On 02.12.2024 11:49, Muchun Song wrote:
On Dec 1, 2024, at 09:03, Dafna Hirschfeld <dafna.hirschfeld@xxxxxxxxx> wrote:
The error ENOSPC is translated in vmf_error to VM_FAULT_SIGBUS which is
further translated in EFAULT in i.e. pin/get_user_pages.
But when running out of pages/hugepages we expect to see ENOMEM and
not EFAULT.
Hi Dafna,
Refers to Documentation/mm/hugetlbfs_reserv.rst. I saw:
If no huge page exists at page fault time, the task is sent
a **SIGBUS** and often dies an unhappy death.
Seems SIGBUS is expected since it is introduced.
Hi,
I see that mlock do return ENOMEM when out of hugepages.
It has the function "__mlock_posix_error_return" that converts EFAULT returned from
"get_user_pages" to ENOMEM.
So callers to "get_user_pages" can override EFAULT with ENOMEM but then it obscure
cases where EFUALT should really be the return code.
thanks,
Dafna
Thanks.
