Add some basic profiling support to the evaluator

Setting the environment variable NIX_COUNT_CALLS to 1 enables some
basic profiling in the evaluator.  It will count calls to functions
and primops as well as evaluations of attributes.

For example, to see where evaluation of a NixOS configuration spends
its time:

$ NIX_SHOW_STATS=1 NIX_COUNT_CALLS=1 ./src/nix-instantiate/nix-instantiate '<nixos>' -A system --readonly-mode
...
calls to 39 primops:
    239532 head
    233962 tail
    191252 hasAttr
...
calls to 1595 functions:
    224157 `/nix/var/nix/profiles/per-user/root/channels/nixos/nixpkgs/pkgs/lib/lists.nix:17:19'
    221767 `/nix/var/nix/profiles/per-user/root/channels/nixos/nixpkgs/pkgs/lib/lists.nix:17:14'
    221767 `/nix/var/nix/profiles/per-user/root/channels/nixos/nixpkgs/pkgs/lib/lists.nix:17:10'
...
evaluations of 7088 attributes:
    167377 undefined position
    132459 `/nix/var/nix/profiles/per-user/root/channels/nixos/nixpkgs/pkgs/lib/attrsets.nix:119:41'
     47322 `/nix/var/nix/profiles/per-user/root/channels/nixos/nixpkgs/pkgs/lib/attrsets.nix:13:21'
...
This commit is contained in:
Eelco Dolstra 2012-08-12 23:29:28 -04:00
parent 325d1cfebf
commit e82767910c
5 changed files with 65 additions and 4 deletions

View file

@ -244,9 +244,21 @@ private:
unsigned long nrAttrsets;
unsigned long nrOpUpdates;
unsigned long nrOpUpdateValuesCopied;
friend class RecursionCounter;
bool countCalls;
typedef std::map<Symbol, unsigned int> PrimOpCalls;
PrimOpCalls primOpCalls;
typedef std::map<Pos, unsigned int> FunctionCalls;
FunctionCalls functionCalls;
typedef std::map<Pos, unsigned int> AttrSelects;
AttrSelects attrSelects;
friend class ExprOpUpdate;
friend class ExprSelect;
friend void prim_getAttr(EvalState & state, Value * * args, Value & v);
};