If hugetlb_cma is enabled, it will skip boot time allocation
when allocating gigantic page, that doesn't means allocation
failure, so suppress this warning info.
Fixes: cf11e85fc08c ("mm: hugetlb: optionally allocate gigantic hugepages using cma")
Signed-off-by: Chen Wandun <[email protected]>
---
mm/hugetlb.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index b6992297aa16..98a49cb9250c 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -2465,7 +2465,7 @@ static void __init hugetlb_hstate_alloc_pages(struct hstate *h)
if (hstate_is_gigantic(h)) {
if (hugetlb_cma_size) {
pr_warn_once("HugeTLB: hugetlb_cma is enabled, skip boot time allocation\n");
- break;
+ goto free;
}
if (!alloc_bootmem_huge_page(h))
break;
@@ -2483,7 +2483,7 @@ static void __init hugetlb_hstate_alloc_pages(struct hstate *h)
h->max_huge_pages, buf, i);
h->max_huge_pages = i;
}
-
+free:
kfree(node_alloc_noretry);
}
--
2.25.1
On 2/19/21 4:39 AM, Chen Wandun wrote:
> If hugetlb_cma is enabled, it will skip boot time allocation
> when allocating gigantic page, that doesn't means allocation
> failure, so suppress this warning info.
>
Normally the addition of warning messages is discouraged. However, in
this case the additional message provides value. Why?
Prior to the commit cf11e85fc08c, one could have a kernel command line
that contains:
hugepagesz=1G hugepages=16
This would allocate 16 1G pages at boot time.
After the commit, someone could specify a command line containing:
hugepagesz=1G hugepages=16 hugetlb_cma=16G
In this case, 16G of CMA will be reserved for 1G huge page allocations
after boot time. The parameter 'hugepages=16' is ignored, and the warning
message is logged. The warning message should only be logged when the
kernel parameter 'hugepages=' is ignored.
IMO, it make sense to log a warning if ignoring a user specified parameter.
The user should not be attempting boot time allocation and CMA reservation
for 1G pages.
I do not think we should drop the warning as the it tells the user thay
have specified two incompatible allocation options.
--
Mike Kravetz
> Fixes: cf11e85fc08c ("mm: hugetlb: optionally allocate gigantic hugepages using cma")
> Signed-off-by: Chen Wandun <[email protected]>
> ---
> mm/hugetlb.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> index b6992297aa16..98a49cb9250c 100644
> --- a/mm/hugetlb.c
> +++ b/mm/hugetlb.c
> @@ -2465,7 +2465,7 @@ static void __init hugetlb_hstate_alloc_pages(struct hstate *h)
> if (hstate_is_gigantic(h)) {
> if (hugetlb_cma_size) {
> pr_warn_once("HugeTLB: hugetlb_cma is enabled, skip boot time allocation\n");
> - break;
> + goto free;
> }
> if (!alloc_bootmem_huge_page(h))
> break;
> @@ -2483,7 +2483,7 @@ static void __init hugetlb_hstate_alloc_pages(struct hstate *h)
> h->max_huge_pages, buf, i);
> h->max_huge_pages = i;
> }
> -
> +free:
> kfree(node_alloc_noretry);
> }
>
>
On 3/4/21 1:35 AM, David Hildenbrand wrote:
> On 19.02.21 20:14, Mike Kravetz wrote:
>> On 2/19/21 4:39 AM, Chen Wandun wrote:
>>> If hugetlb_cma is enabled, it will skip boot time allocation
>>> when allocating gigantic page, that doesn't means allocation
>>> failure, so suppress this warning info.
>>>
>>
>> Normally the addition of warning messages is discouraged. However, in
>> this case the additional message provides value. Why?
>>
>> Prior to the commit cf11e85fc08c, one could have a kernel command line
>> that contains:
>>
>> hugepagesz=1G hugepages=16
>>
>> This would allocate 16 1G pages at boot time.
>>
>> After the commit, someone could specify a command line containing:
>>
>> hugepagesz=1G hugepages=16 hugetlb_cma=16G
>>
>> In this case, 16G of CMA will be reserved for 1G huge page allocations
>> after boot time. The parameter 'hugepages=16' is ignored, and the warning
>> message is logged. The warning message should only be logged when the
>> kernel parameter 'hugepages=' is ignored.
>>
>> IMO, it make sense to log a warning if ignoring a user specified parameter.
>> The user should not be attempting boot time allocation and CMA reservation
>> for 1G pages.
>>
>> I do not think we should drop the warning as the it tells the user thay
>> have specified two incompatible allocation options.
>>
>
> I agree. It has value.
>
Hi David,
Sorry my above reply was too quick as I did not take a close look at
the code/patch. See,
https://lore.kernel.org/mm-commits/[email protected]/
This patch is actually in Andrew's tree.
--
Mike Kravetz
On 19.02.21 20:14, Mike Kravetz wrote:
> On 2/19/21 4:39 AM, Chen Wandun wrote:
>> If hugetlb_cma is enabled, it will skip boot time allocation
>> when allocating gigantic page, that doesn't means allocation
>> failure, so suppress this warning info.
>>
>
> Normally the addition of warning messages is discouraged. However, in
> this case the additional message provides value. Why?
>
> Prior to the commit cf11e85fc08c, one could have a kernel command line
> that contains:
>
> hugepagesz=1G hugepages=16
>
> This would allocate 16 1G pages at boot time.
>
> After the commit, someone could specify a command line containing:
>
> hugepagesz=1G hugepages=16 hugetlb_cma=16G
>
> In this case, 16G of CMA will be reserved for 1G huge page allocations
> after boot time. The parameter 'hugepages=16' is ignored, and the warning
> message is logged. The warning message should only be logged when the
> kernel parameter 'hugepages=' is ignored.
>
> IMO, it make sense to log a warning if ignoring a user specified parameter.
> The user should not be attempting boot time allocation and CMA reservation
> for 1G pages.
>
> I do not think we should drop the warning as the it tells the user thay
> have specified two incompatible allocation options.
>
I agree. It has value.
--
Thanks,
David / dhildenb
On 04.03.21 18:20, Mike Kravetz wrote:
> On 3/4/21 1:35 AM, David Hildenbrand wrote:
>> On 19.02.21 20:14, Mike Kravetz wrote:
>>> On 2/19/21 4:39 AM, Chen Wandun wrote:
>>>> If hugetlb_cma is enabled, it will skip boot time allocation
>>>> when allocating gigantic page, that doesn't means allocation
>>>> failure, so suppress this warning info.
>>>>
>>>
>>> Normally the addition of warning messages is discouraged. However, in
>>> this case the additional message provides value. Why?
>>>
>>> Prior to the commit cf11e85fc08c, one could have a kernel command line
>>> that contains:
>>>
>>> hugepagesz=1G hugepages=16
>>>
>>> This would allocate 16 1G pages at boot time.
>>>
>>> After the commit, someone could specify a command line containing:
>>>
>>> hugepagesz=1G hugepages=16 hugetlb_cma=16G
>>>
>>> In this case, 16G of CMA will be reserved for 1G huge page allocations
>>> after boot time. The parameter 'hugepages=16' is ignored, and the warning
>>> message is logged. The warning message should only be logged when the
>>> kernel parameter 'hugepages=' is ignored.
>>>
>>> IMO, it make sense to log a warning if ignoring a user specified parameter.
>>> The user should not be attempting boot time allocation and CMA reservation
>>> for 1G pages.
>>>
>>> I do not think we should drop the warning as the it tells the user thay
>>> have specified two incompatible allocation options.
>>>
>>
>> I agree. It has value.
>>
>
> Hi David,
>
> Sorry my above reply was too quick as I did not take a close look at
> the code/patch. See,
>
> https://lore.kernel.org/mm-commits/[email protected]/
>
> This patch is actually in Andrew's tree.
>
Oh, I missed that discussion - thanks for the pointer!
--
Thanks,
David / dhildenb