feat: allow hwloc to be optional, but enabled by default

README.md

@@ -56,13 +56,37 @@ The instructions below assume you have independently installed `rust-fil-proofs`
 
 Before building you will need OpenCL to be installed. On Ubuntu, this can be achieved with `apt install ocl-icd-opencl-dev`.  Other system dependencies such as 'gcc/clang', 'wall' and 'cmake' are also required.
 
-You will also need to install the hwloc library. On Ubuntu, this can be achieved with `apt install hwloc libhwloc-dev`. For other platforms, please see the [hwloc-rs Prerequisites section](https://github.com/daschl/hwloc-rs).
+For the `multicore sdr` feature (enabled by default), you will also need to install the `hwloc` library. On Ubuntu, this can be achieved with `apt install hwloc libhwloc-dev`. For other platforms, please see the [hwloc-rs Prerequisites section](https://github.com/daschl/hwloc-rs).
 
 
 ```
 > cargo build --release --all
 ```
 
+The `hwloc` dependency is optional and may be disabled.  Disabling it will not allow the `multicore sdr` feature to be used.  The fallback is single core replication, which is the default unless specified otherwise.
+
+To disable `multicore sdr` so that `hwloc` is not required, you can build proofs like this:
+
+```
+> cargo build --release --all --no-default-features --features pairing,gpu
+```
+
+Note that the `multicore-sdr` feature is omitted from the specified feature list, which removes it from being used by default.
+
+
+## Building for Arm64
+
+In order to build for arm64 the current requirements are
+
+- nightly rust compiler
+
+Example for building `filecoin-proofs`
+
+```
+$ rustup +nightly target add aarch64-unknown-linux-gnu
+$ cargo +nightly build -p filecoin-proofs --release --target aarch64-unknown-linux-gnu
+```
+
 ## Test
 
 ```
@@ -334,19 +358,6 @@ To generate the API documentation locally, follow the instructions to generate d
 - [Go implementation of filecoin-proofs sectorbuilder API](https://github.com/filecoin-project/go-sectorbuilder/blob/master/sectorbuilder.go) and [associated interface structures](https://github.com/filecoin-project/go-sectorbuilder/blob/master/interface.go).
 
 
-## Building for Arm64
-
-In order to build for arm64 the current requirements are
-
-- nightly rust compiler
-
-Example for building `filecoin-proofs`
-
-```
-$ rustup +nightly target add aarch64-unknown-linux-gnu
-$ cargo +nightly build -p filecoin-proofs --release --target aarch64-unknown-linux-gnu
-```
-
 ## Contributing
 
 See [Contributing](CONTRIBUTING.md)

storage-proofs-porep/Cargo.toml

@@ -35,7 +35,7 @@ bincode = "1.1.2"
 byteorder = "1.3.4"
 lazy_static = "1.2"
 byte-slice-cast = "1.0.0"
-hwloc = "0.3.0"
+hwloc = { version = "0.3.0", optional = true }
 libc = "0.2"
 fdlimit = "0.2.0"
 fr32 = { path = "../fr32", version = "^1.0.0", default-features = false }
@@ -54,11 +54,12 @@ pretty_env_logger = "0.4.0"
 filecoin-hashers = { path = "../filecoin-hashers", version = "^3.0.0", default-features = false, features = ["poseidon", "sha256", "blake2s"]}
 
 [features]
-default = ["pairing", "gpu"]
+default = ["pairing", "gpu", "multicore-sdr"]
 gpu = ["storage-proofs-core/gpu", "filecoin-hashers/gpu", "neptune/opencl", "bellperson/gpu", "fr32/gpu"]
 pairing = ["storage-proofs-core/pairing", "bellperson/pairing", "neptune/pairing", "filecoin-hashers/pairing", "fr32/pairing"]
 blst = ["storage-proofs-core/blst", "bellperson/blst", "neptune/blst", "filecoin-hashers/blst", "fr32/blst"]
 single-threaded = []
+multicore-sdr = ["hwloc"]
 
 [[bench]]
 name = "encode"

storage-proofs-porep/src/stacked/vanilla/create_label/mod.rs

@@ -11,6 +11,7 @@ use storage_proofs_core::{
 
 use crate::stacked::vanilla::{proof::LayerState, StackedBucketGraph};
 
+#[cfg(feature = "multicore-sdr")]
 pub mod multi;
 pub mod single;
 

storage-proofs-porep/src/stacked/vanilla/macros.rs

@@ -63,6 +63,8 @@ macro_rules! prefetch {
     };
 }
 
+// Used in multicore sdr only
+#[allow(unused_macros)]
 macro_rules! compress256 {
     ($state:expr, $buf:expr, 1) => {
         let blocks = [*GenericArray::<u8, U64>::from_slice(&$buf[..64])];

storage-proofs-porep/src/stacked/vanilla/mod.rs

@@ -8,15 +8,18 @@ mod cache;
 mod challenges;
 mod column;
 mod column_proof;
+#[cfg(feature = "multicore-sdr")]
 mod cores;
 mod encoding_proof;
 mod graph;
 mod labeling_proof;
+#[cfg(feature = "multicore-sdr")]
 mod memory_handling;
 mod params;
 mod porep;
 mod proof;
 mod proof_scheme;
+#[cfg(feature = "multicore-sdr")]
 mod utils;
 
 pub use challenges::{ChallengeRequirements, LayerChallenges};

storage-proofs-porep/src/stacked/vanilla/proof.rs

@@ -313,16 +313,31 @@ impl<'a, Tree: 'static + MerkleTreeTrait, G: 'static + Hasher> StackedDrg<'a, Tr
     ) -> Result<(Labels<Tree>, Vec<LayerState>)> {
         let mut parent_cache = graph.parent_cache()?;
 
-        if SETTINGS.use_multicore_sdr {
-            info!("multi core replication");
-            create_label::multi::create_labels_for_encoding(
-                graph,
-                &parent_cache,
-                layer_challenges.layers(),
-                replica_id,
-                config,
-            )
-        } else {
+        #[cfg(feature = "multicore-sdr")]
+        {
+            if SETTINGS.use_multicore_sdr {
+                info!("multi core replication");
+                create_label::multi::create_labels_for_encoding(
+                    graph,
+                    &parent_cache,
+                    layer_challenges.layers(),
+                    replica_id,
+                    config,
+                )
+            } else {
+                info!("single core replication");
+                create_label::single::create_labels_for_encoding(
+                    graph,
+                    &mut parent_cache,
+                    layer_challenges.layers(),
+                    replica_id,
+                    config,
+                )
+            }
+        }
+
+        #[cfg(not(feature = "multicore-sdr"))]
+        {
             info!("single core replication");
             create_label::single::create_labels_for_encoding(
                 graph,
@@ -343,16 +358,31 @@ impl<'a, Tree: 'static + MerkleTreeTrait, G: 'static + Hasher> StackedDrg<'a, Tr
     ) -> Result<LabelsCache<Tree>> {
         let mut parent_cache = graph.parent_cache()?;
 
-        if SETTINGS.use_multicore_sdr {
-            info!("multi core replication");
-            create_label::multi::create_labels_for_decoding(
-                graph,
-                &parent_cache,
-                layer_challenges.layers(),
-                replica_id,
-                config,
-            )
-        } else {
+        #[cfg(feature = "multicore-sdr")]
+        {
+            if SETTINGS.use_multicore_sdr {
+                info!("multi core replication");
+                create_label::multi::create_labels_for_decoding(
+                    graph,
+                    &parent_cache,
+                    layer_challenges.layers(),
+                    replica_id,
+                    config,
+                )
+            } else {
+                info!("single core replication");
+                create_label::single::create_labels_for_decoding(
+                    graph,
+                    &mut parent_cache,
+                    layer_challenges.layers(),
+                    replica_id,
+                    config,
+                )
+            }
+        }
+
+        #[cfg(not(feature = "multicore-sdr"))]
+        {
             info!("single core replication");
             create_label::single::create_labels_for_decoding(
                 graph,