From a583a2bc59a4ee2b067e5520f6c5bc0c61852c32 Mon Sep 17 00:00:00 2001 From: Eelco Dolstra Date: Wed, 7 Aug 2013 11:51:55 +0000 Subject: 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 '' -A system real 0m0.974s user 0m0.875s sys 0m0.088s $ NIX_REMOTE=daemon nix-instantiate '' -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 '' -A system real 0m1.074s user 0m0.809s sys 0m0.098s --- src/libstore/remote-store.cc | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) (limited to 'src/libstore/remote-store.cc') diff --git a/src/libstore/remote-store.cc b/src/libstore/remote-store.cc index 2b5a932131..3764b4813a 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 @@ -15,7 +16,6 @@ #include #include - 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) { -- cgit 1.4.1