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41822 Commits

Author SHA1 Message Date
Michael Anthony Knyszek
a120cc8b36 runtime: compute whether a span needs zeroing in the new page allocator
This change adds the allocNeedZero method to mheap which uses the new
heapArena field zeroedBase to determine whether a new allocation needs
zeroing. The purpose of this work is to avoid zeroing memory that is
fresh from the OS in the context of the new allocator, where we no
longer have the concept of a free span to track this information.

The new field in heapArena, zeroedBase, is small, which runs counter to
the advice in the doc comment for heapArena. Since heapArenas are
already not a multiple of the system page size, this advice seems stale,
and we're OK with using an extra physical page for a heapArena. So, this
change also deletes the comment with that advice.

Updates #35112.

Change-Id: I688cd9fd3c57a98a6d43c45cf699543ce16697e2
Reviewed-on: https://go-review.googlesource.com/c/go/+/203858
Run-TryBot: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
2019-11-07 20:52:05 +00:00
Cherry Zhang
933bf75eda runtime: add async preemption support on S390X
This CL adds support of call injection and async preemption on
S390X.

Like ARM64, we need to clobber one register (REGTMP) for
returning from the injected call. Previous CLs have marked code
sequences that use REGTMP async-nonpreemtible.

Change-Id: I78adbc5fd70ca245da390f6266623385b45c9dfc
Reviewed-on: https://go-review.googlesource.com/c/go/+/204106
Reviewed-by: Keith Randall <khr@golang.org>
2019-11-07 20:45:45 +00:00
Cherry Zhang
4751db93ef cmd/internal/obj/s390x: mark unsafe points
For async preemption, we will be using REGTMP as a temporary
register in injected call on S390X, which will clobber it. So any
code that uses REGTMP is not safe for async preemption.

In the assembler backend, we expand a Prog to multiple machine
instructions and use REGTMP as a temporary register if necessary.
These need to be marked unsafe. Unlike ARM64 and MIPS,
instructions on S390X are variable length so we don't use the
length as a condition. Instead, we set a bit on the Prog whenever
REGTMP is used.

Change-Id: Ie5d14068a950f4c7cea51dff2c4a8bdc19ec9348
Reviewed-on: https://go-review.googlesource.com/c/go/+/204105
Run-TryBot: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
2019-11-07 20:34:27 +00:00
Michael Anthony Knyszek
689f6f77f0 runtime: integrate new page allocator into runtime
This change integrates all the bits and pieces of the new page allocator
into the runtime, behind a global constant.

Updates #35112.

Change-Id: I6696bde7bab098a498ab37ed2a2caad2a05d30ec
Reviewed-on: https://go-review.googlesource.com/c/go/+/201764
Run-TryBot: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
2019-11-07 20:14:02 +00:00
Michael Anthony Knyszek
21445b091e runtime: make the scavenger self-paced
Currently the runtime background scavenger is paced externally,
controlled by a collection of variables which together describe a line
that we'd like to stay under.

However, the line to stay under is computed as a function of the number
of free and unscavenged huge pages in the heap at the end of the last
GC. Aside from this number being inaccurate (which is still acceptable),
the scavenging system also makes an order-of-magnitude assumption as to
how expensive scavenging a single page actually is.

This change simplifies the scavenger in preparation for making it
operate on bitmaps. It makes it so that the scavenger paces itself, by
measuring the amount of time it takes to scavenge a single page. The
scavenging methods on mheap already avoid breaking huge pages, so if we
scavenge a real huge page, then we'll have paced correctly, otherwise
we'll sleep for longer to avoid using more than scavengePercent wall
clock time.

Unfortunately, all this involves measuring time, which is quite tricky.
Currently we don't directly account for long process sleeps or OS-level
context switches (which is quite difficult to do in general), but we do
account for Go scheduler overhead and variations in it by maintaining an
EWMA of the ratio of time spent scavenging to the time spent sleeping.
This ratio, as well as the sleep time, are bounded in order to deal with
the aforementioned OS-related anomalies.

Updates #35112.

Change-Id: Ieca8b088fdfca2bebb06bcde25ef14a42fd5216b
Reviewed-on: https://go-review.googlesource.com/c/go/+/201763
Run-TryBot: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
2019-11-07 20:12:18 +00:00
Brian Kessler
68dce4296e math/cmplx: handle special cases
Implement special case handling and testing to ensure
conformance with the C99 standard annex G.6 Complex arithmetic.

Fixes #29320

Change-Id: Ieb0527191dd7fdea5b1aecb42b9e23aae3f74260
Reviewed-on: https://go-review.googlesource.com/c/go/+/169501
Run-TryBot: Brian Kessler <brian.m.kessler@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
2019-11-07 19:48:30 +00:00
Cherry Zhang
3c47eada3f cmd/internal/obj/ppc64: handle MOVDU for SP delta
If a MOVDU instruction is used with an offset of SP, the
instruction changes SP therefore needs an SP delta, which is used
for generating the PC-SP table for stack unwinding. MOVDU is
frequently used for allocating the frame and saving the LR in the
same instruction, so this is particularly useful.

Change-Id: Icb63eb55aa01c3dc350ac4e4cff6371f4c3c5867
Reviewed-on: https://go-review.googlesource.com/c/go/+/205279
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2019-11-07 19:20:57 +00:00
Cherry Zhang
ceca99bdeb cmd/compile, cmd/internal/obj/ppc64: mark unsafe points
We'll use CTR as a scratch register for call injection. Mark code
sequences that use CTR as unsafe for async preemption. Currently
it is only used in LoweredZero and LoweredMove. It is unfortunate
that they are nonpreemptible. But I think it is still better than
using LR for call injection and marking all leaf functions
nonpreemptible.

Also mark the prologue of large frame functions nonpreemptible,
as we write below SP.

Change-Id: I05a75431499f3f4b2f23651a7b17f7fcf2afbe06
Reviewed-on: https://go-review.googlesource.com/c/go/+/203823
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2019-11-07 19:20:35 +00:00
Cherry Zhang
24e549a717 cmd/compile, cmd/internal/obj/ppc64: use LR for indirect calls
On PPC64, indirect calls can be made through LR or CTR. Currently
both are used. This CL changes it to always use LR.

For async preemption, to return from the injected call, we need
an indirect jump back to the PC we preeempted. This jump can be
made through LR or CTR. So we'll have to clobber either LR or CTR.
Currently, LR is used more frequently. In particular, for a leaf
function, LR is live throughout the function. We don't want to
make leaf functions nonpreemptible. So we choose CTR for the call
injection. For code sequences that use CTR, if it is ok to use
another register, change it to.

Plus, it is a call so it will clobber LR anyway. It doesn't need
to also clobber CTR (even without preemption).

Change-Id: I07bd0e93b94a1a3aa2be2cd465801136165d8ab8
Reviewed-on: https://go-review.googlesource.com/c/go/+/203822
Run-TryBot: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
2019-11-07 19:20:03 +00:00
Cherry Zhang
a96cfa75c6 cmd/compile: mark unsafe points for MIPS and MIPS64
Mark atomic LL/SC loops as unsafe for async preemption, as they
use REGTMP.

Change-Id: I5be7f93ad3ee337049ec7c3efd6fdc30eef87d97
Reviewed-on: https://go-review.googlesource.com/c/go/+/203719
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
2019-11-07 19:18:59 +00:00
Cherry Zhang
69dcdbd2ba cmd/internal/obj/mips: mark unsafe points
For async preemption, we will be using REGTMP as a temporary
register in injected call on MIPS, which will clobber it. So any
code that uses REGTMP is not safe for async preemption.

In the assembler backend, we expand a Prog to multiple machine
instructions and use REGTMP as a temporary register if necessary.
These need to be marked unsafe. In fact, most of the
multi-instruction Progs use REGTMP, so we mark all of them,
except ones that are whitelisted.

Change-Id: Ic00ae5589683c2c9525abdaee076d884df6b0d1e
Reviewed-on: https://go-review.googlesource.com/c/go/+/203718
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2019-11-07 19:18:49 +00:00
Cherry Zhang
1b0b980904 runtime: add async preemption support on ARM64
This CL adds support of call injection and async preemption on
ARM64.

There seems no way to return from the injected call without
clobbering *any* register. So we have to clobber one, which is
chosen to be REGTMP. Previous CLs have marked code sequences
that use REGTMP async-nonpreemtible.

Change-Id: Ieca4e3ba5557adf3d0f5d923bce5f1769b58e30b
Reviewed-on: https://go-review.googlesource.com/c/go/+/203461
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
2019-11-07 19:18:12 +00:00
Cherry Zhang
4736088463 cmd/internal/obj/arm64: mark unsafe points
For async preemption, we will be using REGTMP as a temporary
register in injected call on ARM64, which will clobber it. So any
code that uses REGTMP is not safe for async preemption.

In the assembler backend, we expand a Prog to multiple machine
instructions and use REGTMP as a temporary register if necessary.
These need to be marked unsafe. In fact, most of the
multi-instruction Progs use REGTMP, so we mark all of them,
except ones that are whitelisted.

Change-Id: I6e97805a13950e3b693fb606d77834940ac3722e
Reviewed-on: https://go-review.googlesource.com/c/go/+/203460
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2019-11-07 19:17:50 +00:00
Michael Anthony Knyszek
e5ce13c178 runtime: add option to scavenge with lock held throughout
This change adds a "locked" parameter to scavenge() and scavengeone()
which allows these methods to be run with the heap lock acquired, and
synchronously with respect to others which acquire the heap lock.

This mode is necessary for both heap-growth scavenging (multiple
asynchronous scavengers here could be problematic) and
debug.FreeOSMemory.

Updates #35112.

Change-Id: I24eea8e40f971760999c980981893676b4c9b666
Reviewed-on: https://go-review.googlesource.com/c/go/+/195699
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
2019-11-07 19:14:47 +00:00
Michael Anthony Knyszek
e1ddf0507c runtime: count scavenged bits for new allocation for new page allocator
This change makes it so that the new page allocator returns the number
of pages that are scavenged in a new allocation so that mheap can update
memstats appropriately.

The accounting could be embedded into pageAlloc, but that would make
the new allocator more difficult to test.

Updates #35112.

Change-Id: I0f94f563d7af2458e6d534f589d2e7dd6af26d12
Reviewed-on: https://go-review.googlesource.com/c/go/+/195698
Reviewed-by: Austin Clements <austin@google.com>
2019-11-07 19:14:38 +00:00
Michael Anthony Knyszek
73317080e1 runtime: add scavenging code for new page allocator
This change adds a scavenger for the new page allocator along with
tests. The scavenger walks over the heap backwards once per GC, looking
for memory to scavenge. It walks across the heap without any lock held,
searching optimistically. If it finds what appears to be a scavenging
candidate it acquires the heap lock and attempts to verify it. Upon
verification it then scavenges.

Notably, unlike the old scavenger, it doesn't show any preference for
huge pages and instead follows a more strict last-page-first policy.

Updates #35112.

Change-Id: I0621ef73c999a471843eab2d1307ae5679dd18d6
Reviewed-on: https://go-review.googlesource.com/c/go/+/195697
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
2019-11-07 19:14:27 +00:00
Michael Anthony Knyszek
39e8cb0faa runtime: add new page allocator core
This change adds a new bitmap-based allocator to the runtime with tests.
It does not yet integrate the page allocator into the runtime and thus
this change is almost purely additive.

Updates #35112.

Change-Id: Ic3d024c28abee8be8797d3918116a80f901cc2bf
Reviewed-on: https://go-review.googlesource.com/c/go/+/190622
Run-TryBot: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
2019-11-07 19:11:26 +00:00
Ian Lance Taylor
05aa4a7b74 runtime: set GODEBUG=asyncpreemptoff=1 in TestCrashDumpsAllThreads
Fixes #35356

Change-Id: I67b9e57b88d00ed98cbc3aa0aeb26b5f2d75a3f7
Reviewed-on: https://go-review.googlesource.com/c/go/+/205720
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2019-11-07 18:39:03 +00:00
Bryan C. Mills
ee2268c6bc cmd/go: add math/bits to runtime packages in TestNewReleaseRebuildsStalePackagesInGOPATH
This fixes a test failure introduced in CL 190620.

Updates #35112

Change-Id: I568ae85a456ccd8103563b0ce2e42b7348776a5c
Reviewed-on: https://go-review.googlesource.com/c/go/+/205877
Run-TryBot: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
2019-11-07 18:06:59 +00:00
Michael Anthony Knyszek
763d3ac75c runtime: make sysReserve return page-aligned memory on js-wasm
This change ensures js-wasm returns page-aligned memory. While today
its lack of alignment doesn't cause problems, this is an invariant of
sysAlloc which is documented in HACKING.md but isn't upheld by js-wasm.

Any code that calls sysAlloc directly for small structures expects a
certain alignment (e.g. debuglog, tracebufs) but this is not maintained
by js-wasm's sysAlloc.

Where sysReserve comes into play is that sysAlloc is implemented in
terms of sysReserve on js-wasm. Also, the documentation of sysReserve
says that the returned memory is "OS-aligned" which on most platforms
means page-aligned, but the "OS-alignment" on js-wasm is effectively 1,
which doesn't seem right either.

The expected impact of this change is increased memory use on wasm,
since there's no way to decommit memory, and any small structures
allocated with sysAlloc won't be packed quite as tightly. However, any
memory increase should be minimal. Most calls to sysReserve and sysAlloc
already aligned their request to physPageSize before calling it; there
are only a few circumstances where this is not true, and they involve
allocating an amount of memory returned by unsafe.Sizeof where it's
actually quite important that we get the alignment right.

Updates #35112.

Change-Id: I9ca171e507ff3bd186326ccf611b35b9ebea1bfe
Reviewed-on: https://go-review.googlesource.com/c/go/+/205277
Run-TryBot: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Richard Musiol <neelance@gmail.com>
2019-11-07 17:45:27 +00:00
Michael Anthony Knyszek
cec01395c5 runtime: add packed bitmap summaries
This change adds the concept of summaries and of summarizing a set of
pallocBits, a core concept in the new page allocator. These summaries
are really just three integers packed into a uint64. This change also
adds tests and a benchmark for generating these summaries.

Updates #35112.

Change-Id: I69686316086c820c792b7a54235859c2105e5fee
Reviewed-on: https://go-review.googlesource.com/c/go/+/190621
Run-TryBot: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2019-11-07 17:45:15 +00:00
Michael Anthony Knyszek
b3a361337c runtime: add pallocbits and tests
This change adds a per-chunk bitmap for page allocation called
pallocBits with algorithms for allocating and freeing pages out of the
bitmap. This change also adds tests for pallocBits, but does not yet
integrate it into the runtime.

Updates #35112.

Change-Id: I479006ed9f1609c80eedfff0580d5426b064b0ff
Reviewed-on: https://go-review.googlesource.com/c/go/+/190620
Run-TryBot: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
2019-11-07 16:35:53 +00:00
Brian Kessler
6b1d5471b9 cmd/compile: add signed indivisibility by power of 2 rules
Commit 44343c777c (CL 173557) added rules for handling
divisibility checks for powers of 2 for signed integers, x%c ==0.
This change adds the complementary indivisibility rules, x%c != 0.

Fixes #34166

Change-Id: I87379e30af7aff633371acca82db2397da9b2c07
Reviewed-on: https://go-review.googlesource.com/c/go/+/194219
Run-TryBot: Brian Kessler <brian.m.kessler@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2019-11-07 16:30:46 +00:00
Michael Anthony Knyszek
14849f0fa5 runtime: add new page allocator constants and description
This change is the first of a series of changes which replace the
current page allocator (which is based on the contents of mgclarge.go
and some of mheap.go) with one based on free/used bitmaps.

It adds in the key constants for the page allocator as well as a comment
describing the implementation.

Updates #35112.

Change-Id: I839d3a07f46842ad379701d27aa691885afdba63
Reviewed-on: https://go-review.googlesource.com/c/go/+/190619
Run-TryBot: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
2019-11-07 16:20:25 +00:00
Jay Conrod
0bf2eb5d4d cmd/go/internal/modfetch: switch to golang.org/x/mod/zip
zip.Create is now used to filter and translate zip files from VCS tools.

zip.Unzip is now used instead of Unzip.

Fixes #35290

Change-Id: I4aa41b2e96bf147c09db43d1d189b8393cafb06f
Reviewed-on: https://go-review.googlesource.com/c/go/+/204917
Run-TryBot: Jay Conrod <jayconrod@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
2019-11-07 16:13:31 +00:00
Michael Anthony Knyszek
947f8504d9 runtime: map reserved memory as NORESERVE on solaris
This changes makes it so that sysReserve, which creates a PROT_NONE
mapping, maps that memory as NORESERVE. Before this change, relatively
large PROT_NONE mappings could cause fork to fail with ENOMEM, reported
as "not enough space". Presumably this refers to swap space, since
adding this flag causes the failures to go away.

This helps unblock page allocator work, since it allows us to make large
PROT_NONE mappings on solaris safely.

Updates #35112.

Change-Id: Ic3cba310c626e93d5db0f27269e2569bb7bc393e
Reviewed-on: https://go-review.googlesource.com/c/go/+/205759
Run-TryBot: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2019-11-07 15:51:45 +00:00
Jay Conrod
f7d0a42121 cmd/go/internal/modfetch/zip_sum_test: long test for zip sum stability
This CL adds a new test package which downloads specific versions of
~1000 modules in direct mode and verifies that modules have the same
sums and the zip files have the same SHA-256 hashes.

This test takes a long time to run and depends heavily on external
data that may disappear. It must be enabled manually with -zipsum.

Fixes #35290

Change-Id: Ic6959e685096e8b09cea291f19d5bd0255432284
Reviewed-on: https://go-review.googlesource.com/c/go/+/204838
Reviewed-by: Bryan C. Mills <bcmills@google.com>
2019-11-07 15:10:59 +00:00
Bryan C. Mills
73d57bf80f Revert "sync: yield to the waiter when unlocking a starving mutex"
This reverts CL 200577.

Reason for revert: broke linux-arm64-packet and solaris-amd64-oraclerel builders

Fixes #35424
Updates #33747

Change-Id: I2575fd84d37995d458183caae54704f15d8b8426
Reviewed-on: https://go-review.googlesource.com/c/go/+/205817
Run-TryBot: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2019-11-07 15:04:03 +00:00
Russ Cox
e8f01d591f math: test portable FMA even on system with hardware FMA
This makes it a little less likely the portable FMA will be
broken without realizing it.

Change-Id: I7f7f4509b35160a9709f8b8a0e494c09ea6e410a
Reviewed-on: https://go-review.googlesource.com/c/go/+/205337
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2019-11-07 14:53:38 +00:00
Russ Cox
543c6d2e0d math, cmd/compile: rename Fma to FMA
This API was added for #25819, where it was discussed as math.FMA.
The commit adding it used math.Fma, presumably for consistency
with the rest of the unusual names in package math
(Sincos, Acosh, Erfcinv, Float32bits, etc).

I believe that using an idiomatic Go name is more important here
than consistency with these other names, most of which are historical
baggage from C's standard library.

Early additions like Float32frombits happened before "uppercase for export"
(so they were originally like "float32frombits") and they were not properly
reconsidered when we uppercased the symbols to export them.
That's a mistake we live with.

The names of functions we have added since then, and even a few
that were legacy, are more properly Go-cased, such as IsNaN, IsInf,
and RoundToEven, rather than Isnan, Isinf, and Roundtoeven.
And also constants like MaxFloat32.

For new API, we should keep using proper Go-cased symbols
instead of minimally-upper-cased-C symbols.

So math.FMA, not math.Fma.

This API has not yet been released, so this change does not break
the compatibility promise.

This CL also modifies cmd/compile, since the compiler knows
the name of the function. I could have stopped at changing the
string constants, but it seemed to make more sense to use a
consistent casing everywhere.

Change-Id: I0f6f3407f41e99bfa8239467345c33945088896e
Reviewed-on: https://go-review.googlesource.com/c/go/+/205317
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2019-11-07 14:51:06 +00:00
Cuong Manh Le
3b1ae308a4 syscall: revert security_windows.go change of CL 201877
This CL was verified by running:

	go test -gcflags=all=-d=checkptr=2 internal/syscall/windows

internal/syscall/windows.TestRunAtLowIntegrity uses code in question.

Updates #34972

Change-Id: I434530058e2d41f132e9bf154e8c64c03894e9c4
Reviewed-on: https://go-review.googlesource.com/c/go/+/204117
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2019-11-07 09:32:43 +00:00
Rob Pike
7a2baa9c48 cmd/doc: don't bother checking validity of symbols at top level
No need to check as pieces further down do so anyway:

	%  go doc '&&.%$^'
	doc: symbol && is not a type in package fmt installed in "fmt"
	exit status 1
	%

Removing this check allows 'go doc sort.interface' or 'go doc
types.type' to discover sort.Interface and go/types.Type.

Easily

Fixes #34656.

Change-Id: I84352e83dd7f91a232f45a44d1a52f019a1a9a06
Reviewed-on: https://go-review.googlesource.com/c/go/+/205778
Reviewed-by: Caleb Spare <cespare@gmail.com>
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
2019-11-07 08:25:32 +00:00
Brian Kessler
f5949b6067 math/big: allow all values for GCD
Allow the inputs a and b to be zero or negative to GCD
with the following definitions.

If x or y are not nil, GCD sets their value such that z = a*x + b*y.
Regardless of the signs of a and b, z is always >= 0.
If a == b == 0, GCD sets z = x = y = 0.
If a == 0 and b != 0, GCD sets z = |b|, x = 0, y = sign(b) * 1.
If a != 0 and b == 0, GCD sets z = |a|, x = sign(a) * 1, y = 0.

Fixes #28878

Change-Id: Ia83fce66912a96545c95cd8df0549bfd852652f3
Reviewed-on: https://go-review.googlesource.com/c/go/+/164972
Run-TryBot: Brian Kessler <brian.m.kessler@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
2019-11-07 06:58:44 +00:00
Carlo Alberto Ferraris
a8f57f4ada sync: yield to the waiter when unlocking a starving mutex
When we have already assigned the semaphore ticket to a specific
waiter, we want to get the waiter running as fast as possible since
no other G waiting on the semaphore can acquire it optimistically.

The net effect is that, when a sync.Mutex is contented, the code in
the critical section guarded by the Mutex gets a priority boost.

Fixes #33747

Change-Id: I9967f0f763c25504010651bdd7f944ee0189cd45
Reviewed-on: https://go-review.googlesource.com/c/go/+/200577
Reviewed-by: Rhys Hiltner <rhys@justin.tv>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-11-07 05:59:33 +00:00
Ian Lance Taylor
3eabdd291d net: skip TestDialCancel if Dial fails with "connection refused"
Fixes #15191

Change-Id: I86214ede619400acd44f21138b5ddf6cef4649a3
Reviewed-on: https://go-review.googlesource.com/c/go/+/205698
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2019-11-07 05:52:34 +00:00
Michael Anthony Knyszek
198f0452b0 runtime: define darwin/arm64's address space as 33 bits
On iOS, the address space is not 48 bits as one might believe, since
it's arm64 hardware. In fact, all pointers are truncated to 33 bits, and
the OS only gives applications access to the range [1<<32, 2<<32).

While today this has no effect on the Go runtime, future changes which
care about address space size need this to be correct.

Updates #35112.

Change-Id: Id518a2298080f7e3d31cf7d909506a37748cc49a
Reviewed-on: https://go-review.googlesource.com/c/go/+/205758
Run-TryBot: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
2019-11-07 02:33:31 +00:00
Benjamin Peterson
e3a7d6c297 os: fix reference to nonexistent errors.Wrapper
Change-Id: I857d39486cbddbbee0c00fd45eb77f21488f4806
GitHub-Last-Rev: 1b500183cf
GitHub-Pull-Request: golang/go#35399
Reviewed-on: https://go-review.googlesource.com/c/go/+/205602
Reviewed-by: Jonathan Amsterdam <jba@google.com>
2019-11-07 02:14:17 +00:00
Michael Anthony Knyszek
61ef6a39dd runtime: remove MAP_FIXED in sysReserve for raceenabled on darwin
This change removes a hack which was added to deal with Darwin 10.10's
weird ignorance of mapping hints which would cause race mode to fail
since it requires the heap to live within a certain address range.

We no longer support 10.10, and this is potentially causing problems
related to the page allocator, so drop this code.

Updates #26475.
Updates #35112.

Change-Id: I0e1c6f8c924afe715a2aceb659a969d7c7b6f749
Reviewed-on: https://go-review.googlesource.com/c/go/+/205757
Run-TryBot: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2019-11-07 01:38:25 +00:00
Ian Lance Taylor
6ce4384fd6 runtime: mark testSetPanicOnFault as go:nocheckptr
The test deliberately constructs an invalid pointer, so don't check it.

Fixes #35379

Change-Id: Ifeff3484740786b0470de3a4d2d4103d91e06f5d
Reviewed-on: https://go-review.googlesource.com/c/go/+/205717
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2019-11-06 23:48:45 +00:00
Vitaly Zdanevich
63546a03cc doc: Effective Go: formatting of code example
Change-Id: I7f5947cef3ec43746f60abca556dda29a705caf7
GitHub-Last-Rev: b9aefd06ab
GitHub-Pull-Request: golang/go#35404
Reviewed-on: https://go-review.googlesource.com/c/go/+/205610
Reviewed-by: Rob Pike <r@golang.org>
2019-11-06 21:40:43 +00:00
Kevin Burke
00547235b7 cmd/go: fix spelling error
Change-Id: Ib29da1ad77c9a243a623d25113c6f8dd0261f42a
Reviewed-on: https://go-review.googlesource.com/c/go/+/205601
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2019-11-06 19:48:05 +00:00
Bryan C. Mills
db6b66edc8 cmd/go: use lockedfile instead of renameio for go.mod and go.sum files
This change is based on the previous discussion in CL 202442.

Fixes #34634

Change-Id: I1319aa26d5cfcd034bc576555787b3ca79968c38
Reviewed-on: https://go-review.googlesource.com/c/go/+/205637
Run-TryBot: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Jay Conrod <jayconrod@google.com>
2019-11-06 19:20:38 +00:00
Bryan C. Mills
3c2979682d cmd/doc: understand vendor directories in module mode
This change employs the same strategy as in CL 203017
to detect when vendoring is in use, and if so treats
the vendor directory as a (non-module, prefixless) root.

The integration test also verifies that the 'std' and 'cmd'
modules are included and their vendored dependencies are
visible (as they are with 'go list') even when outside of
those modules.

Fixes #35224

Change-Id: I18cd01218e9eb97c1fc6e2401c1907536b0b95f7
Reviewed-on: https://go-review.googlesource.com/c/go/+/205577
Run-TryBot: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Jay Conrod <jayconrod@google.com>
2019-11-06 18:27:09 +00:00
Joel Sing
a2b1dc863f cmd/link,cmd/internal/objabi: factor out direct call identification
Factor out the direct CALL identification code from objabi.IsDirectJump and
use this in two places that have separately maintained lists of reloc types.
Provide an objabi.IsDirectCallOrJump function that implements the original
behaviour of objabi.IsDirectJump.

Change-Id: I48131bae92b2938fd7822110d53df0b4ffb35766
Reviewed-on: https://go-review.googlesource.com/c/go/+/196577
Run-TryBot: Joel Sing <joel@sing.id.au>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2019-11-06 17:03:51 +00:00
Robert Griesemer
4cb926001c cmd/compile/internal/syntax: silence test function output
Don't print to stdout in non-verbose (-v) test mode.

Exception: Timing output (2 lines) of TestStdLib. If
we want to disable that as well we should use another
flag to differenciate between -verbose output and
measurement results. Leaving alone for now.

Fixes #35223.

Change-Id: Ie8160760e8db1138f9031888d654eaeab202128c
Reviewed-on: https://go-review.googlesource.com/c/go/+/204039
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2019-11-06 17:02:19 +00:00
Meng Zhuo
a5936a4894 cmd/asm: add encode tests for MIPS64x
This CL adds basic encode test for mips64x and
most of the instructions are cross checked with 'gas'

Update #35008

Change-Id: I18bb524897aa745bfe23db43fcbb44c3b009463c
Reviewed-on: https://go-review.googlesource.com/c/go/+/204297
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-11-06 16:17:30 +00:00
Ian Lance Taylor
b50fcc88e9 runtime: don't hold scheduler lock when calling timeSleepUntil
Otherwise, we can get into a deadlock: sysmon takes the scheduler lock
and calls timeSleepUntil which takes each P's timer lock. Simultaneously,
some P calls runtimer (holding the P's own timer lock) which wakes up
the scavenger, calling goready, calling wakep, calling startm, getting
the scheduler lock. Now the sysmon thread is holding the scheduler lock
and trying to get a P's timer lock, while some other thread running on
that P is holding the P's timer lock and trying to get the scheduler lock.

So change sysmon to call timeSleepUntil without holding the scheduler
lock, and change timeSleepUntil to use allpLock, which is only held for
limited periods of time and should never compete with timer locks.

This hopefully

Fixes #35375

At least it should fix the linux-arm64-packet builder problems,
which occurred more reliably as that system has GOMAXPROCS == 96,
giving a lot more scope for this deadlock.

Change-Id: I7a7917daf7a4882e0b27ca416e4f6300cfaaa774
Reviewed-on: https://go-review.googlesource.com/c/go/+/205558
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
2019-11-06 15:46:26 +00:00
Bryan C. Mills
cf3be9bbca cmd/go: make commands other than 'tidy' prune go.mod less agressively
Updates #31870
Updates #33326
Fixes #34822

Change-Id: I1337f171133c20800eacc6b0955ede5a394ea7eb
Reviewed-on: https://go-review.googlesource.com/c/go/+/204878
Run-TryBot: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Jay Conrod <jayconrod@google.com>
2019-11-06 15:08:19 +00:00
Elias Naur
1bd974eeb7 cmd/link/internal/ld: omit bitcode-incompatible flags on iOS simulator
The -Wl,-headerpad, -Wl,-no_pie, -Wl,-pagezero_size flags are
incompatible with the bitcode-related flags used for iOS.

We already omitted the flags on darwin/arm and darwin/arm64; this change
omits the flags on all platforms != macOS so that building for the iOS
simulator works.

Updates #32963

Change-Id: Ic9af0daf01608f5ae0f70858e3045e399de7e95b
Reviewed-on: https://go-review.googlesource.com/c/go/+/205340
Run-TryBot: Elias Naur <mail@eliasnaur.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2019-11-06 14:56:38 +00:00
Austin Clements
b82404837d runtime: remove write barrier in WaitForSigusr1
WaitForSigusr1 registers a callback to be called on SIGUSR1 directly
from the runtime signal handler. Currently, this callback has a write
barrier in it, which can crash with a nil P if the GC is active and
the signal arrives on an M that doesn't have a P.

Fix this by recording the ID of the M that receives the signal instead
of the M itself, since that's all we needed anyway. To make sure there
are no other problems, this also lifts the callback into a package
function and marks it "go:nowritebarrierrec".

Fixes #35248.

Updates #35276, since in principle a write barrier at exactly the
wrong time while entering the scheduler could cause issues, though I
suspect that bug is unrelated.

Change-Id: I47b4bc73782efbb613785a93e381d8aaf6850826
Reviewed-on: https://go-review.googlesource.com/c/go/+/204620
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2019-11-06 14:34:46 +00:00