From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 3D7FB1173F; Sun, 4 Aug 2024 12:41:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722775287; cv=none; b=VnbDxyqINF98NAKqkwZwdQk8bHCpqwUUnNp98Y2whZ/1e8VEErT2oa2KCUbmaHvSDMhoMgo9wiX30S5nCybZYOb6mIMQip08WFFTr68fmgNkOTU1DCUTwMpQUIe1AsS/a/QZhxtp5DlWP88Y4uTH7EtYgEKvnbpc8Zl/4YFWq0Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722775287; c=relaxed/simple; bh=hkFT8J4L9Om4+1HcbHi/qiwu8V1ZSM/CvwWOwoQr0e8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=S9caRLR3gGP/3ny8F2i3YfxJxWElvIG1PLIIQu3X9uhakdvimd1PEb9Y1OR4OmYOBuaOhn6ghLX/IAsn0LHCFsRZUM+0Ylozlf8KX+N1/HPrIAs1d8aGqBA3x7dAjI+udP/Gi+AU7PDhDW/MiZHP6INJ8+9cpCC3rlPsmhv2/QE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=dmMd/l8I; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="dmMd/l8I" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A2F91C32786; Sun, 4 Aug 2024 12:41:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1722775286; bh=hkFT8J4L9Om4+1HcbHi/qiwu8V1ZSM/CvwWOwoQr0e8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=dmMd/l8It6O1W9JfjmfFDGfYINuZODnSID4KpxkP0NtekvoU6YrUG6NYN4ZH/9pHI xKxZvIrMwrj8q4i7KrWJT39S04ic5s9qQq7iFy/UELIirE1HrUGviqhr7huOBefZDx /yU+RSogpIaiWwH7soxSXz7rXVLSDE4WwG/KUA0PPvIT2IjS/g3PnZO8JlZGwNYmMr sZeSuD9DO2pZ3clQWq/zqoF59jPhJFhfEnz3zu0JG6Fmz93XkNcfySbnV8BdDEb+0r 1vvYtJq4IXoyO9u8xoCthfh9FBWYztH89C1NqUAEVzHIV34jE+2xwOqGTJh82rYVfD Jifkz6piRomIg== Date: Sun, 4 Aug 2024 14:41:18 +0200 From: Danilo Krummrich To: Boqun Feng Cc: ojeda@kernel.org, alex.gaynor@gmail.com, wedsonaf@gmail.com, gary@garyguo.net, bjorn3_gh@protonmail.com, benno.lossin@proton.me, a.hindborg@samsung.com, aliceryhl@google.com, akpm@linux-foundation.org, daniel.almeida@collabora.com, faith.ekstrand@collabora.com, boris.brezillon@collabora.com, lina@asahilina.net, mcanal@igalia.com, zhiw@nvidia.com, acurrid@nvidia.com, cjia@nvidia.com, jhubbard@nvidia.com, airlied@redhat.com, ajanulgu@redhat.com, lyude@redhat.com, linux-kernel@vger.kernel.org, rust-for-linux@vger.kernel.org, linux-mm@kvack.org, Vlastimil Babka Subject: Re: [PATCH v3 06/25] rust: alloc: implement `Vmalloc` allocator Message-ID: References: <20240801000641.1882-1-dakr@kernel.org> <20240801000641.1882-7-dakr@kernel.org> Precedence: bulk X-Mailing-List: rust-for-linux@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Sat, Aug 03, 2024 at 11:44:58PM -0700, Boqun Feng wrote: > On Thu, Aug 01, 2024 at 02:02:05AM +0200, Danilo Krummrich wrote: > > Implement `Allocator` for `Vmalloc`, the kernel's virtually contiguous > > allocator, typically used for larger objects, (much) larger than page > > size. > > > > All memory allocations made with `Vmalloc` end up in `vrealloc()`. > > > > Signed-off-by: Danilo Krummrich > > --- > > rust/helpers.c | 8 ++++++++ > > rust/kernel/alloc/allocator.rs | 24 ++++++++++++++++++++++++ > > rust/kernel/alloc/allocator_test.rs | 1 + > > 3 files changed, 33 insertions(+) > > > > diff --git a/rust/helpers.c b/rust/helpers.c > > index 92d3c03ae1bd..4c628986f0c9 100644 > > --- a/rust/helpers.c > > +++ b/rust/helpers.c > > @@ -33,6 +33,7 @@ > > #include > > #include > > #include > > +#include > > #include > > #include > > > > @@ -200,6 +201,13 @@ rust_helper_krealloc(const void *objp, size_t new_size, gfp_t flags) > > } > > EXPORT_SYMBOL_GPL(rust_helper_krealloc); > > > > +void * __must_check __realloc_size(2) > > +rust_helper_vrealloc(const void *p, size_t size, gfp_t flags) > > +{ > > + return vrealloc(p, size, flags); > > +} > > +EXPORT_SYMBOL_GPL(rust_helper_vrealloc); > > + > > /* > > * `bindgen` binds the C `size_t` type as the Rust `usize` type, so we can > > * use it in contexts where Rust expects a `usize` like slice (array) indices. > > diff --git a/rust/kernel/alloc/allocator.rs b/rust/kernel/alloc/allocator.rs > > index 397ae5bcc043..e9a3d0694f41 100644 > > --- a/rust/kernel/alloc/allocator.rs > > +++ b/rust/kernel/alloc/allocator.rs > > @@ -16,6 +16,12 @@ > > /// `bindings::krealloc`. > > pub struct Kmalloc; > > > > +/// The virtually contiguous kernel allocator. > > +/// > > +/// The vmalloc allocator allocates pages from the page level allocator and maps them into the > > +/// contiguous kernel virtual space. > > +pub struct Vmalloc; > > + > > /// Returns a proper size to alloc a new object aligned to `new_layout`'s alignment. > > fn aligned_size(new_layout: Layout) -> usize { > > // Customized layouts from `Layout::from_size_align()` can have size < align, so pad first. > > @@ -58,6 +64,10 @@ fn krealloc() -> Self { > > Self(bindings::krealloc) > > } > > > > + fn vrealloc() -> Self { > > + Self(bindings::vrealloc) > > + } > > + > > // SAFETY: `call` has the exact same safety requirements as `Allocator::realloc`. > > unsafe fn call( > > &self, > > @@ -136,6 +146,20 @@ unsafe fn alloc_zeroed(&self, layout: Layout) -> *mut u8 { > > } > > } > > > > +unsafe impl Allocator for Vmalloc { > > + unsafe fn realloc( > > + ptr: Option>, > > + layout: Layout, > > + flags: Flags, > > + ) -> Result, AllocError> { > > + let realloc = ReallocFunc::vrealloc(); > > + > > IIUC, vrealloc() calls __vmalloc_noprof() in allocation case, that is > calling __vmalloc_node_noprof() with align=1. In such a case, how would > vmalloc() guarantee the allocated memory is aligned to layout.align()? True, good catch. I thought of this a while ago and then forgot to fix it. > > [Cc Vlastimil] > > Regards, > Boqun > > > + // SAFETY: If not `None`, `ptr` is guaranteed to point to valid memory, which was previously > > + // allocated with this `Allocator`. > > + unsafe { realloc.call(ptr, layout, flags) } > > + } > > +} > > + > > #[global_allocator] > > static ALLOCATOR: Kmalloc = Kmalloc; > > > > diff --git a/rust/kernel/alloc/allocator_test.rs b/rust/kernel/alloc/allocator_test.rs > > index 4785efc474a7..e7bf2982f68f 100644 > > --- a/rust/kernel/alloc/allocator_test.rs > > +++ b/rust/kernel/alloc/allocator_test.rs > > @@ -7,6 +7,7 @@ > > use core::ptr::NonNull; > > > > pub struct Kmalloc; > > +pub type Vmalloc = Kmalloc; > > > > unsafe impl Allocator for Kmalloc { > > unsafe fn realloc( > > -- > > 2.45.2 > > >