diff options
author | Simon Marlow <marlowsd@gmail.com> | 2011-11-28 16:48:43 +0000 |
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committer | Simon Marlow <marlowsd@gmail.com> | 2011-11-29 12:21:18 +0000 |
commit | 50de6034343abc93a7b01daccff34121042c0e7c (patch) | |
tree | 24496a5fc6bc39c6baaa574608e53c5d76c169f6 /includes/rts/prof/CCS.h | |
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 'includes/rts/prof/CCS.h')
-rw-r--r-- | includes/rts/prof/CCS.h | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/includes/rts/prof/CCS.h b/includes/rts/prof/CCS.h index 4692d166b5..9737fc9c18 100644 --- a/includes/rts/prof/CCS.h +++ b/includes/rts/prof/CCS.h @@ -114,8 +114,6 @@ typedef struct _IndexTable { Pre-defined cost centres and cost centre stacks -------------------------------------------------------------------------- */ -extern CostCentreStack * RTS_VAR(CCCS); /* current CCS */ - #if IN_STG_CODE extern StgWord CC_MAIN[]; @@ -153,6 +151,9 @@ extern CostCentreStack CCS_DONT_CARE[]; // shouldn't ever get set extern CostCentre CC_PINNED[]; extern CostCentreStack CCS_PINNED[]; // pinned memory +extern CostCentre CC_IDLE[]; +extern CostCentreStack CCS_IDLE[]; // capability is idle + #endif /* IN_STG_CODE */ extern unsigned int RTS_VAR(CC_ID); // global ids @@ -165,7 +166,7 @@ extern unsigned int RTS_VAR(era); * ---------------------------------------------------------------------------*/ CostCentreStack * pushCostCentre (CostCentreStack *, CostCentre *); -void enterFunCCS (CostCentreStack *); +void enterFunCCS (StgRegTable *reg, CostCentreStack *); /* ----------------------------------------------------------------------------- Registering CCs and CCSs |