Like bionic, musl also doesn't provide vsyscall helper in %gs:0x10,
and as int $0x80 is as fast as calling %gs:0x10, just use int $0x80
always.
Because we're no longer using vsyscall in VDSO, get rid of VDSO code
for linux/386 too.
Fixes#14476.
Change-Id: I00ec8652060700e0a3c9b524bfe3c16a810263f6
Reviewed-on: https://go-review.googlesource.com/19833
Run-TryBot: Minux Ma <minux@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Bump up the multiplier to 20. Also run the fast version first, so that
the slow version is likely to start up faster.
Change-Id: Ia0654cc1212ab03a45da1904d3e4b57d6a8d02a0
Reviewed-on: https://go-review.googlesource.com/19835
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Minux Ma <minux@golang.org>
They do the same thing, except memequal also has the short-circuit
check if the two pointers are equal.
A) We might as well always do the short-circuit check, it is only 2 instructions.
B) The extra function call (memequal->memeq) is expensive.
benchmark old ns/op new ns/op delta
BenchmarkArrayEqual-8 8.56 5.31 -37.97%
No noticeable affect on the former memeq user (maps).
Fixes#14302
Change-Id: I85d1ada59ed11e64dd6c54667f79d32cc5f81948
Reviewed-on: https://go-review.googlesource.com/19843
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
It's not needed on other OSes.
Change-Id: Ia6b13510585392a7062374806527d33876beba2a
Reviewed-on: https://go-review.googlesource.com/19818
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Also eliminates per-maptype hiter and hmap types, since they're not
really needed anyway. Update packages reflect and runtime
accordingly.
Reduces golang.org/x/tools/cmd/godoc's text segment by ~170kB:
text data bss dec hex filename
13085702 140640 151520 13377862 cc2146 godoc.before
12915382 140640 151520 13207542 c987f6 godoc.after
Updates #6853.
Change-Id: I948b2bc1f22d477c1756204996b4e3e1fb568d81
Reviewed-on: https://go-review.googlesource.com/16610
Reviewed-by: Keith Randall <khr@golang.org>
These functions are really simple, the overhead of calling
them (in both time and code size) is larger than the inlined versions.
Reorganize how the nil case in a type switch is handled, as we have
to check for nil explicitly now anyway.
Saves about 0.8% in the binary size of the go tool.
Change-Id: I8501b62d72fde43650b79f52b5f699f1fbd0e7e7
Reviewed-on: https://go-review.googlesource.com/19814
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Change-Id: I6cb8ac7b59812e82111ab3b0f8303ab8194a5129
Reviewed-on: https://go-review.googlesource.com/19791
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
There's no need for 8 different ways to represent that a type is
non-comparable.
While here, move AMEM out of the runtime-known algorithm values since
it's not needed at run-time, and get rid of the unused AUNK constant.
Change-Id: Ie23972b692c6f27fc5f1a908561b3e26ef5a50e9
Reviewed-on: https://go-review.googlesource.com/19779
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
You can not use cannot, but you cannot spell cannot can not.
Change-Id: I2f0971481a460804de96fd8c9e46a9cc62a3fc5b
Reviewed-on: https://go-review.googlesource.com/19772
Reviewed-by: Rob Pike <r@golang.org>
TestCrashDumpsAllThreads carefully sets the number of Ps to one
greater than the number of non-preemptible loops it starts so that the
main goroutine can continue to run (necessary because of #10958).
However, if GC starts, it can take over that one spare P and lock up
the system while waiting for the non-preemptible loops, causing the
test to eventually time out. This deadlock is easily reproducible if
you run the runtime test with GOGC=1.
Fix this by forcing GOGC=off when running this test.
Change-Id: Ifb22da5ce33f9a61700a326ea92fcf4b049721d1
Reviewed-on: https://go-review.googlesource.com/19516
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
We used to include panic calls in tracebacks; however, when
runtime.panic was renamed to runtime.gopanic in the conversion of the
runtime to Go, we missed the special case in showframe that includes
panic calls even though they're in package runtime.
Fix the function name check in showframe (and, while we're here, fix
the other check for "runtime.panic" in runtime/pprof). Since the
"runtime.gopanic" name doesn't match what users call panic and hence
isn't very user-friendly, make traceback rewrite it to just "panic".
Updates #5832, #13857. Fixes#14315.
Change-Id: I8059621b41ec043e63d5cfb4cbee479f47f64973
Reviewed-on: https://go-review.googlesource.com/19492
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
The code in mem_bsd.go expects that when mmap fails it will return a
positive errno value. This fixes the Solaris implementation of mmap to
work as expected.
Change-Id: Id1c34a9b916e8dc955ced90ea2f4af8321d92265
Reviewed-on: https://go-review.googlesource.com/19477
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
The caller of mmap expects it to return a positive errno value, but the
linux-arm64 and nacl-386 system calls returned a negative errno value.
Correct them to negate the errno value.
The caller of mincore expects it to return a negative errno value (yes,
this is inconsistent), but the linux-mips64x and linux-ppc64x system
call returned a positive errno value. Correct them to negate the errno
value.
Add a test that mmap returns errno with the correct sign. Brad added a
test for mincore's errno value in https://golang.org/cl/19457.
Fixes#14297.
Change-Id: I2b93f32e679bd1eae1c9aef9ae7bcf0ba39521b5
Reviewed-on: https://go-review.googlesource.com/19455
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Minux Ma <minux@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
When using a stack-allocated buffer for the result, don't
expose the uninitialized portion of it by restricting its
capacity to its length.
The other option is to zero the portion between len and cap.
That seems like more work, but might be worth it if the caller
then appends some stuff to the result. But this close to 1.6,
I'm inclined to do the simplest fix possible.
Fixes#14232
Change-Id: I21c50d3cda02fd2df4d60ba5e2cfe2efe272f333
Reviewed-on: https://go-review.googlesource.com/19231
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Currently it's possible for the scheduler to deadlock with the right
confluence of locked Gs, assists, and scheduling of background mark
workers. Broadly, this happens because handoffp is stricter than
findrunnable, and if the only work for a P is GC work, handoffp will
put the P into idle, rather than starting an M to execute that P. One
way this can happen is as follows:
0. There is only one user G, which we'll call G 1. There is more than
one P, but they're all idle except the one running G 1.
1. G 1 locks itself to an M using runtime.LockOSThread.
2. GC starts up and enters mark 1.
3. G 1 performs a GC assist, which completes mark 1 without being
fully satisfied. Completing mark 1 causes all background mark
workers to park. And since the assist isn't fully satisfied, it
parks as well, waiting for a background mark worker to satisfy its
remaining assist debt.
4. The assist park enters the scheduler. Since G 1 is locked to the M,
the scheduler releases the P and calls handoffp to hand the P to
another M.
5. handoffp checks the local and global run queues, which are empty,
and sees that there are idle Ps, so rather than start an M, it puts
the P into idle.
At this point, all of the Gs are waiting and all of the Ps are idle.
In particular, none of the GC workers are running, so no mark work
gets done and the assist on the main G is never satisfied, so the
whole process soft locks up.
Fix this by making handoffp start an M if there is GC work. This
reintroduces a key invariant: that in any situation where findrunnable
would return a G to run on a P, handoffp for that P will start an M to
run work on that P.
Fixes#13645.
Tested by running 2,689 iterations of `go tool dist test -no-rebuild
runtime:cpu124` across 10 linux-amd64-noopt VMs with no failures.
Without this change, the failure rate was somewhere around 1%.
Performance change is negligible.
name old time/op new time/op delta
XBenchGarbage-12 2.48ms ± 2% 2.48ms ± 1% -0.24% (p=0.000 n=92+93)
name old time/op new time/op delta
BinaryTree17-12 2.86s ± 2% 2.87s ± 2% ~ (p=0.667 n=19+20)
Fannkuch11-12 2.52s ± 1% 2.47s ± 1% -2.05% (p=0.000 n=18+20)
FmtFprintfEmpty-12 51.7ns ± 1% 51.5ns ± 3% ~ (p=0.931 n=16+20)
FmtFprintfString-12 170ns ± 1% 168ns ± 1% -0.65% (p=0.000 n=19+19)
FmtFprintfInt-12 160ns ± 0% 160ns ± 0% +0.18% (p=0.033 n=17+19)
FmtFprintfIntInt-12 265ns ± 1% 273ns ± 1% +2.98% (p=0.000 n=17+19)
FmtFprintfPrefixedInt-12 235ns ± 1% 239ns ± 1% +1.99% (p=0.000 n=16+19)
FmtFprintfFloat-12 315ns ± 0% 315ns ± 1% ~ (p=0.250 n=17+19)
FmtManyArgs-12 1.04µs ± 1% 1.05µs ± 0% +0.87% (p=0.000 n=17+19)
GobDecode-12 7.93ms ± 0% 7.85ms ± 1% -1.03% (p=0.000 n=16+18)
GobEncode-12 6.62ms ± 1% 6.58ms ± 1% -0.60% (p=0.000 n=18+19)
Gzip-12 322ms ± 1% 320ms ± 1% -0.46% (p=0.009 n=20+20)
Gunzip-12 42.5ms ± 1% 42.5ms ± 0% ~ (p=0.751 n=19+19)
HTTPClientServer-12 69.7µs ± 1% 70.0µs ± 2% ~ (p=0.056 n=19+19)
JSONEncode-12 16.9ms ± 1% 16.7ms ± 1% -1.13% (p=0.000 n=19+19)
JSONDecode-12 61.5ms ± 1% 61.3ms ± 1% -0.35% (p=0.001 n=20+17)
Mandelbrot200-12 3.94ms ± 0% 3.91ms ± 0% -0.67% (p=0.000 n=20+18)
GoParse-12 3.71ms ± 1% 3.70ms ± 1% ~ (p=0.244 n=17+19)
RegexpMatchEasy0_32-12 101ns ± 1% 102ns ± 2% +0.54% (p=0.037 n=19+20)
RegexpMatchEasy0_1K-12 349ns ± 0% 350ns ± 0% +0.33% (p=0.000 n=17+18)
RegexpMatchEasy1_32-12 84.5ns ± 2% 84.2ns ± 1% -0.43% (p=0.048 n=19+20)
RegexpMatchEasy1_1K-12 510ns ± 1% 513ns ± 2% +0.58% (p=0.002 n=18+20)
RegexpMatchMedium_32-12 132ns ± 1% 134ns ± 1% +0.95% (p=0.000 n=20+20)
RegexpMatchMedium_1K-12 40.1µs ± 1% 39.6µs ± 1% -1.39% (p=0.000 n=20+20)
RegexpMatchHard_32-12 2.08µs ± 0% 2.06µs ± 1% -0.95% (p=0.000 n=18+18)
RegexpMatchHard_1K-12 62.2µs ± 1% 61.9µs ± 1% -0.42% (p=0.001 n=19+20)
Revcomp-12 537ms ± 0% 536ms ± 0% ~ (p=0.076 n=20+20)
Template-12 71.3ms ± 1% 69.3ms ± 1% -2.75% (p=0.000 n=20+20)
TimeParse-12 361ns ± 0% 360ns ± 1% ~ (p=0.056 n=19+19)
TimeFormat-12 353ns ± 0% 352ns ± 0% -0.23% (p=0.000 n=17+18)
[Geo mean] 62.6µs 62.5µs -0.17%
Change-Id: I0fbbbe4d7d99653ba5600ffb4394fa03558bc4e9
Reviewed-on: https://go-review.googlesource.com/19107
Reviewed-by: Rick Hudson <rlh@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Tested by hand with a runtime/cgo modified to return an mmap failure
after 10 calls.
This is an interim patch. For 1.7 we should fix mmap properly to avoid
using the same value as both a pointer and an errno value.
Fixes#14149.
Change-Id: I8f2bbd47d711e283001ba73296f1c34a26c59241
Reviewed-on: https://go-review.googlesource.com/19084
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
We might be forwarding to a C signal handler. C code expects the stack
to be aligned. Should fix darwin/386 build: the testcarchive tests were
hanging as the program got an endless series of SIGSEGV signals.
Change-Id: Ia02485d3736a3c40e12259f02d25f842cf8e4d29
Reviewed-on: https://go-review.googlesource.com/19025
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
It's awkward to get a string value in cgoCheckArg, but SWIG testing
revealed that it is possible. The new handling of extra files in the
ptr.go test emulates what SWIG does with an exported function that
returns a string.
Change-Id: I453717f867b8a49499576c28550e7c93053a0cf8
Reviewed-on: https://go-review.googlesource.com/19020
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
This makes "CGO_ENABLED=0 go list runtime/cgo" work,
which fixes the current cmd/go test failure.
Change-Id: Ia55ce3ba1dbb09f618ae5f4c8547722670360f59
Reviewed-on: https://go-review.googlesource.com/19001
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
We set GOMAXPROCS=1 to prevent test flakiness.
There are two sources of flakiness:
1. Some tests rely on particular execution order.
If the order is different, race does not happen at all.
2. Ironically, ThreadSanitizer runtime contains a logical race condition
that can lead to false negatives if racy accesses happen literally at the same time.
Tests used to work reliably in the good old days of GOMAXPROCS=1.
So let's set it for now. A more reliable solution is to explicitly annotate tests
with required execution order by means of a special "invisible" synchronization primitive
(that's what is done for C++ ThreadSanitizer tests). This is issue #14119.
This reduces flakes on RaceAsFunc3 test from 60/3000 to 1/3000.
Fixes#14086Fixes#14079Fixes#14035
Change-Id: Ibaec6b2b21e27b62563bffbb28473a854722cf41
Reviewed-on: https://go-review.googlesource.com/18968
Reviewed-by: Austin Clements <austin@google.com>
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
CL 18964 included an extra patch (sorry, my first experience of
git-codereview) which defined the conventional breakpoint instruction
used by Plan 9 on arm, but also introduced a benign but unneeded
call to runtime.emptyfunc. This CL removes the redundant call again.
This completes the series of CLs which add support for Plan 9 on arm.
Change-Id: Id293cfd40557c9d79b4b6cb164ed7ed49295b178
Reviewed-on: https://go-review.googlesource.com/19010
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Fields in Plan 9 object headers are big-endian, on all architectures.
Change-Id: If95ad29750b776338178d660646568bf26a4abda
Reviewed-on: https://go-review.googlesource.com/18964
Reviewed-by: Russ Cox <rsc@golang.org>
It's possible for arena_start+MaxArena32 to wrap.
We do the right thing in the bounds check but not in the print.
For #13992 (to fix the print there, not the bug).
Change-Id: I4df845d0c03f0f35461b128e4f6765d3ccb71c6d
Reviewed-on: https://go-review.googlesource.com/18975
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
The previous CL is the real fix. This one is just insurance.
Fixes#14046 again.
Change-Id: I553349504bb1789e4b66c888dbe4034568918ad6
Reviewed-on: https://go-review.googlesource.com/18977
Reviewed-by: Austin Clements <austin@google.com>
It was just completely broken if you gave it the number
of records it asked for. Make it impossible for that particular
inconsistency to happen again.
Also make it exclude system goroutines, to match both
NumGoroutine and Stack.
Fixes#14046.
Change-Id: Ic238c6b89934ba7b47cccd3440dd347ed11e4c3d
Reviewed-on: https://go-review.googlesource.com/18976
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Currently p.gcBgMarkWorker is a *g. Change it to a guintptr. This
eliminates a write barrier during the subtle mark worker parking dance
(which isn't known to be causing problems, but may).
Change-Id: Ibf12c05ac910820448059e69a68e5b882c993ed8
Reviewed-on: https://go-review.googlesource.com/18970
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Rick Hudson <rlh@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
traceEvent records system call events after a G has already entered
_Gsyscall, which means the garbage collector could be installing stack
barriers in the G's stack during the traceEvent. If traceEvent
attempts to capture the user stack during this, it may observe a
inconsistent stack barriers and panic. Fix this by acquiring the stack
lock around the stack walk in traceEvent.
Fixes#14101.
Change-Id: I15f0ab0c70c04c6e182221f65a6f761c5a896459
Reviewed-on: https://go-review.googlesource.com/18973
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
Currently mark workers attach to their designated Ps before parking,
either during initialization or after performing a phase transition.
However, in both of these cases, it's possible that the mark worker is
running on a different P than the one it attaches to. This is a
problem, because as soon as the worker attaches to a P, that P's
scheduler can execute the worker. If the worker hasn't yet parked on
the P it's actually running on, this means the worker G will be
running in two places at once. The most visible consequence of this is
that once the first instance of the worker does park, it will clear
g.m and the second instance will crash shortly when it tries to use
g.m.
Fix this by moving the attach to the gopark callback. At this point,
the G is genuinely stopped and the callback is running on the system
stack, so it's safe for another P's scheduler to pick up the worker G.
Fixes#13363. Fixes#13978.
Change-Id: If2f7c4a4174f9511f6227e14a27c56fb842d1cc8
Reviewed-on: https://go-review.googlesource.com/18761
Reviewed-by: Rick Hudson <rlh@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: Austin Clements <austin@google.com>
Currently we run profiling tests for around 200ms in short mode.
However, even on platforms with good profiling, these tests are
inherently flaky, especially on loaded systems like the builders.
To mitigate this, modify the profiling test harness so that if a test
fails in a way that could indicate there just weren't enough samples,
it retries with a longer duration.
This requires some adjustment to the profile checker to distinguish
"fatal" and "retryable" errors. In particular, we no longer consider
it a fatal error to get a profile with zero samples (which we
previously treated as a parse error). We replace this with a retryable
check that the total number of samples is reasonable.
Fixes#13943. Fixes#13871. Fixes#13223.
Change-Id: I9a08664a7e1734c5334b1f3792a56184fe314c4d
Reviewed-on: https://go-review.googlesource.com/18683
Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
