From nobody Tue Oct 7 14:06:27 2025 Received: from mailrelay-egress16.pub.mailoutpod3-cph3.one.com (mailrelay-egress16.pub.mailoutpod3-cph3.one.com [46.30.212.3]) (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 CA661226D1F for ; Wed, 9 Jul 2025 17:25:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=46.30.212.3 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752081916; cv=none; b=TKBlNg4Vl72j6TN9a37WUWvMMsP8mY5W0/ZnOSMc4em7B+Jd0dNE4F0t1g0vJa3ovfkMkXmgvzrNo84aFyjNEh9fkyL6hEkqDb07xMgG5vOHTyu8yuM/vsf8OMrm+h7YzRpLT1lkYuKyw+DphbhORpuNHuUUuu4gzsUkVpDwdkQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752081916; c=relaxed/simple; bh=7qxUEpd9QQwyJkAUKS96AZjZQn2zLtt4fGlO5K0b0ck=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=HDcIlzU2J9pCc7R9UGT6Z8fKcY6Mnfr10zRBts5+2ryNDt4/9Qq74WxWb0hKHccuSQtqxzsfkuYUUL9gXEH3mdlYu5nHQqIA/ni4LDTE125sU/0O0P36EDXNGSQJkRONI71WNSI+J5FlfqQCp0VY8rrM7pN95j67R32Se0Y5gnU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=konsulko.se; spf=none smtp.mailfrom=konsulko.se; dkim=pass (2048-bit key) header.d=konsulko.se header.i=@konsulko.se header.b=gDlorIcp; dkim=permerror (0-bit key) header.d=konsulko.se header.i=@konsulko.se header.b=hbTRQwrw; arc=none smtp.client-ip=46.30.212.3 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=konsulko.se Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=konsulko.se Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=konsulko.se header.i=@konsulko.se header.b="gDlorIcp"; dkim=permerror (0-bit key) header.d=konsulko.se header.i=@konsulko.se header.b="hbTRQwrw" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; t=1752081913; x=1752686713; d=konsulko.se; s=rsa1; h=content-transfer-encoding:mime-version:references:in-reply-to:message-id:date: subject:cc:to:from:from; bh=Nu0TsAG+vOSry9MLpyc10rSWYKN4T+im9PUF68OMJYc=; b=gDlorIcpYUSIFo7TewO6/tewDFxmcd30T308/OpE0QQ0XIbDPH1eYtwkKzLAvTZmu5JsqploH9Ojo lL92YSsOyOCFFlKm1vfW43iI5ZU/4fzOFhgWcpEjRUzfIg3Mf2JzyremNE8vSQ1gUFiafB/TbPUOLN rlzyv/LBfEy9Sjt3cSkuUd0iVPMPGtI8H29etlNsdnxySbKCkTLKEO+p8TKVYyKXk2FPIvAEukj17O Imc+oAQXX42cENue3RWpHTnmrwLLKvvONflJbdoY3dHKXyxMjsKGUApd1NbQlgebYZSF+bCdObpG3L 6wUjD+O5v7t9xDQDEfwG5qBeRe+PQRA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; t=1752081913; x=1752686713; d=konsulko.se; s=ed1; h=content-transfer-encoding:mime-version:references:in-reply-to:message-id:date: subject:cc:to:from:from; bh=Nu0TsAG+vOSry9MLpyc10rSWYKN4T+im9PUF68OMJYc=; b=hbTRQwrwvqMgxQQTs4t4pHabuI1+rrkDmtI1Wq76M65pbyGP+qj9aaIo5ouUy7ojNfcR2uqh1XVVF 4wm/tklBA== X-HalOne-ID: aace5762-5ce9-11f0-a52e-632fe8569f3f Received: from slottsdator.home (host-90-238-19-233.mobileonline.telia.com [90.238.19.233]) by mailrelay2.pub.mailoutpod3-cph3.one.com (Halon) with ESMTPSA id aace5762-5ce9-11f0-a52e-632fe8569f3f; Wed, 09 Jul 2025 17:25:12 +0000 (UTC) From: Vitaly Wool To: linux-mm@kvack.org Cc: akpm@linux-foundation.org, linux-kernel@vger.kernel.org, Uladzislau Rezki , Danilo Krummrich , Alice Ryhl , Vlastimil Babka , rust-for-linux@vger.kernel.org, Lorenzo Stoakes , "Liam R . Howlett" , Kent Overstreet , linux-bcachefs@vger.kernel.org, bpf@vger.kernel.org, Herbert Xu , Jann Horn , Pedro Falcato , Vitaly Wool Subject: [PATCH v12 4/4] rust: support large alignments in allocations Date: Wed, 9 Jul 2025 19:25:09 +0200 Message-Id: <20250709172509.1032067-1-vitaly.wool@konsulko.se> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20250709172345.1031907-1-vitaly.wool@konsulko.se> References: <20250709172345.1031907-1-vitaly.wool@konsulko.se> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Add support for large (> PAGE_SIZE) alignments in Rust allocators. All the preparations on the C side are already done, we just need to add bindings for _node_align() functions and start using those. Signed-off-by: Vitaly Wool Acked-by: Danilo Krummrich --- rust/helpers/slab.c | 10 ++++++---- rust/helpers/vmalloc.c | 5 +++-- rust/kernel/alloc/allocator.rs | 29 +++++++++-------------------- 3 files changed, 18 insertions(+), 26 deletions(-) diff --git a/rust/helpers/slab.c b/rust/helpers/slab.c index 8472370a4338..d729be798f31 100644 --- a/rust/helpers/slab.c +++ b/rust/helpers/slab.c @@ -3,13 +3,15 @@ #include =20 void * __must_check __realloc_size(2) -rust_helper_krealloc_node(const void *objp, size_t new_size, gfp_t flags, = int node) +rust_helper_krealloc_node_align(const void *objp, size_t new_size, unsigne= d long align, + gfp_t flags, int node) { - return krealloc_node(objp, new_size, flags, node); + return krealloc_node_align(objp, new_size, align, flags, node); } =20 void * __must_check __realloc_size(2) -rust_helper_kvrealloc_node(const void *p, size_t size, gfp_t flags, int no= de) +rust_helper_kvrealloc_node_align(const void *p, size_t size, unsigned long= align, + gfp_t flags, int node) { - return kvrealloc_node(p, size, flags, node); + return kvrealloc_node_align(p, size, align, flags, node); } diff --git a/rust/helpers/vmalloc.c b/rust/helpers/vmalloc.c index 62d30db9a1a6..7d7f7336b3d2 100644 --- a/rust/helpers/vmalloc.c +++ b/rust/helpers/vmalloc.c @@ -3,7 +3,8 @@ #include =20 void * __must_check __realloc_size(2) -rust_helper_vrealloc_node(const void *p, size_t size, gfp_t flags, int nod= e) +rust_helper_vrealloc_node_align(const void *p, size_t size, unsigned long = align, + gfp_t flags, int node) { - return vrealloc_node(p, size, flags, node); + return vrealloc_node_align(p, size, align, flags, node); } diff --git a/rust/kernel/alloc/allocator.rs b/rust/kernel/alloc/allocator.rs index 8af7e04e3cc6..429d1b060f31 100644 --- a/rust/kernel/alloc/allocator.rs +++ b/rust/kernel/alloc/allocator.rs @@ -56,25 +56,26 @@ fn aligned_size(new_layout: Layout) -> usize { =20 /// # Invariants /// -/// One of the following: `krealloc_node`, `vrealloc_node`, `kvrealloc_nod= e`. +/// One of the following: `krealloc_node_align`, `vrealloc_node_align`, `k= vrealloc_node_align`. struct ReallocFunc( unsafe extern "C" fn( *const crate::ffi::c_void, usize, + crate::ffi::c_ulong, u32, crate::ffi::c_int, ) -> *mut crate::ffi::c_void, ); =20 impl ReallocFunc { - // INVARIANT: `krealloc_node` satisfies the type invariants. - const KREALLOC: Self =3D Self(bindings::krealloc_node); + // INVARIANT: `krealloc_node_align` satisfies the type invariants. + const KREALLOC: Self =3D Self(bindings::krealloc_node_align); =20 - // INVARIANT: `vrealloc_node` satisfies the type invariants. - const VREALLOC: Self =3D Self(bindings::vrealloc_node); + // INVARIANT: `vrealloc_node_align` satisfies the type invariants. + const VREALLOC: Self =3D Self(bindings::vrealloc_node_align); =20 - // INVARIANT: `kvrealloc_node` satisfies the type invariants. - const KVREALLOC: Self =3D Self(bindings::kvrealloc_node); + // INVARIANT: `kvrealloc_node_align` satisfies the type invariants. + const KVREALLOC: Self =3D Self(bindings::kvrealloc_node_align); =20 /// # Safety /// @@ -116,7 +117,7 @@ unsafe fn call( // - Those functions provide the guarantees of this function. let raw_ptr =3D unsafe { // If `size =3D=3D 0` and `ptr !=3D NULL` the memory behind th= e pointer is freed. - self.0(ptr.cast(), size, flags.0, nid.0).cast() + self.0(ptr.cast(), size, layout.align(), flags.0, nid.0).cast() }; =20 let ptr =3D if size =3D=3D 0 { @@ -160,12 +161,6 @@ unsafe fn realloc( flags: Flags, nid: NumaNode, ) -> Result, AllocError> { - // TODO: Support alignments larger than PAGE_SIZE. - if layout.align() > bindings::PAGE_SIZE { - pr_warn!("Vmalloc does not support alignments larger than PAGE= _SIZE yet.\n"); - return Err(AllocError); - } - // SAFETY: If not `None`, `ptr` is guaranteed to point to valid me= mory, which was previously // allocated with this `Allocator`. unsafe { ReallocFunc::VREALLOC.call(ptr, layout, old_layout, flags= , nid) } @@ -185,12 +180,6 @@ unsafe fn realloc( flags: Flags, nid: NumaNode, ) -> Result, AllocError> { - // TODO: Support alignments larger than PAGE_SIZE. - if layout.align() > bindings::PAGE_SIZE { - pr_warn!("KVmalloc does not support alignments larger than PAG= E_SIZE yet.\n"); - return Err(AllocError); - } - // SAFETY: If not `None`, `ptr` is guaranteed to point to valid me= mory, which was previously // allocated with this `Allocator`. unsafe { ReallocFunc::KVREALLOC.call(ptr, layout, old_layout, flag= s, nid) } --=20 2.39.2