From 291f72c55aeffc663d7d49626e10fd6970696b84 Mon Sep 17 00:00:00 2001
From: Bruno Rodrigues <bruno@brodrigues.co>
Date: Fri, 9 Aug 2024 15:03:27 +0200
Subject: [PATCH 1/3] rPackages.torch: use binary

---
 pkgs/development/r-modules/default.nix | 21 +++++++++++++++++----
 1 file changed, 17 insertions(+), 4 deletions(-)

diff --git a/pkgs/development/r-modules/default.nix b/pkgs/development/r-modules/default.nix
index 678604f04af2e..8937f8ce4a52f 100644
--- a/pkgs/development/r-modules/default.nix
+++ b/pkgs/development/r-modules/default.nix
@@ -1803,10 +1803,23 @@ let
       '';
     });
 
-    torch = old.torch.overrideAttrs (attrs: {
-      preConfigure = ''
-        patchShebangs configure
-      '';
+    torch = let
+      # Sets the correct string to download either the binary for
+      # the cpu version of the torch package, or the
+      # the cuda-enabled version.
+      # To use gpu acceleration, set `config.cudaSupport = true;`
+      # when importing nixpkgs in your shell
+       accel = if pkgs.config.cudaSupport then "cu118" else "cpu";
+
+       binary_sha = if pkgs.config.cudaSupport then
+         "sha256-a80sG89C0svZzkjNRpY0rTR2P1JdvKAbWDGIIghsv2Y=" else
+         "sha256-qUn8Rot6ME7iTvtNd52iw3ebqMnpLz7kwl/9GoPHD+I=";
+      in
+     old.torch.overrideAttrs (attrs: {
+      src = pkgs.fetchzip {
+       url = "https://torch-cdn.mlverse.org/packages/${accel}/0.13.0/src/contrib/torch_0.13.0_R_x86_64-pc-linux-gnu.tar.gz";
+       sha256 = binary_sha;
+      };
     });
 
     pak = old.pak.overrideAttrs (attrs: {

From 6b4943ee634127b42303e35cdf55d461f4a7e19a Mon Sep 17 00:00:00 2001
From: Bruno Rodrigues <bruno@brodrigues.co>
Date: Fri, 9 Aug 2024 15:05:13 +0200
Subject: [PATCH 2/3] doc: update R section to explain how to use gpu
 acceleration for torch

---
 doc/languages-frameworks/r.section.md | 48 +++++++++++++++++++++++++++
 1 file changed, 48 insertions(+)

diff --git a/doc/languages-frameworks/r.section.md b/doc/languages-frameworks/r.section.md
index ad0fb10987c98..21829586fbb0e 100644
--- a/doc/languages-frameworks/r.section.md
+++ b/doc/languages-frameworks/r.section.md
@@ -94,6 +94,54 @@ Executing `nix-shell` will then drop you into an environment equivalent to the
 one above. If you need additional packages just add them to the list and
 re-enter the shell.
 
+## torch with GPU acceleration {#torch-gpu-accel}
+
+The `torch` package included in `nixpkgs` is based on the binary packages by the
+mlverse team. By default, the CPU version of the package is installed. On Linux
+distributions other than NixOS, it is possible to enable GPU acceleration by
+setting `config.cudaSupport` to true when importing `nixpkgs` in a `shell.nix`.
+You will also need to use `nixglhost`. Here is an example of such a shell:
+
+```nix
+{ pkgs ? import <nixpkgs> {config.cudaSupport = true; }, lib ? pkgs.lib }:
+
+let
+ nixglhost-sources = pkgs.fetchFromGitHub {
+   owner = "numtide";
+   repo = "nix-gl-host";
+   rev = "main";
+   # Replace this with the hash Nix will complain about, TOFU style.
+   hash = "";
+ };
+
+ nixglhost = pkgs.callPackage "${nixglhost-sources}/default.nix" { };
+
+ rpkgs = builtins.attrValues {
+   inherit (pkgs.rPackages)
+     torch;
+ };
+
+ wrapped_pkgs = pkgs.rWrapper.override {
+   packages = [ rpkgs ];
+ };
+
+in pkgs.mkShell {
+  buildInputs = [
+    nixglhost
+    wrapped_pkgs
+  ];
+}
+
+```
+
+After executing `nix-shell` to drop in that environment, call `nixglhost R` to
+start a GPU accelerated R session. Test that everything worked well by calling
+`torch::cuda_memory_summary()` which should return a list of summary statistics
+regarding the available GPU memory.
+
+We are looking for contributors that could help us package the darwin binaries
+as well as fix `torch` for NixOS as well.
+
 ## Updating the package set {#updating-the-package-set}
 
 There is a script and associated environment for regenerating the package

From 3482c1135c52147baecd400b309f9bfde563e16c Mon Sep 17 00:00:00 2001
From: Someone Serge <sergei.kozlukov@aalto.fi>
Date: Fri, 16 Aug 2024 13:41:29 +0000
Subject: [PATCH 3/3] rPackages.torch: (torch-bin) link cuda libraries

---
 pkgs/development/r-modules/default.nix | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/pkgs/development/r-modules/default.nix b/pkgs/development/r-modules/default.nix
index 8937f8ce4a52f..bf1c3e22b6cbd 100644
--- a/pkgs/development/r-modules/default.nix
+++ b/pkgs/development/r-modules/default.nix
@@ -1816,6 +1816,16 @@ let
          "sha256-qUn8Rot6ME7iTvtNd52iw3ebqMnpLz7kwl/9GoPHD+I=";
       in
      old.torch.overrideAttrs (attrs: {
+       nativeBuildInputs = attrs.nativeBuildInputs or [ ] ++ [
+         pkgs.autoPatchelfHook
+         pkgs.autoAddDriverRunpath
+       ];
+      buildInputs = attrs.buildInputs or [ ] ++ [
+        "${lib.getLib R}/lib/R" # libR
+        pkgs.zlib
+      ] ++ lib.optionals pkgs.config.cudaSupport [
+        pkgs.cudaPackages.cuda_cudart
+      ];
       src = pkgs.fetchzip {
        url = "https://torch-cdn.mlverse.org/packages/${accel}/0.13.0/src/contrib/torch_0.13.0_R_x86_64-pc-linux-gnu.tar.gz";
        sha256 = binary_sha;