GitLab

This adds a new primop called traceBinaryEvent# that takes the length
of binary data and a pointer to the data, then emits it to the eventlog.

There is some example code that uses this primop and the new event:

* [traceBinaryEventIO][1] that calls `traceBinaryEvent#`

* [A patch to ghc-events][2] that parses the new `EVENT_USER_BINARY_MSG`

There's no corresponding issue on Trac but it was discussed at
ghc-devs [3].

[1] https://github.com/maoe/ghc-trace-events/blob
    /fb226011ef1f85a97b4da7cc9d5f98f9fe6316ae/src/Debug/Trace/Binary.hs#L29)
[2] https://github.com/maoe/ghc-events/commit
    /239ca77c24d18cdd10d6d85a0aef98e4a7c56ae6)
[3] https://mail.haskell.org/pipermail/ghc-devs/2018-May/015791.html

Reviewers: bgamari, erikd, simonmar

Reviewed By: bgamari

Subscribers: rwbarton, thomie, carter

Differential Revision: https://phabricator.haskell.org/D5007

Currently ap_0_fast doesn't maintain the invariant for PAP fun fields
which says if the closure can be tagged, it should be. This is checked
by `Sanity.c:checkPAP` and correctly implemented by `genautoapply`.

This causes sanity check failures when we have a profiling code like

    f = {-# SCC scc #-} g

where g is a PAP or a FUN, and `scc` is different than the current cost
centre.

Test Plan: Slow validate (not done yet)

Reviewers: simonmar, bgamari, erikd

Reviewed By: simonmar

Subscribers: rwbarton, carter

GHC Trac Issues: #15508

Differential Revision: https://phabricator.haskell.org/D5051

In a previous attempt (c6cc93bc) I had
tried aligning to 8 bytes under the assumption that the problem was that
the_gc_thread, a StgWord8[], wasn't being aligned to 8-bytes as the
gc_thread struct would expect. However, we actually need even stronger
alignment due to the alignment attribute attached to gen_workspace,
which claims it should be aligned to a 64-byte boundary.

This fixes #15482.

Reviewers: erikd, simonmar

Reviewed By: simonmar

Subscribers: rwbarton, carter

GHC Trac Issues: #15482

Differential Revision: https://phabricator.haskell.org/D5052

Add an additional line to the output of +RTS --info.  It shows the value
of the flag -with-rtsopts provided at compile/link time.

Test Plan: make test TESTS="T15261a T15261b"

Reviewers: hvr, erikd, dfeuer, thomie, austin, bgamari, simonmar, osa1,
monoidal

Reviewed By: osa1, monoidal

Subscribers: osa1, rwbarton, carter

GHC Trac Issues: #15261

Differential Revision: https://phabricator.haskell.org/D5053

While investigating #15529, I noticed that the `barf`ed
error message in `pop()` doesn't print out the closure type that
causes it to crash. Let's do so.

Reviewers: bgamari, erikd, simonmar

Reviewed By: bgamari

Subscribers: rwbarton, carter

GHC Trac Issues: #15529

Differential Revision: https://phabricator.haskell.org/D5072

This caused segmentation faults on Darwin.

This reverts commit c6cc93bc.

Since we cast this to a gc_thread the compiler may assume that it's aligned.
Make sure that this is so. Fixes #15482.

Simplify #ifdef nesting and use MAP_GUARD on FreeBSD and similar
systems. This allows the two-step allocator to be used on FreeBSD,
fixing #15348.

But keep it as a comment since it is quite useful yet not very discoverable.

Reviewers: simonmar, alpmestan

Reviewed By: alpmestan

Subscribers: rwbarton, thomie, carter

Differential Revision: https://phabricator.haskell.org/D4999

The test here should have been changed after D1106.  It was harmless
but we caught fewer GC'd CAFs than we should have.

Test Plan:
Using `nofib/imaginary/primes` compiled with `-debug`.

Before:
```
> ./primes 100 +RTS -G1 -A32k -DG
CAF gc'd at 0x0x7b0960
CAF gc'd at 0x0x788728
CAF gc'd at 0x0x790db0
CAF gc'd at 0x0x790de0
12 CAFs live
CAF gc'd at 0x0x788880
12 CAFs live
12 CAFs live
12 CAFs live
12 CAFs live
12 CAFs live
12 CAFs live
12 CAFs live
12 CAFs live
12 CAFs live
12 CAFs live
12 CAFs live
547
CAF gc'd at 0x0x7995c8
13 CAFs live
```

After:

```
> ./primes 100 +RTS -G1 -A32k -DG
CAF gc'd at 0x0x7b0960
CAF gc'd at 0x0x788728
CAF gc'd at 0x0x790db0
CAF gc'd at 0x0x790de0
12 CAFs live
CAF gc'd at 0x0x788880
12 CAFs live
12 CAFs live
12 CAFs live
12 CAFs live
12 CAFs live
12 CAFs live
12 CAFs live
12 CAFs live
12 CAFs live
12 CAFs live
12 CAFs live
547
CAF gc'd at 0x0x7995c8
CAF gc'd at 0x0x790ea0
12 CAFs live
```

Reviewers: bgamari, osa1, erikd, noamz

Reviewed By: bgamari

Subscribers: rwbarton, thomie, carter

Differential Revision: https://phabricator.haskell.org/D4963

Without this change RTS typically doesn't flush some important
events until the process terminates or it doesn't write them at
all in case it terminates abnormally.

Here is a list of such events:

* EVENT_WALL_CLOCK_TIME
* EVENT_OS_PROCESS_PID
* EVENT_OS_PROCESS_PPID
* EVENT_RTS_IDENTIFIER
* EVENT_PROGRAM_ARGS
* EVENT_PROGRAM_ENV

Before the change osReserveHeapMemory() attempted
to allocate chunks of memory via osTryReserveHeapMemory()
not multiple of MBLOCK_SIZE in the following fallback code:

```
    if (at == NULL) {
        *len -= *len / 8;
```

and caused assertion failure:

```
$ make fulltest TEST=T11607 WAY=threaded1
T11607: internal error: ASSERTION FAILED: file rts/posix/OSMem.c, line 457
    (GHC version 8.7.20180716 for riscv64_unknown_linux)

```

The change applies alignment mask before each MBLOCK allocation attempt
and fixes WAY=threaded1 test failures on qemu-riscv64.
Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org>

Test Plan: run 'make fulltest WAY=threaded1'

Reviewers: simonmar, bgamari, erikd

Reviewed By: simonmar

Subscribers: rwbarton, thomie, carter

Differential Revision: https://phabricator.haskell.org/D4982

* All the tests in tests/ghci.debugger now pass with
  -fexternal-interpreter. These tests are now run with the ghci-ext way
  in addition to the normal way so we won't break it in the future.

* I removed all the unsafeCoerce# calls from RtClosureInspect. Yay!

The main changes are:

* New messages: GetClosure and Seq.  GetClosure is a remote interface to
  GHC.Exts.Heap.getClosureData, which required Binary instances for
  various datatypes. Fortunately this wasn't too painful thanks to
  DeriveGeneric.

* No cheating by unsafeCoercing values when printing them. Now we have
  to turn the Closure representation back into the native representation
  when printing Int, Float, Double, Integer and Char. Of these, Integer
  was the most painful - we now have a dependency on integer-gmp due to
  needing access to the representation.

* Fixed a bug in rts/Heap.c - it was bogusly returning stack content as
  pointers for an AP_STACK closure.

Test Plan:
* `cd testsuite/tests/ghci.debugger && make`
* validate

Reviewers: bgamari, patrickdoc, nomeata, angerman, hvr, erikd, goldfire

Subscribers: alpmestan, snowleopard, rwbarton, thomie, carter

GHC Trac Issues: #13184

Differential Revision: https://phabricator.haskell.org/D4955

Reviewers: simonmar, hvr, bgamari, erikd, fryguybob, rrnewton

Reviewed By: simonmar

Subscribers: fryguybob, rwbarton, thomie, carter

GHC Trac Issues: #15364

Differential Revision: https://phabricator.haskell.org/D4884

Avoids repeated wakeup messages being sent when a TVar is written to
multiple times. See comments for details.

Test Plan:
* Test from #15136 (will be added to stm shortly)
* existing stm tests

Reviewers: bgamari, osa1, erikd

Reviewed By: bgamari

Subscribers: rwbarton, thomie, carter

GHC Trac Issues: #15136

Differential Revision: https://phabricator.haskell.org/D4961

CONSTR_NOCAF was introduced with 55d535da as a replacement for
CONSTR_STATIC and CONSTR_NOCAF_STATIC, however, as explained in Note
[static constructors], we copy CONSTR_NOCAFs (which can also be seen in
evacuate) during GC, and they can become dead, like other CONSTR_X_Ys.
processHeapClosureForDead is updated to reflect this.

Test Plan: Validates on x86_64. Existing failures on i386.

Reviewers: simonmar, bgamari, erikd

Reviewed By: simonmar, bgamari

Subscribers: rwbarton, thomie, carter

GHC Trac Issues: #7836, #15063, #15087, #15165

Differential Revision: https://phabricator.haskell.org/D4928

There was a lock-order reversal between lockTSO() and the TVar lock,
see #15136 for the details.

It turns out we can fix this pretty easily by just deleting all the
locking code(!).  The principle for unblocking a `BlockedOnSTM` thread
then becomes the same as for other kinds of blocking: if the TSO
belongs to this capability then we do it directly, otherwise we send a
message to the capability that owns the TSO. That is, a thread blocked
on STM is owned by its capability, as it should be.

The possible downside of this is that we might send multiple messages
to wake up a thread when the thread is on another capability. This is
safe, it's just not very efficient.  I'll try to do some experiments
to see if this is a problem.

Test Plan: Test case from #15136 doesn't deadlock any more.

Reviewers: bgamari, osa1, erikd

Reviewed By: osa1

Subscribers: rwbarton, thomie, carter

GHC Trac Issues: #15136

Differential Revision: https://phabricator.haskell.org/D4956

This reverts commit 87367158.

I hadn't intended on merging this.

Previously we would prevent any operating system not providing the
MEM_NORESERVE flag
from using the two-step allocator. Afterall, Linux will reserve
swap-space for
a mapping unless this flag is given, which is most certainly not what
we want.

However, it seems that FreeBSD provides the reservation-only mapping
behavior
that we expect despite not providing the MEM_NORESERVE macro. In fact,
it
provided the macro until 2014, when it was removed on account of not
being
implemented in the kernel. However, empirical evidence suggests that
just plain
mmap does what we want.

Reviewers: erikd, simonmar

Subscribers: rwbarton, thomie, erikd, carter

GHC Trac Issues: #15348

Differential Revision: https://phabricator.haskell.org/D4939

This reverts commit 6bb0c5db.

See discussion in D4905.

It shouldn't be necessary to lock the `MVar` closure on `tryReadMVar`, since it
just reads one field of the structure and doesn't make any modifications. So
let's not.

Reviewers: bgamari, erikd, simonmar, fryguybob, osa1

Reviewed By: osa1

Subscribers: osa1, rwbarton, thomie, carter

Differential Revision: https://phabricator.haskell.org/D4905

Reviewers: simonmar, bgamari, erikd

Reviewed By: simonmar

Subscribers: rwbarton, thomie, carter

Differential Revision: https://phabricator.haskell.org/D4893

protect mmaped addresses from writes after being initially manipulated

Test Plan: ./validate

Reviewers: bgamari, erikd, simonmar

Reviewed By: bgamari

Subscribers: angerman, carlostome, rwbarton, thomie, carter

GHC Trac Issues: #14069

Differential Revision: https://phabricator.haskell.org/D4817

Currently we belch some output to stderr but fail to abort, resulting in
a busy loop. Fixes #15292.

Test Plan:
 * Validate
 * try running program under environment without timerfd capabilities;
ensure we don't busy-loop

Reviewers: simonmar, erikd

Reviewed By: simonmar

Subscribers: rwbarton, thomie, carter

GHC Trac Issues: #15929

Differential Revision: https://phabricator.haskell.org/D4875

* Use bool instead of HsBool
* Use barf instead of sysErrorBelch; stg_exit

Test Plan: Validate

Reviewers: erikd, simonmar

Subscribers: rwbarton, thomie, carter

Differential Revision: https://phabricator.haskell.org/D4874

Test Plan: Used it in anger

Reviewers: bgamari, erikd

Reviewed By: bgamari

Subscribers: rwbarton, thomie, carter

Differential Revision: https://phabricator.haskell.org/D4873

It seems like we currently support string literals in Cmm, so we can use
__LINE__ CPP macro in assertion macros. This improves error messages
that previously looked like

    ASSERTION FAILED: file (null), line 1302

(null) part now shows the actual file name.

Also inline some single-use string literals in PrimOps.cmm.

Reviewers: bgamari, simonmar, erikd

Reviewed By: bgamari

Subscribers: rwbarton, thomie, carter

Differential Revision: https://phabricator.haskell.org/D4862

This reverts commit 86210b23.

As pointed out in #12951, this was a temporary measure to allow GHC to be
bootstrapped on Windows with GHC 7.10. This release is now out of our bootstrap
support window so let's remove it.

Test Plan: Validate using LLVM assembler

Reviewers: carter, erikd, simonmar

Reviewed By: simonmar

Subscribers: rwbarton, thomie

GHC Trac Issues: #15207

Differential Revision: https://phabricator.haskell.org/D4781

Fixes #15040.

Reviewers: bgamari, simonmar

Reviewed By: bgamari

Subscribers: rwbarton, thomie, carter

Differential Revision: https://phabricator.haskell.org/D4772

This reverts commit e4c41ec2.

rts.cabal.in isn't processed by CPP.

Test Plan: Test with Hadrian

Reviewers: simonmar, snowleopard, erikd

Subscribers: rwbarton, thomie, carter

Differential Revision: https://phabricator.haskell.org/D4846

Reviewers: erikd, simonmar

Reviewed By: simonmar

Subscribers: rwbarton, thomie, carter

GHC Trac Issues: #14492

Differential Revision: https://phabricator.haskell.org/D4811

Reviewers: bgamari, simonmar, erikd

Reviewed By: simonmar

Subscribers: rwbarton, thomie, carter

Differential Revision: https://phabricator.haskell.org/D4835