The runtime is not instrumented, but the calls to msanread in the
runtime can sometimes refer to the system stack. An example is the call
to copy in stkbucket in mprof.go. Depending on what C code has done,
the system stack may appear uninitialized to msan.
Change-Id: Ic21705b9ac504ae5cf7601a59189302f072e7db1
Reviewed-on: https://go-review.googlesource.com/16660
Reviewed-by: David Crawshaw <crawshaw@golang.org>
This is a fix for the -msan option when using cgo callbacks. A cgo
callback works by writing out C code that puts a struct on the stack and
passes the address of that struct into Go. The result parameters are
fields of the struct. The Go code will write to the result parameters,
but the Go code thinks it is just writing into the Go stack, and
therefore won't call msanwrite. This CL adds a call to msanwrite in the
cgo callback code so that the C knows that results were written.
Change-Id: I80438dbd4561502bdee97fad3f02893a06880ee1
Reviewed-on: https://go-review.googlesource.com/16611
Reviewed-by: David Crawshaw <crawshaw@golang.org>
This changes "mark worker (idle)" to "GC worker (idle)" so it's more
clear to users that these goroutines are GC-related. It changes "GC
assist" to "GC assist wait" to make it clear that the assist is
blocked.
Change-Id: Iafbc0903c84f9250ff6bee14baac6fcd4ed5ef76
Reviewed-on: https://go-review.googlesource.com/16511
Reviewed-by: Rick Hudson <rlh@golang.org>
We couldn't do this before this point because it must be done before
the next GC cycle starts. Hence, if it delayed the start of the next
cycle, that would widen the window between reaching the heap trigger
of the next cycle and starting the next GC cycle, during which the
mutator could over-allocate. With the decentralized GC, any mutators
that reach the heap trigger will block on the GC starting, so it's
safe to widen the time between starting the world and being able to
start the next GC cycle.
Fixes#11465.
Change-Id: Ic7ea7e9eba5b66fc050299f843a9c9001ad814aa
Reviewed-on: https://go-review.googlesource.com/16394
Reviewed-by: Rick Hudson <rlh@golang.org>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This implements part of the proposal in issue 12416 by adding dynamic
checks for passing pointers from Go to C. This code is intended to be
on at all times. It does not try to catch every case. It does not
implement checks on calling Go functions from C.
The new cgo checks may be disabled using GODEBUG=cgocheck=0.
Update #12416.
Change-Id: I48de130e7e2e83fb99a1e176b2c856be38a4d3c8
Reviewed-on: https://go-review.googlesource.com/16003
Reviewed-by: Russ Cox <rsc@golang.org>
This change breaks out most of the atomics functions in the runtime
into package runtime/internal/atomic. It adds some basic support
in the toolchain for runtime packages, and also modifies linux/arm
atomics to remove the dependency on the runtime's mutex. The mutexes
have been replaced with spinlocks.
all trybots are happy!
In addition to the trybots, I've tested on the darwin/arm64 builder,
on the darwin/arm builder, and on a ppc64le machine.
Change-Id: I6698c8e3cf3834f55ce5824059f44d00dc8e3c2f
Reviewed-on: https://go-review.googlesource.com/14204
Run-TryBot: Michael Matloob <matloob@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
This change is the same as CL #9345 which was reverted,
except for a small bug fix.
The only change is to the body of sendDirect and its callsite.
Also added a test.
The problem was during a channel send operation. The target
of the send was a sleeping goroutine waiting to receive. We
basically do:
1) Read the destination pointer out of the sudog structure
2) Copy the value we're sending to that destination pointer
Unfortunately, the previous change had a goroutine suspend
point between 1 & 2 (the call to sendDirect). At that point
the destination goroutine's stack could be copied (shrunk).
The pointer we read in step 1 is no longer valid for step 2.
Fixed by not allowing any suspension points between 1 & 2.
I suspect the old code worked correctly basically by accident.
Fixes#13169
The original 9345:
This change removes the retry mechanism we use for buffered channels.
Instead, any sender waking up a receiver or vice versa completes the
full protocol with its counterpart. This means the counterpart does
not need to relock the channel when it wakes up. (Currently
buffered channels need to relock on wakeup.)
For sends on a channel with waiting receivers, this change replaces
two copies (sender->queue, queue->receiver) with one (sender->receiver).
For receives on channels with a waiting sender, two copies are still required.
This change unifies to a large degree the algorithm for buffered
and unbuffered channels, simplifying the overall implementation.
Fixes#11506
Change-Id: I57dfa3fc219cffa4d48301ee15fe5479299efa09
Reviewed-on: https://go-review.googlesource.com/16740
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Other systems use pthread_sigmask. It was a mistake to use sigprocmask
here.
Change-Id: Ie045aa3f09cf035fcf807b7543b96fa5b847958a
Reviewed-on: https://go-review.googlesource.com/16720
Reviewed-by: Dave Cheney <dave@cheney.net>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Make sure that we're moving or zeroing pointers atomically.
Anything that is a multiple of pointer size and at least
pointer aligned might have pointers in it. All the code looks
ok except for the 1-pointer-sized moves.
Fixes#13160
Update #12552
Change-Id: Ib97d9b918fa9f4cc5c56c67ed90255b7fdfb7b45
Reviewed-on: https://go-review.googlesource.com/16668
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Revert for now until #13169 is understood.
This reverts commit 8e496f1d69.
Change-Id: Ib3eb2588824ef47a2b6eb9e377a24e5c817fcc81
Reviewed-on: https://go-review.googlesource.com/16716
Reviewed-by: Keith Randall <khr@golang.org>
Currently mallocgc detects if the GC is in a state where it can't
assist, but also can't allocate uncontrolled and yields to help out
the GC. This was a workaround for periods when we were trying to
schedule the GC coordinator. It is no longer necessary because there
is no GC coordinator and malloc can always assist with any GC
transitions that are necessary.
Updates #11970.
Change-Id: I4f7beb7013e85e50ae99a3a8b0bb708ba49cbcd4
Reviewed-on: https://go-review.googlesource.com/16392
Reviewed-by: Rick Hudson <rlh@golang.org>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This moves all of the mark 1 to mark 2 transition and mark termination
to the mark done transition function. This means these transitions are
now handled on the goroutine that detected mark completion. This also
means that the GC coordinator and the background completion barriers
are no longer used and various workarounds to yield to the coordinator
are no longer necessary. These will be removed in follow-up commits.
One consequence of this is that mark workers now need to be
preemptible when performing the mark done transition. This allows them
to stop the world and to perform the final clean-up steps of GC after
restarting the world. They are only made preemptible while performing
this transition, so if the worker findRunnableGCWorker would schedule
isn't available, we didn't want to schedule it anyway.
Fixes#11970.
Change-Id: I9203a2d6287eeff62d589ec02ad9cb1e29ddb837
Reviewed-on: https://go-review.googlesource.com/16391
Reviewed-by: Rick Hudson <rlh@golang.org>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Currently gcMarkDone takes basically no time, so it's okay to account
the worker time after calling it. However, gcMarkDone is about to take
potentially *much* longer because it may perform all of mark
termination. Prepare for this by swapping the order so we account the
time before calling gcMarkDone.
Change-Id: I90c7df68192acfc4fd02a7254dae739dda4e2fcb
Reviewed-on: https://go-review.googlesource.com/16390
Reviewed-by: Rick Hudson <rlh@golang.org>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Currently the code for completion of mark 1/mark 2 is duplicated in
background workers and assists. Factor this in to a single function
that will serve as the transition function for concurrent mark.
Change-Id: I4d9f697a15da0d349db3b34d56f3a220dd41d41b
Reviewed-on: https://go-review.googlesource.com/16359
Reviewed-by: Rick Hudson <rlh@golang.org>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Currently, findRunnableGCWorker will perform mark completion if there
is no remaining work and no running workers. This used to be necessary
to resolve a race in the transition from mark 1 to mark 2 where we
would enter mark 2 with no mark work (and no dedicated workers), so no
workers would run, so no worker would signal mark completion.
However, we're about to make mark completion also perform the entire
follow-on process, which includes mark termination. We really don't
want to do that in the scheduler if it happens to detect completion.
Conveniently, this hack is no longer necessary because we always
enqueue root scanning work at the beginning of both mark 1 and mark 2,
so a mark worker will always run. Hence, we can simply eliminate it.
Change-Id: I3fc8f27c8da632f0fb732c9f6425e1f457f5652e
Reviewed-on: https://go-review.googlesource.com/16358
Reviewed-by: Rick Hudson <rlh@golang.org>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Currently, we don't start dedicated or fractional mark workers unless
the mark 1 or mark 2 barriers have been cleared. One intended
consequence of this is that no background workers run between the
forEachP that disposes all gcWork caches and the beginning of mark 2.
However, we (unintentionally) did not apply this restriction to idle
mark workers. As a result, these can start in the interim between mark
1 completion and mark 2 starting. This explains why it was necessary
to reset the root marking jobs using carefully ordered atomic writes
when setting up mark 2. It also means that, even though we definitely
enqueue work before starting mark 2, it may be drained by the time we
reset the mark 2 barrier. If this happens, currently the only thing
preventing the runtime from deadlocking is that the scheduler itself
also checks for mark completion and will signal mark 2 completion.
Were it not for the odd behavior of idle workers, this check in the
scheduler would not be necessary.
Clean all of this up and prepare to remove this check in the scheduler
by applying the same restriction to starting idle mark workers.
Change-Id: Ic1b479e1591bd7773dc27b320ca399a215603b5a
Reviewed-on: https://go-review.googlesource.com/16631
Reviewed-by: Rick Hudson <rlh@golang.org>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This moves all of GC initialization, sweep termination, and the
transition to concurrent marking in to the off->mark transition
function. This means it's now handled on the goroutine that detected
the state exit condition.
As a result, malloc no longer needs to Gosched() at the beginning of
the GC cycle to prevent over-allocation while the GC is starting up
because it will now *help* the GC to start up. The Gosched hack is
still necessary during GC shutdown (this is easy to test by enabling
gctrace and hitting Ctrl-S to block the gctrace output).
At this point, the GC coordinator still handles later phases. This
requires a small tweak to how we start the GC coordinator. Currently,
starting the GC coordinator is best-effort and may fail if the
coordinator is about to park from the previous cycle but hasn't yet.
We fix this by replacing the park/ready to wake up the coordinator
with a semaphore. This is temporary since the coordinator will be
going away in a few commits.
Updates #11970.
Change-Id: I2c6a11c91e72dfbc59c2d8e7c66146dee9a444fe
Reviewed-on: https://go-review.googlesource.com/16357
Reviewed-by: Rick Hudson <rlh@golang.org>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This moves concurrent sweep termination from the coordinator to the
off->mark transition. This allows it to be performed by all Gs
attempting to start the GC.
Updates #11970.
Change-Id: I24428e8599a759398c2ef7ec996ba755a448f947
Reviewed-on: https://go-review.googlesource.com/16356
Reviewed-by: Rick Hudson <rlh@golang.org>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This begins the conversion of the centralized GC coordinator to a
decentralized state machine by introducing the internal API that
triggers the first state transition from _GCoff to _GCmark (or
_GCmarktermination).
This change introduces the transition lock, the off->mark transition
condition (which is very similar to shouldtriggergc()), and the
general structure of a state transition. Since we're doing this
conversion in stages, it then falls back to the GC coordinator to
actually execute the cycle. We'll start moving logic out of the GC
coordinator and in to transition functions next.
This fixes a minor bug in gcstoptheworld debug mode where passing the
heap trigger once could trigger multiple STW GCs.
Updates #11970.
Change-Id: I964087dd190a639eb5766398f8e1bbf8b352902f
Reviewed-on: https://go-review.googlesource.com/16355
Reviewed-by: Rick Hudson <rlh@golang.org>
Run-TryBot: Austin Clements <austin@google.com>
For historical reasons we currently do a lot of the concurrent mark
setup on the system stack. In fact, at this point the one and only
thing that needs to happen on the system stack is the start-the-world.
Clean up this code by lifting everything other than the
start-the-world off the system stack.
The diff for this change looks large, but the only code change is to
narrow the systemstack call. Everything else is re-indentation.
Change-Id: I1e03b8afc759fad726f2397b05a17d183c2713ce
Reviewed-on: https://go-review.googlesource.com/16354
Reviewed-by: Rick Hudson <rlh@golang.org>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
We're about to split func gc across several functions, so lift the
local variables it uses for tracking statistics and state across the
cycle into the global "work" variable.
Change-Id: Ie955f2f1758c7f5a5543ea1f3f33b222bc4b1d37
Reviewed-on: https://go-review.googlesource.com/16353
Reviewed-by: Rick Hudson <rlh@golang.org>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This change removes the retry mechanism we use for buffered channels.
Instead, any sender waking up a receiver or vice versa completes the
full protocol with its counterpart. This means the counterpart does
not need to relock the channel when it wakes up. (Currently
buffered channels need to relock on wakeup.)
For sends on a channel with waiting receivers, this change replaces
two copies (sender->queue, queue->receiver) with one (sender->receiver).
For receives on channels with a waiting sender, two copies are still required.
This change unifies to a large degree the algorithm for buffered
and unbuffered channels, simplifying the overall implementation.
Fixes#11506
benchmark old ns/op new ns/op delta
BenchmarkChanProdCons10 125 110 -12.00%
BenchmarkChanProdCons0 303 284 -6.27%
BenchmarkChanProdCons100 75.5 71.3 -5.56%
BenchmarkChanContended 6452 6125 -5.07%
BenchmarkChanNonblocking 11.5 11.0 -4.35%
BenchmarkChanCreation 149 143 -4.03%
BenchmarkChanSem 63.6 61.6 -3.14%
BenchmarkChanUncontended 6390 6212 -2.79%
BenchmarkChanSync 282 276 -2.13%
BenchmarkChanProdConsWork10 516 506 -1.94%
BenchmarkChanProdConsWork0 696 685 -1.58%
BenchmarkChanProdConsWork100 470 469 -0.21%
BenchmarkChanPopular 660427 660012 -0.06%
Change-Id: I164113a56432fbc7cace0786e49c5a6e6a708ea4
Reviewed-on: https://go-review.googlesource.com/9345
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Currently dedicated mark workers participate in the getfull barrier
during concurrent mark. However, the getfull barrier wasn't designed
for concurrent work and this causes no end of headaches.
In the concurrent setting, participants come and go. This makes mark
completion susceptible to live-lock: since dedicated workers are only
periodically polling for completion, it's possible for the program to
be in some transient worker each time one of the dedicated workers
wakes up to check if it can exit the getfull barrier. It also
complicates reasoning about the system because dedicated workers
participate directly in the getfull barrier, but transient workers
must instead use trygetfull because they have exit conditions that
aren't captured by getfull (e.g., fractional workers exit when
preempted). The complexity of implementing these exit conditions
contributed to #11677. Furthermore, the getfull barrier is inefficient
because we could be running user code instead of spinning on a P. In
effect, we're dedicating 25% of the CPU to marking even if that means
we have to spin to make that 25%. It also causes issues on Windows
because we can't actually sleep for 100µs (#8687).
Fix this by making dedicated workers no longer participate in the
getfull barrier. Instead, dedicated workers simply return to the
scheduler when they fail to get more work, regardless of what others
workers are doing, and the scheduler only starts new dedicated workers
if there's work available. Everything that needs to be handled by this
barrier is already handled by detection of mark completion.
This makes the system much more symmetric because all workers and
assists now use trygetfull during concurrent mark. It also loosens the
25% CPU target so that we can give some of that 25% back to user code
if there isn't enough work to keep the mark worker busy. And it
eliminates the problematic 100µs sleep on Windows during concurrent
mark (though not during mark termination).
The downside of this is that if we hit a bottleneck in the heap graph
that then expands back out, the system may shut down dedicated workers
and take a while to start them back up. We'll address this in the next
commit.
Updates #12041 and #8687.
No effect on the go1 benchmarks. This slows down the garbage benchmark
by 9%, but we'll more than make it up in the next commit.
name old time/op new time/op delta
XBenchGarbage-12 5.80ms ± 2% 6.32ms ± 4% +9.03% (p=0.000 n=20+20)
Change-Id: I65100a9ba005a8b5cf97940798918672ea9dd09b
Reviewed-on: https://go-review.googlesource.com/16297
Reviewed-by: Rick Hudson <rlh@golang.org>
This introduces a recursive variant of the go:nowritebarrier
annotation that prohibits write barriers not only in the annotated
function, but in all functions it calls, recursively. The error
message gives the shortest call stack from the annotated function to
the function containing the prohibited write barrier, including the
names of the functions and the line numbers of the calls.
To demonstrate the annotation, we apply it to gcmarkwb_m, the write
barrier itself.
This is a new annotation rather than a modification of the existing
go:nowritebarrier annotation because, for better or worse, there are
many go:nowritebarrier functions that do call functions with write
barriers. In most of these cases this is benign because the annotation
was conservative, but it prohibits simply coopting the existing
annotation.
Change-Id: I225ca483c8f699e8436373ed96349e80ca2c2479
Reviewed-on: https://go-review.googlesource.com/16554
Reviewed-by: Keith Randall <khr@golang.org>
Handling of special records for tiny allocations has two problems:
1. Once we queue a finalizer we mark the object. As the result any
subsequent finalizers for the same object will not be queued
during this GC cycle. If we have 16 finalizers setup (the worst case),
finalization will take 16 GC cycles. This is what caused misbehave
of tinyfin.go. The actual flakiness was caused by the fact that fing
is asynchronous and don't always run before the check.
2. If a tiny block has both finalizer and profile specials,
it is possible that we both queue finalizer, preserve the object live
and free the profile record. As the result heap profile can be skewed.
Fix both issues by analyzing all special records for a single object at once.
Also, make tinyfin test stricter and remove reliance on real time.
Also, add a test for the problem 2. Currently heap profile missed about
a half of live memory.
Fixes#13100
Change-Id: I9ae4dc1c44893724138a4565ca5cae29f2e97544
Reviewed-on: https://go-review.googlesource.com/16591
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Dmitry Vyukov <dvyukov@google.com>
Declare a function's arguments as having already been
spilled so their use just requires a restore.
Allow spill locations to be portions of larger objects the stack.
Required to load portions of compound input arguments.
Rename the memory input to InputMem. Use Arg for the
pre-spilled argument values.
Change-Id: I8fe2a03ffbba1022d98bfae2052b376b96d32dda
Reviewed-on: https://go-review.googlesource.com/16536
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Currently the GC work buffers are only 256 bytes and hence can record
only 24 64-bit pointer. They were reduced from 4K in commits db7fd1c
and a15818f as a way to minimize the amount of work the per-P workbuf
caches could "hide" from the mark phase and carry in to the mark
termination phase. However, this approach wasn't very robust and we
later added a "mark 2" phase to address this problem head-on.
Because of mark 2, there's now no benefit to having very small work
buffers. But there are plenty of downsides: small work buffers
increase contention on the work lists, increase the frequency and
hence net overhead of acquiring and releasing work buffers, and
somewhat increase memory overhead of the GC.
This commit expands work buffers back to 4K (504 64-bit pointers).
This reduces the rate of writes to work.full in the garbage benchmark
from a peak of ~780,000 writes/sec to a peak of ~32,000 writes/sec.
This has negligible effect on the go1 benchmarks. It slightly slows
down the garbage benchmark.
name old time/op new time/op delta
XBenchGarbage-12 5.37ms ± 5% 5.60ms ± 2% +4.37% (p=0.000 n=20+20)
Change-Id: Ic9cc28e7a125d23d9faf4f5e690fb8aa9bcdfb28
Reviewed-on: https://go-review.googlesource.com/15893
Reviewed-by: Rick Hudson <rlh@golang.org>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Currently, assists are non-preemptible, which means a heavily
assisting G can block other Gs from running. At the beginning of a GC
cycle, it can also delay scang, which will spin until the assist is
done. Since scanning is currently done sequentially, this can
seriously extend the length of the scan phase.
Fix this by making assists preemptible. Since the assist holds work
buffers and runs on the system stack, this must be done cooperatively:
we make gcDrainN return on preemption, and make the assist return from
the system stack and voluntarily Gosched.
This is prerequisite to enlarging the work buffers. Without this
change, the delays and spinning in scang increase significantly.
This has no effect on the go1 benchmarks.
name old time/op new time/op delta
XBenchGarbage-12 5.72ms ± 4% 5.37ms ± 5% -6.11% (p=0.000 n=20+20)
Change-Id: I829e732a0f23b126da633516a1a9ec1a508fdbf1
Reviewed-on: https://go-review.googlesource.com/15894
Reviewed-by: Rick Hudson <rlh@golang.org>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
GC assists must block until the assist can be satisfied (either
through stealing credit or doing work) or the GC cycle ends.
Currently, this is implemented as a retry loop with a 100 µs delay.
This obviously isn't ideal, as it wastes CPU and delays mutator
execution. It also has the somewhat peculiar downside that sleeping a
G requires allocation, and this requires working around recursive
allocation.
Replace this timed delay with a proper scheduling queue. When an
assist can't be satisfied immediately, it adds the allocating G to a
queue and parks it. Any time background scan credit is flushed, it
consults this queue, directly satisfies the debt of queued assists,
and wakes up satisfied assists before flushing any remaining credit to
the background credit pool.
No effect on the go1 benchmarks. Slightly speeds up the garbage
benchmark.
name old time/op new time/op delta
XBenchGarbage-12 5.81ms ± 1% 5.72ms ± 4% -1.65% (p=0.011 n=20+20)
Updates #12041.
Change-Id: I8ee3b6274dd097b12b10a8030796a958a4b0e7b7
Reviewed-on: https://go-review.googlesource.com/15890
Reviewed-by: Rick Hudson <rlh@golang.org>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This eliminates many write barriers in the scheduler code that are
unnecessary and will interfere with upcoming changes where the garbage
collector will have to invoke run queue functions in contexts that
must not have write barriers.
Change-Id: I702d0ac99cfd00ffff406e7362917db6a43e7e55
Reviewed-on: https://go-review.googlesource.com/16556
Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: Austin Clements <austin@google.com>
To avoid collisions with what existing code may already be doing.
Change-Id: Ice639440aafc0724714c25333d90a49954372230
Reviewed-on: https://go-review.googlesource.com/16503
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Currently the concurrent root scan is performed in its entirety by the
GC coordinator before entering concurrent mark (which enables GC
workers). This scan is done sequentially, which can prolong the scan
phase, delay the mark phase, and means that the scan phase does not
obey the 25% CPU goal. Furthermore, there's no need to complete the
root scan before starting marking (in fact, we already allow GC
assists to happen during the scan phase), so this acts as an
unnecessary barrier between root scanning and marking.
This change shifts the root scan work out of the GC coordinator and in
to the GC workers. The coordinator simply sets up the scan state and
enqueues the right number of root scan jobs. The GC workers then drain
the root scan jobs prior to draining heap scan jobs.
This parallelizes the root scan process, makes it obey the 25% CPU
goal, and effectively eliminates root scanning as an isolated phase,
allowing the system to smoothly transition from root scanning to heap
marking. This also eliminates a major non-STW responsibility of the GC
coordinator, which will make it easier to switch to a decentralized
state machine. Finally, it puts us in a good position to perform root
scanning in assists as well, which will help satisfy assists at the
beginning of the GC cycle.
This is mostly straightforward. One tricky aspect is that we have to
deal with preemption deadlock: where two non-preemptible gorountines
are trying to preempt each other to perform a stack scan. Given the
context where this happens, the only instance of this is two
background workers trying to scan each other. We avoid this by simply
not scanning the stacks of background workers during the concurrent
phase; this is safe because we'll scan them during mark termination
(and their stacks are *very* small and should not contain any new
pointers).
This change also switches the root marking during mark termination to
use the same gcDrain-based code path as concurrent mark. This
shouldn't affect performance because STW root marking was already
parallel and tasks switched to heap marking immediately when no more
root marking tasks were available. However, it simplifies the code and
unifies these code paths.
This has negligible effect on the go1 benchmarks. It slightly slows
down the garbage benchmark, possibly by making GC run slightly more
frequently.
name old time/op new time/op delta
XBenchGarbage-12 5.10ms ± 1% 5.24ms ± 1% +2.87% (p=0.000 n=18+18)
name old time/op new time/op delta
BinaryTree17-12 3.25s ± 3% 3.20s ± 5% -1.57% (p=0.013 n=20+20)
Fannkuch11-12 2.45s ± 1% 2.46s ± 1% +0.38% (p=0.019 n=20+18)
FmtFprintfEmpty-12 49.7ns ± 3% 49.9ns ± 4% ~ (p=0.851 n=19+20)
FmtFprintfString-12 170ns ± 2% 170ns ± 1% ~ (p=0.775 n=20+19)
FmtFprintfInt-12 161ns ± 1% 160ns ± 1% -0.78% (p=0.000 n=19+18)
FmtFprintfIntInt-12 267ns ± 1% 270ns ± 1% +1.04% (p=0.000 n=19+19)
FmtFprintfPrefixedInt-12 238ns ± 2% 238ns ± 1% ~ (p=0.133 n=18+19)
FmtFprintfFloat-12 311ns ± 1% 310ns ± 2% -0.35% (p=0.023 n=20+19)
FmtManyArgs-12 1.08µs ± 1% 1.06µs ± 1% -2.31% (p=0.000 n=20+20)
GobDecode-12 8.65ms ± 1% 8.63ms ± 1% ~ (p=0.377 n=18+20)
GobEncode-12 6.49ms ± 1% 6.52ms ± 1% +0.37% (p=0.015 n=20+20)
Gzip-12 319ms ± 3% 318ms ± 1% ~ (p=0.975 n=19+17)
Gunzip-12 41.9ms ± 1% 42.1ms ± 2% +0.65% (p=0.004 n=19+20)
HTTPClientServer-12 61.7µs ± 1% 62.6µs ± 1% +1.40% (p=0.000 n=18+20)
JSONEncode-12 16.8ms ± 1% 16.9ms ± 1% ~ (p=0.239 n=20+18)
JSONDecode-12 58.4ms ± 1% 60.7ms ± 1% +3.85% (p=0.000 n=19+20)
Mandelbrot200-12 3.86ms ± 0% 3.86ms ± 1% ~ (p=0.092 n=18+19)
GoParse-12 3.75ms ± 2% 3.75ms ± 2% ~ (p=0.708 n=19+20)
RegexpMatchEasy0_32-12 100ns ± 1% 100ns ± 2% +0.60% (p=0.010 n=17+20)
RegexpMatchEasy0_1K-12 341ns ± 1% 342ns ± 2% ~ (p=0.203 n=20+19)
RegexpMatchEasy1_32-12 82.5ns ± 2% 83.2ns ± 2% +0.83% (p=0.007 n=19+19)
RegexpMatchEasy1_1K-12 495ns ± 1% 495ns ± 2% ~ (p=0.970 n=19+18)
RegexpMatchMedium_32-12 130ns ± 2% 130ns ± 2% +0.59% (p=0.039 n=19+20)
RegexpMatchMedium_1K-12 39.2µs ± 1% 39.3µs ± 1% ~ (p=0.214 n=18+18)
RegexpMatchHard_32-12 2.03µs ± 2% 2.02µs ± 1% ~ (p=0.166 n=18+19)
RegexpMatchHard_1K-12 61.0µs ± 1% 60.9µs ± 1% ~ (p=0.169 n=20+18)
Revcomp-12 533ms ± 1% 535ms ± 1% ~ (p=0.071 n=19+17)
Template-12 68.1ms ± 2% 73.0ms ± 1% +7.26% (p=0.000 n=19+20)
TimeParse-12 355ns ± 2% 356ns ± 2% ~ (p=0.530 n=19+20)
TimeFormat-12 357ns ± 2% 347ns ± 1% -2.59% (p=0.000 n=20+19)
[Geo mean] 62.1µs 62.3µs +0.31%
name old speed new speed delta
GobDecode-12 88.7MB/s ± 1% 88.9MB/s ± 1% ~ (p=0.377 n=18+20)
GobEncode-12 118MB/s ± 1% 118MB/s ± 1% -0.37% (p=0.015 n=20+20)
Gzip-12 60.9MB/s ± 3% 60.9MB/s ± 1% ~ (p=0.944 n=19+17)
Gunzip-12 464MB/s ± 1% 461MB/s ± 2% -0.64% (p=0.004 n=19+20)
JSONEncode-12 115MB/s ± 1% 115MB/s ± 1% ~ (p=0.236 n=20+18)
JSONDecode-12 33.2MB/s ± 1% 32.0MB/s ± 1% -3.71% (p=0.000 n=19+20)
GoParse-12 15.5MB/s ± 2% 15.5MB/s ± 2% ~ (p=0.702 n=19+20)
RegexpMatchEasy0_32-12 320MB/s ± 1% 318MB/s ± 2% ~ (p=0.094 n=18+20)
RegexpMatchEasy0_1K-12 3.00GB/s ± 1% 2.99GB/s ± 1% ~ (p=0.194 n=20+19)
RegexpMatchEasy1_32-12 388MB/s ± 2% 385MB/s ± 2% -0.83% (p=0.008 n=19+19)
RegexpMatchEasy1_1K-12 2.07GB/s ± 1% 2.07GB/s ± 1% ~ (p=0.964 n=19+18)
RegexpMatchMedium_32-12 7.68MB/s ± 1% 7.64MB/s ± 2% -0.57% (p=0.020 n=19+20)
RegexpMatchMedium_1K-12 26.1MB/s ± 1% 26.1MB/s ± 1% ~ (p=0.211 n=18+18)
RegexpMatchHard_32-12 15.8MB/s ± 1% 15.8MB/s ± 1% ~ (p=0.180 n=18+19)
RegexpMatchHard_1K-12 16.8MB/s ± 1% 16.8MB/s ± 2% ~ (p=0.236 n=20+19)
Revcomp-12 477MB/s ± 1% 475MB/s ± 1% ~ (p=0.071 n=19+17)
Template-12 28.5MB/s ± 2% 26.6MB/s ± 1% -6.77% (p=0.000 n=19+20)
[Geo mean] 100MB/s 99.0MB/s -0.82%
Change-Id: I875bf6ceb306d1ee2f470cabf88aa6ede27c47a0
Reviewed-on: https://go-review.googlesource.com/16059
Reviewed-by: Rick Hudson <rlh@golang.org>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
We already have gcMarkWorkAvailable, but the check for GC mark work is
open-coded in several places. Generalize gcMarkWorkAvailable slightly
and replace these open-coded checks with calls to gcMarkWorkAvailable.
In addition to cleaning up the code, this puts us in a better position
to make this check slightly more complicated.
Change-Id: I1b29883300ecd82a1bf6be193e9b4ee96582a860
Reviewed-on: https://go-review.googlesource.com/16058
Reviewed-by: Rick Hudson <rlh@golang.org>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Abandon (but still support) the old numbering system.
GOTRACEBACK=none is old 0
GOTRACEBACK=single is the new behavior
GOTRACEBACK=all is old 1
GOTRACEBACK=system is old 2
GOTRACEBACK=crash is unchanged
See doc comment change in runtime1.go for details.
Filed #13107 to decide whether to change default back to GOTRACEBACK=all for Go 1.6 release.
If you run into programs where printing only the current goroutine omits
needed information, please add details in a comment on that issue.
Fixes#12366.
Change-Id: I82ca8b99b5d86dceb3f7102d38d2659d45dbe0db
Reviewed-on: https://go-review.googlesource.com/16512
Reviewed-by: Austin Clements <austin@google.com>
On ppc64x, the thread pointer, held in R13, points 0x7000 bytes past where
thread-local storage begins (presumably to maximize the amount of storage that
can be accessed with a 16-bit signed displacement). The relocations used to
indicate thread-local storage to the platform linker account for this, so to be
able to support external linking we need to change things so the linker applies
this offset instead of the runtime assembly.
Change-Id: I2556c249ab2d802cae62c44b2b4c5b44787d7059
Reviewed-on: https://go-review.googlesource.com/14233
Reviewed-by: Russ Cox <rsc@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
This is needed to make external linking work.
Change-Id: I4cf7edb4ea318849cab92a697952f8745eed40c4
Reviewed-on: https://go-review.googlesource.com/14237
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Android linker does not handle TLS for us. We set up the TLS slot
for g, as darwin/386,amd64 handle instead. This is disgusting and
fragile. We will eventually fix this ugly hack by taking advantage
of the recent TLS IE model implementation. (Instead of referencing
an GOT entry, make the code sequence look into the TLS variable that
holds the offset.)
The TLS slot for g in android/amd64 assumes a fixed offset from %fs.
See runtime/cgo/gcc_android_amd64.c for details.
For golang/go#10743
Change-Id: I1a3fc207946c665515f79026a56ea19134ede2dd
Reviewed-on: https://go-review.googlesource.com/15991
Reviewed-by: David Crawshaw <crawshaw@golang.org>
In the Go signal handler on Plan 9, when a signal with
the _SigThrow flag is received, we call startpanic before
printing the stack trace.
The startpanic function calls systemstack which calls
startpanic_m. In the startpanic_m function, we call
allocmcache to allocate _g_.m.mcache. The problem is
that allocmcache calls nextSample, which does a floating
point operation to return a sampling point for heap profiling.
However, Plan 9 doesn't support floating point in the
signal handler.
This change adds a new function nextSampleNoFP, only
called when in the Plan 9 signal handler, which is
similar to nextSample, but avoids floating point.
Change-Id: Iaa30437aa0f7c8c84d40afbab7567ad3bd5ea2de
Reviewed-on: https://go-review.googlesource.com/16307
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The dynamic linker on linux/386 stores the address of the vsyscall helper at a
fixed offset from the %gs register on linux/386 for easy access from PIC code.
Change-Id: I635305cfecceef2289985d62e676e16810ed6b94
Reviewed-on: https://go-review.googlesource.com/16346
Reviewed-by: Ian Lance Taylor <iant@golang.org>
arena_{start,used,end} are already uintptr, so no need to convert them
to uintptr, much less to convert them to unsafe.Pointer and then to
uintptr. No binary change to pkg/linux_amd64/runtime.a.
Change-Id: Ia4232ed2a724c44fde7eba403c5fe8e6dccaa879
Reviewed-on: https://go-review.googlesource.com/16339
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Implement an abort note on Plan 9, as an
equivalent of the SIGABRT signal on other
operating systems.
Updates #11975.
Change-Id: I010c9b10f2fbd2471aacd1d073368d975a2f0592
Reviewed-on: https://go-review.googlesource.com/16300
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: David du Colombier <0intro@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
When a new tiny block is allocated because we're allocating an object
that won't fit into the current block, mallocgc saves the new block if
it has more space leftover than the old block. However, the logic for
this was subtly broken in golang.org/cl/2814, resulting in never
saving (or consequently reusing) a tiny block.
Change-Id: Ib5f6769451fb82877ddeefe75dfe79ed4a04fd40
Reviewed-on: https://go-review.googlesource.com/16330
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
I went looking for an arm system whose stacks are by default smaller
than 64KB. In fact the smallest common linux target I could find was
Android, which like iOS uses 1MB stacks.
Fixes#11873
Change-Id: Ieeb66ad095b3da18d47ba21360ea75152a4107c6
Reviewed-on: https://go-review.googlesource.com/14602
Reviewed-by: Michael Hudson-Doyle <michael.hudson@canonical.com>
Reviewed-by: Minux Ma <minux@golang.org>
This copies the change from CL 16158 (applied as
22d4c8bf13).
Updates #13013
Change-Id: Id7d02e63d92806f06a4e064a91b2fb6574fe385f
Reviewed-on: https://go-review.googlesource.com/16291
Reviewed-by: Minux Ma <minux@golang.org>
Run-TryBot: Minux Ma <minux@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Modified GOSSA{HASH.PKG} environment variable filters to
make it easier to make/run with all SSA for testing.
Disable attempts at SSA for architectures that are not
amd64 (avoid spurious errors/unimplementeds.)
Removed easy out for unimplemented features.
Add convert op for proper liveness in presence of uintptr
to/from unsafe.Pointer conversions.
Tweaked stack sizes to get a pass on windows;
1024 instead 768, was observed to pass at least once.
Change-Id: Ida3800afcda67d529e3b1cf48ca4a3f0fa48b2c5
Reviewed-on: https://go-review.googlesource.com/16201
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: David Chase <drchase@google.com>
This CL introduces a new mSpanList type to replace the empty mspan
variables that were previously used as list heads.
To be type safe, the previous circular linked list data structure is
now a tail queue instead. One complication of this is
mSpanList_Remove needs to know the list a span is being removed from,
but this appears to be computable in all circumstances.
As a temporary sanity check, mSpanList_Insert and mSpanList_InsertBack
record the list that an mspan has been inserted into so that
mSpanList_Remove can verify that the correct list was specified.
Whereas mspan is 112 bytes on amd64, mSpanList is only 16 bytes. This
shrinks the size of mheap from 50216 bytes to 12584 bytes.
Change-Id: I8146364753dbc3b4ab120afbb9c7b8740653c216
Reviewed-on: https://go-review.googlesource.com/15906
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Austin Clements <austin@google.com>
It's never used as a *byte anyway, so might as well just make it an
unsafe.Pointer instead.
Change-Id: I68ee418781ab2fc574eeac0498f2515b5561b7a8
Reviewed-on: https://go-review.googlesource.com/16175
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reduces the size of m by ~8% on linux/amd64 (1040 bytes -> 960 bytes).
There are also windows-specific fields, but they're currently
referenced in OS-independent source files (but only when
GOOS=="windows").
Change-Id: I13e1471ff585ccced1271f74209f8ed6df14c202
Reviewed-on: https://go-review.googlesource.com/16173
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Change compiler-invoked interface functions to directly take
iface/eface parameters instead of fInterface/interface{} to avoid
needing to always convert.
For the handful of functions that legitimately need to take an
interface{} parameter, add efaceOf to type-safely convert *interface{}
to *eface.
Change-Id: I8928761a12fd3c771394f36adf93d3006a9fcf39
Reviewed-on: https://go-review.googlesource.com/16166
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Add explicit memory 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.
Change-Id: I2d66073f713fe67e33a6720460d2bb8f72f31394
Reviewed-on: https://go-review.googlesource.com/16164
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Allows removing a few gratuitous unsafe.Pointer conversions and
parallels the type of reflect.funcType's in and out fields ([]*rtype).
Change-Id: Ie5ca230a94407301a854dfd8782a3180d5054bc4
Reviewed-on: https://go-review.googlesource.com/16163
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
These are the runtime support functions for letting Go code interoperate
with the C/C++ memory sanitizer. Calls to msanread/msanwrite are now
inserted by the compiler with the -msan option. Calls to
msanmalloc/msanfree will be from other runtime functions in a subsequent
CL.
Change-Id: I64fb061b38cc6519153face242eccd291c07d1f2
Reviewed-on: https://go-review.googlesource.com/16162
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
The ragged barrier after entering the concurrent mark phase is
vestigial. This used to be the point where we enabled write barriers,
so it was necessary to synchronize all Ps to ensure write barriers
were enabled before any marking occurred. However, we've long since
switched to enabling write barriers during the concurrent scan phase,
so the start-the-world at the beginning of the concurrent scan phase
ensures that all Ps have enabled the write barrier.
Hence, we can eliminate the old "install write barrier" phase.
Fixes#11971.
Change-Id: I8cdcb84b5525cef19927d51ea11ba0a4db991ea8
Reviewed-on: https://go-review.googlesource.com/16044
Reviewed-by: Rick Hudson <rlh@golang.org>
Instead of open-coding conversions from *string to unsafe.Pointer then
to *stringStruct, add a helper function to add some type safety.
Bonus: This caught two **string values being converted to
*stringStruct in heapdump.go.
While here, get rid of the redundant _string type, but add in a
stringStructDWARF type used for generating DWARF debug info.
Change-Id: I8882f8cca66ac45190270f82019a5d85db023bd2
Reviewed-on: https://go-review.googlesource.com/16131
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The '1' part is left over from the C conversion, but no longer makes
sense given that print1.go no longer exists.
Change-Id: Iec171251370d740f234afdbd6fb1a4009fde6696
Reviewed-on: https://go-review.googlesource.com/16036
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
access, connect, socket.
In Android-L, logging is done by writing the log messages to the logd
process through a unix domain socket.
Also, changed the arg types of those syscall stubs to match linux
programming APIs.
For golang/go#10743
Change-Id: I66368a03316e253561e9e76aadd180c2cd2e48f3
Reviewed-on: https://go-review.googlesource.com/15993
Reviewed-by: David Crawshaw <crawshaw@golang.org>
When I saw that it was labelled "legacy", I went looking for users of it
to see how it was still used. But there aren't any. Save the next person
the trouble.
Change-Id: I921dd6c57b60331c9816542272555153ac133c02
Reviewed-on: https://go-review.googlesource.com/16035
Reviewed-by: Dave Cheney <dave@cheney.net>
Run-TryBot: Dave Cheney <dave@cheney.net>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Building Go shared libraries requires that all functions that have declarations
without bodies have implementations and vice versa, so remove the
implementation of call16 and add a stub implementation of sigreturn.
Change-Id: I4d5a30c8637a5da7991054e151a536611d5bea46
Reviewed-on: https://go-review.googlesource.com/15966
Reviewed-by: Ian Lance Taylor <iant@golang.org>
These functions are always called together and perform logically
related state resets, so combine them in to just gcResetMarkState.
Fixes#11427.
Change-Id: I06c17ef65f66186494887a767b3993126955b5fe
Reviewed-on: https://go-review.googlesource.com/16041
Reviewed-by: Rick Hudson <rlh@golang.org>
Currently gcResetGState is called by func gcscan_m for concurrent GC
and directly by func gc for STW GC. Simplify this by consolidating
these two calls in to one call by func gc above where it splits for
concurrent and STW GC.
As a consequence, gcResetGState and gcResetMarkState are always called
together, so the next commit will consolidate these.
Change-Id: Ib62d404c7b32b28f7d3080d26ecf3966cbc4aca0
Reviewed-on: https://go-review.googlesource.com/16040
Reviewed-by: Rick Hudson <rlh@golang.org>
This work queue is no longer used (there are many reads of
work.partial, but the only write is in putpartial, which is never
called).
Fixes#11922.
Change-Id: I08b76c0c02a0867a9cdcb94783e1f7629d44249a
Reviewed-on: https://go-review.googlesource.com/15892
Reviewed-by: Rick Hudson <rlh@golang.org>
It appears this was made possible by commit 89f185f; before that, g was
not dereferenced above.
Change-Id: I70bc571d924b36351392fd4c13d681e938cfb573
Reviewed-on: https://go-review.googlesource.com/16033
Reviewed-by: Andrew Gerrand <adg@golang.org>
PIC code on ppc64le uses R2 as a TOC pointer and when calling a function
through a function pointer must ensure the function pointer is in R12. These
rules are easy enough to follow unconditionally in our assembly, so do that.
Change-Id: Icfc4e47ae5dfbe15f581cbdd785cdeed6e40bc32
Reviewed-on: https://go-review.googlesource.com/15526
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Shared libraries on ppc64le will require a larger minimum stack frame (because
the ABI mandates that the TOC pointer is available at 24(R1)). Part 3 of that
is using a #define in the ppc64 assembly to refer to the size of the fixed
part of the stack (finding all these took me about a week!).
Change-Id: I50f22fe1c47af1ec59da1bd7ea8f84a4750df9b7
Reviewed-on: https://go-review.googlesource.com/15525
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Shared libraries on ppc64le will require a larger minimum stack frame (because
the ABI mandates that the TOC pointer is available at 24(R1)). So to prepare
for this, make a constant for the fixed part of a stack and use that where
necessary.
Change-Id: I447949f4d725003bb82e7d2cf7991c1bca5aa887
Reviewed-on: https://go-review.googlesource.com/15523
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Michael Hudson-Doyle <michael.hudson@canonical.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Replace the confusing game where a frame size of $-8 would suppress the
implicit setting up of a stack frame with a nice explicit flag.
The code to set up the function prologue is still a little confusing but better
than it was.
Change-Id: I1d49278ff42c6bc734ebfb079998b32bc53f8d9a
Reviewed-on: https://go-review.googlesource.com/15670
Reviewed-by: Minux Ma <minux@golang.org>
Changed racewalk/race detector to use FP in a more
sensible way.
Relaxed checks for CONVNOP when race detecting.
Modified tighten to ensure that GetClosurePtr cannot float
out of entry block (turns out this cannot be relaxed, DX is
sometimes stomped by other code accompanying race detection).
Added case for addr(CONVNOP)
Modified addr to take "bounded" flag to suppress nilchecks
where it is set (usually, by race detector).
Cannot leave unimplemented-complainer enabled because it
turns out we are optimistically running SSA on every platform.
Change-Id: Ife021654ee4065b3ffac62326d09b4b317b9f2e0
Reviewed-on: https://go-review.googlesource.com/15710
Reviewed-by: Keith Randall <khr@golang.org>
A TODO to merge is removed from panic1.go.
The rest is appended to panic.go
Updates #12952
Change-Id: Ied4382a455abc20bc2938e34d031802e6b4baf8b
Reviewed-on: https://go-review.googlesource.com/15905
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
