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Commit Graph

17956 Commits

Author SHA1 Message Date
Carl Shapiro
0368a7ceb6 runtime: move stack scanning into the parallel mark phase
This change reduces the cost of the stack scanning by frames.
It moves the stack scanning from the serial root enumeration
phase to the parallel tracing phase.  The output that follows
are timings for the issue 6482 benchmark

Baseline

BenchmarkGoroutineSelect	      50	 108027405 ns/op
BenchmarkGoroutineBlocking	      50	  89573332 ns/op
BenchmarkGoroutineForRange	      20	  95614116 ns/op
BenchmarkGoroutineIdle		      20	 122809512 ns/op

Stack scan by frames, non-parallel

BenchmarkGoroutineSelect	      20	 297138929 ns/op
BenchmarkGoroutineBlocking	      20	 301137599 ns/op
BenchmarkGoroutineForRange	      10	 312499469 ns/op
BenchmarkGoroutineIdle		      10	 209428876 ns/op

Stack scan by frames, parallel

BenchmarkGoroutineSelect	      20	 183938431 ns/op
BenchmarkGoroutineBlocking	      20	 170109999 ns/op
BenchmarkGoroutineForRange	      20	 179628882 ns/op
BenchmarkGoroutineIdle		      20	 157541498 ns/op

The remaining performance disparity is due to inefficiencies
in gentraceback and its callees.  The effect was isolated by
using a parallel stack scan where scanstack was modified to do
a conservative scan of the stack segments without gentraceback
followed by a call of gentrackback with a no-op callback.

The output that follows are the top-10 most frequent tops of
stacks as determined by the Linux perf record facility.

Baseline

+  25.19%  gc.test  gc.test            [.] runtime.xchg
+  19.00%  gc.test  gc.test            [.] scanblock
+   8.53%  gc.test  gc.test            [.] scanstack
+   8.46%  gc.test  gc.test            [.] flushptrbuf
+   5.08%  gc.test  gc.test            [.] procresize
+   3.57%  gc.test  gc.test            [.] runtime.chanrecv
+   2.94%  gc.test  gc.test            [.] dequeue
+   2.74%  gc.test  gc.test            [.] addroots
+   2.25%  gc.test  gc.test            [.] runtime.ready
+   1.33%  gc.test  gc.test            [.] runtime.cas64

Gentraceback

+  18.12%  gc.test  gc.test             [.] runtime.xchg
+  14.68%  gc.test  gc.test             [.] scanblock
+   8.20%  gc.test  gc.test             [.] runtime.gentraceback
+   7.38%  gc.test  gc.test             [.] flushptrbuf
+   6.84%  gc.test  gc.test             [.] scanstack
+   5.92%  gc.test  gc.test             [.] runtime.findfunc
+   3.62%  gc.test  gc.test             [.] procresize
+   3.15%  gc.test  gc.test             [.] readvarint
+   1.92%  gc.test  gc.test             [.] addroots
+   1.87%  gc.test  gc.test             [.] runtime.chanrecv

R=golang-dev, dvyukov, rsc
CC=golang-dev
https://golang.org/cl/17410043
2013-12-03 14:12:55 -08:00
Keith Randall
24699fb05c runtime: get rid of concatstring's vararg C argument.
Pass as a slice of strings instead.  For 2-5 strings, implement
dedicated routines so no slices are needed.

static call counts in the go binary:
 2 strings: 342 occurrences
 3 strings:  98
 4 strings:  30
 5 strings:  13
6+ strings:  14

Why?  C varags, bad for stack scanning and copying.

R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/36380043
2013-12-03 10:39:19 -08:00
Keith Randall
c0f2294577 runtime: fix race detector when map keys/values are passed by pointer.
Now that the map implementation is reading the keys and values from
arbitrary memory (instead of from stack slots), it needs to tell the
race detector when it does so.

Fixes #6875.

R=golang-dev, dave
CC=golang-dev
https://golang.org/cl/36360043
2013-12-02 18:03:25 -08:00
Keith Randall
742f755a29 reflect: test to make sure big Zero()-obtained objects are really zero.
Update #6876.

R=dave, bradfitz
CC=golang-dev
https://golang.org/cl/36370043
2013-12-02 17:58:19 -08:00
Keith Randall
e7d899cba5 reflect: fix Zero() implementation - not every type has a
zero object allocated, so we still need to allocate a new
zero area every time.

Fixes #6876.

R=golang-dev
CC=golang-dev
https://golang.org/cl/36320043
2013-12-02 16:54:29 -08:00
Keith Randall
85138da832 reflect: prevent the callXX routines from calling makeFuncStub
and methodValueCall directly.  Instead, we inline their behavior
inside of reflect.call.

This change is required because otherwise we have a situation where
reflect.callXX calls makeFuncStub, neither of which knows the
layout of the args passed between them.  That's bad for
precise gc & stack copying.

Fixes #6619.

R=golang-dev, dvyukov, rsc, iant, khr
CC=golang-dev
https://golang.org/cl/26970044
2013-12-02 13:36:50 -08:00
Keith Randall
c792bde9ef runtime: don't use ... formal argument to deferreturn.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/28860043
2013-12-02 13:07:15 -08:00
Keith Randall
3278dc158e runtime: pass key/value to map accessors by reference, not by value.
This change is part of the plan to get rid of all vararg C calls
which are a pain for getting exact stack scanning.

We allocate a chunk of zero memory to return a pointer to when a
map access doesn't find the key.  This is simpler than returning nil
and fixing things up in the caller.  Linker magic allocates a single
zero memory area that is shared by all (non-reflect-generated) map
types.

Passing things by reference gets rid of some copies, so it speeds
up code with big keys/values.

benchmark             old ns/op    new ns/op    delta
BenchmarkBigKeyMap           34           31   -8.48%
BenchmarkBigValMap           37           30  -18.62%
BenchmarkSmallKeyMap         26           23  -11.28%

R=golang-dev, dvyukov, khr, rsc
CC=golang-dev
https://golang.org/cl/14794043
2013-12-02 13:05:04 -08:00
Andrew Gerrand
de0fd9acee tag go1.2
R=golang-dev, dsymonds, alex.brainman
CC=golang-dev
https://golang.org/cl/35000043
2013-12-02 09:06:41 +11:00
David Symonds
ee261b75e1 misc/vim: send Fmt errors to the quickfix list instead of the location list.
Output from gofmt is a list of errors, so they should appear in the error list.

R=adg
CC=golang-dev
https://golang.org/cl/33760043
2013-11-27 19:32:15 +11:00
Oling Cat
07d2195c66 doc/install.html: fix a tag.
R=golang-dev, adg
CC=golang-dev
https://golang.org/cl/30900044
2013-11-25 13:36:16 +11:00
David Symonds
74eb115b1c misc/vim: describe how to get gofmt-on-save behaviour.
Fixes #6826.

R=golang-dev, bradfitz, adg
CC=golang-dev
https://golang.org/cl/31770043
2013-11-25 11:03:47 +11:00
Rob Pike
624f9da386 README: Fix installation instructions
They were out of date and should refer to the source installation instructions.

Fixes #6783.

R=golang-dev, rsc, adg, dave
CC=golang-dev
https://golang.org/cl/28500043
2013-11-20 13:47:37 -08:00
Andrew Gerrand
c497c9ea4b doc: update installation instructions
Clarify that GOROOT should only be set when using a custom install path.
Remove NetBSD from binary install page (we don't provide binaries).
Remove "What's next" links from installation instructions.
Emphasize "How to Write Go Code" page.

Fixes #6613.

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/28700043
2013-11-21 07:55:29 +11:00
dvyukov
b3d400c35e test: revert unintentional commits
I thought I am in a different repo...
2013-11-19 15:36:13 +04:00
dvyukov
aa9d2cb2c7 - 2013-11-19 15:31:01 +04:00
dvyukov
24be1b2b29 13+ 2013-11-19 12:55:12 +04:00
Andrew Gerrand
7cfcd2f87a misc/dist: fix file regexp
This step makes it possible to upload the -osx10.x binaries
separately to their construction (after signing, for example).

R=golang-dev, dsymonds
CC=golang-dev
https://golang.org/cl/28160043
2013-11-18 13:30:25 +11:00
Andrew Gerrand
bad181e2c2 tag go1.2rc5
R=dsymonds
CC=golang-dev
https://golang.org/cl/28150043
2013-11-18 12:47:37 +11:00
Brad Fitzpatrick
49f6415b95 C: add Marko Mikulicic (Google CLA)
R=golang-dev, crawshaw
CC=golang-dev
https://golang.org/cl/27000043
2013-11-15 11:01:54 -08:00
Russ Cox
a664b49457 doc/asm: more about SP, ARM R11
Also rename URL to /doc/asm.

R=golang-dev, minux.ma, r
CC=golang-dev
https://golang.org/cl/26170043
2013-11-13 21:29:34 -05:00
Russ Cox
7dd086e52d encoding/gob: do not use MarshalText, UnmarshalText
This seems to be the best of a long list of bad ways to fix this issue.

Fixes #6760.

R=r
CC=golang-dev
https://golang.org/cl/22770044
2013-11-13 21:29:19 -05:00
Andrew Gerrand
b6c7cc3241 encoding/gob: expose encode/decode example
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/26220045
2013-11-14 09:20:29 +11:00
Andrew Gerrand
833dc85c0f tag go1.2rc4
R=golang-dev, dsymonds
CC=golang-dev
https://golang.org/cl/25580045
2013-11-13 15:32:40 +11:00
Rob Pike
0bdd90bc0a src/cmd/?a: link to new assembler document
Blocked on 20930043, the CL the new text references.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/18430044
2013-11-12 20:07:08 -08:00
Rob Pike
2fbcb08192 doc/asm.html: new document, a brief guide to the assembler
Fixes #6060

R=golang-dev, iant, bradfitz, josharian, minux.ma, aram, rsc
CC=golang-dev
https://golang.org/cl/20930043
2013-11-12 20:04:22 -08:00
Robert Griesemer
f57bf7a556 spec: clarify rules for blank identifiers
This documents the status quo more precisely.
Not a language change.

Fixes #6006.

R=r, rsc, iant, ken
CC=golang-dev
https://golang.org/cl/14415043
2013-11-12 21:06:54 -05:00
Andrew Gerrand
c72bce901e doc: use the same wording for OS X as the other OSes
I used "and above" when I should have said "or later".

Sorry for the churn.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/25670043
2013-11-13 11:53:01 +11:00
Andrew Gerrand
14b32ed7b2 doc: we support all recent versions of OS X
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/25370045
2013-11-13 11:35:25 +11:00
Robert Griesemer
885e462e47 CONTRIBUTORS: add additional e-mail address for Richard Musiol
R=adonovan
CC=golang-dev
https://golang.org/cl/25360043
2013-11-12 10:03:13 -08:00
Robert Griesemer
9a459e1863 A+C: Richard Musiol (individual CLA)
Generated by addca.

R=gobot
CC=golang-dev
https://golang.org/cl/25350043
2013-11-12 09:57:00 -08:00
David Crawshaw
c4f5421bc7 misc/vim: add a gofmt_command flag for :Fmt
R=dsymonds, dominik.honnef, n13m3y3r, rsc, kamil.kisiel
CC=golang-dev
https://golang.org/cl/22940044
2013-11-12 09:28:07 +11:00
Olivier Duperray
8f10c76471 cmd/godoc: document package-level examples
Fixes  issue  5807 .

R=golang-dev, adg
CC=golang-dev
https://golang.org/cl/23940043
2013-11-11 12:09:24 +11:00
Dominik Honnef
597b9c0d19 misc/emacs: various cleanups
- Use #' for function symbols
- Remove unused variables
- Use declare-function to shut up byte compiler

This is identical to CL 19010044 with one exception: Making sure
it doesn't break on Emacs 22.1

R=adonovan, bradfitz, shendaras
CC=golang-dev
https://golang.org/cl/20100043
2013-11-08 15:23:12 -05:00
Sameer Ajmani
19dda5cd74 emacs: allow users to customize the gofmt command, in particular, to use goimports instead.
R=adonovan
CC=golang-dev
https://golang.org/cl/23680043
2013-11-08 11:31:44 -05:00
Russ Cox
6be1cb8c7a cmd/cgo: fix handling of array of pointers when using clang
Clang does not record the "size" field for pointer types,
so we must insert the size ourselves. We were already
doing this, but only for the case of pointer types.
For an array of pointer types, the setting of the size for
the nested pointer type was happening after the computation
of the size of the array type, meaning that the array type
was always computed as 0 bytes. Delay the size computation.

This bug happens on all Clang systems, not just FreeBSD.
Our test checked that cgo wrote something, not that it was correct.
FreeBSD's default clang rejects array[0] as a C struct field,
so it noticed the incorrect sizes. But the sizes were incorrect
everywhere.

Update testcdefs to check the output has the right semantics.

Fixes #6292.

R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/22840043
2013-11-07 15:24:51 -05:00
Ian Lance Taylor
8d206d9d80 doc: update note about GCC 4.8.2 in gccgo instructions
R=golang-dev, minux.ma
CC=golang-dev
https://golang.org/cl/22510043
2013-11-06 13:58:35 -08:00
Ato Araki
df03aeb67c go/doc: add full stop of Japanese, Chinese and Korean.
This fix will show a good synopsis on package listings in that languages.

R=adg, r
CC=golang-dev
https://golang.org/cl/21130043
2013-11-05 15:13:50 +11:00
Andrew Gerrand
f931970b6b A+C: Ato Araki (individual CLA)
Generated by addca.

R=gobot
CC=golang-dev
https://golang.org/cl/21790043
2013-11-05 15:10:24 +11:00
Andrew Gerrand
c1ef845a71 doc/go1.2: link to cgo documentation
I know it's linked in the previous sentence, but this new link is where I want it to be while reading this sentence.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/21770043
2013-11-05 13:54:48 +11:00
Brad Fitzpatrick
692a14787f net/textproto: fix CanonicalMIMEHeaderKey panic
Fixes #6712

R=golang-dev, adg, rsc
CC=golang-dev
https://golang.org/cl/21450043
2013-11-04 12:35:11 -05:00
Andrew Gerrand
3a7ab7eab4 C: add Robert Snedegar (Google CLA)
R=golang-dev
CC=golang-dev
https://golang.org/cl/21390044
2013-11-04 17:41:08 +11:00
Brad Fitzpatrick
ea0251f2d2 C: add Brad Garcia (Google CLA)
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/19990045
2013-11-01 09:18:35 -07:00
Andrew Gerrand
5455eb23ef tag go1.2rc3
R=golang-dev, dsymonds
CC=golang-dev
https://golang.org/cl/20680043
2013-11-01 12:53:31 +11:00
Russ Cox
2c98a3bc2e cmd/5l, runtime: fix divide for profiling tracebacks on ARM
Two bugs:
1. The first iteration of the traceback always uses LR when provided,
which it is (only) during a profiling signal, but in fact LR is correct
only if the stack frame has not been allocated yet. Otherwise an
intervening call may have changed LR, and the saved copy in the stack
frame should be used. Fix in traceback_arm.c.

2. The division runtime call adds 8 bytes to the stack. In order to
keep the traceback routines happy, it must copy the saved LR into
the new 0(SP). Change

        SUB $8, SP

into

        MOVW    0(SP), R11 // r11 is temporary, for use by linker
        MOVW.W  R11, -8(SP)

to update SP and 0(SP) atomically, so that the traceback always
sees a saved LR at 0(SP).

Fixes #6681.

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/19910044
2013-10-31 18:15:55 +00:00
Russ Cox
b88148b9a0 undo CL 19810043 / 352f3b7c9664
The CL causes misc/cgo/test to fail randomly.
I suspect that the problem is the use of a division instruction
in usleep, which can be called while trying to acquire an m
and therefore cannot store the denominator in m.
The solution to that would be to rewrite the code to use a
magic multiply instead of a divide, but now we're getting
pretty far off the original code.

Go back to the original in preparation for a different,
less efficient but simpler fix.

««« original CL description
cmd/5l, runtime: make ARM integer division profiler-friendly

The implementation of division constructed non-standard
stack frames that could not be handled by the traceback
routines.

CL 13239052 left the frames non-standard but fixed them
for the specific case of a divide-by-zero panic.
A profiling signal can arrive at any time, so that fix
is not sufficient.

Change the division to store the extra argument in the M struct
instead of in a new stack slot. That keeps the frames bog standard
at all times.

Also fix a related bug in the traceback code: when starting
a traceback, the LR register should be ignored if the current
function has already allocated its stack frame and saved the
original LR on the stack. The stack copy should be used, as the
LR register may have been modified.

Combined, these make the torture test from issue 6681 pass.

Fixes #6681.

R=golang-dev, r, josharian
CC=golang-dev
https://golang.org/cl/19810043
»»»

TBR=r
CC=golang-dev
https://golang.org/cl/20350043
2013-10-31 17:18:57 +00:00
Russ Cox
b0db472ea2 cmd/5l, runtime: make ARM integer division profiler-friendly
The implementation of division constructed non-standard
stack frames that could not be handled by the traceback
routines.

CL 13239052 left the frames non-standard but fixed them
for the specific case of a divide-by-zero panic.
A profiling signal can arrive at any time, so that fix
is not sufficient.

Change the division to store the extra argument in the M struct
instead of in a new stack slot. That keeps the frames bog standard
at all times.

Also fix a related bug in the traceback code: when starting
a traceback, the LR register should be ignored if the current
function has already allocated its stack frame and saved the
original LR on the stack. The stack copy should be used, as the
LR register may have been modified.

Combined, these make the torture test from issue 6681 pass.

Fixes #6681.

R=golang-dev, r, josharian
CC=golang-dev
https://golang.org/cl/19810043
2013-10-30 18:50:34 +00:00
Rob Pike
95ae85fb82 doc/go1.2.html: delete repeated word
TBR=rsc

R=golang-dev
CC=golang-dev
https://golang.org/cl/19840043
2013-10-30 09:39:20 -07:00
Rob Pike
0f706d39d4 doc/go1.2.html: stack sizes, thread limits
R=golang-dev, minux.ma, adg, rsc
CC=golang-dev
https://golang.org/cl/19600043
2013-10-30 08:54:53 -07:00
Russ Cox
797d1bac0d cmd/cgo: accept extra leading _ on __cgodebug_data for all object formats
The current Windows build breakage appears to be because
the Windows code should be looking for __cgodebug_data
not ___cgodebug_data. Dodge the question everywhere by
accepting both.

R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/19780043
2013-10-30 10:24:42 -04:00