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RDMA/umem: ib_umem_get(): use kmalloc() to allocate page array

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ib_umem_get() allocates an array of pointers to struct page for
pin_user_pages_fast() calls during memory registration.

This array can be allocated with kmalloc() as there's nothing special
about it to go directly to the page allocator.

kmalloc() provides a better API that does not require ugly casts and
kfree() does not need to know the size of the freed object.

Performance difference between kmalloc() and __get_free_pages() is not
measurable as both allocators take an object/page from a per-CPU list for
fast path allocations.

For the slow path the performance is anyway determined by the amount of
reclaim involved rather than by what allocator is used.

Replace use of __get_free_page() with kmalloc() and free_page() with
kfree().

Link: https://lore.kernel.org/all/635405e4-9423-4a25-a6e7-e03c8ea0bcbe@redhat.com
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Link: https://patch.msgid.link/20260713-b4-rdma-v2-1-65d2a1a5180c@kernel.org
Signed-off-by: Leon Romanovsky <leon@kernel.org>
This commit is contained in:
Mike Rapoport (Microsoft)
2026-07-13 10:17:22 +03:00
committed by Leon Romanovsky
parent eeb9697db6
commit 66073100a7
1 changed files with 3 additions and 2 deletions
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5
drivers/infiniband/core/umem.c
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@@ -209,7 +209,8 @@ static struct ib_umem *__ib_umem_get_va(struct ib_device *device,
mmgrab(mm);
page_list = (struct page **) __get_free_page(GFP_KERNEL);
/* TODO: switch to "fast and as large as possible" allocation helper */
page_list = kmalloc(PAGE_SIZE, GFP_KERNEL);
if (!page_list) {
ret = -ENOMEM;
goto umem_kfree;
@@ -269,7 +270,7 @@ static struct ib_umem *__ib_umem_get_va(struct ib_device *device,
__ib_umem_release(device, umem, 0);
atomic64_sub(ib_umem_num_pages(umem), &mm->pinned_vm);
out:
free_page((unsigned long) page_list);
kfree(page_list);
umem_kfree:
if (ret) {
mmdrop(umem->owning_mm);