Hi All,
This patch series attempt to update book3s 64 linux page table format to
make it more flexible. Our current pte format is very restrictive and we
overload multiple pte bits. This is due to the non-availability of free bits
in pte_t. We use pte_t to track the validity of 4K subpages. This patch
series free up pte_t of 11 bits by moving 4K subpage tracking to the
lower half of PTE page. The pte format is updated such that we have a
better method for identifying a pte entry at pmd level. This will also enable
us to implement hugetlb migration(not yet done in this series).
Before making the changes to the pte format, I am splitting the
pte header definition such that we now have the below layout for headers
book3s
32
hash.h pgtable.h
64
hash.h pgtable.h hash-4k.h hash-64k.h
booke
32
pgtable.h pte-40x.h pte-44x.h pte-8xx.h pte-fsl-booke.h
64
pgtable-4k.h pgtable-64k.h pgtable.h
I have done the header split such that booke headers and modified to the
minimum so as to avoid
causing breakage in booke.
The patch series can also be found at
https://github.com/kvaneesh/linux.git book3s-pte-format
https://github.com/kvaneesh/linux/commits/book3s-pte-format
Performance numbers with and without patch series.
Path length __hash_page_4k
with patch: 196
without patch: 142
Path length __hash_page_64k
with patch: 219
without patch: 154
But even if we have a path lengh increase of around 50 instructions. We don't
see
the impact when running workload. I tried the kernelbuild test.
With THP enabled (which is default) we see an improvement. I haven't fully
looked at
the reason. This could be due to reduced contention of ptl lock.
__hash_thp_page is
already a C code.
make -j64 vmlinux modules
With fix:
---------
real 1m35.509s
user 56m8.565s
sys 4m34.973s
real 1m32.174s
user 57m2.336s
sys 4m39.142s
Without fix:
---------------
real 1m37.703s
user 58m50.783s
sys 7m52.440s
real 1m37.890s
user 57m55.445s
sys 7m50.501s
THP disabled:
make -j64 vmlinux modules
With fix:
---------
real 1m37.197s
user 58m28.672s
sys 7m58.188s
real 1m44.638s
user 58m37.551s
sys 7m53.960s
Without fix:
------------
real 1m41.224s
user 58m46.944s
sys 7m49.714s
real 1m42.585s
user 59m14.019s
sys 7m52.714s
Changes from V1:
1) Build fix with STRICT_MM_TYPES enabled
2) pte_mkwrite fix for nohash
3) rebase to latest linus tree.
Aneesh Kumar K.V (31):
powerpc/mm: move pte headers to book3s directory
powerpc/mm: move pte headers to book3s directory (part 2)
powerpc/mm: make a separate copy for book3s
powerpc/mm: make a separate copy for book3s (part 2)
powerpc/mm: Move hash specific pte width and other defines to book3s
powerpc/mm: Delete booke bits from book3s
powerpc/mm: Don't have generic headers introduce functions touching
pte bits
powerpc/mm: Drop pte-common.h from BOOK3S 64
powerpc/mm: Don't use pte_val as lvalue
powerpc/mm: Don't use pmd_val,pud_val and pgd_val as lvalue
powerpc/mm: Move hash64 PTE bits from book3s/64/pgtable.h to hash.h
powerpc/mm: Move PTE bits from generic functions to hash64 functions.
powerpc/booke: Move booke headers (part 1)
powerpc/booke: Move booke headers (part 2)
powerpc/booke: Move booke headers (part 3)
powerpc/booke: Move booke headers (part 4)
powerpc/booke: Move booke headers (part 5)
powerpc/mm: Increase the pte frag size.
powerpc/mm: Convert 4k hash insert to C
powerpc/mm: update __real_pte to take address as argument
powerpc/mm: make pte page hash index slot 8 bits
powerpc/mm: Don't track subpage valid bit in pte_t
powerpc/mm: Increase the width of #define
powerpc/mm: Convert __hash_page_64K to C
powerpc/mm: Convert 4k insert from asm to C
powerpc/mm: Remove the dependency on pte bit position in asm code
powerpc/mm: Add helper for converting pte bit to hpte bits
powerpc/mm: Move WIMG update to helper.
powerpc/mm: Move hugetlb related headers
powerpc/mm: Move THP headers around
powerpc/mm: Add a _PAGE_PTE bit
.../include/asm/{pte-hash32.h => book3s/32/hash.h} | 6 +-
arch/powerpc/include/asm/book3s/32/pgtable.h | 476 ++++++++++
arch/powerpc/include/asm/book3s/64/hash-4k.h | 132 +++
arch/powerpc/include/asm/book3s/64/hash-64k.h | 285 ++++++
arch/powerpc/include/asm/book3s/64/hash.h | 513 ++++++++++
arch/powerpc/include/asm/book3s/64/pgtable.h | 266 ++++++
arch/powerpc/include/asm/book3s/pgtable.h | 29 +
arch/powerpc/include/asm/mmu-hash64.h | 2 +-
.../asm/{pgtable-ppc32.h => nohash/32/pgtable.h} | 25 +-
arch/powerpc/include/asm/{ => nohash/32}/pte-40x.h | 6 +-
arch/powerpc/include/asm/{ => nohash/32}/pte-44x.h | 6 +-
arch/powerpc/include/asm/{ => nohash/32}/pte-8xx.h | 6 +-
.../include/asm/{ => nohash/32}/pte-fsl-booke.h | 6 +-
.../{pgtable-ppc64-4k.h => nohash/64/pgtable-4k.h} | 12 +-
.../64/pgtable-64k.h} | 6 +-
.../asm/{pgtable-ppc64.h => nohash/64/pgtable.h} | 299 +-----
arch/powerpc/include/asm/nohash/pgtable.h | 252 +++++
arch/powerpc/include/asm/{ => nohash}/pte-book3e.h | 6 +-
arch/powerpc/include/asm/page.h | 75 +-
arch/powerpc/include/asm/pgalloc-32.h | 34 +-
arch/powerpc/include/asm/pgalloc-64.h | 29 +-
arch/powerpc/include/asm/pgtable.h | 200 +---
arch/powerpc/include/asm/pte-common.h | 5 +
arch/powerpc/include/asm/pte-hash64-4k.h | 17 -
arch/powerpc/include/asm/pte-hash64-64k.h | 102 --
arch/powerpc/include/asm/pte-hash64.h | 54 --
arch/powerpc/kernel/exceptions-64s.S | 16 +-
arch/powerpc/mm/Makefile | 9 +-
arch/powerpc/mm/hash64_4k.c | 123 +++
arch/powerpc/mm/hash64_64k.c | 313 ++++++
arch/powerpc/mm/hash_low_64.S | 1003 --------------------
arch/powerpc/mm/hash_native_64.c | 10 +
arch/powerpc/mm/hash_utils_64.c | 105 +-
arch/powerpc/mm/hugepage-hash64.c | 20 +-
arch/powerpc/mm/hugetlbpage-hash64.c | 15 +-
arch/powerpc/mm/hugetlbpage.c | 57 +-
arch/powerpc/mm/pgtable.c | 4 +
arch/powerpc/mm/pgtable_64.c | 28 +-
arch/powerpc/mm/tlb_hash64.c | 2 +-
arch/powerpc/platforms/pseries/lpar.c | 10 +
40 files changed, 2670 insertions(+), 1894 deletions(-)
rename arch/powerpc/include/asm/{pte-hash32.h => book3s/32/hash.h} (93%)
create mode 100644 arch/powerpc/include/asm/book3s/32/pgtable.h
create mode 100644 arch/powerpc/include/asm/book3s/64/hash-4k.h
create mode 100644 arch/powerpc/include/asm/book3s/64/hash-64k.h
create mode 100644 arch/powerpc/include/asm/book3s/64/hash.h
create mode 100644 arch/powerpc/include/asm/book3s/64/pgtable.h
create mode 100644 arch/powerpc/include/asm/book3s/pgtable.h
rename arch/powerpc/include/asm/{pgtable-ppc32.h => nohash/32/pgtable.h} (96%)
rename arch/powerpc/include/asm/{ => nohash/32}/pte-40x.h (95%)
rename arch/powerpc/include/asm/{ => nohash/32}/pte-44x.h (96%)
rename arch/powerpc/include/asm/{ => nohash/32}/pte-8xx.h (95%)
rename arch/powerpc/include/asm/{ => nohash/32}/pte-fsl-booke.h (88%)
rename arch/powerpc/include/asm/{pgtable-ppc64-4k.h => nohash/64/pgtable-4k.h}
(92%)
rename arch/powerpc/include/asm/{pgtable-ppc64-64k.h =>
nohash/64/pgtable-64k.h} (90%)
rename arch/powerpc/include/asm/{pgtable-ppc64.h => nohash/64/pgtable.h} (56%)
create mode 100644 arch/powerpc/include/asm/nohash/pgtable.h
rename arch/powerpc/include/asm/{ => nohash}/pte-book3e.h (95%)
delete mode 100644 arch/powerpc/include/asm/pte-hash64-4k.h
delete mode 100644 arch/powerpc/include/asm/pte-hash64-64k.h
delete mode 100644 arch/powerpc/include/asm/pte-hash64.h
create mode 100644 arch/powerpc/mm/hash64_4k.c
create mode 100644 arch/powerpc/mm/hash64_64k.c
delete mode 100644 arch/powerpc/mm/hash_low_64.S
--
2.5.0
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