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IB/mthca: mthca_reg_user_mr(): use kmalloc() to allocate addresses array

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mthca_reg_user_mr() allocates an array of DMA addresses during memory
registration.

This buffer 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-v2-3-65d2a1a5180c@kernel.org
Signed-off-by: Leon Romanovsky <leon@kernel.org>
This commit is contained in:
Mike Rapoport (Microsoft) 2026-07-13 10:17:24 +03:00 committed by Leon Romanovsky
parent e3d8c413e2
commit 5036553f0e
1 changed files with 3 additions and 2 deletions
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5
drivers/infiniband/hw/mthca/mthca_provider.c
View File

@ -893,7 +893,8 @@ static struct ib_mr *mthca_reg_user_mr(struct ib_pd *pd, u64 start, u64 length,
goto err_umem;
}
pages = (u64 *) __get_free_page(GFP_KERNEL);
/* TODO: switch to "fast and as large as possible" allocation helper */
pages = kmalloc(PAGE_SIZE, GFP_KERNEL);
if (!pages) {
err = -ENOMEM;
goto err_mtt;
@ -922,7 +923,7 @@ static struct ib_mr *mthca_reg_user_mr(struct ib_pd *pd, u64 start, u64 length,
if (i)
err = mthca_write_mtt(dev, mr->mtt, n, pages, i);
mtt_done:
free_page((unsigned long) pages);
kfree(pages);
if (err)
goto err_mtt;