Re: [RFC PATCH 3/3] powerpc/mm/hugetlb: Don't enable HugeTLB if we don't have a page table cache
From: Michael Ellerman <mpe@ellerman.id.au>
Date: 2019-05-16 14:48:31
"Aneesh Kumar K.V" [off-list ref] writes:
quoted hunk ↗ jump to hunk
This makes sure we don't enable HugeTLB if the cache is not configured. I am still not sure about this. IMHO hugetlb support should be a hardware support derivative and any cache allocation failure should be handled as I did in the earlier patch. But then if we were not able to create hugetlb page table cache, we can as well declare hugetlb support disabled thereby avoiding calling into allocation routines. Signed-off-by: Aneesh Kumar K.V <redacted> --- arch/powerpc/mm/hugetlbpage.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-)diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c index ee16a3fb788a..4bf8bc659cc7 100644 --- a/arch/powerpc/mm/hugetlbpage.c +++ b/arch/powerpc/mm/hugetlbpage.c@@ -602,6 +602,7 @@ __setup("hugepagesz=", hugepage_setup_sz); static int __init hugetlbpage_init(void) { int psize; + bool configured = false;
Where's my reverse Christmas tree! :)
quoted hunk ↗ jump to hunk
if (hugetlb_disabled) { pr_info("HugeTLB support is disabled!\n");@@ -651,10 +652,16 @@ static int __init hugetlbpage_init(void) pgtable_cache_add(pdshift - shift); else if (IS_ENABLED(CONFIG_PPC_FSL_BOOK3E) || IS_ENABLED(CONFIG_PPC_8xx)) pgtable_cache_add(PTE_T_ORDER); + + if (!configured) + configured = true;
I'd just not worry about the if.
}
- if (IS_ENABLED(CONFIG_HUGETLB_PAGE_SIZE_VARIABLE))
- hugetlbpage_init_default();
+ if (configured) {
+ if (IS_ENABLED(CONFIG_HUGETLB_PAGE_SIZE_VARIABLE))
+ hugetlbpage_init_default();
+ } else
+ pr_info("Disabling HugeTLB");We're not actually doing anything to disable it in the CONFIG_HUGETLB_PAGE_SIZE_VARIABLE=n case, but I guess the print is still correct because we didn't enable a size in the for loop above? Can we make it a bit more explicit? Maybe like: "Disabling HugeTLB, no usable page sizes found." ?? cheers