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22126 Commits

Author SHA1 Message Date
Russ Cox
271a650245 [dev.cc] doc/go1.5: mention cmd/go meaning of std change
Change-Id: I259e88f019b6818c57caaa1ec236b7c2e2ae1382
Reviewed-on: https://go-review.googlesource.com/5551
Reviewed-by: Rob Pike <r@golang.org>
2015-02-23 15:13:34 +00:00
Russ Cox
096b294f21 [dev.cc] cmd/go: fix expansion of 'std', add 'cmd'
The wildcard 'std' is defined in documentation to be all the packages
in the Go standard library. It has also historically matched commands
in the main repo, but as we implement core commands in Go, that
becomes problematic. We need a wildcard that means just the library,
and since 'std' is already documented to have that definition, make it so.

Add a new wildcard 'cmd' for the commands in the main repo ($GOROOT).
Commands that want both can say 'std cmd' (or 'cmd std') to get the
effect of the old 'std'.

Update make.bash etc to say both std and cmd most of the time.

Exception: in race.bash, do not install race-enabled versions of
the actual commands. This avoids trying to write binaries while
using them, but more importantly it avoids enabling the race
detector and its associated memory overhead for the already
memory-hungry compilers.

Change-Id: I26bb06cb13b636dfbe71a015ee0babeb270a0275
Reviewed-on: https://go-review.googlesource.com/5550
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
2015-02-23 15:13:17 +00:00
David du Colombier
48469a2c86 cmd/ld: fix warning on Plan 9
cpp: src/cmd/ld/lib.h:349 No newline at end of file

Change-Id: Id21851963f7778364ba9337da3bacd312443f51f
Reviewed-on: https://go-review.googlesource.com/5520
Reviewed-by: Minux Ma <minux@golang.org>
2015-02-23 07:54:13 +00:00
Matthew Dempsky
57cefa657d runtime: remove unneeded C header files
Change-Id: I239ae86cfebfece607dce39a96d9123cbacbee7d
Reviewed-on: https://go-review.googlesource.com/5562
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Minux Ma <minux@golang.org>
2015-02-23 07:16:06 +00:00
Aaron Jacobs
d5630142fd net/http: Removed some unused constants in request.go.
Change-Id: I05cdf357249166a45105703e9317793aa2088844
Reviewed-on: https://go-review.googlesource.com/5560
Reviewed-by: Andrew Gerrand <adg@golang.org>
2015-02-22 23:52:44 +00:00
Jan Kratochvil
02d80b9e93 gdb: fix "gdb.error: No struct named reflect.rtype."
With a trivial Golang-built program loaded in gdb-7.8.90.20150214-7.fc23.x86_64
I get this error:

(gdb) source ./src/runtime/runtime-gdb.py
Loading Go Runtime support.
Traceback (most recent call last):
  File "./src/runtime/runtime-gdb.py", line 230, in <module>
    _rctp_type = gdb.lookup_type("struct reflect.rtype").pointer()
gdb.error: No struct type named reflect.rtype.
(gdb) q

No matter if this struct should or should not be in every Golang-built binary
this change should fix that with no disadvantages.

Change-Id: I0c490d3c9bbe93c65a2183b41bfbdc0c0f405bd1
Reviewed-on: https://go-review.googlesource.com/5521
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-02-22 19:27:07 +00:00
Mark Bucciarelli
4e408e0cc9 Call --> CallSlice in two spots. No logic change, docs only.
Change-Id: I6011e162214db2d65efc1ecdb5ec600ca8e5bfe9
Reviewed-on: https://go-review.googlesource.com/5542
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-02-22 17:22:04 +00:00
Russ Cox
5944cb8d1a [dev.cc] cmd/asm/internal/asm: fix test on nacl
Need to add testdata to NaCl's testing file system.

Change-Id: Ie9703b5475c7f87e737a06de85d1f88e2062f090
Reviewed-on: https://go-review.googlesource.com/5541
Reviewed-by: Russ Cox <rsc@golang.org>
2015-02-21 18:11:28 +00:00
Russ Cox
6406acf338 [dev.cc] cmd/asm/internal/asm: fix test on windows
Change-Id: Ia6cf3204d71740bc2b6e26c53ac5206e8a33a180
Reviewed-on: https://go-review.googlesource.com/5540
Reviewed-by: Russ Cox <rsc@golang.org>
2015-02-21 17:54:38 +00:00
Russ Cox
c80ff3cb87 [dev.cc] cmd/go: reenable verifyCompiler
Change-Id: Ic7367f2c6e6d4e6b802ce8436022412a1862ca58
Reviewed-on: https://go-review.googlesource.com/5472
Reviewed-by: Rob Pike <r@golang.org>
2015-02-21 14:03:14 +00:00
Russ Cox
f6791da7ad [dev.cc] cmd/new6g etc: reconvert from C
Reconvert using rsc.io/c2go rev 27b3f59.
(Same as last conversion, but C sources have changed
due to merging master into this branch.)

Change-Id: Ib314bb9ac14a726ceb83e2ecf4d1ad2d0b331c38
Reviewed-on: https://go-review.googlesource.com/5471
Reviewed-by: Rob Pike <r@golang.org>
2015-02-21 14:03:04 +00:00
Rob Pike
1996f276d2 [dev.cc] cmd/asm: fix build: broken end to end test
This time for sure.

Change-Id: I77ed6b70d82a6f4ba371afba2f53c8b146ac110f
Reviewed-on: https://go-review.googlesource.com/5530
Reviewed-by: Rob Pike <r@golang.org>
2015-02-21 03:33:09 +00:00
Rob Pike
7ed429d99c [dev.cc] cmd/asm: fix build
Representation in printout of MRC instruction differs between
32- and 64-bit machines. It's just a hex dump. Fix this one day,
but for now just comment out the instruction.

Change-Id: I4709390659e2e0f2d18ff6f8e762f97cdbfb4c16
Reviewed-on: https://go-review.googlesource.com/5424
Reviewed-by: Rob Pike <r@golang.org>
2015-02-21 02:16:37 +00:00
Rob Pike
634049dbe6 [dev.cc] cmd/asm: add end-to-end test
Add trivial golden test that verifies output matches expectation.
The input is based on the old grammar and is intended to cover
the space of the input language.

PPC64 and ARM only for now; others to follow.

Change-Id: Ib5957822bcafd5b9d4c1dea1c03cc6ee1238f7ef
Reviewed-on: https://go-review.googlesource.com/5421
Reviewed-by: Russ Cox <rsc@golang.org>
2015-02-21 02:02:23 +00:00
Rob Pike
5d111b898a [dev.cc] cm/asm: fix up arm after cross-check with 5a
As with the previous round for ppc64, this CL fixes a couple of things
that 5a supported but asm did not, both simple.

1) Allow condition code on MRC instruction; this was marked as a TODO.
2) Allow R(n) notation in ARM register shifts.  The code needs a rethink
but the tests we're leading toward will make the rewrite easier to test and
trust.

Change-Id: I5b52ad25d177a74cf07e089dddfeeab21863c424
Reviewed-on: https://go-review.googlesource.com/5422
Reviewed-by: Russ Cox <rsc@golang.org>
2015-02-21 01:53:30 +00:00
Russ Cox
c11dadc503 [dev.cc] crypto/md5, crypto/sha1: restore a few SP references
Applying my post-submit comments from CL 5120.
The rewrite there changed the code from writing to the stack
frame to writing below the stack frame.

Change-Id: Ie7e0563c0c1731fede2bcefeaf3c9d88a0cf4063
Reviewed-on: https://go-review.googlesource.com/5470
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2015-02-20 18:54:29 +00:00
Russ Cox
9c0c050773 [dev.cc] cmd/asm: add ppc64le support
Change-Id: I780ed76c9217d387a73fd7530af2f40948aa1fe4
Reviewed-on: https://go-review.googlesource.com/5452
Reviewed-by: Rob Pike <r@golang.org>
2015-02-20 18:42:54 +00:00
Russ Cox
cf6a77b36d [dev.cc] cmd/go: install cmd/asm as a tool
cmd/dist was doing the right thing, but not cmd/go.

Change-Id: I5412140cfc07e806152915cc49db7f63352d01ca
Reviewed-on: https://go-review.googlesource.com/5451
Reviewed-by: Rob Pike <r@golang.org>
2015-02-20 18:42:49 +00:00
Dmitry Vyukov
edadffa2f3 cmd/trace: add new command
Trace command allows to visualize and analyze traces.
Run as:
$ go tool trace binary trace.file
The commands opens web browser with the main page,
which contains links for trace visualization,
blocking profiler, network IO profiler and per-goroutine
traces.

Also move trace parser from runtime/pprof/trace_parser_test.go
to internal/trace/parser.go, so that it can be shared between
tests and the command.

Change-Id: Ic97ed59ad6e4c7e1dc9eca5e979701a2b4aed7cf
Reviewed-on: https://go-review.googlesource.com/3601
Reviewed-by: Andrew Gerrand <adg@golang.org>
2015-02-20 18:31:25 +00:00
David Crawshaw
84e200cbcb [dev.cc] runtime: print to stderr as well as android logd
Restores stack traces in the android/arm builder.

Change-Id: If637aa2ed6f8886126b77cf9cc8a0535ec7c4369
Reviewed-on: https://go-review.googlesource.com/5453
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
2015-02-20 18:30:09 +00:00
Dmitry Vyukov
58125ffe73 runtime/race: update race runtime to rev 229396
Fixes #9720
Fixes #8053
Fixes https://code.google.com/p/thread-sanitizer/issues/detail?id=89

Change-Id: I7d598e53de86586bb9702d8e9276a4d6aece2dfc
Reviewed-on: https://go-review.googlesource.com/4950
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-02-20 18:06:15 +00:00
Dmitry Vyukov
3fc529eabe runtime: adjust program counters in race detector
In most cases we pass return PC to race detector,
and race runtime subtracts one from them.
However, in manual instrumentation in runtime
we pass function start PC to race runtime.
Race runtime can't distinguish these cases
and so it does not subtract one from top PC.
This leads to bogus line numbers in some cases.
Make it consistent and always pass what looks
like a return PC, so that race runtime can
subtract one and still get PC in the same function.

Also delete two unused functions.

Update #8053

Change-Id: I4242dec5e055e460c9a8990eaca1d085ae240ed2
Reviewed-on: https://go-review.googlesource.com/4902
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-02-20 18:04:16 +00:00
Russ Cox
89a091de24 runtime: split gc_m into gcMark and gcSweep
This is a nice split but more importantly it provides a better
way to fit the checkmark phase into the sequencing.

Also factor out common span copying into gcSpanCopy.

Change-Id: Ia058644974e4ed4ac3cf4b017a3446eb2284d053
Reviewed-on: https://go-review.googlesource.com/5333
Reviewed-by: Austin Clements <austin@google.com>
2015-02-20 17:00:39 +00:00
Russ Cox
929597b9e9 runtime: unroll gc_m loop
The loop made more sense when gc_m was not its own function.

Change-Id: I71a7f21d777e69c1924e3b534c507476daa4dfdd
Reviewed-on: https://go-review.googlesource.com/5332
Reviewed-by: Austin Clements <austin@google.com>
2015-02-20 17:00:30 +00:00
Russ Cox
2b655c0b92 runtime: tidy GC driver
Change-Id: I0da26e89ae73272e49e82c6549c774e5bc97f64c
Reviewed-on: https://go-review.googlesource.com/5331
Reviewed-by: Austin Clements <austin@google.com>
2015-02-20 17:00:22 +00:00
Dmitry Vyukov
6e70fddec0 runtime: fix cputicks on x86
See the following issue for context:
https://github.com/golang/go/issues/9729#issuecomment-74648287
In short, RDTSC can produce skewed results without preceding LFENCE/MFENCE.
Information on this matter is very scrappy in the internet.
But this is what linux kernel does (see rdtsc_barrier).
It also fixes the test program on my machine.

Update #9729

Change-Id: I3c1ffbf129fdfdd388bd5b7911b392b319248e68
Reviewed-on: https://go-review.googlesource.com/5033
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-02-20 16:52:13 +00:00
Rob Pike
adff896e4c [dev.cc] cmd/asm: implement FMADD for ppc64
Missed this one instruction in the previous pass.

Change-Id: Ic8cdae4d3bfd626c6bbe0ce49fce28b53db2ad1c
Reviewed-on: https://go-review.googlesource.com/5420
Reviewed-by: Russ Cox <rsc@golang.org>
2015-02-20 16:34:15 +00:00
Russ Cox
b4a7806724 [dev.cc] all: merge master (5868ce3) into dev.cc
This time for sure!

Change-Id: I7e7ea24edb7c2f711489e162fb97237a87533089
2015-02-20 10:28:36 -05:00
Russ Cox
d90bbf91d4 [dev.cc] cmd/go: disable verifyCompiler
The merge brought in new C sources without Go updates.

Change-Id: Iad08b58f894173a7b34396275b72db34f3031fe3
Reviewed-on: https://go-review.googlesource.com/5352
Reviewed-by: Russ Cox <rsc@golang.org>
2015-02-20 15:26:21 +00:00
Andrew Gerrand
5868ce3519 path/filepath: add example for filepath.Split
Fixes #9928

Change-Id: Iab37051078755a132f211ad48e756422f7c55a39
Reviewed-on: https://go-review.googlesource.com/5416
Reviewed-by: Minux Ma <minux@golang.org>
2015-02-20 07:35:57 +00:00
Mikio Hara
69275eef5e net, syscall: more accurate parsers for routing messages on BSD variants
This changes fixes two issues with regard to handling routing messages
as follows:
- Misparsing on platforms (such as FreeBSD) supporting multiple
  architectures in the same kernel (kern.supported_archs="amd64 i386")
- Misparsing with unimplemented messages such as route, interface
  address state notifications

To fix those issues, this change implements all the required socket
address parsers, adds a processor architecture identifying function to
FreeBSD and tests.

Fixes #9707.
Fixes #8203.

Change-Id: I7ed7b4a0b6f10f54b29edc681a2f35603f2d8d45
Reviewed-on: https://go-review.googlesource.com/4330
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-02-20 04:33:28 +00:00
Ingo Oeser
668762c570 cmd/go: simplify/fix handling private github repos
Before Go 1.4, the traditional way to work with a private Github
repository was to run something similar the following:

```
git config --global url."git@github.com:".insteadOf "https://github.com/"
```

It would allow go get and friends to transparently work as expected,
automatically rewriting https URLs to use SSH for auth. This worked both
when pushing and pulling.

In Go 1.4 this broke, now requiring the use of `go get -f` instead of `go get`
in order to fetch private repositories. This seems neither intended nor
practical, as it requires changing a lot of tooling.

So just use `git config remote.origin.url` instead of `git remote -v` as
this reflects the actual substitution intended in the `insteadOf` config
directive.

Also remove now useless parsing.

Also add a check against supported schemes to avoid errors in later
commands using this URL and expecting such a scheme.

Fixes #9697

Change-Id: I907327f83504302288f913a68f8222a5c2d673ee
Reviewed-on: https://go-review.googlesource.com/3504
Reviewed-by: Andrew Gerrand <adg@golang.org>
2015-02-20 03:21:29 +00:00
Russ Cox
ea1306a150 doc: dummy commit in go1.5.txt
Change-Id: I678336daf99f7d7d19f99506f1a604de8e05bf43
Reviewed-on: https://go-review.googlesource.com/5400
Reviewed-by: Russ Cox <rsc@golang.org>
2015-02-20 01:42:37 +00:00
Rob Pike
5b9429d122 [dev.cc] cmd/asm: bring asm on ppc64 in sync with 9a
I created a .s file that covered every instruction and operand production
in 9a/a.y and made sure that 9a and asm give bit-identical results for it.
I found a few things, including one addressing mode (R1+R2) that was
not present in the source we use. Fixed those

I also found quite a few things where 9a's grammar accepts the instruction
but liblink rejects it. These need to be sorted out, and I will do that separately.
Once that's done, I'll turn my test file into a proper test.

Change-Id: Ib093271b0f7ffd64ffed164ed2a820ebf2420e34
Reviewed-on: https://go-review.googlesource.com/5361
Reviewed-by: Russ Cox <rsc@golang.org>
2015-02-20 00:42:09 +00:00
Rob Pike
c21f1d5ef3 [dev.cc] runtime,syscall: quiet some more vet errors
Fix many incorrect FP references and a few other details.

Some errors remain, especially in vlop, but fixing them requires semantics. For another day.

Change-Id: Ib769fb519b465e79fc08d004a51acc5644e8b259
Reviewed-on: https://go-review.googlesource.com/5288
Reviewed-by: Russ Cox <rsc@golang.org>
2015-02-20 00:20:54 +00:00
Russ Cox
dc7b54bed2 [dev.cc] cmd/internal/obj, cmd/internal/gc, new6g: reconvert
Reconvert using rsc.io/c2go rev 27b3f59.

Changes to converter:
 - fatal does not return, so no fallthrough after fatal in switch
 - many more function results and variables identified as bool
 - simplification of negated boolean expressions

Change-Id: I3bc67da5e46cb7ee613e230cf7e9533036cc870b
Reviewed-on: https://go-review.googlesource.com/5171
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2015-02-20 00:17:03 +00:00
Russ Cox
786825c5e8 [dev.cc] cmd/gc: tweak default fatal in ordersafeexpr for c2go
c2go was putting a fallthrough after the fatal call.
Changed c2go to know that fatal doesn't return,
but then there is a missing return at the end of
the translated Go function.
Move code around a little to make C and Go agree.

Change-Id: Icef3d55ccdde0709c02dd0c2b78826f6da33a146
Reviewed-on: https://go-review.googlesource.com/5170
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2015-02-20 00:16:53 +00:00
Andrew Gerrand
5f84238444 cmd/dist: show friendlier error message when building outside a Git repo
Fixes #9932

Change-Id: I7943470a1784278a5c6e99c3b66c59d4953734ba
Reviewed-on: https://go-review.googlesource.com/5340
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2015-02-19 22:33:45 +00:00
Russ Cox
5254b7e9ce runtime: do not unmap work.spans until after checkmark phase
This is causing crashes.

Change-Id: I1832f33d114bc29894e491dd2baac45d7ab3a50d
Reviewed-on: https://go-review.googlesource.com/5330
Reviewed-by: Rick Hudson <rlh@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
2015-02-19 21:33:06 +00:00
Rob Pike
218ff3f9a4 [dev.cc] runtime,syscall: add symbols for FP and SP references in darwin-arm
Maybe fix build.

Change-Id: I99ea76f0e6e472f0e88405bf5d77f72d4b097abd
Reviewed-on: https://go-review.googlesource.com/5287
Reviewed-by: Russ Cox <rsc@golang.org>
2015-02-19 21:29:21 +00:00
Rob Pike
caf2bf26f8 [dev.cc] cmd/go: enable verifyAsm for all architectures
Change-Id: Ia1ba28c81e31d149c59a48d5f71628ac0ff14d8e
Reviewed-on: https://go-review.googlesource.com/5283
Reviewed-by: Minux Ma <minux@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
2015-02-19 21:10:27 +00:00
Rob Pike
f60fb5c5ad [dev.cc] cmd/asm: accept #define A /* nothing */
Was rejected but should be legal.

Change-Id: I0189e3bef6b67c6ba390c75a48a8d9d8f39b7636
Reviewed-on: https://go-review.googlesource.com/5286
Reviewed-by: Russ Cox <rsc@golang.org>
2015-02-19 21:06:51 +00:00
Russ Cox
6c4b54f409 runtime: missed change from reorganization CL
That is, I accidentally dropped this change of Austin's
when preparing my CL. I blame Git.

Change-Id: I9dd772c84edefad96c4b16785fdd2dea04a4a0d6
Reviewed-on: https://go-review.googlesource.com/5320
Reviewed-by: Austin Clements <austin@google.com>
2015-02-19 20:46:59 +00:00
Russ Cox
484f801ff4 runtime: reorganize memory code
Move code from malloc1.go, malloc2.go, mem.go, mgc0.go into
appropriate locations.

Factor mgc.go into mgc.go, mgcmark.go, mgcsweep.go, mstats.go.

A lot of this code was in certain files because the right place was in
a C file but it was written in Go, or vice versa. This is one step toward
making things actually well-organized again.

Change-Id: I6741deb88a7cfb1c17ffe0bcca3989e10207968f
Reviewed-on: https://go-review.googlesource.com/5300
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Rick Hudson <rlh@golang.org>
2015-02-19 20:17:01 +00:00
Russ Cox
d7eb51e70e [dev.cc] test: disable rotate tests
They use too much memory in the current Go compiler draft.
This should fix some builders.

Reenabling is #9933.

Change-Id: Ib5ef348b2c55d2012ffed765f2a6df99dec171f4
Reviewed-on: https://go-review.googlesource.com/5302
Reviewed-by: Russ Cox <rsc@golang.org>
2015-02-19 20:14:21 +00:00
Dmitry Vyukov
d384545a45 cmd/pprof: add -runtime flag
The flag disables stripping of runtime frames in profiles.
This is useful when analyzing runtime itself.

Before:
$ go tool pprof --text --alloc_objects --lines fmt.test /tmp/mprof
      flat  flat%   sum%        cum   cum%
      2768 79.65% 79.65%      32768 79.65%  fmt_test.TestComplexFormatting fmt/fmt_test.go:744
      6554 15.93% 95.58%       6554 15.93%  regexp/syntax.(*compiler).rune regexp/syntax/compile.go:267
      1820  4.42%   100%       1820  4.42%  runtime.malg runtime/proc1.go:1977

After:
$ go tool pprof --text --alloc_objects --lines --runtime fmt.test /tmp/mprof
      flat  flat%   sum%        cum   cum%
     32768 79.65% 79.65%      32768 79.65%  runtime.convT2E runtime/iface.go:139
      6554 15.93% 95.58%       6554 15.93%  runtime.growslice runtime/slice.go:89
      1820  4.42%   100%       1820  4.42%  runtime.malg runtime/proc1.go:1977

Change-Id: If468dfa5c5bbd0809c45a58d912d3115fac009ed
Reviewed-on: https://go-review.googlesource.com/5291
Reviewed-by: Russ Cox <rsc@golang.org>
Reviewed-by: Rick Hudson <rlh@golang.org>
2015-02-19 19:46:20 +00:00
Josh Bleecher Snyder
5dbbb77633 runtime: don't test gdb on darwin
Fixes #9927

Change-Id: I2114cc21f7a4772e3d42bcad9642a8a545cd8e16
Reviewed-on: https://go-review.googlesource.com/5285
Reviewed-by: Minux Ma <minux@golang.org>
2015-02-19 17:36:52 +00:00
Austin Clements
c25c371098 runtime: use more natural types in struct workbuf
Until recently, struct workbuf had only lfnode and uintptr fields
before the obj array to make it convenient to compute the size of the
obj array.  It slowly grew more fields until this became inconvenient
enough that it was restructured to make the size computation easy.
Now the size computation doesn't care what the field types are, so
switch to more natural types.

Change-Id: I966140ba7ebb4aeb41d5c66d9d2a3bdc17dd4bcf
Reviewed-on: https://go-review.googlesource.com/5262
Reviewed-by: Russ Cox <rsc@golang.org>
2015-02-19 17:00:30 +00:00
Austin Clements
02dcdba7c8 runtime: switch to gcWork abstraction
This converts the garbage collector from directly manipulating work
buffers to using the new gcWork abstraction.

The previous management of work buffers was rather ad hoc.  As a
result, switching to the gcWork abstraction changes many details of
work buffer management.

If greyobject fills a work buffer, it can now pull from work.partial
in addition to work.empty.

Previously, gcDrain started with a partial or empty work buffer and
fetched an empty work buffer if it filled its current buffer (in
greyobject).  Now, gcDrain starts with a full work buffer and fetches
an partial or empty work buffer if it fills its current buffer (in
greyobject).  The original behavior was bad because gcDrain would
immediately drop the empty work buffer returned by greyobject and
fetch a full work buffer, which greyobject was likely to immediately
overflow, fetching another empty work buffer, etc.  The new behavior
isn't great at the start because greyobject is likely to immediately
overflow the full buffer, but the steady-state behavior should be more
stable.  Both before and after this change, gcDrain fetches a full
work buffer if it drains its current buffer.  Basically all of these
choices are bad; the right answer is to use a dual work buffer scheme.

Previously, shade always fetched a work buffer (though usually from
m.currentwbuf), even if the object was already marked.  Now it only
fetches a work buffer if it actually greys an object.

Change-Id: I8b880ed660eb63135236fa5d5678f0c1c041881f
Reviewed-on: https://go-review.googlesource.com/5232
Reviewed-by: Russ Cox <rsc@golang.org>
Reviewed-by: Rick Hudson <rlh@golang.org>
2015-02-19 16:59:34 +00:00
Austin Clements
b30d19de59 runtime: introduce higher-level GC work abstraction
This introduces a producer/consumer abstraction for GC work pointers
that internally handles the details of filling, draining, and
shuffling work buffers.

In addition to simplifying the GC code, this should make it easy for
us to change how we use work buffers, including cleaning up how we use
the work.partial queue, reintroducing a FIFO lookahead cache, adding
prefetching, and using dual buffers to avoid flapping.

This commit doesn't change any existing code.  The following commit
will switch the garbage collector from explicit workbuf manipulation
to gcWork.

Change-Id: Ifbfe5fff45bf0362d6d7c3cecb061f0c9874077d
Reviewed-on: https://go-review.googlesource.com/5231
Reviewed-by: Russ Cox <rsc@golang.org>
Reviewed-by: Rick Hudson <rlh@golang.org>
2015-02-19 16:59:26 +00:00