-10 17:47 ` Aneesh Kumar K.V
2013-04-10 17:47 ` Aneesh Kumar K.V
2013-04-11 1:20 ` David Gibson
2013-04-11 1:20 ` David Gibson
2013-04-11 1:12 ` David Gibson
2013-04-11 1:12 ` David Gibson
2013-04-10 7:14 ` Michael Ellerman
2013-04-10 7:14 ` Michael Ellerman
2013-04-10 7:54 ` Aneesh Kumar K.V
2013-04-10 7:54 ` Aneesh Kumar K.V
2013-04-10 8:52 ` Aneesh Kumar K.V
2013-04-10 8:52 ` Aneesh Kumar K.V
2013-04-04 5:57 ` [PATCH -V5 07/25] powerpc: Use encode avpn where we need only avpn values Aneesh Kumar K.V
2013-04-04 5:57 ` Aneesh Kumar K.V
2013-04-04 5:57 ` [PATCH -V5 08/25] powerpc: Decode the pte-lp-encoding bits correctly Aneesh Kumar K.V
2013-04-04 5:57 ` Aneesh Kumar K.V
2013-04-10 7:19 ` David Gibson
2013-04-10 7:19 ` David Gibson
2013-04-10 8:11 ` Aneesh Kumar K.V
2013-04-10 8:11 ` Aneesh Kumar K.V
2013-04-10 17:49 ` Aneesh Kumar K.V
2013-04-10 17:49 ` Aneesh Kumar K.V
2013-04-11 1:28 ` David Gibson
2013-04-11 1:28 ` David Gibson
2013-04-04 5:57 ` [PATCH -V5 09/25] powerpc: Fix hpte_decode to use the correct decoding for page sizes Aneesh Kumar K.V
2013-04-04 5:57 ` Aneesh Kumar K.V
2013-04-11 3:20 ` David Gibson
2013-04-11 3:20 ` David Gibson
2013-04-04 5:57 ` [PATCH -V5 10/25] powerpc: print both base and actual page size on hash failure Aneesh Kumar K.V
2013-04-04 5:57 ` Aneesh Kumar K.V
2013-04-11 3:21 ` David Gibson
2013-04-11 3:21 ` David Gibson
2013-04-04 5:57 ` [PATCH -V5 11/25] powerpc: Print page size info during boot Aneesh Kumar K.V
2013-04-04 5:57 ` Aneesh Kumar K.V
2013-04-04 5:57 ` [PATCH -V5 12/25] powerpc: Return all the valid pte ecndoing in KVM_PPC_GET_SMMU_INFO ioctl Aneesh Kumar K.V
2013-04-04 5:57 ` Aneesh Kumar K.V
2013-04-11 3:24 ` David Gibson
2013-04-11 3:24 ` David Gibson
2013-04-11 5:11 ` Aneesh Kumar K.V
2013-04-11 5:11 ` Aneesh Kumar K.V
2013-04-11 5:57 ` David Gibson
2013-04-11 5:57 ` David Gibson
2013-04-04 5:57 ` [PATCH -V5 13/25] powerpc: Update tlbie/tlbiel as per ISA doc Aneesh Kumar K.V
2013-04-04 5:57 ` Aneesh Kumar K.V
2013-04-11 3:30 ` David Gibson
2013-04-11 3:30 ` David Gibson
2013-04-11 5:20 ` Aneesh Kumar K.V
2013-04-11 5:20 ` Aneesh Kumar K.V
2013-04-11 6:16 ` David Gibson
2013-04-11 6:16 ` David Gibson
2013-04-11 6:36 ` Aneesh Kumar K.V
2013-04-11 6:36 ` Aneesh Kumar K.V
2013-04-04 5:57 ` [PATCH -V5 14/25] mm/THP: HPAGE_SHIFT is not a #define on some arch Aneesh Kumar K.V
2013-04-04 5:57 ` Aneesh Kumar K.V
2013-04-11 3:36 ` David Gibson
2013-04-11 3:36 ` David Gibson
2013-04-04 5:57 ` [PATCH -V5 15/25] mm/THP: Add pmd args to pgtable deposit and withdraw APIs Aneesh Kumar K.V
2013-04-04 5:57 ` Aneesh Kumar K.V
2013-04-11 3:40 ` David Gibson
2013-04-11 3:40 ` David Gibson
2013-04-04 5:57 ` [PATCH -V5 16/25] mm/THP: withdraw the pgtable after pmdp related operations Aneesh Kumar K.V
2013-04-04 5:57 ` Aneesh Kumar K.V
2013-04-04 5:57 ` [PATCH -V5 17/25] powerpc/THP: Implement transparent hugepages for ppc64 Aneesh Kumar K.V
2013-04-04 5:57 ` Aneesh Kumar K.V
2013-04-11 5:38 ` David Gibson
2013-04-11 5:38 ` David Gibson
2013-04-11 7:40 ` Aneesh Kumar K.V
2013-04-11 7:40 ` Aneesh Kumar K.V
2013-04-12 0:51 ` David Gibson
2013-04-12 0:51 ` David Gibson
2013-04-12 5:06 ` Aneesh Kumar K.V [this message]
2013-04-12 5:06 ` Aneesh Kumar K.V
2013-04-12 5:39 ` David Gibson
2013-04-12 5:39 ` David Gibson
2013-04-04 5:57 ` [PATCH -V5 18/25] powerpc/THP: Double the PMD table size for THP Aneesh Kumar K.V
2013-04-04 5:57 ` Aneesh Kumar K.V
2013-04-11 6:18 ` David Gibson
2013-04-11 6:18 ` David Gibson
2013-04-04 5:57 ` [PATCH -V5 19/25] powerpc/THP: Differentiate THP PMD entries from HUGETLB PMD entries Aneesh Kumar K.V
2013-04-04 5:57 ` Aneesh Kumar K.V
2013-04-10 7:21 ` Michael Ellerman
2013-04-10 7:21 ` Michael Ellerman
2013-04-10 18:26 ` Aneesh Kumar K.V
2013-04-10 18:26 ` Aneesh Kumar K.V
2013-04-12 1:28 ` David Gibson
2013-04-12 1:28 ` David Gibson
2013-04-04 5:57 ` [PATCH -V5 20/25] powerpc/THP: Add code to handle HPTE faults for large pages Aneesh Kumar K.V
2013-04-04 5:57 ` Aneesh Kumar K.V
2013-04-12 4:01 ` David Gibson
2013-04-12 4:01 ` David Gibson
2013-04-04 5:57 ` [PATCH -V5 21/25] powerpc: Handle hugepage in perf callchain Aneesh Kumar K.V
2013-04-04 5:57 ` Aneesh Kumar K.V
2013-04-12 1:34 ` David Gibson
2013-04-12 1:34 ` David Gibson
2013-04-12 5:05 ` Aneesh Kumar K.V
2013-04-12 5:05 ` Aneesh Kumar K.V
2013-04-04 5:58 ` [PATCH -V5 22/25] powerpc/THP: get_user_pages_fast changes Aneesh Kumar K.V
2013-04-04 5:58 ` Aneesh Kumar K.V
2013-04-12 1:41 ` David Gibson
2013-04-12 1:41 ` David Gibson
2013-04-04 5:58 ` [PATCH -V5 23/25] powerpc/THP: Enable THP on PPC64 Aneesh Kumar K.V
2013-04-04 5:58 ` Aneesh Kumar K.V
2013-04-04 5:58 ` [PATCH -V5 24/25] powerpc: Optimize hugepage invalidate Aneesh Kumar K.V
2013-04-04 5:58 ` Aneesh Kumar K.V
2013-04-12 4:21 ` David Gibson
2013-04-12 4:21 ` David Gibson
2013-04-14 10:02 ` Aneesh Kumar K.V
2013-04-14 10:02 ` Aneesh Kumar K.V
2013-04-15 1:18 ` David Gibson
2013-04-15 1:18 ` David Gibson
2013-04-04 5:58 ` [PATCH -V5 25/25] powerpc: Handle hugepages in kvm Aneesh Kumar K.V
2013-04-04 5:58 ` Aneesh Kumar K.V
2013-04-04 6:00 ` [PATCH -V5 00/25] THP support for PPC64 Simon Jeons
2013-04-04 6:00 ` Simon Jeons
2013-04-04 6:10 ` Aneesh Kumar K.V
2013-04-04 6:10 ` Aneesh Kumar K.V
2013-04-04 6:14 ` Simon Jeons
2013-04-04 6:14 ` Simon Jeons
2013-04-04 8:38 ` Aneesh Kumar K.V
2013-04-04 8:38 ` Aneesh Kumar K.V
2013-04-19 1:55 ` Simon Jeons
2013-04-19 1:55 ` Simon Jeons
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=8761zsmj65.fsf@linux.vnet.ibm.com \
--to=aneesh.kumar@linux.vnet.ibm.com \
--cc=dwg@au1.ibm.com \
--cc=linux-mm@kvack.org \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=paulus@samba.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.