Hi Mike,
On 28/04/20 12:39 am, Mike Kravetz wrote:
> On 4/27/20 10:25 AM, Mike Kravetz wrote:
>> On 4/26/20 10:04 PM, Sandipan Das wrote:
>>> On 18/04/20 12:20 am, Mike Kravetz wrote:
>>>> Now that architectures provide arch_hugetlb_valid_size(), parsing
>>>> of "hugepagesz=" can be done in architecture independent code.
>>>
>>> This isn't working as expected on powerpc64.
>>>
>>> [ 0.000000] Kernel command line:
>>> root=UUID=dc7b49cf-95a2-4996-8e7d-7c64ddc7a6ff hugepagesz=16G hugepages=2
>>> [ 0.000000] HugeTLB: huge pages not supported, ignoring hugepagesz =
>>> 16G
>>> [ 0.000000] HugeTLB: huge pages not supported, ignoring hugepages = 2
>>> [ 0.284177] HugeTLB registered 16.0 MiB page size, pre-allocated 0
>>> pages
>>> [ 0.284182] HugeTLB registered 16.0 GiB page size, pre-allocated 0
>>> pages
>>> [ 2.585062] hugepagesz=16G
>>> [ 2.585063] hugepages=2
>>>
>>
>> In the new arch independent version of hugepages_setup, I added the following
>> code in patch 4 off this series:
>>
>>> + if (!hugepages_supported()) {
>>> + pr_warn("HugeTLB: huge pages not supported, ignoring hugepages
>>> = %s\n", s);
>>> + return 0;
>>> + }
>>> +
>>
>> The easy solution is to remove all the hugepages_supported() checks from
>> command line parsing routines and rely on the later check in hugetlb_init().
>
> Here is a patch to address the issue. Sorry, as my series breaks all hugetlb
> command line processing on powerpc.
>
> Sandipan, can you test the following patch?
>
The following patch does fix the issue. Thanks.
Tested-by: Sandipan Das <sandi...@linux.ibm.com>
> From 480fe2847361e2a85aeec1fb39fe643bb7100a07 Mon Sep 17 00:00:00 2001
> From: Mike Kravetz <mike.krav...@oracle.com>
> Date: Mon, 27 Apr 2020 11:37:30 -0700
> Subject: [PATCH] hugetlbfs: fix changes to command line processing
>
> Previously, a check for hugepages_supported was added before processing
> hugetlb command line parameters. On some architectures such as powerpc,
> hugepages_supported() is not set to true until after command line
> processing. Therefore, no hugetlb command line parameters would be
> accepted.
>
> Remove the additional checks for hugepages_supported. In hugetlb_init,
> print a warning if !hugepages_supported and command line parameters were
> specified.
>
> Signed-off-by: Mike Kravetz <mike.krav...@oracle.com>
> ---
> mm/hugetlb.c | 20 ++++----------------
> 1 file changed, 4 insertions(+), 16 deletions(-)
>
> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> index 1075abdb5717..5548e8851b93 100644
> --- a/mm/hugetlb.c
> +++ b/mm/hugetlb.c
> @@ -3212,8 +3212,11 @@ static int __init hugetlb_init(void)
> {
> int i;
>
> - if (!hugepages_supported())
> + if (!hugepages_supported()) {
> + if (hugetlb_max_hstate || default_hstate_max_huge_pages)
> + pr_warn("HugeTLB: huge pages not supported, ignoring
> associated command-line parameters\n");
> return 0;
> + }
>
> /*
> * Make sure HPAGE_SIZE (HUGETLB_PAGE_ORDER) hstate exists. Some
> @@ -3315,11 +3318,6 @@ static int __init hugepages_setup(char *s)
> unsigned long *mhp;
> static unsigned long *last_mhp;
>
> - if (!hugepages_supported()) {
> - pr_warn("HugeTLB: huge pages not supported, ignoring hugepages
> = %s\n", s);
> - return 0;
> - }
> -
> if (!parsed_valid_hugepagesz) {
> pr_warn("HugeTLB: hugepages=%s does not follow a valid
> hugepagesz, ignoring\n", s);
> parsed_valid_hugepagesz = true;
> @@ -3372,11 +3370,6 @@ static int __init hugepagesz_setup(char *s)
> struct hstate *h;
>
> parsed_valid_hugepagesz = false;
> - if (!hugepages_supported()) {
> - pr_warn("HugeTLB: huge pages not supported, ignoring hugepagesz
> = %s\n", s);
> - return 0;
> - }
> -
> size = (unsigned long)memparse(s, NULL);
>
> if (!arch_hugetlb_valid_size(size)) {
> @@ -3424,11 +3417,6 @@ static int __init default_hugepagesz_setup(char *s)
> unsigned long size;
>
> parsed_valid_hugepagesz = false;
> - if (!hugepages_supported()) {
> - pr_warn("HugeTLB: huge pages not supported, ignoring
> default_hugepagesz = %s\n", s);
> - return 0;
> - }
> -
> if (parsed_default_hugepagesz) {
> pr_err("HugeTLB: default_hugepagesz previously specified,
> ignoring %s\n", s);
> return 0;
>
