2019-04-09 06:16:42

by Alexandre Ghiti

[permalink] [raw]
Subject: [PATCH v2 0/2] Hugetlbfs support for riscv

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

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
**********

Changes in v2:
- Merge comment fix about task size.
- Patch about mmap base address was merged separately.
- Rebased on top of linux-next where series about the capability
to free gigantic pages regardless of the configuration was merged.
- Add huge pmd sharing as suggested by Mike Kravetz.
- Gigantic page hstate is automatically created if CONTIG_ALLOC is
set, even if not explicitly asked for in command line, as suggested
by Mike.
- Replace #ifdef CONFIG_64BIT into IS_ENABLED(CONFIG_64BIT), as suggested
by Christoph Hellwig.

Alexandre Ghiti (2):
x86, arm64: Move ARCH_WANT_HUGE_PMD_SHARE config in arch/Kconfig
riscv: Introduce huge page support for 32/64bit kernel

arch/Kconfig | 3 +++
arch/arm64/Kconfig | 2 +-
arch/riscv/Kconfig | 8 ++++++
arch/riscv/include/asm/hugetlb.h | 18 +++++++++++++
arch/riscv/include/asm/page.h | 10 ++++++++
arch/riscv/include/asm/pgtable.h | 8 ++++--
arch/riscv/mm/Makefile | 2 ++
arch/riscv/mm/hugetlbpage.c | 44 ++++++++++++++++++++++++++++++++
arch/x86/Kconfig | 4 +--
9 files changed, 93 insertions(+), 6 deletions(-)
create mode 100644 arch/riscv/include/asm/hugetlb.h
create mode 100644 arch/riscv/mm/hugetlbpage.c

--
2.20.1


2019-04-09 06:19:27

by Alexandre Ghiti

[permalink] [raw]
Subject: [PATCH v2 1/2] x86, arm64: Move ARCH_WANT_HUGE_PMD_SHARE config in arch/Kconfig

ARCH_WANT_HUGE_PMD_SHARE config was declared in both architectures:
move this declaration in arch/Kconfig and make those architectures
select it.

Signed-off-by: Alexandre Ghiti <[email protected]>
---
arch/Kconfig | 3 +++
arch/arm64/Kconfig | 2 +-
arch/x86/Kconfig | 4 +---
3 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/arch/Kconfig b/arch/Kconfig
index 8c858bb133c9..273cefc6b787 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -567,6 +567,9 @@ config HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
config HAVE_ARCH_HUGE_VMAP
bool

+config ARCH_WANT_HUGE_PMD_SHARE
+ bool
+
config HAVE_ARCH_SOFT_DIRTY
bool

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 870ef86a64ed..8b7870974961 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -68,6 +68,7 @@ config ARM64
select ARCH_SUPPORTS_NUMA_BALANCING
select ARCH_WANT_COMPAT_IPC_PARSE_VERSION
select ARCH_WANT_FRAME_POINTERS
+ select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36)
select ARCH_HAS_UBSAN_SANITIZE_ALL
select ARM_AMBA
select ARM_ARCH_TIMER
@@ -885,7 +886,6 @@ config SYS_SUPPORTS_HUGETLBFS
def_bool y

config ARCH_WANT_HUGE_PMD_SHARE
- def_bool y if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36)

config ARCH_HAS_CACHE_LINE_SIZE
def_bool y
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 0f2ab09da060..fd5fc2d288be 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -82,6 +82,7 @@ config X86
select ARCH_USE_QUEUED_SPINLOCKS
select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
select ARCH_WANTS_DYNAMIC_TASK_STRUCT
+ select ARCH_WANT_HUGE_PMD_SHARE
select ARCH_WANTS_THP_SWAP if X86_64
select BUILDTIME_EXTABLE_SORT
select CLKEVT_I8253
@@ -298,9 +299,6 @@ config ARCH_HIBERNATION_POSSIBLE
config ARCH_SUSPEND_POSSIBLE
def_bool y

-config ARCH_WANT_HUGE_PMD_SHARE
- def_bool y
-
config ARCH_WANT_GENERAL_HUGETLB
def_bool y

--
2.20.1

2019-04-09 06:19:30

by Alexandre Ghiti

[permalink] [raw]
Subject: [PATCH v2 2/2] riscv: Introduce huge page support for 32/64bit kernel

This patch implements both 4MB huge page support for 32bit kernel
and 2MB/1GB huge pages support for 64bit kernel.

Signed-off-by: Alexandre Ghiti <[email protected]>
---
arch/riscv/Kconfig | 8 ++++++
arch/riscv/include/asm/hugetlb.h | 18 +++++++++++++
arch/riscv/include/asm/page.h | 10 ++++++++
arch/riscv/include/asm/pgtable.h | 8 ++++--
arch/riscv/mm/Makefile | 2 ++
arch/riscv/mm/hugetlbpage.c | 44 ++++++++++++++++++++++++++++++++
6 files changed, 88 insertions(+), 2 deletions(-)
create mode 100644 arch/riscv/include/asm/hugetlb.h
create mode 100644 arch/riscv/mm/hugetlbpage.c

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index eb56c82d8aa1..a400d4b4e1b3 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -49,6 +49,8 @@ config RISCV
select GENERIC_IRQ_MULTI_HANDLER
select ARCH_HAS_PTE_SPECIAL
select HAVE_EBPF_JIT if 64BIT
+ select ARCH_HAS_GIGANTIC_PAGE
+ select ARCH_WANT_HUGE_PMD_SHARE if 64BIT

config MMU
def_bool y
@@ -63,6 +65,12 @@ config PAGE_OFFSET
default 0xffffffff80000000 if 64BIT && MAXPHYSMEM_2GB
default 0xffffffe000000000 if 64BIT && MAXPHYSMEM_128GB

+config ARCH_WANT_GENERAL_HUGETLB
+ def_bool y
+
+config SYS_SUPPORTS_HUGETLBFS
+ def_bool y
+
config STACKTRACE_SUPPORT
def_bool y

diff --git a/arch/riscv/include/asm/hugetlb.h b/arch/riscv/include/asm/hugetlb.h
new file mode 100644
index 000000000000..728a5db66597
--- /dev/null
+++ b/arch/riscv/include/asm/hugetlb.h
@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_RISCV_HUGETLB_H
+#define _ASM_RISCV_HUGETLB_H
+
+#include <asm-generic/hugetlb.h>
+#include <asm/page.h>
+
+static inline int is_hugepage_only_range(struct mm_struct *mm,
+ unsigned long addr,
+ unsigned long len) {
+ return 0;
+}
+
+static inline void arch_clear_hugepage_flags(struct page *page)
+{
+}
+
+#endif /* _ASM_RISCV_HUGETLB_H */
diff --git a/arch/riscv/include/asm/page.h b/arch/riscv/include/asm/page.h
index 2a546a52f02a..4ef2936295aa 100644
--- a/arch/riscv/include/asm/page.h
+++ b/arch/riscv/include/asm/page.h
@@ -24,6 +24,16 @@
#define PAGE_SIZE (_AC(1, UL) << PAGE_SHIFT)
#define PAGE_MASK (~(PAGE_SIZE - 1))

+#ifdef CONFIG_64BIT
+#define HUGE_MAX_HSTATE 2
+#else
+#define HUGE_MAX_HSTATE 1
+#endif
+#define HPAGE_SHIFT PMD_SHIFT
+#define HPAGE_SIZE (_AC(1, UL) << HPAGE_SHIFT)
+#define HPAGE_MASK (~(HPAGE_SIZE - 1))
+#define HUGETLB_PAGE_ORDER (HPAGE_SHIFT - PAGE_SHIFT)
+
/*
* PAGE_OFFSET -- the first address of the first page of memory.
* When not using MMU this corresponds to the first free page in
diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index 1141364d990e..f3456fcdff92 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -121,7 +121,6 @@ static inline void pmd_clear(pmd_t *pmdp)
set_pmd(pmdp, __pmd(0));
}

-
static inline pgd_t pfn_pgd(unsigned long pfn, pgprot_t prot)
{
return __pgd((pfn << _PAGE_PFN_SHIFT) | pgprot_val(prot));
@@ -258,6 +257,11 @@ static inline pte_t pte_mkspecial(pte_t pte)
return __pte(pte_val(pte) | _PAGE_SPECIAL);
}

+static inline pte_t pte_mkhuge(pte_t pte)
+{
+ return pte;
+}
+
/* Modify page protection bits */
static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
{
@@ -417,7 +421,7 @@ static inline void pgtable_cache_init(void)
#define VMALLOC_START (PAGE_OFFSET - VMALLOC_SIZE)

/*
- * Task size is 0x40000000000 for RV64 or 0xb800000 for RV32.
+ * Task size is 0x4000000000 for RV64 or 0xb800000 for RV32.
* Note that PGDIR_SIZE must evenly divide TASK_SIZE.
*/
#ifdef CONFIG_64BIT
diff --git a/arch/riscv/mm/Makefile b/arch/riscv/mm/Makefile
index b68aac701803..7bbe533d92f5 100644
--- a/arch/riscv/mm/Makefile
+++ b/arch/riscv/mm/Makefile
@@ -9,3 +9,5 @@ obj-y += fault.o
obj-y += extable.o
obj-y += ioremap.o
obj-y += cacheflush.o
+
+obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o
diff --git a/arch/riscv/mm/hugetlbpage.c b/arch/riscv/mm/hugetlbpage.c
new file mode 100644
index 000000000000..0d4747e9d5b5
--- /dev/null
+++ b/arch/riscv/mm/hugetlbpage.c
@@ -0,0 +1,44 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/hugetlb.h>
+#include <linux/err.h>
+
+int pud_huge(pud_t pud)
+{
+ return pud_present(pud) &&
+ (pud_val(pud) & (_PAGE_READ | _PAGE_WRITE | _PAGE_EXEC));
+}
+
+int pmd_huge(pmd_t pmd)
+{
+ return pmd_present(pmd) &&
+ (pmd_val(pmd) & (_PAGE_READ | _PAGE_WRITE | _PAGE_EXEC));
+}
+
+static __init int setup_hugepagesz(char *opt)
+{
+ unsigned long ps = memparse(opt, &opt);
+
+ if (ps == HPAGE_SIZE) {
+ hugetlb_add_hstate(HPAGE_SHIFT - PAGE_SHIFT);
+ } else if (IS_ENABLED(CONFIG_64BIT) && ps == PUD_SIZE) {
+ hugetlb_add_hstate(PUD_SHIFT - PAGE_SHIFT);
+ } else {
+ hugetlb_bad_size();
+ pr_err("hugepagesz: Unsupported page size %lu M\n", ps >> 20);
+ return 0;
+ }
+
+ return 1;
+}
+__setup("hugepagesz=", setup_hugepagesz);
+
+#ifdef CONFIG_CONTIG_ALLOC
+static __init int gigantic_pages_init(void)
+{
+ /* With CONTIG_ALLOC, we can allocate gigantic pages at runtime */
+ if (IS_ENABLED(CONFIG_64BIT) && !size_to_hstate(1UL << PUD_SHIFT))
+ hugetlb_add_hstate(PUD_SHIFT - PAGE_SHIFT);
+ return 0;
+}
+arch_initcall(gigantic_pages_init);
+#endif
--
2.20.1

2019-04-25 18:41:01

by Palmer Dabbelt

[permalink] [raw]
Subject: Re: [PATCH v2 1/2] x86, arm64: Move ARCH_WANT_HUGE_PMD_SHARE config in arch/Kconfig

On Mon, 08 Apr 2019 23:14:48 PDT (-0700), [email protected] wrote:
> ARCH_WANT_HUGE_PMD_SHARE config was declared in both architectures:
> move this declaration in arch/Kconfig and make those architectures
> select it.
>
> Signed-off-by: Alexandre Ghiti <[email protected]>
> ---
> arch/Kconfig | 3 +++
> arch/arm64/Kconfig | 2 +-
> arch/x86/Kconfig | 4 +---
> 3 files changed, 5 insertions(+), 4 deletions(-)
>
> diff --git a/arch/Kconfig b/arch/Kconfig
> index 8c858bb133c9..273cefc6b787 100644
> --- a/arch/Kconfig
> +++ b/arch/Kconfig
> @@ -567,6 +567,9 @@ config HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
> config HAVE_ARCH_HUGE_VMAP
> bool
>
> +config ARCH_WANT_HUGE_PMD_SHARE
> + bool
> +
> config HAVE_ARCH_SOFT_DIRTY
> bool
>
> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> index 870ef86a64ed..8b7870974961 100644
> --- a/arch/arm64/Kconfig
> +++ b/arch/arm64/Kconfig
> @@ -68,6 +68,7 @@ config ARM64
> select ARCH_SUPPORTS_NUMA_BALANCING
> select ARCH_WANT_COMPAT_IPC_PARSE_VERSION
> select ARCH_WANT_FRAME_POINTERS
> + select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36)
> select ARCH_HAS_UBSAN_SANITIZE_ALL
> select ARM_AMBA
> select ARM_ARCH_TIMER
> @@ -885,7 +886,6 @@ config SYS_SUPPORTS_HUGETLBFS
> def_bool y
>
> config ARCH_WANT_HUGE_PMD_SHARE
> - def_bool y if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36)
>
> config ARCH_HAS_CACHE_LINE_SIZE
> def_bool y
> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> index 0f2ab09da060..fd5fc2d288be 100644
> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -82,6 +82,7 @@ config X86
> select ARCH_USE_QUEUED_SPINLOCKS
> select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
> select ARCH_WANTS_DYNAMIC_TASK_STRUCT
> + select ARCH_WANT_HUGE_PMD_SHARE
> select ARCH_WANTS_THP_SWAP if X86_64
> select BUILDTIME_EXTABLE_SORT
> select CLKEVT_I8253
> @@ -298,9 +299,6 @@ config ARCH_HIBERNATION_POSSIBLE
> config ARCH_SUSPEND_POSSIBLE
> def_bool y
>
> -config ARCH_WANT_HUGE_PMD_SHARE
> - def_bool y
> -
> config ARCH_WANT_GENERAL_HUGETLB
> def_bool y

Reviewed-by: Palmer Dabbelt <[email protected]>

Let me know if you want this via my tree, as I'd also like patch 2 which
depends on this one. I've tenatively added both to my for-next tree for now.

2019-04-25 18:41:09

by Palmer Dabbelt

[permalink] [raw]
Subject: Re: [PATCH v2 2/2] riscv: Introduce huge page support for 32/64bit kernel

On Mon, 08 Apr 2019 23:14:49 PDT (-0700), [email protected] wrote:
> This patch implements both 4MB huge page support for 32bit kernel
> and 2MB/1GB huge pages support for 64bit kernel.
>
> Signed-off-by: Alexandre Ghiti <[email protected]>
> ---
> arch/riscv/Kconfig | 8 ++++++
> arch/riscv/include/asm/hugetlb.h | 18 +++++++++++++
> arch/riscv/include/asm/page.h | 10 ++++++++
> arch/riscv/include/asm/pgtable.h | 8 ++++--
> arch/riscv/mm/Makefile | 2 ++
> arch/riscv/mm/hugetlbpage.c | 44 ++++++++++++++++++++++++++++++++
> 6 files changed, 88 insertions(+), 2 deletions(-)
> create mode 100644 arch/riscv/include/asm/hugetlb.h
> create mode 100644 arch/riscv/mm/hugetlbpage.c
>
> diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
> index eb56c82d8aa1..a400d4b4e1b3 100644
> --- a/arch/riscv/Kconfig
> +++ b/arch/riscv/Kconfig
> @@ -49,6 +49,8 @@ config RISCV
> select GENERIC_IRQ_MULTI_HANDLER
> select ARCH_HAS_PTE_SPECIAL
> select HAVE_EBPF_JIT if 64BIT
> + select ARCH_HAS_GIGANTIC_PAGE
> + select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
>
> config MMU
> def_bool y
> @@ -63,6 +65,12 @@ config PAGE_OFFSET
> default 0xffffffff80000000 if 64BIT && MAXPHYSMEM_2GB
> default 0xffffffe000000000 if 64BIT && MAXPHYSMEM_128GB
>
> +config ARCH_WANT_GENERAL_HUGETLB
> + def_bool y
> +
> +config SYS_SUPPORTS_HUGETLBFS
> + def_bool y
> +
> config STACKTRACE_SUPPORT
> def_bool y
>
> diff --git a/arch/riscv/include/asm/hugetlb.h b/arch/riscv/include/asm/hugetlb.h
> new file mode 100644
> index 000000000000..728a5db66597
> --- /dev/null
> +++ b/arch/riscv/include/asm/hugetlb.h
> @@ -0,0 +1,18 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#ifndef _ASM_RISCV_HUGETLB_H
> +#define _ASM_RISCV_HUGETLB_H
> +
> +#include <asm-generic/hugetlb.h>
> +#include <asm/page.h>
> +
> +static inline int is_hugepage_only_range(struct mm_struct *mm,
> + unsigned long addr,
> + unsigned long len) {
> + return 0;
> +}
> +
> +static inline void arch_clear_hugepage_flags(struct page *page)
> +{
> +}
> +
> +#endif /* _ASM_RISCV_HUGETLB_H */
> diff --git a/arch/riscv/include/asm/page.h b/arch/riscv/include/asm/page.h
> index 2a546a52f02a..4ef2936295aa 100644
> --- a/arch/riscv/include/asm/page.h
> +++ b/arch/riscv/include/asm/page.h
> @@ -24,6 +24,16 @@
> #define PAGE_SIZE (_AC(1, UL) << PAGE_SHIFT)
> #define PAGE_MASK (~(PAGE_SIZE - 1))
>
> +#ifdef CONFIG_64BIT
> +#define HUGE_MAX_HSTATE 2
> +#else
> +#define HUGE_MAX_HSTATE 1
> +#endif
> +#define HPAGE_SHIFT PMD_SHIFT
> +#define HPAGE_SIZE (_AC(1, UL) << HPAGE_SHIFT)
> +#define HPAGE_MASK (~(HPAGE_SIZE - 1))
> +#define HUGETLB_PAGE_ORDER (HPAGE_SHIFT - PAGE_SHIFT)
> +
> /*
> * PAGE_OFFSET -- the first address of the first page of memory.
> * When not using MMU this corresponds to the first free page in
> diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
> index 1141364d990e..f3456fcdff92 100644
> --- a/arch/riscv/include/asm/pgtable.h
> +++ b/arch/riscv/include/asm/pgtable.h
> @@ -121,7 +121,6 @@ static inline void pmd_clear(pmd_t *pmdp)
> set_pmd(pmdp, __pmd(0));
> }
>
> -
> static inline pgd_t pfn_pgd(unsigned long pfn, pgprot_t prot)
> {
> return __pgd((pfn << _PAGE_PFN_SHIFT) | pgprot_val(prot));
> @@ -258,6 +257,11 @@ static inline pte_t pte_mkspecial(pte_t pte)
> return __pte(pte_val(pte) | _PAGE_SPECIAL);
> }
>
> +static inline pte_t pte_mkhuge(pte_t pte)
> +{
> + return pte;
> +}
> +
> /* Modify page protection bits */
> static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
> {
> @@ -417,7 +421,7 @@ static inline void pgtable_cache_init(void)
> #define VMALLOC_START (PAGE_OFFSET - VMALLOC_SIZE)
>
> /*
> - * Task size is 0x40000000000 for RV64 or 0xb800000 for RV32.
> + * Task size is 0x4000000000 for RV64 or 0xb800000 for RV32.
> * Note that PGDIR_SIZE must evenly divide TASK_SIZE.
> */
> #ifdef CONFIG_64BIT
> diff --git a/arch/riscv/mm/Makefile b/arch/riscv/mm/Makefile
> index b68aac701803..7bbe533d92f5 100644
> --- a/arch/riscv/mm/Makefile
> +++ b/arch/riscv/mm/Makefile
> @@ -9,3 +9,5 @@ obj-y += fault.o
> obj-y += extable.o
> obj-y += ioremap.o
> obj-y += cacheflush.o
> +
> +obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o
> diff --git a/arch/riscv/mm/hugetlbpage.c b/arch/riscv/mm/hugetlbpage.c
> new file mode 100644
> index 000000000000..0d4747e9d5b5
> --- /dev/null
> +++ b/arch/riscv/mm/hugetlbpage.c
> @@ -0,0 +1,44 @@
> +// SPDX-License-Identifier: GPL-2.0
> +#include <linux/hugetlb.h>
> +#include <linux/err.h>
> +
> +int pud_huge(pud_t pud)
> +{
> + return pud_present(pud) &&
> + (pud_val(pud) & (_PAGE_READ | _PAGE_WRITE | _PAGE_EXEC));
> +}
> +
> +int pmd_huge(pmd_t pmd)
> +{
> + return pmd_present(pmd) &&
> + (pmd_val(pmd) & (_PAGE_READ | _PAGE_WRITE | _PAGE_EXEC));
> +}
> +
> +static __init int setup_hugepagesz(char *opt)
> +{
> + unsigned long ps = memparse(opt, &opt);
> +
> + if (ps == HPAGE_SIZE) {
> + hugetlb_add_hstate(HPAGE_SHIFT - PAGE_SHIFT);
> + } else if (IS_ENABLED(CONFIG_64BIT) && ps == PUD_SIZE) {
> + hugetlb_add_hstate(PUD_SHIFT - PAGE_SHIFT);
> + } else {
> + hugetlb_bad_size();
> + pr_err("hugepagesz: Unsupported page size %lu M\n", ps >> 20);
> + return 0;
> + }
> +
> + return 1;
> +}
> +__setup("hugepagesz=", setup_hugepagesz);
> +
> +#ifdef CONFIG_CONTIG_ALLOC
> +static __init int gigantic_pages_init(void)
> +{
> + /* With CONTIG_ALLOC, we can allocate gigantic pages at runtime */
> + if (IS_ENABLED(CONFIG_64BIT) && !size_to_hstate(1UL << PUD_SHIFT))
> + hugetlb_add_hstate(PUD_SHIFT - PAGE_SHIFT);
> + return 0;
> +}
> +arch_initcall(gigantic_pages_init);
> +#endif

I'm getting some build errors when this is applied to 5.1-c6. I think all I've
done is turn on hugetlb:

$ diff -u arch/riscv/configs/defconfig defconfig
--- arch/riscv/configs/defconfig 2019-04-24 16:23:39.027994174 -0700
+++ defconfig 2019-04-25 10:39:34.722544413 -0700
@@ -5,6 +5,7 @@
CONFIG_CGROUPS=y
CONFIG_CGROUP_SCHED=y
CONFIG_CFS_BANDWIDTH=y
+CONFIG_CGROUP_HUGETLB=y
CONFIG_CGROUP_BPF=y
CONFIG_NAMESPACES=y
CONFIG_USER_NS=y
@@ -72,6 +73,7 @@
CONFIG_VFAT_FS=y
CONFIG_TMPFS=y
CONFIG_TMPFS_POSIX_ACL=y
+CONFIG_HUGETLBFS=y
CONFIG_NFS_FS=y
CONFIG_NFS_V4=y
CONFIG_NFS_V4_1=y

2019-04-25 21:36:21

by Alexandre Ghiti

[permalink] [raw]
Subject: Re: [PATCH v2 2/2] riscv: Introduce huge page support for 32/64bit kernel

On 4/25/19 1:42 PM, Palmer Dabbelt wrote:
> On Mon, 08 Apr 2019 23:14:49 PDT (-0700), [email protected] wrote:
>> This patch implements both 4MB huge page support for 32bit kernel
>> and 2MB/1GB huge pages support for 64bit kernel.
>>
>> Signed-off-by: Alexandre Ghiti <[email protected]>
>> ---
>>  arch/riscv/Kconfig               |  8 ++++++
>>  arch/riscv/include/asm/hugetlb.h | 18 +++++++++++++
>>  arch/riscv/include/asm/page.h    | 10 ++++++++
>>  arch/riscv/include/asm/pgtable.h |  8 ++++--
>>  arch/riscv/mm/Makefile           |  2 ++
>>  arch/riscv/mm/hugetlbpage.c      | 44 ++++++++++++++++++++++++++++++++
>>  6 files changed, 88 insertions(+), 2 deletions(-)
>>  create mode 100644 arch/riscv/include/asm/hugetlb.h
>>  create mode 100644 arch/riscv/mm/hugetlbpage.c
>>
>> diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
>> index eb56c82d8aa1..a400d4b4e1b3 100644
>> --- a/arch/riscv/Kconfig
>> +++ b/arch/riscv/Kconfig
>> @@ -49,6 +49,8 @@ config RISCV
>>      select GENERIC_IRQ_MULTI_HANDLER
>>      select ARCH_HAS_PTE_SPECIAL
>>      select HAVE_EBPF_JIT if 64BIT
>> +    select ARCH_HAS_GIGANTIC_PAGE
>> +    select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
>>
>>  config MMU
>>      def_bool y
>> @@ -63,6 +65,12 @@ config PAGE_OFFSET
>>      default 0xffffffff80000000 if 64BIT && MAXPHYSMEM_2GB
>>      default 0xffffffe000000000 if 64BIT && MAXPHYSMEM_128GB
>>
>> +config ARCH_WANT_GENERAL_HUGETLB
>> +    def_bool y
>> +
>> +config SYS_SUPPORTS_HUGETLBFS
>> +    def_bool y
>> +
>>  config STACKTRACE_SUPPORT
>>      def_bool y
>>
>> diff --git a/arch/riscv/include/asm/hugetlb.h
>> b/arch/riscv/include/asm/hugetlb.h
>> new file mode 100644
>> index 000000000000..728a5db66597
>> --- /dev/null
>> +++ b/arch/riscv/include/asm/hugetlb.h
>> @@ -0,0 +1,18 @@
>> +/* SPDX-License-Identifier: GPL-2.0 */
>> +#ifndef _ASM_RISCV_HUGETLB_H
>> +#define _ASM_RISCV_HUGETLB_H
>> +
>> +#include <asm-generic/hugetlb.h>
>> +#include <asm/page.h>
>> +
>> +static inline int is_hugepage_only_range(struct mm_struct *mm,
>> +                     unsigned long addr,
>> +                     unsigned long len) {
>> +    return 0;
>> +}
>> +
>> +static inline void arch_clear_hugepage_flags(struct page *page)
>> +{
>> +}
>> +
>> +#endif /* _ASM_RISCV_HUGETLB_H */
>> diff --git a/arch/riscv/include/asm/page.h
>> b/arch/riscv/include/asm/page.h
>> index 2a546a52f02a..4ef2936295aa 100644
>> --- a/arch/riscv/include/asm/page.h
>> +++ b/arch/riscv/include/asm/page.h
>> @@ -24,6 +24,16 @@
>>  #define PAGE_SIZE    (_AC(1, UL) << PAGE_SHIFT)
>>  #define PAGE_MASK    (~(PAGE_SIZE - 1))
>>
>> +#ifdef CONFIG_64BIT
>> +#define HUGE_MAX_HSTATE        2
>> +#else
>> +#define HUGE_MAX_HSTATE        1
>> +#endif
>> +#define HPAGE_SHIFT        PMD_SHIFT
>> +#define HPAGE_SIZE        (_AC(1, UL) << HPAGE_SHIFT)
>> +#define HPAGE_MASK              (~(HPAGE_SIZE - 1))
>> +#define HUGETLB_PAGE_ORDER      (HPAGE_SHIFT - PAGE_SHIFT)
>> +
>>  /*
>>   * PAGE_OFFSET -- the first address of the first page of memory.
>>   * When not using MMU this corresponds to the first free page in
>> diff --git a/arch/riscv/include/asm/pgtable.h
>> b/arch/riscv/include/asm/pgtable.h
>> index 1141364d990e..f3456fcdff92 100644
>> --- a/arch/riscv/include/asm/pgtable.h
>> +++ b/arch/riscv/include/asm/pgtable.h
>> @@ -121,7 +121,6 @@ static inline void pmd_clear(pmd_t *pmdp)
>>      set_pmd(pmdp, __pmd(0));
>>  }
>>
>> -
>>  static inline pgd_t pfn_pgd(unsigned long pfn, pgprot_t prot)
>>  {
>>      return __pgd((pfn << _PAGE_PFN_SHIFT) | pgprot_val(prot));
>> @@ -258,6 +257,11 @@ static inline pte_t pte_mkspecial(pte_t pte)
>>      return __pte(pte_val(pte) | _PAGE_SPECIAL);
>>  }
>>
>> +static inline pte_t pte_mkhuge(pte_t pte)
>> +{
>> +    return pte;
>> +}
>> +
>>  /* Modify page protection bits */
>>  static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
>>  {
>> @@ -417,7 +421,7 @@ static inline void pgtable_cache_init(void)
>>  #define VMALLOC_START    (PAGE_OFFSET - VMALLOC_SIZE)
>>
>>  /*
>> - * Task size is 0x40000000000 for RV64 or 0xb800000 for RV32.
>> + * Task size is 0x4000000000 for RV64 or 0xb800000 for RV32.
>>   * Note that PGDIR_SIZE must evenly divide TASK_SIZE.
>>   */
>>  #ifdef CONFIG_64BIT
>> diff --git a/arch/riscv/mm/Makefile b/arch/riscv/mm/Makefile
>> index b68aac701803..7bbe533d92f5 100644
>> --- a/arch/riscv/mm/Makefile
>> +++ b/arch/riscv/mm/Makefile
>> @@ -9,3 +9,5 @@ obj-y += fault.o
>>  obj-y += extable.o
>>  obj-y += ioremap.o
>>  obj-y += cacheflush.o
>> +
>> +obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o
>> diff --git a/arch/riscv/mm/hugetlbpage.c b/arch/riscv/mm/hugetlbpage.c
>> new file mode 100644
>> index 000000000000..0d4747e9d5b5
>> --- /dev/null
>> +++ b/arch/riscv/mm/hugetlbpage.c
>> @@ -0,0 +1,44 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +#include <linux/hugetlb.h>
>> +#include <linux/err.h>
>> +
>> +int pud_huge(pud_t pud)
>> +{
>> +    return pud_present(pud) &&
>> +        (pud_val(pud) & (_PAGE_READ | _PAGE_WRITE | _PAGE_EXEC));
>> +}
>> +
>> +int pmd_huge(pmd_t pmd)
>> +{
>> +    return pmd_present(pmd) &&
>> +        (pmd_val(pmd) & (_PAGE_READ | _PAGE_WRITE | _PAGE_EXEC));
>> +}
>> +
>> +static __init int setup_hugepagesz(char *opt)
>> +{
>> +    unsigned long ps = memparse(opt, &opt);
>> +
>> +    if (ps == HPAGE_SIZE) {
>> +        hugetlb_add_hstate(HPAGE_SHIFT - PAGE_SHIFT);
>> +    } else if (IS_ENABLED(CONFIG_64BIT) && ps == PUD_SIZE) {
>> +        hugetlb_add_hstate(PUD_SHIFT - PAGE_SHIFT);
>> +    } else {
>> +        hugetlb_bad_size();
>> +        pr_err("hugepagesz: Unsupported page size %lu M\n", ps >> 20);
>> +        return 0;
>> +    }
>> +
>> +    return 1;
>> +}
>> +__setup("hugepagesz=", setup_hugepagesz);
>> +
>> +#ifdef CONFIG_CONTIG_ALLOC
>> +static __init int gigantic_pages_init(void)
>> +{
>> +    /* With CONTIG_ALLOC, we can allocate gigantic pages at runtime */
>> +    if (IS_ENABLED(CONFIG_64BIT) && !size_to_hstate(1UL << PUD_SHIFT))
>> +        hugetlb_add_hstate(PUD_SHIFT - PAGE_SHIFT);
>> +    return 0;
>> +}
>> +arch_initcall(gigantic_pages_init);
>> +#endif
>
> I'm getting some build errors when this is applied to 5.1-c6.  I think
> all I've
> done is turn on hugetlb:

Hi Palmer,

This patchset is based on linux-next where my series "Fix
free/allocation of runtime gigantic pages"
was merged, it is not yet present in v5.1-rc*.

Thanks,

Alex
>
>    $ diff -u arch/riscv/configs/defconfig defconfig
>    --- arch/riscv/configs/defconfig        2019-04-24
> 16:23:39.027994174 -0700
>    +++ defconfig   2019-04-25 10:39:34.722544413 -0700
>    @@ -5,6 +5,7 @@
>     CONFIG_CGROUPS=y
>     CONFIG_CGROUP_SCHED=y
>     CONFIG_CFS_BANDWIDTH=y
>    +CONFIG_CGROUP_HUGETLB=y
>     CONFIG_CGROUP_BPF=y
>     CONFIG_NAMESPACES=y
>     CONFIG_USER_NS=y
>    @@ -72,6 +73,7 @@
>     CONFIG_VFAT_FS=y
>     CONFIG_TMPFS=y
>     CONFIG_TMPFS_POSIX_ACL=y
>    +CONFIG_HUGETLBFS=y
>     CONFIG_NFS_FS=y
>     CONFIG_NFS_V4=y
>     CONFIG_NFS_V4_1=y