1. 30 Jan, 2006 1 commit
    • Simon Marlow's avatar
      fix bug #664 in printSample() · a0f8de19
      Simon Marlow authored
      printSample() was attempting to round the fractional part of the time,
      but not propagated to the non-fractional part.  It's probably better not
      to attempt to round the time at all.
      a0f8de19
  2. 18 Jan, 2006 1 commit
  3. 17 Jan, 2006 2 commits
    • simonmar's avatar
      [project @ 2006-01-17 16:13:18 by simonmar] · 91b07216
      simonmar authored
      Improve the GC behaviour of IORefs (see Ticket #650).
      
      This is a small change to the way IORefs interact with the GC, which
      should improve GC performance for programs with plenty of IORefs.
      
      Previously we had a single closure type for mutable variables,
      MUT_VAR.  Mutable variables were *always* on the mutable list in older
      generations, and always traversed on every GC.
      
      Now, we have two closure types: MUT_VAR_CLEAN and MUT_VAR_DIRTY.  The
      latter is on the mutable list, but the former is not.  (NB. this
      differs from MUT_ARR_PTRS_CLEAN and MUT_ARR_PTRS_DIRTY, both of which
      are on the mutable list).  writeMutVar# now implements a write
      barrier, by calling dirty_MUT_VAR() in the runtime, that does the
      necessary modification of MUT_VAR_CLEAN into MUT_VAR_DIRY, and adding
      to the mutable list if necessary.
      
      This results in some pretty dramatic speedups for GHC itself.  I've
      just measureed a 30% overall speedup compiling a 31-module program
      (anna) with the default heap settings :-D
      91b07216
    • simonmar's avatar
      [project @ 2006-01-17 16:03:47 by simonmar] · da69fa9c
      simonmar authored
      Improve the GC behaviour of IOArrays/STArrays
      
      See Ticket #650
      
      This is a small change to the way mutable arrays interact with the GC,
      that can have a dramatic effect on performance, and make tricks with
      unsafeThaw/unsafeFreeze redundant.  Data.HashTable should be faster
      now (I haven't measured it yet).
      
      We now have two mutable array closure types, MUT_ARR_PTRS_CLEAN and
      MUT_ARR_PTRS_DIRTY.  Both are on the mutable list if the array is in
      an old generation.  writeArray# sets the type to MUT_ARR_PTRS_DIRTY.
      The garbage collector can set the type to MUT_ARR_PTRS_CLEAN if it
      finds that no element of the array points into a younger generation
      (discovering this required a small addition to evacuate(), but rough
      tests indicate that it doesn't measurably affect performance).
      
      NOTE: none of this affects unboxed arrays (IOUArray/STUArray), only
      boxed arrays (IOArray/STArray).
      
      We could go further and extend the DIRTY bit to be per-block rather
      than for the whole array, but for now this is an easy improvement.
      da69fa9c
  4. 21 Oct, 2005 1 commit
    • simonmar's avatar
      [project @ 2005-10-21 14:02:17 by simonmar] · 03a9ff01
      simonmar authored
      Big re-hash of the threaded/SMP runtime
      
      This is a significant reworking of the threaded and SMP parts of
      the runtime.  There are two overall goals here:
      
        - To push down the scheduler lock, reducing contention and allowing
          more parts of the system to run without locks.  In particular,
          the scheduler does not require a lock any more in the common case.
      
        - To improve affinity, so that running Haskell threads stick to the
          same OS threads as much as possible.
      
      At this point we have the basic structure working, but there are some
      pieces missing.  I believe it's reasonably stable - the important
      parts of the testsuite pass in all the (normal,threaded,SMP) ways.
      
      In more detail:
      
        - Each capability now has a run queue, instead of one global run
          queue.  The Capability and Task APIs have been completely
          rewritten; see Capability.h and Task.h for the details.
      
        - Each capability has its own pool of worker Tasks.  Hence, Haskell
          threads on a Capability's run queue will run on the same worker
          Task(s).  As long as the OS is doing something reasonable, this
          should mean they usually stick to the same CPU.  Another way to
          look at this is that we're assuming each Capability is associated
          with a fixed CPU.
      
        - What used to be StgMainThread is now part of the Task structure.
          Every OS thread in the runtime has an associated Task, and it
          can ask for its current Task at any time with myTask().
      
        - removed RTS_SUPPORTS_THREADS symbol, use THREADED_RTS instead
          (it is now defined for SMP too).
      
        - The RtsAPI has had to change; we must explicitly pass a Capability
          around now.  The previous interface assumed some global state.
          SchedAPI has also changed a lot.
      
        - The OSThreads API now supports thread-local storage, used to
          implement myTask(), although it could be done more efficiently
          using gcc's __thread extension when available.
      
        - I've moved some POSIX-specific stuff into the posix subdirectory,
          moving in the direction of separating out platform-specific
          implementations.
      
        - lots of lock-debugging and assertions in the runtime.  In particular,
          when DEBUG is on, we catch multiple ACQUIRE_LOCK()s, and there is
          also an ASSERT_LOCK_HELD() call.
      
      What's missing so far:
      
        - I have almost certainly broken the Win32 build, will fix soon.
      
        - any kind of thread migration or load balancing.  This is high up
          the agenda, though.
      
        - various performance tweaks to do
      
        - throwTo and forkProcess still do not work in SMP mode
      03a9ff01
  5. 14 Oct, 2005 1 commit
  6. 16 Sep, 2005 1 commit
  7. 26 Jul, 2005 1 commit
  8. 25 Jul, 2005 2 commits
  9. 21 May, 2005 1 commit
  10. 22 Apr, 2005 1 commit
    • simonmar's avatar
      [project @ 2005-04-22 09:32:39 by simonmar] · 0f3205e6
      simonmar authored
      SMP: the rest of the changes to support safe thunk entry & updates.  I
      thought the compiler changes were independent, but I ended up breaking
      the HEAD, so I'll have to commit the rest.  non-SMP compilation should
      not be affected.
      0f3205e6
  11. 05 Apr, 2005 2 commits
    • simonmar's avatar
      [project @ 2005-04-05 12:19:54 by simonmar] · 16214216
      simonmar authored
      Some multi-processor hackery, including
      
        - Don't hang blocked threads off BLACKHOLEs any more, instead keep
          them all on a separate queue which is checked periodically for
          threads to wake up.
      
          This is good because (a) we don't have to worry about locking the
          closure in SMP mode when we want to block on it, and (b) it means
          the standard update code doesn't need to wake up any threads or
          check for a BLACKHOLE_BQ, simplifying the update code.
      
          The downside is that if there are lots of threads blocked on
          BLACKHOLEs, we might have to do a lot of repeated list traversal.
          We don't expect this to be common, though.  conc023 goes slower
          with this change, but we expect most programs to benefit from the
          shorter update code.
      
        - Fixing up the Capability code to handle multiple capabilities (SMP
          mode), and related changes to get the SMP mode at least building.
      16214216
    • simonmar's avatar
      [project @ 2005-04-05 09:30:11 by simonmar] · b0ac0f91
      simonmar authored
      printf format type fixup
      b0ac0f91
  12. 27 Mar, 2005 1 commit
    • panne's avatar
      [project @ 2005-03-27 13:41:13 by panne] · 03dc2dd3
      panne authored
      * Some preprocessors don't like the C99/C++ '//' comments after a
        directive, so use '/* */' instead. For consistency, a lot of '//' in
        the include files were converted, too.
      
      * UnDOSified libraries/base/cbits/runProcess.c.
      
      * My favourite sport: Killed $Id$s.
      03dc2dd3
  13. 10 Feb, 2005 1 commit
    • simonmar's avatar
      [project @ 2005-02-10 13:01:52 by simonmar] · e7c3f957
      simonmar authored
      GC changes: instead of threading old-generation mutable lists
      through objects in the heap, keep it in a separate flat array.
      
      This has some advantages:
      
        - the IND_OLDGEN object is now only 2 words, so the minimum
          size of a THUNK is now 2 words instead of 3.  This saves
          some amount of allocation (about 2% on average according to
          my measurements), and is more friendly to the cache by
          squashing objects together more.
      
        - keeping the mutable list separate from the IND object
          will be necessary for our multiprocessor implementation.
      
        - removing the mut_link field makes the layout of some objects
          more uniform, leading to less complexity and special cases.
      
        - I also unified the two mutable lists (mut_once_list and mut_list)
          into a single mutable list, which lead to more simplifications
          in the GC.
      e7c3f957
  14. 10 Nov, 2004 1 commit
  15. 12 Sep, 2004 1 commit
  16. 03 Sep, 2004 1 commit
    • simonmar's avatar
      [project @ 2004-09-03 15:28:18 by simonmar] · 95ca6bff
      simonmar authored
      Cleanup: all (well, most) messages from the RTS now go through the
      functions in RtsUtils: barf(), debugBelch() and errorBelch().  The
      latter two were previously called belch() and prog_belch()
      respectively.  See the comments for the right usage of these message
      functions.
      
      One reason for doing this is so that we can avoid spurious uses of
      stdout/stderr by Haskell apps on platforms where we shouldn't be using
      them (eg. non-console apps on Windows).
      95ca6bff
  17. 13 Aug, 2004 1 commit
  18. 11 May, 2004 1 commit
  19. 19 Mar, 2004 1 commit
    • panne's avatar
      [project @ 2004-03-19 23:20:20 by panne] · 9b5e0886
      panne authored
      Fixed  the JOB line in heap  profiles, it contained superfluous spaces
      and an evil line break.
      
      Merge to STABLE
      (This fix looks quite right, but again, I leave this to the Master of
      Releases (tm), because there might already be tools depending on the
      slightly wrong old format.)
      9b5e0886
  20. 12 Nov, 2003 1 commit
    • sof's avatar
      [project @ 2003-11-12 17:49:05 by sof] · 20593d1d
      sof authored
      Tweaks to have RTS (C) sources compile with MSVC. Apart from wibbles
      related to the handling of 'inline', changed Schedule.h:POP_RUN_QUEUE()
      not to use expression-level statement blocks.
      20593d1d
  21. 24 Oct, 2003 1 commit
  22. 23 Sep, 2003 1 commit
    • simonmar's avatar
      [project @ 2003-09-23 15:38:35 by simonmar] · 76ebf3dc
      simonmar authored
      Add a BF_PINNED block flag, and attach it to blocks containing pinned
      objects (in addition to the usual BF_LARGE).
      
      In heapCensus, we now ignore blocks containing pinned objects, because
      they might contain gaps, and in any case it isn't clear that we want
      to include the whole block in a heap census, because much of it might
      well be dead.  Ignoring it isn't right either, though, so this patch
      just fixes the crash and leaves a ToDo.
      76ebf3dc
  23. 22 Aug, 2003 1 commit
    • sof's avatar
      [project @ 2003-08-22 22:24:12 by sof] · cffcb52b
      sof authored
      setupRtsFlags(): don't overwrite argv[0] with its basename:
         - argv[] may not point to writeable memory
         - System.Environment.getProgName strips off the 'dirname' portion
           anyway.
         - Not possible to get at the untransformed argv[0] from
           Haskell code, should such a need arise.
      
      Uses of prog_argv[0] within the RTS has now been replaced with prog_name,
      which is the basename of prog_argv[0].
      cffcb52b
  24. 16 May, 2003 1 commit
  25. 24 Mar, 2003 1 commit
    • simonmar's avatar
      [project @ 2003-03-24 14:46:53 by simonmar] · b3f53081
      simonmar authored
      Fix some bugs in compacting GC.
      
      Bug 1: When threading the fields of an AP or PAP, we were grabbing the
      info table of the function without unthreading it first.
      
      Bug 2: eval_thunk_selector() might accidentally find itself in
      to-space when going through indirections in a compacted generation.
      We must check for this case and bale out if necessary.
      
      Bug 3: This is somewhat more nasty.  When we have an AP or PAP that
      points to a BCO, the layout info for the AP/PAP is in the BCO's
      instruction array, which is two objects deep from the AP/PAP itself.
      The trouble is, during compacting GC, we can only safely look one
      object deep from the current object, because pointers from objects any
      deeper might have been already updated to point to their final
      destinations.
      
      The solution is to put the arity and bitmap info for a BCO into the
      BCO object itself.  This means BCOs become variable-length, which is a
      slight annoyance, but it also means that looking up the arity/bitmap
      is quicker.  There is a slight reduction in complexity in the byte
      code generator due to not having to stuff the bitmap at the front of
      the instruction stream.
      b3f53081
  26. 18 Mar, 2003 1 commit
    • simonmar's avatar
      [project @ 2003-03-18 14:36:56 by simonmar] · 428c025e
      simonmar authored
      Fix a profiling crash on Windows.
      
      fprint_ccs used snprintf() to avoid overflowing a buffer; on mingw32
      where snprintf() doesn't exist we were just using the straight
      sprintf(), which inevitably lead to a crash.  Rewritten to use a
      homegrown non-overflowing string copying function - it actually looks
      nicer now, anwyay.
      428c025e
  27. 20 Feb, 2003 1 commit
    • simonmar's avatar
      [project @ 2003-02-20 15:39:59 by simonmar] · 51a1c2a2
      simonmar authored
      closureSatisfiesConstraints: check whether the retainer set is valid
      before attempting to match it against a constraint.  It might not be
      valid if the object is an ex-weak-pointer which was finalized after
      the last GC.
      
      MERGE TO STABLE
      51a1c2a2
  28. 23 Jan, 2003 2 commits
    • simonmar's avatar
      [project @ 2003-01-23 16:39:30 by simonmar] · e989066d
      simonmar authored
      Fix compilation with DEBUG
      e989066d
    • simonmar's avatar
      [project @ 2003-01-23 12:13:10 by simonmar] · 70c1ca01
      simonmar authored
      - Add a new flag, -xt, which enables inclusion of TSOs in a heap profile.
      
      - Include large objects in heap profiles (except TSOs unless the -xt flag
        is given).
      
      - In order to make this work, I had to set the bd->free field of the
        block descriptor for a large object to the correct value.  Previously,
        it pointed to the start of the block (i.e. the same as bd->start).
        I hope this doesn't have any other consequences; it looks more
        correct this way in any case.
      70c1ca01
  29. 11 Dec, 2002 1 commit
    • simonmar's avatar
      [project @ 2002-12-11 15:36:20 by simonmar] · 0bffc410
      simonmar authored
      Merge the eval-apply-branch on to the HEAD
      ------------------------------------------
      
      This is a change to GHC's evaluation model in order to ultimately make
      GHC more portable and to reduce complexity in some areas.
      
      At some point we'll update the commentary to describe the new state of
      the RTS.  Pending that, the highlights of this change are:
      
        - No more Su.  The Su register is gone, update frames are one
          word smaller.
      
        - Slow-entry points and arg checks are gone.  Unknown function calls
          are handled by automatically-generated RTS entry points (AutoApply.hc,
          generated by the program in utils/genapply).
      
        - The stack layout is stricter: there are no "pending arguments" on
          the stack any more, the stack is always strictly a sequence of
          stack frames.
      
          This means that there's no need for LOOKS_LIKE_GHC_INFO() or
          LOOKS_LIKE_STATIC_CLOSURE() any more, and GHC doesn't need to know
          how to find the boundary between the text and data segments (BIG WIN!).
      
        - A couple of nasty hacks in the mangler caused by the neet to
          identify closure ptrs vs. info tables have gone away.
      
        - Info tables are a bit more complicated.  See InfoTables.h for the
          details.
      
        - As a side effect, GHCi can now deal with polymorphic seq.  Some bugs
          in GHCi which affected primitives and unboxed tuples are now
          fixed.
      
        - Binary sizes are reduced by about 7% on x86.  Performance is roughly
          similar, some programs get faster while some get slower.  I've seen
          GHCi perform worse on some examples, but haven't investigated
          further yet (GHCi performance *should* be about the same or better
          in theory).
      
        - Internally the code generator is rather better organised.  I've moved
          info-table generation from the NCG into the main codeGen where it is
          shared with the C back-end; info tables are now emitted as arrays
          of words in both back-ends.  The NCG is one step closer to being able
          to support profiling.
      
      This has all been fairly thoroughly tested, but no doubt I've messed
      up the commit in some way.
      0bffc410
  30. 01 Nov, 2002 1 commit
    • simonmar's avatar
      [project @ 2002-11-01 11:05:46 by simonmar] · 6226441f
      simonmar authored
      Fix the heapCensus crash.
      
      It turned out that after a GC, the small_alloc_list might be non-empty
      if a new finalizer thread had been started.  The last block on
      small_alloc_list doesn't have the free pointer set correctly (as a
      small optimisation, we don't normally set the free pointer after each
      allocation, only when the block is full).  The result was that the
      free pointer contains the wrong value, and the heap census traverses
      garbage.  The fix is to set the free pointer correctly before
      traversing small_alloc_list.
      
      The bug doesn't show up when DEBUG is on, because extra DEBUG checks
      cause the free pointer to be initialised to a sensible(-ish) value.
      Hence my difficulty in reproducing the bug.
      
      To reproduce: compile ghc-regress/lib/should_run/memo002 with
      profiling and run it with a sufficiently small sample interval (-i0.02
      did it for me).
      
      Thanks to the kind folks at ARM for helping out with the debugging of
      this one.
      
      MERGE TO STABLE
      6226441f
  31. 16 Aug, 2002 1 commit
  32. 18 Jul, 2002 1 commit
  33. 07 May, 2002 1 commit
  34. 12 Dec, 2001 3 commits
    • simonmar's avatar
      [project @ 2001-12-12 15:59:33 by simonmar] · 7738ad97
      simonmar authored
      Include the CCS ID in the heap profile, so you can find the full CCS
      description in <foo>.prof or the XML profile output.
      7738ad97
    • simonmar's avatar
      [project @ 2001-12-12 15:01:25 by simonmar] · 8098d689
      simonmar authored
      Fix a couple of assertions.
      8098d689
    • simonmar's avatar
      [project @ 2001-12-12 14:31:42 by simonmar] · 55c8be52
      simonmar authored
      - Add a new type of restriction: -hC, which restricts to closures
        whose CCS contains the specified CCs *anywhere* (not just at the
        top).
      
      - Complain if the user tries to request both retainer and biographical
        profiling.  We don't support both simultaneously, because they use
        the same header word in the closure.
      
      - Allow for the fact that the heap might contain some closures which
        don't have a valid retainer set during the heap census.  The only
        known closures of this kind so far are DEAD_WEAK closures.
      
      - Some cruft-removal and renaming of functions to follow conventions.
      55c8be52