From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 31E0B35A3BF; Mon, 13 Jul 2026 07:17:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783927048; cv=none; b=O/Sy4TYnZ/DP2WPl6ItXW0zt/8JQfY57gHnFrJhmGBUx7H8u+P5k+EIGFD7p0nnElZj8Hg7R88dbTWvYN/HhN5OMp/J51gGdGEa7hJmFZPRUHIemntAxAmoyyfrbpc7xbCuVZVLxeXwUUPlTApfV5nc0zmH7DCs/ca8STemZLg4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783927048; c=relaxed/simple; bh=3aMpVNkIfCpNjyvsoQXjAGPkKSP0K1S4+Hi4PRHTbec=; h=From:Subject:Date:Message-Id:MIME-Version:Content-Type:To:Cc; b=tG0dvpx7z/ZUPpzGGjJLIOmHvEsL/fnywhTT+/HWYQe80QmSMGDBrihHrPYxwIokgE+phw2fteVRks/gaMsA6ST1Jkcn+Uvt2mTL8zR64CM2kjNvU+ogkq1nW2rZQNcis/LO5BRgtjmBtOaPB9HL5K2Hx9JOsnZf7qTI3z0llSA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=he5Tv/j7; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="he5Tv/j7" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 22BCB1F000E9; Mon, 13 Jul 2026 07:17:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1783927046; bh=fwA5EpywXnBLHbH1Cr7rvC6VIBFsJ89S1zKzZ9uxu9I=; h=From:Subject:Date:To:Cc; b=he5Tv/j7cf3zzOFF47BF5dVhJt/X5kCa24N3c52eT8BHbY1t0kZ4lsYFZbV9vUrhx AZvs71m9CxHplrEPXkiso3D1O4Rmy+cU8viW9XHnJsbrrbOyqIjdn+rFAw7A+h7PMb TKUHscFL/5MvI6sFQFSc/yeudYs3k8SLDfuYsg2lxDUcUrFMTpZ2wMaZepgCa/uXvx jKwUpdXiZ6NLweDj9z8bjCYNyN3AEPOqievSC5pB7aTB+ceLStoBEqdCP1k6BzH0Ju lbGrgl6zuqLu1YCxoIXEo/CxNSZEncKtqEpGGqZONcJwBKnzMTSPfhQNeNPXmiwpbe Dy1O+vMvMTxzQ== From: "Mike Rapoport (Microsoft)" Subject: [PATCH v2 0/5] RDMA, IB: replace __get_free_pages() with kmalloc() Date: Mon, 13 Jul 2026 10:17:21 +0300 Message-Id: <20260713-b4-rdma-v2-0-65d2a1a5180c@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-B4-Tracking: v=1; b=H4sIAAGRVGoC/0WOyw6CMBBFf4V07Zh2rE1w5X8YFm0ZoD4KmSLRE P5diiYuz819zSIRB0riVMyCaQop9HEF3BXCdza2BKFeWaBEI42S4DRw/bCgtcFjidiQMmJ1D0x NeG1Nl+rL6emu5Mcczw5nE4FjG32XpYxZ7kIae35vDyaV47+xw39sUiDBOo3ON7KmEs834kj3f c+tqJZl+QByGhutyAAAAA== X-Change-ID: 20260610-b4-rdma-44625922fe16 To: Jason Gunthorpe , Leon Romanovsky Cc: Dennis Dalessandro , Mike Rapoport , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-rdma@vger.kernel.org X-Mailer: b4 0.16-dev This is a (small) part of larger work of replacing page allocator calls with kmalloc. My initial intention a few month ago was to remove ugly casts [1], but then willy pointed out that Linus objected to something like this [2] and it looks like more than a decade old technical debt. Largely, anything that doesn't need struct page (or a memdesc in the future) should just use kmalloc() or kvmalloc() to allocate memory. kmalloc() guarantees alignment, physical contiguity and working virt_to_phys() and beside nicer API that returns void * on alloc and doesn't require to know the allocation size on free, kmalloc() provides better debugging capabilities than page allocator. Another thing is that touching these allocation sites gives the reviewers opportunity to see if a PAGE_SIZE buffer is actually needed or maybe another size is appropriate. For larger allocations that don't need physically contiguous memory kvmalloc() can be a better option that __get_free_pages() because under memory pressure it's is easier to allocate several order-0 pages than a physically contiguous chunk with the same number of pages. And last, but not least, removing needless calls to page allocator should help with memdesc (aka project folio) conversion. There will be way less places to audit to see if the user was actually using struct page. Also in git: https://git.kernel.org/pub/scm/linux/kernel/git/rppt/linux.git gfp-to-kmalloc/rdma [1] https://lore.kernel.org/all/20251018093002.3660549-1-rppt@kernel.org/ [2] https://lore.kernel.org/all/CA+55aFwp4iy4rtX2gE2WjBGFL=NxMVnoFeHqYa2j1dYOMMGqxg@mail.gmail.com/ --- v2 changes: * add comment to keep markers for sites that need "fast and as large as possible" allocation helper v1: https://patch.msgid.link/20260630-b4-rdma-v1-0-ab42bcf0de92@kernel.org --- Mike Rapoport (Microsoft) (5): RDMA/umem: ib_umem_get(): use kmalloc() to allocate page array RDMA/mlx5: replace __get_free_page() with kmalloc() IB/mthca: mthca_reg_user_mr(): use kmalloc() to allocate addresses array IB/mthca: allocate mthca_array memory with kzalloc() IB/rdmavt: use kzalloc() to allocate QPN-map pages drivers/infiniband/core/umem.c | 5 +++-- drivers/infiniband/hw/mlx5/odp.c | 6 ++++-- drivers/infiniband/hw/mthca/mthca_allocator.c | 6 +++--- drivers/infiniband/hw/mthca/mthca_provider.c | 5 +++-- drivers/infiniband/sw/rdmavt/qp.c | 8 ++++---- 5 files changed, 17 insertions(+), 13 deletions(-) --- base-commit: dc59e4fea9d83f03bad6bddf3fa2e52491777482 change-id: 20260610-b4-rdma-44625922fe16 -- Sincerely yours, Mike.