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| author | Simon Marlow <marlowsd@gmail.com> | 2011-11-28 16:48:43 +0000 |
|---|---|---|
| committer | Simon Marlow <marlowsd@gmail.com> | 2011-11-29 12:21:18 +0000 |
| commit | 50de6034343abc93a7b01daccff34121042c0e7c (patch) | |
| tree | 24496a5fc6bc39c6baaa574608e53c5d76c169f6 /rts/Schedule.c | |
| parent | 1c2b838131134d44004dfdff18c302131478390d (diff) | |
| download | haskell-50de6034343abc93a7b01daccff34121042c0e7c.tar.gz | |
Make profiling work with multiple capabilities (+RTS -N)
This means that both time and heap profiling work for parallel
programs. Main internal changes:
- CCCS is no longer a global variable; it is now another
pseudo-register in the StgRegTable struct. Thus every
Capability has its own CCCS.
- There is a new built-in CCS called "IDLE", which records ticks for
Capabilities in the idle state. If you profile a single-threaded
program with +RTS -N2, you'll see about 50% of time in "IDLE".
- There is appropriate locking in rts/Profiling.c to protect the
shared cost-centre-stack data structures.
This patch does enough to get it working, I have cut one big corner:
the cost-centre-stack data structure is still shared amongst all
Capabilities, which means that multiple Capabilities will race when
updating the "allocations" and "entries" fields of a CCS. Not only
does this give unpredictable results, but it runs very slowly due to
cache line bouncing.
It is strongly recommended that you use -fno-prof-count-entries to
disable the "entries" count when profiling parallel programs. (I shall
add a note to this effect to the docs).
Diffstat (limited to 'rts/Schedule.c')
| -rw-r--r-- | rts/Schedule.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/rts/Schedule.c b/rts/Schedule.c index 8c305008ae..04a66e31df 100644 --- a/rts/Schedule.c +++ b/rts/Schedule.c @@ -501,7 +501,7 @@ run_thread: // Costs for the scheduler are assigned to CCS_SYSTEM stopHeapProfTimer(); #if defined(PROFILING) - CCCS = CCS_SYSTEM; + cap->r.rCCCS = CCS_SYSTEM; #endif schedulePostRunThread(cap,t); @@ -2262,7 +2262,7 @@ raiseExceptionHelper (StgRegTable *reg, StgTSO *tso, StgClosure *exception) if (raise_closure == NULL) { raise_closure = (StgThunk *)allocate(cap,sizeofW(StgThunk)+1); - SET_HDR(raise_closure, &stg_raise_info, CCCS); + SET_HDR(raise_closure, &stg_raise_info, cap->r.rCCCS); raise_closure->payload[0] = exception; } updateThunk(cap, tso, ((StgUpdateFrame *)p)->updatee, |