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| author | Eelco Dolstra <eelco.dolstra@logicblox.com> | 2013-08-07T11·51+0000 |
|---|---|---|
| committer | Eelco Dolstra <eelco.dolstra@logicblox.com> | 2013-08-07T12·02+0200 |
| commit | a583a2bc59a4ee2b067e5520f6c5bc0c61852c32 (patch) | |
| tree | 137be66f58b664dbf0aa21138000d711d5e00162 /src/libstore/remote-store.cc | |
| parent | 263d6682224f516aed74286453c5e2e097a38aa6 (diff) | |
Run the daemon worker on the same CPU as the client
On a system with multiple CPUs, running Nix operations through the daemon is significantly slower than "direct" mode: $ NIX_REMOTE= nix-instantiate '<nixos>' -A system real 0m0.974s user 0m0.875s sys 0m0.088s $ NIX_REMOTE=daemon nix-instantiate '<nixos>' -A system real 0m2.118s user 0m1.463s sys 0m0.218s The main reason seems to be that the client and the worker get moved to a different CPU after every call to the worker. This patch adds a hack to lock them to the same CPU. With this, the overhead of going through the daemon is very small: $ NIX_REMOTE=daemon nix-instantiate '<nixos>' -A system real 0m1.074s user 0m0.809s sys 0m0.098s
Diffstat (limited to 'src/libstore/remote-store.cc')
| -rw-r--r-- | src/libstore/remote-store.cc | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/src/libstore/remote-store.cc b/src/libstore/remote-store.cc index 2b5a932131c3..3764b4813a4e 100644 --- a/src/libstore/remote-store.cc +++ b/src/libstore/remote-store.cc @@ -3,6 +3,7 @@ #include "remote-store.hh" #include "worker-protocol.hh" #include "archive.hh" +#include "affinity.hh" #include "globals.hh" #include <sys/types.h> @@ -15,7 +16,6 @@ #include <unistd.h> #include <cstring> - namespace nix { @@ -71,8 +71,19 @@ void RemoteStore::openConnection(bool reserveSpace) if (GET_PROTOCOL_MAJOR(daemonVersion) != GET_PROTOCOL_MAJOR(PROTOCOL_VERSION)) throw Error("Nix daemon protocol version not supported"); writeInt(PROTOCOL_VERSION, to); + + if (GET_PROTOCOL_MINOR(daemonVersion) >= 14) { + int cpu = lockToCurrentCPU(); + if (cpu != -1) { + writeInt(1, to); + writeInt(cpu, to); + } else + writeInt(0, to); + } + if (GET_PROTOCOL_MINOR(daemonVersion) >= 11) writeInt(reserveSpace, to); + processStderr(); } catch (Error & e) { |