Messages in this thread | | | Date | Wed, 12 Jul 2017 12:15:10 -0300 | From | victora <> | Subject | Re: [PATCH] powerpc/mm: Implemented default_hugepagesz verification for powerpc |
| |
Em 2017-07-05 13:03, victora escreveu: > Em 2017-07-05 01:26, Aneesh Kumar K.V escreveu: >> On Tuesday 04 July 2017 01:35 AM, Victor Aoqui wrote: >>> Implemented default hugepage size verification (default_hugepagesz=) >>> in order to allow allocation of defined number of pages (hugepages=) >>> only for supported hugepage sizes. >>> >>> Signed-off-by: Victor Aoqui <victora@br.ibm.com> >>> --- >>> arch/powerpc/mm/hugetlbpage.c | 15 +++++++++++++++ >>> 1 file changed, 15 insertions(+) >>> >>> diff --git a/arch/powerpc/mm/hugetlbpage.c >>> b/arch/powerpc/mm/hugetlbpage.c >>> index a4f33de..464e72e 100644 >>> --- a/arch/powerpc/mm/hugetlbpage.c >>> +++ b/arch/powerpc/mm/hugetlbpage.c >>> @@ -797,6 +797,21 @@ static int __init hugepage_setup_sz(char *str) >>> } >>> __setup("hugepagesz=", hugepage_setup_sz); >>> >>> +static int __init default_hugepage_setup_sz(char *str) >>> +{ >>> + unsigned long long size; >>> + >>> + size = memparse(str, &str); >>> + >>> + if (add_huge_page_size(size) != 0) { >>> + hugetlb_bad_size(); >>> + pr_err("Invalid default huge page size >>> specified(%llu)\n", size); >>> + } >>> + >>> + return 1; >>> +} >>> +__setup("default_hugepagesz=", default_hugepage_setup_sz); >> >> isn't that a behavior change in what we have now ? . Right now if size >> specified is not supported, we fallback to HPAGE_SIZE. > > Yes, it is. However, is this a correct behavior? If we specify an > unsupported value, for example default_hugepagesz=1M and > hugepages=1000, 1M will be ignored and 1000 pages of 16M (arch > default) will be allocated. This could lead to non-expected out of of > memory/performance issue. > >> >> mm/hugetlb.c >> >> if (!size_to_hstate(default_hstate_size)) { >> default_hstate_size = HPAGE_SIZE; >> if (!size_to_hstate(default_hstate_size)) >> hugetlb_add_hstate(HUGETLB_PAGE_ORDER); >> } >> >> >>> + >>> struct kmem_cache *hugepte_cache; >>> static int __init hugetlbpage_init(void) >>> { >>> >> >> Even if we want to do this, this should be done in generic code and >> should not be powerpc specific >> > > The verification of supported powerpc hugepage size (hugepagesz=) is > being performed on add_huge_page_size(), which is currently defined in > arch/powerpc/mm/hugetlbpage.c. I think it makes more sense to > implement default_hugepagesz= verification on arch/powerpc, don't you > think? > >> -aneesh
Hi Aneesh,
Did you have time to review the comments above?
Thanks Victor
| |