ib_umem_find_best_pgsz(9)

💖 ib_umem_find_best_pgsz(9) 💖

okay bestie, this is the Kernel API Manual page for ib_umem_find_best_pgsz(9), and it's literally the "which HW page size is best for this MR" helper. We're gonna keep all the deets, no cap. 🫶

🌸 NAME 🌸

ib_umem_find_best_pgsz — Find best HW page size to use for this MR ✨

✨ SYNOPSIS ✨

unsigned long ib_umem_find_best_pgsz (struct ib_umem *umem , unsigned
       long pgsz_bitmap , u64 virt );

🎀 ARGUMENTS 🎀

• umem — the umem struct. That's it, that's the vibe. 💅
• pgsz_bitmap — a bitmap of HW supported page sizes. Like the menu of page sizes your hardware can serve. 🍓
• virt — the IOVA. 👑

🦋 DESCRIPTION 🦋

This helper is intended for HW that can juggle multiple page sizes but can do only a single page size in an MR. It's giving "pick one, bestie" energy. 😭

It returns 0 if the umem requires page sizes not supported by the driver to be mapped. So a 0 is the "nope, can't map this with the sizes your driver supports" result. 💀

Drivers always supporting PAGE_SIZE or smaller will never see a 0 result. Iconic, honestly. 🎀

🌈 SEE ALSO 🌈

Kernel file ./drivers/infiniband/core/umem.c — go read the source, bestie:

• ib_umem_get_desc(9)
• ib_umem_get_attr(9)
• ib_umem_get_attr_or_va(9)
• ib_umem_get_cq_buf(9)
• ib_umem_get_cq_buf_or_va(9)
• ib_umem_release(9)

okay that's the whole page! source/version vibe: ./drivers/infiniband/core; dated October 2026; page: ib_umem_find_best_pgsz(9). mwah 💖🦋💅