Re: [PATCH v3 3/4] hugetlbfs: remove hugetlb_add_hstate() warning for existing hstate
On 4/22/20 3:42 AM, Aneesh Kumar K.V wrote:
> Mike Kravetz writes:
>
>> The routine hugetlb_add_hstate prints a warning if the hstate already
>> exists. This was originally done as part of kernel command line
>> parsing. If 'hugepagesz=' was specified more than once, the warning
>> pr_warn("hugepagesz= specified twice, ignoring\n");
>> would be printed.
>>
>> Some architectures want to enable all huge page sizes. They would
>> call hugetlb_add_hstate for all supported sizes. However, this was
>> done after command line processing and as a result hstates could have
>> already been created for some sizes. To make sure no warning were
>> printed, there would often be code like:
>> if (!size_to_hstate(size)
>> hugetlb_add_hstate(ilog2(size) - PAGE_SHIFT)
>>
>> The only time we want to print the warning is as the result of command
>> line processing.
>
> Does this patch break hugepages=x command line? I haven't tested this
> yet. But one of the details w.r.t. skipping that hugetlb_add_hstate is
> to make sure we can configure the max_huge_pages.
>
Are you asking about hugepages=x being the only option on the command line?
If so, then the behavior is not changed. This will result in x pages of
default huge page size being allocated. Where default huge page size is of
course architecture dependent. On an x86 VM,
[0.040474] Kernel command line: BOOT_IMAGE=/vmlinuz-5.6.0-mm1+
root=/dev/mapper/fedora_new--host-root ro rd.lvm.lv=fedora_new-host/root
rd.lvm.lv=fedora_new-host/swap console=tty0 console=ttyS0,115200 audit=0
transparent_hugepage=always hugepages=128
[0.332618] HugeTLB registered 1.00 GiB page size, pre-allocated 0 pages
[0.333245] HugeTLB registered 2.00 MiB page size, pre-allocated 128 pages
BTW - Here are the command line options I tested on x86 with this series.
No errors or warnings
-
hugepages=128
hugepagesz=2M hugepages=128
default_hugepagesz=2M hugepages=128
hugepages=128 default_hugepagesz=2M
hugepagesz=1G hugepages=2
hugepages=2 default_hugepagesz=1G
default_hugepagesz=1G hugepages=2
hugepages=128 hugepagesz=1G hugepages=2
hugepagesz=1G hugepages=2 hugepagesz=2M hugepages=128
default_hugepagesz=2M hugepages=128 hugepagesz=1G hugepages=2
hugepages=128 default_hugepagesz=2M hugepagesz=1G hugepages=2
hugepages=2 default_hugepagesz=1G hugepagesz=2M hugepages=128
default_hugepagesz=1G hugepages=2 hugepagesz=2M hugepages=128
default_hugepagesz=2M hugepagesz=2M hugepages=128
default_hugepagesz=2M hugepagesz=1G hugepages=2 hugepagesz=2M hugepages=128
Error or warning
hugepages=128 hugepagesz=2M hugepages=256
hugepagesz=2M hugepages=128 hugepagesz=2M hugepages=256
default_hugepagesz=2M hugepages=128 hugepagesz=2M hugepages=256
hugepages=128 hugepages=256
hugepagesz=2M hugepages=128 hugepages=2 default_hugepagesz=1G
--
Mike Kravetz
Re: [PATCH v3 3/4] hugetlbfs: remove hugetlb_add_hstate() warning for existing hstate
Mike Kravetz writes:
> The routine hugetlb_add_hstate prints a warning if the hstate already
> exists. This was originally done as part of kernel command line
> parsing. If 'hugepagesz=' was specified more than once, the warning
> pr_warn("hugepagesz= specified twice, ignoring\n");
> would be printed.
>
> Some architectures want to enable all huge page sizes. They would
> call hugetlb_add_hstate for all supported sizes. However, this was
> done after command line processing and as a result hstates could have
> already been created for some sizes. To make sure no warning were
> printed, there would often be code like:
> if (!size_to_hstate(size)
> hugetlb_add_hstate(ilog2(size) - PAGE_SHIFT)
>
> The only time we want to print the warning is as the result of command
> line processing.
Does this patch break hugepages=x command line? I haven't tested this
yet. But one of the details w.r.t. skipping that hugetlb_add_hstate is
to make sure we can configure the max_huge_pages.
>So, remove the warning from hugetlb_add_hstate and
> add it to the single arch independent routine processing "hugepagesz=".
> After this, calls to size_to_hstate() in arch specific code can be
> removed and hugetlb_add_hstate can be called without worrying about
> warning messages.
>
-aneesh
Re: [PATCH v3 3/4] hugetlbfs: remove hugetlb_add_hstate() warning for existing hstate
On Fri, 17 Apr 2020 at 20:52, Mike Kravetz wrote:
>
> The routine hugetlb_add_hstate prints a warning if the hstate already
> exists. This was originally done as part of kernel command line
> parsing. If 'hugepagesz=' was specified more than once, the warning
> pr_warn("hugepagesz= specified twice, ignoring\n");
> would be printed.
>
> Some architectures want to enable all huge page sizes. They would
> call hugetlb_add_hstate for all supported sizes. However, this was
> done after command line processing and as a result hstates could have
> already been created for some sizes. To make sure no warning were
> printed, there would often be code like:
> if (!size_to_hstate(size)
> hugetlb_add_hstate(ilog2(size) - PAGE_SHIFT)
>
> The only time we want to print the warning is as the result of command
> line processing. So, remove the warning from hugetlb_add_hstate and
> add it to the single arch independent routine processing "hugepagesz=".
> After this, calls to size_to_hstate() in arch specific code can be
> removed and hugetlb_add_hstate can be called without worrying about
> warning messages.
>
> Signed-off-by: Mike Kravetz
> Acked-by: Mina Almasry
When I build an arm64 kernel on today's next-20200420 and ran that in
qemu I got the following output [1]:
...
[ 311.326817][T1] kobject: 'drivers' ((ptrval)):
kobject_add_internal: parent: 'coresight', set: ''
[ 311.331513][T1] kobject: 'drivers' ((ptrval)): kobject_uevent_env
[ 311.334514][T1] kobject: 'drivers' ((ptrval)):
kobject_uevent_env: filter function caused the event to drop!
[ 311.340127][T1] bus: 'coresight': registered
[ 311.342228][T1] initcall coresight_init+0x0/0x64 returned 0
after 27343 usecs
[ 311.349740][T1] calling debug_traps_init+0x0/0xa4 @ 1
[ 311.352138][T1] initcall debug_traps_init+0x0/0xa4 returned 0
after 0 usecs
[ 311.30][T1] calling reserve_memblock_reserved_regions+0x0/0x374 @ 1
[ 311.364913][T1] initcall
reserve_memblock_reserved_regions+0x0/0x374 returned 0 after 7812
usecs
[ 311.368937][T1] calling aarch32_alloc_vdso_pages+0x0/0x1d0 @ 1
[ 311.371819][T1] initcall aarch32_alloc_vdso_pages+0x0/0x1d0
returned 0 after 0 usecs
[ 311.375608][T1] calling vdso_init+0x0/0x52c @ 1
[ 311.378092][T1] initcall vdso_init+0x0/0x52c returned 0 after 0 usecs
[ 311.381386][T1] calling arch_hw_breakpoint_init+0x0/0x178 @ 1
[ 311.384007][T1] hw-breakpoint: found 6 breakpoint and 4
watchpoint registers.
[ 311.388120][T1] initcall arch_hw_breakpoint_init+0x0/0x178
returned 0 after 3906 usecs
[ 311.391924][T1] calling asids_update_limit+0x0/0x110 @ 1
[ 311.394390][T1] ASID allocator initialised with 65536 entries
[ 311.397427][T1] initcall asids_update_limit+0x0/0x110 returned
0 after 3906 usecs
[ 311.400749][T1] calling hugetlbpage_init+0x0/0x7c @ 1
[ 311.403581][T1] Unexpected kernel BRK exception at EL1
[ 311.405771][T1] Internal error: ptrace BRK handler: f20003e8
[#1] PREEMPT SMP
[ 311.408759][T1] Modules linked in:
[ 311.410514][T1] CPU: 0 PID: 1 Comm: swapper/0 Tainted: G
T 5.7.0-rc2-next-20200420-03722-ge4ba9b47e4ed #1
[ 311.415175][T1] Hardware name: linux,dummy-virt (DT)
[ 311.417466][T1] pstate: 8045 (Nzcv daif +PAN -UAO)
[ 311.419887][T1] pc : hugetlb_add_hstate+0x68/0x4f0
[ 311.422171][T1] lr : hugetlb_add_hstate+0x68/0x4f0
[ 311.424354][T1] sp : 69c07c60
[ 311.426124][T1] x29: 69c07c60 x28: 6a7f8058
[ 311.428754][T1] x27: x26: a00013f56950
[ 311.431376][T1] x25: a000141b8000 x24: 6a7f8040
[ 311.433987][T1] x23: 1fffed380fae x22: fff8
[ 311.436574][T1] x21: 0001 x20: a000141b8000
[ 311.439167][T1] x19: ec632d51be3d2507 x18: 1a68
[ 311.441763][T1] x17: 13e0 x16: 1a94
[ 311.444386][T1] x15: 1a68 x14: 6573752036303933
[ 311.447034][T1] x13: 2072657466612030 x12: 25b0
[ 311.449639][T1] x11: f1f1f1f1 x10: 41b58ab3
[ 311.452238][T1] x9 : a000139a833c x8 : 140002bf2c23
[ 311.454849][T1] x7 : 940002bf2c23 x6 : a00015f9611b
[ 311.457480][T1] x5 : 6a7f8040 x4 :
[ 311.460124][T1] x3 : a000139fd98c x2 : fff8
[ 311.462737][T1] x1 : 6a7f8040 x0 :
[ 311.465322][T1] Call trace:
[ 311.466818][T1] hugetlb_add_hstate+0x68/0x4f0
[ 311.468934][T1] hugetlbpage_init+0x34/0x7c
[ 311.470934][T1] do_one_initcall+0x480/0xa40
[ 311.472996][T1] kernel_init_freeable+0x7a0/0x968
[ 311.475224][T1] kernel_init+0x20/0x1f8
[ 311.477078][T1] ret_from_fork+0x10/0x18
[ 311.479053][T1] Code: 972762be 7100fedf 5469 97276197 (d4207d00)
[ 311.482106][T1]
[PATCH v3 3/4] hugetlbfs: remove hugetlb_add_hstate() warning for existing hstate
The routine hugetlb_add_hstate prints a warning if the hstate already
exists. This was originally done as part of kernel command line
parsing. If 'hugepagesz=' was specified more than once, the warning
pr_warn("hugepagesz= specified twice, ignoring\n");
would be printed.
Some architectures want to enable all huge page sizes. They would
call hugetlb_add_hstate for all supported sizes. However, this was
done after command line processing and as a result hstates could have
already been created for some sizes. To make sure no warning were
printed, there would often be code like:
if (!size_to_hstate(size)
hugetlb_add_hstate(ilog2(size) - PAGE_SHIFT)
The only time we want to print the warning is as the result of command
line processing. So, remove the warning from hugetlb_add_hstate and
add it to the single arch independent routine processing "hugepagesz=".
After this, calls to size_to_hstate() in arch specific code can be
removed and hugetlb_add_hstate can be called without worrying about
warning messages.
Signed-off-by: Mike Kravetz
Acked-by: Mina Almasry
---
arch/arm64/mm/hugetlbpage.c | 16
arch/powerpc/mm/hugetlbpage.c | 3 +--
arch/riscv/mm/hugetlbpage.c | 2 +-
arch/sparc/mm/init_64.c | 19 ---
arch/x86/mm/hugetlbpage.c | 2 +-
mm/hugetlb.c | 9 ++---
6 files changed, 17 insertions(+), 34 deletions(-)
diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c
index f706b821aba6..21fa98b51e00 100644
--- a/arch/arm64/mm/hugetlbpage.c
+++ b/arch/arm64/mm/hugetlbpage.c
@@ -441,22 +441,14 @@ void huge_ptep_clear_flush(struct vm_area_struct *vma,
clear_flush(vma->vm_mm, addr, ptep, pgsize, ncontig);
}
-static void __init add_huge_page_size(unsigned long size)
-{
- if (size_to_hstate(size))
- return;
-
- hugetlb_add_hstate(ilog2(size) - PAGE_SHIFT);
-}
-
static int __init hugetlbpage_init(void)
{
#ifdef CONFIG_ARM64_4K_PAGES
- add_huge_page_size(PUD_SIZE);
+ hugetlb_add_hstate(PUD_SHIFT - PAGE_SHIFT);
#endif
- add_huge_page_size(CONT_PMD_SIZE);
- add_huge_page_size(PMD_SIZE);
- add_huge_page_size(CONT_PTE_SIZE);
+ hugetlb_add_hstate(CONT_PMD_SHIFT - PAGE_SHIFT);
+ hugetlb_add_hstate(PMD_SHIFT - PAGE_SHIFT);
+ hugetlb_add_hstate(CONT_PTE_SHIFT - PAGE_SHIFT);
return 0;
}
diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index 2c3fa0a7787b..4d5ed1093615 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -584,8 +584,7 @@ static int __init add_huge_page_size(unsigned long long
size)
if (!arch_hugetlb_valid_size((unsigned long)size))
return -EINVAL;
- if (!size_to_hstate(size))
- hugetlb_add_hstate(shift - PAGE_SHIFT);
+ hugetlb_add_hstate(shift - PAGE_SHIFT);
return 0;
}
diff --git a/arch/riscv/mm/hugetlbpage.c b/arch/riscv/mm/hugetlbpage.c
index 4e5d7e9f0eef..932dadfdca54 100644
--- a/arch/riscv/mm/hugetlbpage.c
+++ b/arch/riscv/mm/hugetlbpage.c
@@ -26,7 +26,7 @@ bool __init arch_hugetlb_valid_size(unsigned long size)
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))
+ if (IS_ENABLED(CONFIG_64BIT))
hugetlb_add_hstate(PUD_SHIFT - PAGE_SHIFT);
return 0;
}
diff --git a/arch/sparc/mm/init_64.c b/arch/sparc/mm/init_64.c
index 4618f96fd30f..ae819a16d07a 100644
--- a/arch/sparc/mm/init_64.c
+++ b/arch/sparc/mm/init_64.c
@@ -325,23 +325,12 @@ static void __update_mmu_tsb_insert(struct mm_struct *mm,
unsigned long tsb_inde
}
#ifdef CONFIG_HUGETLB_PAGE
-static void __init add_huge_page_size(unsigned long size)
-{
- unsigned int order;
-
- if (size_to_hstate(size))
- return;
-
- order = ilog2(size) - PAGE_SHIFT;
- hugetlb_add_hstate(order);
-}
-
static int __init hugetlbpage_init(void)
{
- add_huge_page_size(1UL << HPAGE_64K_SHIFT);
- add_huge_page_size(1UL << HPAGE_SHIFT);
- add_huge_page_size(1UL << HPAGE_256MB_SHIFT);
- add_huge_page_size(1UL << HPAGE_2GB_SHIFT);
+ hugetlb_add_hstate(HPAGE_64K_SHIFT - PAGE_SHIFT);
+ hugetlb_add_hstate(HPAGE_SHIFT - PAGE_SHIFT);
+ hugetlb_add_hstate(HPAGE_256MB_SHIFT - PAGE_SHIFT);
+ hugetlb_add_hstate(HPAGE_2GB_SHIFT - PAGE_SHIFT);
return 0;
}
diff --git a/arch/x86/mm/hugetlbpage.c b/arch/x86/mm/hugetlbpage.c
index 937d640a89e3..cf5781142716 100644
--- a/arch/x86/mm/hugetlbpage.c
+++ b/arch/x86/mm/hugetlbpage.c
@@ -195,7 +195,7 @@ bool __init arch_hugetlb_valid_size(unsigned long size)
static __init int gigantic_pages_init(void)
{
/* With compaction or CMA we can allocate gigantic pages at runtime */
- if (boot_cpu_has(X86_FEATURE_GBPAGES) &&
