https://golang.org/cl/246763 accidentally changed this from upper + 0 +
carry to upper + old vdsoSP + carry.
The old value of vdsoPC is usually zero, so this typically works.
However, the reentrant case will have a non-zero value, resulting in a
bogus returned time.
Fixes#49481
Change-Id: I0110b84277bf911804cb0ff8097aebf1b7eb100a
Reviewed-on: https://go-review.googlesource.com/c/go/+/362674
Trust: Michael Pratt <mpratt@google.com>
Run-TryBot: Michael Pratt <mpratt@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
For tests of pprof label support having the sample labels in the output
is needed for effective debugging.
For #48577
Change-Id: Ic7c5bc90cb33e8fb477f7db62d9b56a7a9d6ffa8
Reviewed-on: https://go-review.googlesource.com/c/go/+/362614
Trust: Michael Pratt <mpratt@google.com>
Run-TryBot: Michael Pratt <mpratt@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Recent changes to runtime enabled crashdumps, which under some
circumstances apparently might result in memory being uploaded to
Microsoft. A change like this should go through the proper proposals
process where we can discuss how to gate it and what all of its
implications are.
This reverts CL 307372 and its cleanup CL 360617.
Change-Id: If2e74015899d746831da40546c82eacacdf739e1
Reviewed-on: https://go-review.googlesource.com/c/go/+/362454
Trust: Jason A. Donenfeld <Jason@zx2c4.com>
Run-TryBot: Jason A. Donenfeld <Jason@zx2c4.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TestPanicSystemstack spins up a subprocess that has 2 goroutines
deadlock on a runtime lock while on the system stack, with GOMAXPROCS=2.
Each goroutine is going to be running on a P, and then is going to wedge
itself up on that P.
If a GC is active and a worker starts executing (using a P), then it
could try to preempt a goroutine that is already blocked. It won't be
able to, so it'll just sit there forever trying to suspend it. At this
point there are no more Ps to execute the remaining goroutine that needs
to print something so the parent process can continue the test.
This change fixes this issue by disabling GCs in the child process. An
alternative fix could be to increase GOMAXPROCS in the child, but maybe
letting the GC be on (which assumes it'll always be able to *eventually*
suspend a G) is just asking for trouble.
Fixes#49388.
Change-Id: I405c9dad50e24e1e68f2c52a646538da15797fbe
Reviewed-on: https://go-review.googlesource.com/c/go/+/361897
Trust: Michael Knyszek <mknyszek@google.com>
Run-TryBot: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Michael Pratt <mpratt@google.com>
Currently the debug call protocol implementation we use for testing is
riddled with write barriers, and called from a signal handler. This is
not safe, as write barriers need a P to execute.
Ideally this implementation would be rewritten to avoid the write
barriers, but it's not straightforward, and needs some thought. As a
temporary measure, disable GC during the debug call tests to avoid a
write barrier.
Note that this does not indicate a problem with real use of the debug
call protocol. Only our test implementation has this issue, because it
needs to get executed in a signal handler, normally a separate process
is interfacing with the protocol via process signals and ptrace (and the
like).
Fixes#49370.
Change-Id: Ic0fde5d0f4c64f9ecc9789b7dabb3954538fe0a8
Reviewed-on: https://go-review.googlesource.com/c/go/+/361896
Trust: Michael Knyszek <mknyszek@google.com>
Run-TryBot: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Michael Pratt <mpratt@google.com>
CL 344955 and CL 359476 removed almost all // +build lines, but leaving
some assembly files and generating scripts. Also, some files were added
with // +build lines after CL 359476 was merged. Remove these or rename
files where more appropriate.
For #41184
Change-Id: I7eb85a498ed9788b42a636e775f261d755504ffa
Reviewed-on: https://go-review.googlesource.com/c/go/+/361480
Trust: Tobias Klauser <tobias.klauser@gmail.com>
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
The previous change was an automated change that made gcPercent a
type-safe atomic variable. However, that introduced a lot of redundant
formal atomic loads of the variable. Remove them by only loading once in
each case, and reusing the value.
Change-Id: I49647135f423574f94506d456d1cc390150fad02
Reviewed-on: https://go-review.googlesource.com/c/go/+/357795
Trust: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
Currently, newstack loads gp.stackguard0 twice to check for different
poison values. The race window between these two checks can lead to
unintentional stack doubling, and ultimately to stack overflows.
Specifically, newstack checks if stackguard0 is stackPreempt first,
then it checks if it's stackForceMove. If stackguard0 is set to
stackForceMove on entry, but changes to stackPreempt between the two
checks, newstack will incorrectly double the stack allocation.
Fix this by loading stackguard0 exactly once and then checking it
against different poison values.
The effect of this is relatively minor because stackForceMove is only
used by a small number of runtime tests. I found this because
mayMorestackMove uses stackForceMove aggressively, which makes this
failure mode much more likely.
Change-Id: I1f8b6a6744e45533580a3f45d7030ec2ec65a5fb
Reviewed-on: https://go-review.googlesource.com/c/go/+/361775
Trust: Austin Clements <austin@google.com>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
This test appears to deadlock frequently on the only netbsd-arm64
builder we have (netbsd-arm64-bsiegert). Skip the test to provide
more useful test coverage for other failures.
For #49382
Change-Id: I3be32f58ce1e396f7c69163e70cf58f779f57ac6
Reviewed-on: https://go-review.googlesource.com/c/go/+/361615
Trust: Bryan C. Mills <bcmills@google.com>
Trust: Benny Siegert <bsiegert@gmail.com>
Run-TryBot: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Benny Siegert <bsiegert@gmail.com>
consistentHeapStats is updated during a stack allocation, so a stack
growth during an acquire or release could cause another acquire to
happen before the operation completes fully. This may lead to an invalid
sequence number.
Fixes#49395.
Change-Id: I41ce3393dff80201793e053d4d6394d7b211a5b7
Reviewed-on: https://go-review.googlesource.com/c/go/+/361158
Trust: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
Reviewed-by: Austin Clements <austin@google.com>
Currently the scavenger is paced to 1% of 1 CPU because it had
scalability problems. As of the last few CLs, that should be largely
resolved. This change resolves the TODO and paces the scavenger
according to 1% of overall CPU time.
This change is made separately to allow it to be more easily rolled
back.
Change-Id: I1ab4de24ba41c564960701634a128a813c55ece9
Reviewed-on: https://go-review.googlesource.com/c/go/+/358675
Trust: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
Currently the scavenge rate is determined by a bunch of ad-hoc
mechanisms. Just use a controller instead, now that we have one.
To facilitate this, the scavenger now attempts to scavenge for at least
1 ms at a time, because any less and the timer system is too imprecise to
give useful feedback to the controller. Also increase the amount that we
scavenge at once, to try to reduce the overheads involved (at the
expense of a little bit of latency).
This change also modifies the controller to accept an update period,
because it's useful to allow that to be variable.
Change-Id: I8a15b2355d0a7c6cbac68c957082d5819618f7d7
Reviewed-on: https://go-review.googlesource.com/c/go/+/353975
Trust: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
This change adds a new debug flag that makes the runtime map pages
PROT_NONE in sysUnused on Linux, in addition to the usual madvise calls.
This behavior mimics the behavior of decommit on Windows, and is helpful
in debugging the scavenger. sysUsed is also updated to re-map the pages
as PROT_READ|PROT_WRITE, mimicing Windows' explicit commit behavior.
Change-Id: Iaac5fcd0e6920bd1d0e753dd4e7f0c0b128fe842
Reviewed-on: https://go-review.googlesource.com/c/go/+/356612
Trust: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
This change modifies the scavenger to no longer hold the heap lock while
actively scavenging pages. To achieve this, the change also:
* Reverses the locking behavior of the (*pageAlloc).scavenge API, to
only acquire the heap lock when necessary.
* Introduces a new lock on the scavenger-related fields in a pageAlloc
so that access to those fields doesn't require the heap lock. There
are a few places in the scavenge path, notably reservation, that
requires synchronization. The heap lock is far too heavy handed for
this case.
* Changes the scavenger to marks pages that are actively being scavenged
as allocated, and "frees" them back to the page allocator the usual
way.
* Lifts the heap-growth scavenging code out of mheap.grow, where the
heap lock is held, and into allocSpan, just after the lock is
released. Releasing the lock during mheap.grow is not feasible if we
want to ensure that allocation always makes progress (post-growth,
another allocator could come in and take all that space, forcing the
goroutine that just grew the heap to do so again).
This change means that the scavenger now must do more work for each
scavenge, but it is also now much more scalable. Although in theory it's
not great by always taking the locked paths in the page allocator, it
takes advantage of some properties of the allocator:
* Most of the time, the scavenger will be working with one page at a
time. The page allocator's locked path is optimized for this case.
* On the allocation path, it doesn't need to do the find operation at
all; it can go straight to setting bits for the range and updating the
summary structure.
Change-Id: Ie941d5e7c05dcc96476795c63fef74bcafc2a0f1
Reviewed-on: https://go-review.googlesource.com/c/go/+/353974
Trust: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
The first stack-trace in #49361 shows that traceBuf must precede fin in
lockrank ordering, since traceBuf is acquired in StartTrace(), which
eventually leads to getting fin in queueFinalizer(). It is fine to move
traceBuf above fin, since there are no other conflicting dependencies.
The second stack trace shows that there is an edge bewtween reflectOffs
and fin, since reflectOffs is acquired in addReflectOff, and map
operations can lead to an allocation that eventually causes fin to be
acquired in queueFinalizer().
Fixes#49361
Change-Id: I8e857ef9ecdff37fdd229e4dba22e15bc71d4ba5
Reviewed-on: https://go-review.googlesource.com/c/go/+/361407
Trust: Dan Scales <danscales@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
The argument liveness tests expect outputs where a dead stack slot
has a poisoned value. If the test function is preempted at the
prologue, it will go with the morestack code path which will spill
all the argument registers. Mark them nosplit to avoid that.
Should fix#49354.
Change-Id: I3b13e72e925748687a53c494bfaa70f07d9496fa
Reviewed-on: https://go-review.googlesource.com/c/go/+/361211
Trust: Cherry Mui <cherryyz@google.com>
Run-TryBot: Cherry Mui <cherryyz@google.com>
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Reviewed-by: Austin Clements <austin@google.com>
This adds a maymorestack hook that moves the stack at every
cooperative preemption point.
For #48297.
Change-Id: Ic15f9bcbc163345e6422586302d57fda4744caec
Reviewed-on: https://go-review.googlesource.com/c/go/+/359797
Trust: Austin Clements <austin@google.com>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
Reviewed-by: David Chase <drchase@google.com>
This adds a maymorestack hook that forces a preemption at every
possible cooperative preemption point. This would have helped us catch
several recent preemption-related bugs earlier, including #47302,
#47304, and #47441.
For #48297.
Change-Id: Ib82c973589c8a7223900e1842913b8591938fb9f
Reviewed-on: https://go-review.googlesource.com/c/go/+/359796
Trust: Austin Clements <austin@google.com>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
Reviewed-by: David Chase <drchase@google.com>
A code comment on amd64 for windows and plan9 contained a snippet for
splitting apart the sec and nsec components of a unix timestamp, with
produced assembly below, which was then cleaned up by hand. When arm64
was ported, that code snippet in the comment went through the compiler
to produce some code that was then pasted and cleaned up. Unfortunately,
the comment had a typo in it, containing 8 zeros instead of 9.
This resulted in the constant used in the assembly being wrong, spotted
by @bufflig's eagle eyes. So, this commit fixes the comment on all three
platforms, and the assembly on windows/arm64.
Fixes#48072.
Change-Id: I786fe89147328b0d25544f52c927ddfdb9f6f1cf
Reviewed-on: https://go-review.googlesource.com/c/go/+/361474
Trust: Jason A. Donenfeld <Jason@zx2c4.com>
Run-TryBot: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Patrik Nyblom <pnyb@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
The new GC pacer has a bug where the hard goal isn't set in relation to
the original heap goal, but rather to the one already extrapolated for
overshoot.
In practice, I have never once seen this case arise because the
extrapolated goal used for overshoot is conservative. No test because
writing a test for this case is impossible in the idealized model the
pacer tests create. It is possible to simulate but will take more work.
For now, just leave a TODO.
Change-Id: I24ff710016cd8100fad54f71b2c8cdea0f7dfa79
Reviewed-on: https://go-review.googlesource.com/c/go/+/361435
Reviewed-by: Michael Pratt <mpratt@google.com>
Trust: Michael Knyszek <mknyszek@google.com>
Run-TryBot: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Currently allocToCache ham-handedly calls pageAlloc.allocRange on the
full size of the cache. This is fine as long as scavenged bits are never
set when alloc bits are set. This is true right now, but won't be true
as of the next CL.
This change makes allocToCache more carefully set the bits. Note that in
the allocToCache path, we were also calling update *twice*, erroneously.
The first time, with contig=true! Luckily today there's no correctness
error there because the page cache is small enough that the contig=true
logic doesn't matter, but this should at least improve allocation
performance a little bit.
Change-Id: I3ff9590ac86d251e4c5063cfd633570238b0cdbf
Reviewed-on: https://go-review.googlesource.com/c/go/+/356609
Trust: Michael Knyszek <mknyszek@google.com>
Run-TryBot: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Michael Pratt <mpratt@google.com>
The first step toward acquiring the heap lock less frequently in the
scavenger.
Change-Id: Idc69fd8602be2c83268c155951230d60e20b42fe
Reviewed-on: https://go-review.googlesource.com/c/go/+/353973
Trust: Michael Knyszek <mknyszek@google.com>
Run-TryBot: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Michael Pratt <mpratt@google.com>
This change implements the GC pacer redesign outlined in #44167 and the
accompanying design document, behind a GOEXPERIMENT flag that is on by
default.
In addition to adding the new pacer, this CL also includes code to track
and account for stack and globals scan work in the pacer and in the
assist credit system.
The new pacer also deviates slightly from the document in that it
increases the bound on the minimum trigger ratio from 0.6 (scaled by
GOGC) to 0.7. The logic behind this change is that the new pacer much
more consistently hits the goal (good!) leading to slightly less
frequent GC cycles, but _longer_ ones (in this case, bad!). It turns out
that the cost of having the GC on hurts throughput significantly (per
byte of memory used), though tail latencies can improve by up to 10%! To
be conservative, this change moves the value to 0.7 where there is a
small improvement to both throughput and latency, given the memory use.
Because the new pacer accounts for the two most significant sources of
scan work after heap objects, it is now also safer to reduce the minimum
heap size without leading to very poor amortization. This change thus
decreases the minimum heap size to 512 KiB, which corresponds to the
fact that the runtime has around 200 KiB of scannable globals always
there, up-front, providing a baseline.
Benchmark results: https://perf.golang.org/search?q=upload:20211001.6
tile38's KNearest benchmark shows a memory increase, but throughput (and
latency) per byte of memory used is better.
gopher-lua showed an increase in both CPU time and memory usage, but
subsequent attempts to reproduce this behavior are inconsistent.
Sometimes the overall performance is better, sometimes it's worse. This
suggests that the benchmark is fairly noisy in a way not captured by the
benchmarking framework itself.
biogo-igor is the only benchmark to show a significant performance loss.
This benchmark exhibits a very high GC rate, with relatively little work
to do in each cycle. The idle mark workers are quite active. In the new
pacer, mark phases are longer, mark assists are fewer, and some of that
time in mark assists has shifted to idle workers. Linux perf indicates
that the difference in CPU time can be mostly attributed to write-barrier
slow path related calls, which in turn indicates that the write barrier
being on for longer is the primary culprit. This also explains the memory
increase, as a longer mark phase leads to more memory allocated black,
surviving an extra cycle and contributing to the heap goal.
For #44167.
Change-Id: I8ac7cfef7d593e4a642c9b2be43fb3591a8ec9c4
Reviewed-on: https://go-review.googlesource.com/c/go/+/309869
Trust: Michael Knyszek <mknyszek@google.com>
Run-TryBot: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
https://golang.org/cl/246763 accidentally changed this to assign the old
value of vdsoPC to the upper half of sec as that is the last value in
R1.
The old value of vdsoPC is usually zero, so this typically works.
However, the reentrant case will have a non-zero value, resulting in a
bogus returned time. I am unsure if walltime is reachable from a signal
handler, so this may never occur.
Change-Id: I8562d6ec2a845fcffee9618d994b8ea57fbd199e
Reviewed-on: https://go-review.googlesource.com/c/go/+/361159
Trust: Michael Pratt <mpratt@google.com>
Run-TryBot: Michael Pratt <mpratt@google.com>
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Reviewed-by: Cherry Mui <cherryyz@google.com>
The x/sys/windows package currently uses go:linkname for other facilities
inside of runtime that are not suitable to be exposed as a public API
due to their dangers but are still necessary for manipulating any
low-level plumbing that the runtime controls.
Logging, via the built-in println and panic handler, is one such
low-level plumbing feature. In this case, x/sys/windows/svc needs to be
able to redirect panics to the Windows event log. Because the event log
is a complicated interface, this requires a bit more fiddling than the
simple solution used on Android (baking it into runtime itself), and
because Windows services are very diverse, the event log might not even
always be a desirable destination.
This commit accomplishes this by exposing a function pointer called
"overrideWrite" that low-level runtime packages like x/sys/windows/svc
can use to redirect output logs toward the event log or otherwise.
It is not safe or acceptable to use as a generic mechanism, and for that
reason, we wouldn't want to expose this as a real stable API, similar to
the other instances of go:linkname in x/sys/windows. But for packages
that must interoperate with low-level Go runtime fundamentals, this is a
safety hatch for packages that are developed in tandem with the runtime.
x/sys/windows is one such package.
Updates #42888.
Change-Id: I77a32ff7e1494324e8cc38e792e007f86d32672d
Reviewed-on: https://go-review.googlesource.com/c/go/+/278792
Trust: Jason A. Donenfeld <Jason@zx2c4.com>
Run-TryBot: Jason A. Donenfeld <Jason@zx2c4.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
It appears Windows 7 ignores WER_FAULT_REPORTING_NO_UI WerSetFlags
API flag.
And now after CL 307372, runtime will display WER GUI dialogue.
We don't want to introduce random GUI dialogues during Go program
execution. So disable dump crash creation on Windows 7 altogether.
Updates #20498
Change-Id: Ie268a7d4609f8a0eba4fe9ecf250856b0a61b331
Reviewed-on: https://go-review.googlesource.com/c/go/+/360617
Trust: Alex Brainman <alex.brainman@gmail.com>
Run-TryBot: Alex Brainman <alex.brainman@gmail.com>
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Reviewed-by: Patrik Nyblom <pnyb@google.com>
On 64-bit, this is more efficient, and on ARM64, this prevents the time
from moving backwards due to the weaker memory model. On ARM32 due to
the weaker memory model, we issue a memory barrier.
Updates #48072.
Change-Id: If4695716c3039d8af14e14808af217f5c99fc93a
Reviewed-on: https://go-review.googlesource.com/c/go/+/361057
Trust: Jason A. Donenfeld <Jason@zx2c4.com>
Run-TryBot: Jason A. Donenfeld <Jason@zx2c4.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
TestCPUProfileMultithreadMagnitude compares Go's CPU profile against the
OS's accounting of the process's execution time, expecting them to be
near equal. Background work from the runtime (especially in the garbage
collector) can add significant noise to that measurement and flakiness
to the test. Disable automatic GC cycles during the test.
Updates #49065
Change-Id: Ie88895bfea17374278c5187f3a83e9f486bd37fb
Reviewed-on: https://go-review.googlesource.com/c/go/+/359934
Reviewed-by: Michael Pratt <mpratt@google.com>
Trust: Michael Pratt <mpratt@google.com>
Trust: Michael Knyszek <mknyszek@google.com>
This provides the runtime glue (_rt0_riscv64_linux_lib) for c-archive and c-shared
support, along with enabling both of these buildmodes on linux/riscv64.
Both misc/cgo/testcarchive and misc/cgo/testcshared now pass on this platform.
Fixes#47100
Change-Id: I7ad75b23ae1d592dbac60d15bba557668287711f
Reviewed-on: https://go-review.googlesource.com/c/go/+/334872
Trust: Joel Sing <joel@sing.id.au>
Run-TryBot: Joel Sing <joel@sing.id.au>
Reviewed-by: Cherry Mui <cherryyz@google.com>
The X3 (aka GP) register will potentially be loaded with the __global_pointer$ symbol
during program start up (usually by the dynamic linker). As such, non-Go code may depend
on the contents of GP and calculate offsets based on it, including code called via cgo
and signal handlers installed by non-Go code. As such, stop using the X3 register so
that there are fewer issues interacting between Go and non-Go code.
While here remove the X4 (TP) name from the assembler such that any references must
use the 'TP' name. This should reduce the likelihood of accidental use (like we do
for the 'g' register). The same applies for X3 (GP) when the -shared flag is given.
Updates #47100
Change-Id: I72e82b5ca3f80c46a781781345ca0432a4111b74
Reviewed-on: https://go-review.googlesource.com/c/go/+/351859
Trust: Joel Sing <joel@sing.id.au>
Run-TryBot: Joel Sing <joel@sing.id.au>
Reviewed-by: Cherry Mui <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Fixes#49288
Change-Id: I7bfcbecbefa68871a3e556935a73f241fff44c0e
Reviewed-on: https://go-review.googlesource.com/c/go/+/360861
Trust: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Fixes#49287
Change-Id: I3f970d6db0b1dee886df2f7bb6cbeb56a37c42c2
Reviewed-on: https://go-review.googlesource.com/c/go/+/360860
Trust: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Make Go runtime throw if it's been compiled to assume instruction
set extensions that aren't available on the CPU.
Updates #48506
Change-Id: Ic4d6696e1cd6b28d389a86fe64e8175ea3ca135a
GitHub-Last-Rev: ba338377f5
GitHub-Pull-Request: golang/go#48514
Reviewed-on: https://go-review.googlesource.com/c/go/+/351191
Run-TryBot: Martin Möhrmann <martin@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Martin Möhrmann <martin@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Trust: Martin Möhrmann <martin@golang.org>
This reverts CL 351751.
Reason for revert: new test is failing on many builders.
Change-Id: I066211c9f25607ca9eb5299aedea2ecc5069e34f
Reviewed-on: https://go-review.googlesource.com/c/go/+/360757
Trust: Bryan C. Mills <bcmills@google.com>
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Michael Pratt <mpratt@google.com>
Use gp.m.curg instead of the gp when recording cpu profiler stack
traces. This ensures profiler labels are captured when systemstack or similar
is executing on behalf of the current goroutine.
After this there are still rare cases of samples containing the labelHog
function, so more work might be needed. This patch should fix ~99% of the
problem.
Fixes#48577.
Change-Id: I27132110e3d09721ec3b3ef417122bc70d8f3279
Reviewed-on: https://go-review.googlesource.com/c/go/+/351751
Reviewed-by: Michael Pratt <mpratt@google.com>
Run-TryBot: Michael Pratt <mpratt@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Trust: Michael Knyszek <mknyszek@google.com>
Go exchanges siginfo and sigevent structures with the kernel. They
contain unions, but Go's use is limited to the first few fields. Pad out
the rest so the size Go sees is the same as what the Linux kernel sees.
This is a follow-up to CL 342052 which added the sigevent struct without
padding, and to CL 353136 which added the padding but with an assertion
that confused several type-checkers. It updates the siginfo struct as
well so there are no bad examples in the defs_linux_*.go files.
Reviewed-on: https://go-review.googlesource.com/c/go/+/353136
Change-Id: I9610632ff0ec43eba91f560536f5441fa907b36f
Reviewed-on: https://go-review.googlesource.com/c/go/+/360094
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Michael Pratt <mpratt@google.com>
Add explicit address sanitizer instrumentation to the runtime and
syscall packages. The compiler does not instrument the runtime
package. It does instrument the syscall package, but we need to add
a couple of cases that it can't see.
Refer to the implementation of the asan malloc runtime library,
this patch also allocates extra memory as the redzone, around the
returned memory region, and marks the redzone as unaddressable to
detect the overflows or underflows.
Updates #44853.
Change-Id: I2753d1cc1296935a66bf521e31ce91e35fcdf798
Reviewed-on: https://go-review.googlesource.com/c/go/+/298614
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Trust: fannie zhang <Fannie.Zhang@arm.com>
Fix two defer bugs related to adding/removing open defer entries.
The bugs relate to the way that we add and remove open defer entries
from the defer chain. At the point of a panic, when we want to start
processing defer entries in order during the panic process, we need to
add entries to the defer chain for stack frames with open defers, since
the normal fast-defer code does not add these entries. We do this by
calling addOneOpenDeferFrame() at the beginning of each time around the
defer loop in gopanic(). Those defer entries get sorted with other open
and non-open-coded defer frames.
However, the tricky part is that we also need to remove defer entries if
they end not being needed because of a recover (which means we are back
to executing the defer code inline at function exits). But we need
to deal with multiple panics and in-process defers on the stack, so we
can't just remove all open-coded defers from the the defer chain during
a recover.
The fix (and new invariant) is that we should not add any open-coded
defers to the defer chain that are higher up the stack than an open-coded
defer that is in progress. We know that open-coded defer will still be
run until completed, and when it is completed, then a more outer frame
will be added (if there is one). This fits with existing code in gopanic
that only removes open-coded defer entries up to any defer in progress.
These bugs were because of the previous inconsistency between adding and
removing open defer entries, which meant that stale defer entries could
be left on the list, in these unusual cases with both recursive
panics plus multiple independent (non-nested) cases of panic & recover.
The test for #48898 was difficult to add to defer_test.go (while keeping
the failure mode), so I added as a go/test/fixedbug test instead.
Fixes#43920
Updates #43941Fixes#48898
Change-Id: I593b77033e08c33094315abf8089fbc4cab07376
Reviewed-on: https://go-review.googlesource.com/c/go/+/356011
Trust: Dan Scales <danscales@google.com>
Trust: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: Austin Clements <austin@google.com>
This change creates a formal exported interface for the GC pacer and
creates tests for it that simulate some series of GC cycles. The tests
are completely driven by the real pacer implementation, except for
assists, which are idealized (though revise is called repeatedly).
For #44167.
Change-Id: I0112242b07e7702595ca71001d781ad6c1fddd2d
Reviewed-on: https://go-review.googlesource.com/c/go/+/353354
Trust: Michael Knyszek <mknyszek@google.com>
Run-TryBot: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
If register ABI is used, no need to store the arguments to stack.
I forgot them in CL 323937.
Change-Id: I888af2b547a8fc97d13716bc8e8f3acd5c5bc127
Reviewed-on: https://go-review.googlesource.com/c/go/+/351609
Trust: Cherry Mui <cherryyz@google.com>
Run-TryBot: Cherry Mui <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
This is to facilitate testing of the pacer, since otherwise this is
accessing global state, which is impossible to stub out properly.
For #44167.
Change-Id: I52c3b51fc0ffff38e3bbe534bd66e5761c0003a8
Reviewed-on: https://go-review.googlesource.com/c/go/+/353353
Trust: Michael Knyszek <mknyszek@google.com>
Run-TryBot: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Michael Pratt <mpratt@google.com>
For #44167.
Change-Id: I2cd13229d88f630451fabd113b0e5a04841e9e79
Reviewed-on: https://go-review.googlesource.com/c/go/+/309590
Trust: Michael Knyszek <mknyszek@google.com>
Run-TryBot: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Michael Pratt <mpratt@google.com>
This change adds two fields to gcControllerState: stackScan, used for
pacing decisions, and scannableStackSize, which directly tracks the
amount of space allocated for inuse stacks that will be scanned.
scannableStackSize is not updated directly, but is instead flushed from
each P when at an least 8 KiB delta has accumulated. This helps reduce
issues with atomics contention for newly created goroutines. Stack
growth paths are largely unaffected.
StackGrowth-48 51.4ns ± 0% 51.4ns ± 0% ~ (p=0.927 n=10+10)
StackGrowthDeep-48 6.14µs ± 3% 6.25µs ± 4% ~ (p=0.090 n=10+9)
CreateGoroutines-48 273ns ± 1% 273ns ± 1% ~ (p=0.676 n=9+10)
CreateGoroutinesParallel-48 65.5ns ± 5% 66.6ns ± 7% ~ (p=0.340 n=9+9)
CreateGoroutinesCapture-48 2.06µs ± 1% 2.07µs ± 4% ~ (p=0.217 n=10+10)
CreateGoroutinesSingle-48 550ns ± 3% 563ns ± 4% +2.41% (p=0.034 n=8+10)
For #44167.
Change-Id: Id1800d41d3a6c211b43aeb5681c57c0dc8880daf
Reviewed-on: https://go-review.googlesource.com/c/go/+/309589
Trust: Michael Knyszek <mknyszek@google.com>
Run-TryBot: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Michael Pratt <mpratt@google.com>
This change moves heapLive and heapScan updates on gcController into a
method for better testability. It's also less error-prone because code
that updates these fields needs to remember to emit traces and/or call
gcController.revise; this method now handles those cases.
For #44167.
Change-Id: I3d6f2e7abb22def27c93feacff50162b0b074da2
Reviewed-on: https://go-review.googlesource.com/c/go/+/309275
Trust: Michael Knyszek <mknyszek@google.com>
Run-TryBot: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Michael Pratt <mpratt@google.com>
Currently GC pacer updates are applied somewhat haphazardly via direct
field access. To facilitate ease of testing, move these field updates
into methods. Further CLs will move more of these updates into methods.
For #44167.
Change-Id: I25b10d2219ae27b356b5f236d44827546c86578d
Reviewed-on: https://go-review.googlesource.com/c/go/+/309274
Trust: Michael Knyszek <mknyszek@google.com>
Run-TryBot: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
CL 333389 erroneously moved traceGCSweepDone inside the sl.valid block
that it introduced in mcentral.cacheSpan, when it should have left it
outside that scope, because the trace event is created unconditionally
at the top of the method.
Fixes#49231.
Change-Id: If719c05063d4f4d330a320da6dc00d1e9d8102e4
Reviewed-on: https://go-review.googlesource.com/c/go/+/359775
Trust: Michael Knyszek <mknyszek@google.com>
Run-TryBot: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
The sweeper's pacing state is global, so detangle it from the GC pacer's
state updates so that the GC pacer can be tested.
For #44167.
Change-Id: Ibcea989cd435b73c5891f777d9f95f9604e03bd1
Reviewed-on: https://go-review.googlesource.com/c/go/+/309273
Trust: Michael Knyszek <mknyszek@google.com>
Run-TryBot: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Michael Pratt <mpratt@google.com>
This change provides ability to create dumps on Windows that can be used by
"dlv core" command. Currently only full dumps can be correctly read by Delve.
Below are the steps to create and use the dumps.
1. Configure Windows OS to collect dumps before running the program.
Instructions on how to do the configuration are here:
https://docs.microsoft.com/en-us/windows/win32/wer/collecting-user-mode-dumps.
In order for Delve to read the dump, set the DumpType to full dump, i.e. DumpType=2.
2. Go program only generates dumps when the environment variable GOTRACEBACK
is set to crash. Run command "set GOTRACEBACK=crash" before running the program.
3. Dump files will be generated in %LOCALAPPDATA%\CrashDumps
4. Use Delve command "dlv core" to open the dump, e.g.: "dlv core a.exe a.exe.3840.dmp".
Fixes#20498
Change-Id: Ib9aa82e7aea9da19594dc49348876997b24e9600
Reviewed-on: https://go-review.googlesource.com/c/go/+/307372
Run-TryBot: Alessandro Arzilli <alessandro.arzilli@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Patrik Nyblom <pnyb@google.com>
Trust: Alex Brainman <alex.brainman@gmail.com>
Michael Pratt
Jason A. Donenfeld
Michael Anthony Knyszek
Tobias Klauser
Austin Clements
Bryan C. Mills
Dan Scales
Cherry Mui
Alex Brainman
Rhys Hiltner
Joel Sing
Ian Lance Taylor
vpachkov
Felix Geisendörfer
fanzha02
Zhi Zheng