[PATCH 0/3] Hugetlbfs support for riscv

Alexandre Ghiti
2018-12-10T06:22:23Z

This series introduces hugetlbfs support for both riscv 32/64. Riscv32
is architecturally limited to huge pages of size 4MB whereas riscv64 has
2MB/1G huge pages support. Transparent huge page support is not
implemented here, I will submit another series later.

As stated in "The RISC-V Instruction Set Manual, Volume II: Privileged
Architecture", riscv page table entries are marked as non-leaf entries
as soon as at least one of the R/W/X bit set:

- pmd_huge/pud_huge check if one of those bits are set,
- pte_mkhuge simply returns the same pte value and does not set any of
the R/W/X bits

CMA or (MEMORY_ISOLATION && COMPACTION) must be enabled so that boot
reserved gigantic pages can be freed: indeed, one can reduce the number
of huge pages by calling free_gigantic_pages which in turn calls
free_contig_range, defined only with those configs defined.
However I don't see any strong dependency between free_contig_range
and those configs, maybe we could allow hugetlbfs users to free boot
reserved hugepages without those configs activated, I will propose
something if Mike Kravetz agrees.

For the below validation, I activated CMA so that tests like counters do
not fail when freeing pages.
This series was validated using libhugetlbfs testsuite ported to riscv64
without linker script support.
(https://github.com/AlexGhiti/libhugetlbfs.git, branch dev/alex/riscv).

- libhugetlbfs testsuite on riscv64/2M:
- brk_near_huge triggers an assert in malloc.c, does not on x86.

- libhugetlbfs testsuite on riscv64/1G:
- brk_near_huge triggers an assert in malloc.c, does not on x86.
- mmap-gettest, mmap-cow: testsuite passes the number of default free
pages as parameters and then fails for 1G which is not the default.
Otherwise succeeds when given the right number of pages.
- map_high_truncate_2 fails on x86 too: 0x60000000 is not 1G aligned
and fails at line 694 of fs/hugetlbfs/inode.c.
- heapshrink on 1G fails on x86 too, not investigated.
- counters.sh on 1G fails on x86 too: alloc_surplus_huge_page returns
NULL in case of gigantic pages.
- icache-hygiene succeeds after patch #3 of this series which lowers
the base address of mmap.
- fallocate_stress.sh on 1G never ends, on x86 too, not investigated.

- libhugetlbfs testsuite on riscv32/4M: kernel build passes, lacks
libhugetlbfs support for 32bits.

* Output for riscv64 2M and 1G libhugetbfs testsuite:

zero_filesize_segment (2M: 64):
zero_filesize_segment (1024M: 64):
test_root (2M: 64): PASS
test_root (1024M: 64): PASS
meminfo_nohuge (2M: 64): PASS
meminfo_nohuge (1024M: 64): PASS
gethugepagesize (2M: 64): PASS
gethugepagesize (1024M: 64): PASS
gethugepagesizes (2M: 64): PASS
gethugepagesizes (1024M: 64): PASS
HUGETLB_VERBOSE=1 empty_mounts (2M: 64): PASS
HUGETLB_VERBOSE=1 empty_mounts (1024M: 64): PASS
HUGETLB_VERBOSE=1 large_mounts (2M: 64): PASS
HUGETLB_VERBOSE=1 large_mounts (1024M: 64): PASS
find_path (2M: 64): PASS
find_path (1024M: 64): PASS
unlinked_fd (2M: 64): PASS
unlinked_fd (1024M: 64): PASS
readback (2M: 64): PASS
readback (1024M: 64): PASS
truncate (2M: 64): PASS
truncate (1024M: 64): PASS
shared (2M: 64): PASS
shared (1024M: 64): PASS
mprotect (2M: 64): PASS
mprotect (1024M: 64): PASS
mlock (2M: 64): PASS
mlock (1024M: 64): PASS
misalign (2M: 64): PASS
misalign (1024M: 64): PASS
fallocate_basic.sh (2M: 64): PASS
fallocate_basic.sh (1024M: 64): PASS
fallocate_align.sh (2M: 64): PASS
fallocate_align.sh (1024M: 64): PASS
ptrace-write-hugepage (2M: 64): PASS
ptrace-write-hugepage (1024M: 64): PASS
icache-hygiene (2M: 64): PASS
icache-hygiene (1024M: 64): PASS
slbpacaflush (2M: 64): PASS (inconclusive)
slbpacaflush (1024M: 64): PASS (inconclusive)
straddle_4GB_static (2M: 64): PASS
straddle_4GB_static (1024M: 64): PASS
huge_at_4GB_normal_below_static (2M: 64): PASS
huge_at_4GB_normal_below_static (1024M: 64): PASS
huge_below_4GB_normal_above_static (2M: 64): PASS
huge_below_4GB_normal_above_static (1024M: 64): PASS
map_high_truncate_2 (2M: 64): PASS
map_high_truncate_2 (1024M: 64): FAIL ftruncate(): Invalid
argument
misaligned_offset (2M: 64): PASS (inconclusive)
misaligned_offset (1024M: 64): PASS (inconclusive)
truncate_above_4GB (2M: 64): PASS
truncate_above_4GB (1024M: 64): PASS
brk_near_huge (2M: 64): brk_near_huge: malloc.c:2385: sysmalloc:
Assertion `(old_top == initial_top (av) && old_size == 0) || ((unsigned
long) (old_size) >= MINSIZE && prev_inuse (old_top) && ((unsigned long)
old_end & (pagesize - 1)) == 0)' failed.
brk_near_huge (1024M: 64): brk_near_huge: malloc.c:2385: sysmalloc:
Assertion `(old_top == initial_top (av) && old_size == 0) || ((unsigned
long) (old_size) >= MINSIZE && prev_inuse (old_top) && ((unsigned long)
old_end & (pagesize - 1)) == 0)' failed.
task-size-overrun (2M: 64): PASS
task-size-overrun (1024M: 64): PASS
stack_grow_into_huge (2M: 64): PASS
stack_grow_into_huge (1024M: 64): PASS
corrupt-by-cow-opt (2M: 64): PASS
corrupt-by-cow-opt (1024M: 64): PASS
noresv-preserve-resv-page (2M: 64): PASS
noresv-preserve-resv-page (1024M: 64): PASS
noresv-regarded-as-resv (2M: 64): PASS
noresv-regarded-as-resv (1024M: 64): PASS
readahead_reserve.sh (2M: 64): PASS
readahead_reserve.sh (1024M: 64): PASS
madvise_reserve.sh (2M: 64): PASS
madvise_reserve.sh (1024M: 64): PASS
fadvise_reserve.sh (2M: 64): PASS
fadvise_reserve.sh (1024M: 64): PASS
mremap-expand-slice-collision.sh (2M: 64): PASS
mremap-expand-slice-collision.sh (1024M: 64): PASS
mremap-fixed-normal-near-huge.sh (2M: 64): PASS
mremap-fixed-normal-near-huge.sh (1024M: 64): PASS
mremap-fixed-huge-near-normal.sh (2M: 64): PASS
mremap-fixed-huge-near-normal.sh (1024M: 64): PASS
set shmmax limit to 67108864
shm-perms (2M: 64): PASS
private (2M: 64): PASS
private (1024M: 64): PASS
fork-cow (2M: 64): PASS
fork-cow (1024M: 64): PASS
direct (2M: 64): Bad configuration: Failed to open direct-IO
file: Invalid argument
direct (1024M: 64): Bad configuration: Failed to open direct-IO
file: File exists
malloc (2M: 64): PASS
malloc (1024M: 64): PASS
LD_PRELOAD=libhugetlbfs.so HUGETLB_MORECORE=yes malloc (2M: 64):
PASS
LD_PRELOAD=libhugetlbfs.so HUGETLB_MORECORE=yes malloc (1024M: 64):
PASS
LD_PRELOAD=libhugetlbfs.so HUGETLB_RESTRICT_EXE=unknown:none
HUGETLB_MORECORE=yes malloc (2M: 64): PASS
LD_PRELOAD=libhugetlbfs.so HUGETLB_RESTRICT_EXE=unknown:none
HUGETLB_MORECORE=yes malloc (1024M: 64):PASS
LD_PRELOAD=libhugetlbfs.so HUGETLB_RESTRICT_EXE=unknown:malloc
HUGETLB_MORECORE=yes malloc (2M: 64): PASS
LD_PRELOAD=libhugetlbfs.so HUGETLB_RESTRICT_EXE=unknown:malloc
HUGETLB_MORECORE=yes malloc (1024M: 64): PASS
malloc_manysmall (2M: 64): PASS
malloc_manysmall (1024M: 64): PASS
LD_PRELOAD=libhugetlbfs.so HUGETLB_MORECORE=yes malloc_manysmall (2M:
64): PASS
LD_PRELOAD=libhugetlbfs.so HUGETLB_MORECORE=yes malloc_manysmall (1024M:
64): PASS
heapshrink (2M: 64): PASS
heapshrink (1024M: 64): PASS
LD_PRELOAD=libheapshrink.so heapshrink (2M: 64): PASS
LD_PRELOAD=libheapshrink.so heapshrink (1024M: 64): PASS
LD_PRELOAD=libhugetlbfs.so HUGETLB_MORECORE=yes heapshrink (2M: 64):
PASS
LD_PRELOAD=libhugetlbfs.so HUGETLB_MORECORE=yes heapshrink (1024M: 64):
PASS
LD_PRELOAD=libhugetlbfs.so libheapshrink.so HUGETLB_MORECORE=yes
heapshrink (2M: 64): PASS
LD_PRELOAD=libhugetlbfs.so libheapshrink.so HUGETLB_MORECORE=yes
heapshrink (1024M: 64): PASS
LD_PRELOAD=libheapshrink.so HUGETLB_MORECORE_SHRINK=yes
HUGETLB_MORECORE=yes heapshrink (2M: 64): PASS (inconclusive)
LD_PRELOAD=libheapshrink.so HUGETLB_MORECORE_SHRINK=yes
HUGETLB_MORECORE=yes heapshrink (1024M: 64): PASS (inconclusive)
LD_PRELOAD=libhugetlbfs.so libheapshrink.so HUGETLB_MORECORE_SHRINK=yes
HUGETLB_MORECORE=yes heapshrink (2M: 64): PASS
LD_PRELOAD=libhugetlbfs.so libheapshrink.so HUGETLB_MORECORE_SHRINK=yes
HUGETLB_MORECORE=yes heapshrink (1024M: 64): FAIL Heap did not
shrink
HUGETLB_VERBOSE=1 HUGETLB_MORECORE=yes heap-overflow (2M: 64): PASS
HUGETLB_VERBOSE=1 HUGETLB_MORECORE=yes heap-overflow (1024M: 64):
PASS
HUGETLB_VERBOSE=0 linkhuge_nofd (2M: 64):
HUGETLB_VERBOSE=0 linkhuge_nofd (1024M: 64):
LD_PRELOAD=libhugetlbfs.so HUGETLB_VERBOSE=0 linkhuge_nofd (2M: 64):
LD_PRELOAD=libhugetlbfs.so HUGETLB_VERBOSE=0 linkhuge_nofd (1024M: 64):
linkhuge (2M: 64):
linkhuge (1024M: 64):
LD_PRELOAD=libhugetlbfs.so linkhuge (2M: 64):
LD_PRELOAD=libhugetlbfs.so linkhuge (1024M: 64):
linkhuge_rw (2M: 64):
linkhuge_rw (1024M: 64):
HUGETLB_ELFMAP=R linkhuge_rw (2M: 64):
HUGETLB_ELFMAP=R linkhuge_rw (1024M: 64):
HUGETLB_ELFMAP=W linkhuge_rw (2M: 64):
HUGETLB_ELFMAP=W linkhuge_rw (1024M: 64):
HUGETLB_ELFMAP=RW linkhuge_rw (2M: 64):
HUGETLB_ELFMAP=RW linkhuge_rw (1024M: 64):
HUGETLB_ELFMAP=no linkhuge_rw (2M: 64):
HUGETLB_ELFMAP=no linkhuge_rw (1024M: 64):
HUGETLB_ELFMAP=R HUGETLB_MINIMAL_COPY=no linkhuge_rw (2M: 64):
HUGETLB_ELFMAP=R HUGETLB_MINIMAL_COPY=no linkhuge_rw (1024M: 64):
HUGETLB_ELFMAP=W HUGETLB_MINIMAL_COPY=no linkhuge_rw (2M: 64):
HUGETLB_ELFMAP=W HUGETLB_MINIMAL_COPY=no linkhuge_rw (1024M: 64):
HUGETLB_ELFMAP=RW HUGETLB_MINIMAL_COPY=no linkhuge_rw (2M: 64):
HUGETLB_ELFMAP=RW HUGETLB_MINIMAL_COPY=no linkhuge_rw (1024M: 64):
HUGETLB_SHARE=0 HUGETLB_ELFMAP=R linkhuge_rw (2M: 64):
HUGETLB_SHARE=0 HUGETLB_ELFMAP=R linkhuge_rw (1024M: 64):
HUGETLB_SHARE=1 HUGETLB_ELFMAP=R linkhuge_rw (2M: 64):
HUGETLB_SHARE=1 HUGETLB_ELFMAP=R linkhuge_rw (1024M: 64):
HUGETLB_SHARE=0 HUGETLB_ELFMAP=W linkhuge_rw (2M: 64):
HUGETLB_SHARE=0 HUGETLB_ELFMAP=W linkhuge_rw (1024M: 64):
HUGETLB_SHARE=1 HUGETLB_ELFMAP=W linkhuge_rw (2M: 64):
HUGETLB_SHARE=1 HUGETLB_ELFMAP=W linkhuge_rw (1024M: 64):
HUGETLB_SHARE=0 HUGETLB_ELFMAP=RW linkhuge_rw (2M: 64):
HUGETLB_SHARE=0 HUGETLB_ELFMAP=RW linkhuge_rw (1024M: 64):
HUGETLB_SHARE=1 HUGETLB_ELFMAP=RW linkhuge_rw (2M: 64):
HUGETLB_SHARE=1 HUGETLB_ELFMAP=RW linkhuge_rw (1024M: 64):
chunk-overcommit (2M: 64): PASS
chunk-overcommit (1024M: 64): PASS
alloc-instantiate-race shared (2M: 64): PASS
alloc-instantiate-race shared (1024M: 64): PASS
alloc-instantiate-race private (2M: 64): PASS
alloc-instantiate-race private (1024M: 64): PASS
truncate_reserve_wraparound (2M: 64): PASS
truncate_reserve_wraparound (1024M: 64): PASS
truncate_sigbus_versus_oom (2M: 64): PASS
truncate_sigbus_versus_oom (1024M: 64): PASS
get_huge_pages (2M: 64): PASS
get_huge_pages (1024M: 64): PASS
shmoverride_linked (2M: 64): PASS
HUGETLB_SHM=yes shmoverride_linked (2M: 64): PASS
shmoverride_linked_static (2M: 64):
HUGETLB_SHM=yes shmoverride_linked_static (2M: 64):
LD_PRELOAD=libhugetlbfs.so shmoverride_unlinked (2M: 64): PASS
LD_PRELOAD=libhugetlbfs.so HUGETLB_SHM=yes shmoverride_unlinked (2M:
64): PASS
quota.sh (2M: 64): PASS
quota.sh (1024M: 64): PASS
counters.sh (2M: 64): PASS
counters.sh (1024M: 64): FAIL mmap failed: Invalid argument
mmap-gettest 10 35 (2M: 64): PASS
mmap-gettest 10 35 (1024M: 64): FAIL Failed to mmap the hugetlb file:
Cannot allocate memory
mmap-cow 34 35 (2M: 64): PASS
mmap-cow 34 35 (1024M: 64): FAIL Thread 15 (pid=514) failed
set shmmax limit to 73400320
shm-fork 10 17 (2M: 64): PASS
set shmmax limit to 73400320
shm-fork 10 35 (2M: 64): PASS
set shmmax limit to 73400320
shm-getraw 35 /dev/full (2M: 64): PASS
fallocate_stress.sh (2M: 64): libgcc_s.so.1 must be installed for
pthread_cancel to work
fallocate_stress.sh (1024M: 64):
********** TEST SUMMARY
* 2M 1024M
* 32-bit 64-bit 32-bit 64-bit
* Total testcases: 0 93 0 83
* Skipped: 0 0 0 0
* PASS: 0 69 0 56
* FAIL: 0 0 0 5
* Killed by signal: 0 1 0 2
* Bad configuration: 0 1 0 1
* Expected FAIL: 0 0 0 0
* Unexpected PASS: 0 0 0 0
* Test not present: 0 21 0 19
* Strange test result: 0 1 0 0
**********

Alexandre Ghiti (3):
riscv: Introduce huge page support for 32/64bit kernel
riscv: Fix wrong comment about task size for riscv64
riscv: Adjust mmap base address at a third of task size

arch/riscv/Kconfig | 7 +++++++
arch/riscv/include/asm/hugetlb.h | 22 ++++++++++++++++++++++
arch/riscv/include/asm/page.h | 10 ++++++++++
arch/riscv/include/asm/pgtable.h | 8 ++++++--
arch/riscv/include/asm/processor.h | 2 +-
arch/riscv/mm/Makefile | 2 ++
arch/riscv/mm/hugetlbpage.c | 36 ++++++++++++++++++++++++++++++++++++
7 files changed, 84 insertions(+), 3 deletions(-)
create mode 100644 arch/riscv/include/asm/hugetlb.h
create mode 100644 arch/riscv/mm/hugetlbpage.c

--
2.16.2