Commit Graph

251 Commits

Author SHA1 Message Date
Russ Cox 19309779ac all: gofmt main repo
[This CL is part of a sequence implementing the proposal #51082.
The design doc is at https://go.dev/s/godocfmt-design.]

Run the updated gofmt, which reformats doc comments,
on the main repository. Vendored files are excluded.

For #51082.

Change-Id: I7332f099b60f716295fb34719c98c04eb1a85407
Reviewed-on: https://go-review.googlesource.com/c/go/+/384268
Reviewed-by: Jonathan Amsterdam <jba@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2022-04-11 16:34:30 +00:00
Russ Cox 9839668b56 all: separate doc comment from //go: directives
A future change to gofmt will rewrite

	// Doc comment.
	//go:foo

to

	// Doc comment.
	//
	//go:foo

Apply that change preemptively to all comments (not necessarily just doc comments).

For #51082.

Change-Id: Iffe0285418d1e79d34526af3520b415a12203ca9
Reviewed-on: https://go-review.googlesource.com/c/go/+/384260
Trust: Russ Cox <rsc@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
2022-04-05 17:54:15 +00:00
Russ Cox 690ac4071f all: remove trailing blank doc comment lines
A future change to gofmt will rewrite

	// Doc comment.
	//
	func f()

to

	// Doc comment.
	func f()

Apply that change preemptively to all doc comments.

For #51082.

Change-Id: I4023e16cfb0729b64a8590f071cd92f17343081d
Reviewed-on: https://go-review.googlesource.com/c/go/+/384259
Trust: Russ Cox <rsc@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
2022-04-01 18:18:07 +00:00
Rhys Hiltner 212bda0669 runtime/pprof: rerun magnitude test on failure
Restructure TestCPUProfileMultithreadMagnitude so it will run again with
a longer duration on failure. Log the split between the user vs system
CPU time that rusage reports.

For #50232

Change-Id: Ice5b38ee7594dbee1eaa5686d32b968c306e3e85
Reviewed-on: https://go-review.googlesource.com/c/go/+/393934
Run-TryBot: Rhys Hiltner <rhys@justin.tv>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Michael Pratt <mpratt@google.com>
Trust: Michael Knyszek <mknyszek@google.com>
2022-03-22 21:31:40 +00:00
Bryan C. Mills 1a2f726195 runtime/pprof: do not require a GOROOT/src prefix in tests
When paths are trimmed, the reported file locations begin with the
package import path (not GOROOT/src).

Updates #51461

Change-Id: Idbd408a02e8d03329d10e30b0b08263e69e66285
Reviewed-on: https://go-review.googlesource.com/c/go/+/391812
Trust: Bryan Mills <bcmills@google.com>
Run-TryBot: Bryan Mills <bcmills@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
2022-03-16 15:20:22 +00:00
Tobias Klauser 3c2e73c8c3 runtime/pprof: use syscall.RUSAGE_SELF
Change-Id: Idc37429de5a48e708eda868ca7fa26b28620bac0
Reviewed-on: https://go-review.googlesource.com/c/go/+/391854
Trust: Tobias Klauser <tobias.klauser@gmail.com>
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2022-03-13 21:31:06 +00:00
Tobias Klauser c1f22134f2 runtime/pprof, syscall: report MaxRSS on all unix platforms
All unix platforms currently supported by Go provide the getrusage
syscall. On aix and solaris the Getrusage syscall wrapper is not
available yet, so add and use it to report MaxRSS in memory profiles.

Change-Id: Ie880a3058171031fd2e12ccf9adfb85ce18858b1
Reviewed-on: https://go-review.googlesource.com/c/go/+/391434
Trust: Tobias Klauser <tobias.klauser@gmail.com>
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Michael Pratt <mpratt@google.com>
Trust: Michael Pratt <mpratt@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2022-03-11 06:03:26 +00:00
Rhys Hiltner 0d33a99675 runtime/pprof: fix pcDeck's frame indexing
When building the inlining deck, correctly identify which is the last
frame in the deck. Otherwise, when some forms of inlining cause a PC to
expand to multiple frames, the length of the deck's two slices will
diverge.

Fixes #51567

Change-Id: I24e7ba32cb16b167f4307178b3f03c29e5362c4b
Reviewed-on: https://go-review.googlesource.com/c/go/+/391134
Reviewed-by: Michael Pratt <mpratt@google.com>
Trust: Than McIntosh <thanm@google.com>
2022-03-09 17:07:49 +00:00
Rhys Hiltner bd77d6e240 runtime/pprof: check if PC is reused for inlining
When describing call stacks that include inlined function calls, the
runtime uses "fake" PCs to represent the frames that inlining removed.
Those PCs correspond to real NOP instructions that the compiler inserts
for this purpose.

Describing the call stack in a protobuf-formatted profile requires the
runtime/pprof package to collapse any sequences of fake call sites back
into single PCs, removing the NOPs but retaining their line info.

But because the NOP instructions are part of the function, they can
appear as leaf nodes in a CPU profile. That results in an address that
should sometimes be ignored (when it appears as a call site) and that
sometimes should be present in the profile (when it is observed
consuming CPU time).

When processing a PC address, consider it first as a fake PC to add to
the current inlining deck, and then as a previously-seen (real) PC.

Fixes #50996

Change-Id: I80802369978bd7ac9969839ecfc9995ea4f84ab4
Reviewed-on: https://go-review.googlesource.com/c/go/+/384239
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
2022-03-08 21:23:02 +00:00
Bryan C. Mills 18c2033ba5 runtime/pprof: remove arbitrary sleeps in TestBlockProfile
The "block" helpers in TestBlockProfile previously slept for an
arbitrary duration and assumed that that duration was long enough for
the parent goroutine to have registered as blocking. However —
especially on slow or overloaded builders — the current arbitrary
duration is sometimes not quite long enough.

Rather than increasing the duration to a different arbitrary value
(which would make the test slower but not actually eliminate the
possibility of flakes!), we can use the runtime's own accounting to
detect when the goroutine is actually blocked: we obtain a goroutine
dump from the runtime, and assume that blocking has been registered in
the profile only if the runtime shows the test goroutine in the
appropriate blocked state.

That not only makes the test more reliable, but also makes it
significantly lower-latency when run on a fast machine.

Fixes #6999
Fixes #37844

Change-Id: I465ed2afd406fd2b621419e1f06925f283525f25
Reviewed-on: https://go-review.googlesource.com/c/go/+/384534
Trust: Bryan Mills <bcmills@google.com>
Trust: Benny Siegert <bsiegert@gmail.com>
Run-TryBot: Bryan Mills <bcmills@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2022-02-10 17:31:59 +00:00
Michael Pratt 9eba5ff521 runtime/pprof: TestLabelSystemstack parallelLabelHog.func1 must be labeled
The closure in parallelLabelHog should be labeled in a addition to
parallelLabelHog itself. Generally samples on that goroutine land on
labelHog, but there is a small portion of the closure outside of
labelHog.

Fixes #50740.

Change-Id: I363b6d8eec2e6920c215686e2039fce6d5b29a98
Reviewed-on: https://go-review.googlesource.com/c/go/+/380055
Reviewed-by: Bryan Mills <bcmills@google.com>
Trust: Michael Pratt <mpratt@google.com>
2022-01-21 16:59:19 +00:00
Michael Pratt 59122f85bd runtime/pprof: allow labels on racecall in TestLabelSystemstack
Fixes #50705.

Change-Id: I85857f836cbe58447625df6cd56756d3a69880ff
Reviewed-on: https://go-review.googlesource.com/c/go/+/379834
Trust: Michael Pratt <mpratt@google.com>
Run-TryBot: Michael Pratt <mpratt@google.com>
Reviewed-by: Bryan Mills <bcmills@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
2022-01-20 16:31:11 +00:00
Michael Pratt d1640d8652 runtime/pprof: compare all samples vs rusage in TestCPUProfileMultithreadMagnitude
TestCPUProfileMultithreadMagnitude compares pprof results vs OS rusage
to verify that pprof is capturing all CPU usage. Presently it compares
the sum of cpuHog1 samples vs rusage. However, background usage from the
scheduler, GC, etc can cause additional CPU usage causing test failures
if rusage is too far off from the cpuHog1 samples.

That said, this test doesn't actually need to care about cpuHog1
samples. It simply cares that pprof samples match rusage, not what the
breakdown of usage was. As a result, we can compare the sum of _all_
pprof samples vs rusage, which should implicitly include any background
CPU usage.

Fixes #50097.

Change-Id: I649a18de5b3dcf58b62be5962fa508d14cd4dc79
Reviewed-on: https://go-review.googlesource.com/c/go/+/379535
Trust: Michael Pratt <mpratt@google.com>
Run-TryBot: Michael Pratt <mpratt@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
2022-01-19 20:07:20 +00:00
Michael Pratt 985d97e602 runtime/pprof: assert that labels never appear on unexpected samples
This makes TestLabelSystemstack much more strict, enabling it to detect
any misplacement of labels.

Unfortunately, there are several edge cases where we may not have an
obviously correct stack trace, so we generally except the runtime
package, with the exception of background goroutines that we know should
not be labeled.

For #50007
For #50032

Change-Id: I8dce7e7da04f278ce297422227901efe52782ca0
Reviewed-on: https://go-review.googlesource.com/c/go/+/369984
Trust: Michael Pratt <mpratt@google.com>
Run-TryBot: Michael Pratt <mpratt@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
2022-01-19 16:33:11 +00:00
Michael Pratt a40c7b1c77 runtime/pprof: run TestCPUProfileMultithreadMagnitude subtests separately
Currently TestCPUProfileMultithreadMagnitude runs two CPU consumption
functions in a single profile and then analyzes the results as separate
subtests.

This works fine, but when debugging failures it makes manual analysis of
the profile dump a bit annoying.

Refactor the test to collect separate profiles for each subtest for
easier future analysis.

For #50097.
For #50232.

Change-Id: Ia1c8bb86aaaf652e64c5e660dcc2da47d2194c2b
Reviewed-on: https://go-review.googlesource.com/c/go/+/372800
Trust: Michael Pratt <mpratt@google.com>
Run-TryBot: Michael Pratt <mpratt@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Rhys Hiltner <rhys@justin.tv>
Reviewed-by: Bryan Mills <bcmills@google.com>
2022-01-10 16:48:38 +00:00
Russ Cox 2580d0e08d all: gofmt -w -r 'interface{} -> any' src
And then revert the bootstrap cmd directories and certain testdata.
And adjust tests as needed.

Not reverting the changes in std that are bootstrapped,
because some of those changes would appear in API docs,
and we want to use any consistently.
Instead, rewrite 'any' to 'interface{}' in cmd/dist for those directories
when preparing the bootstrap copy.

A few files changed as a result of running gofmt -w
not because of interface{} -> any but because they
hadn't been updated for the new //go:build lines.

Fixes #49884.

Change-Id: Ie8045cba995f65bd79c694ec77a1b3d1fe01bb09
Reviewed-on: https://go-review.googlesource.com/c/go/+/368254
Trust: Russ Cox <rsc@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
2021-12-13 18:45:54 +00:00
Michael Pratt f5ddd94334 runtime/pprof: increase systemstack calls in TestLabelSystemstack
TestLabelSystemstack needs to collect samples within runtime.systemstack
to complete the test.

The current approach uses fmt.Fprintf, which gets into systemstack
through the allocator and GC, but also does lots of other work. In my
measurements, approximately 2% of samples contain runtime.systemstack.

The new approach uses debug.SetGCPercent, which uses systemstack for
most of its work, including contention on mheap_.lock, which extends
usage even more. In my measurements, approximately 99% of samples
contain runtime.systemstack.

Fixes #50050

Change-Id: I59e5bb756341b716a12e13d2e3fe0adadd7fe956
Reviewed-on: https://go-review.googlesource.com/c/go/+/370375
Reviewed-by: Bryan Mills <bcmills@google.com>
Trust: Michael Pratt <mpratt@google.com>
Run-TryBot: Michael Pratt <mpratt@google.com>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
2021-12-08 23:00:01 +00:00
Michael Pratt 0a15e7851a runtime/pprof: assert that labelHog samples are always labeled
With https://golang.org/issue/50007 resolved, there are no known issues
with pprof labels remaining. Thus, the 10% allowed error in
TestLabelSystemstack should not be required.

Drop it in favor of an explicit assertion that all samples containing
labelHog are properly labeled.

This is no flaky in my local testing. It is possible that other bugs
will appear at larger testing scale, in which case this CL will be
reverted, but then at least we will be aware of additional failure
modes.

For #50007.

Change-Id: I1ef530c303bd9a01af649b8b08d4b35505e8aada
Reviewed-on: https://go-review.googlesource.com/c/go/+/369744
Reviewed-by: Bryan Mills <bcmills@google.com>
Trust: Michael Pratt <mpratt@google.com>
Run-TryBot: Michael Pratt <mpratt@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
2021-12-07 22:33:39 +00:00
Michael Pratt a3ae45ebe1 runtime/pprof: consume tag for first CPU record
profBuf.write uses an index in b.tags for each entry, even if that entry
has no tag (that slice entry just remains 0). profBuf.read similarly
returns a tags slice with exactly as many entries as there are records
in data.

profileBuilder.addCPUData iterates through the tags in lockstep with the
data records. Except in the special case of the first record, where it
forgets to increment tags. Thus the first read of profiling data has all
tags off-by-one.

To help avoid regressions, addCPUData is changed to assert that tags
contains exactly the correct number of tags.

For #50007.

Change-Id: I5f32f93003297be8d6e33ad472c185d924a63256
Reviewed-on: https://go-review.googlesource.com/c/go/+/369741
Reviewed-by: Austin Clements <austin@google.com>
Trust: Michael Pratt <mpratt@google.com>
Run-TryBot: Michael Pratt <mpratt@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
2021-12-07 22:33:33 +00:00
Felix Geisendörfer 9b0de0854d runtime: fix missing pprof labels
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.

Also change testCPUProfile interface a little to allow the new test to
re-run with a longer duration if it fails during a -short run.

Fixes #48577.

Change-Id: I3dbc9fd5af3c513544e822acaa43055b2e00dfa9
Reviewed-on: https://go-review.googlesource.com/c/go/+/367200
Trust: Michael Pratt <mpratt@google.com>
Trust: Bryan Mills <bcmills@google.com>
Run-TryBot: Michael Pratt <mpratt@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Michael Pratt <mpratt@google.com>
2021-12-03 16:11:38 +00:00
Michael Pratt 95196512b6 runtime/pprof: mark TestCPUProfileMultithreadMagnitude as flaky
The Linux kernel starting in 5.9 and fixed in 5.16 has a bug that can
break CPU timer signal delivery on new new threads if the timer
interrupt fires during handling of the clone system call.

Broken CPU timer signal deliver will skew CPU profile results and cause
this test to fail.

There is currently no known workaround, so mark the test as flaky on
builders with known broken kernels.

For #49065

Change-Id: I37ceb9ea244869b0aab5cd9a36b27ca2f7e5d315
Reviewed-on: https://go-review.googlesource.com/c/go/+/363214
Trust: Michael Pratt <mpratt@google.com>
Run-TryBot: Michael Pratt <mpratt@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
2021-11-12 20:02:21 +00:00
Michael Pratt 90f47dbba6 runtime/pprof: include labels in profile dump
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>
2021-11-09 17:02:38 +00:00
Rhys Hiltner 5f0e5d21bb runtime/pprof: disable GC during calibration test
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>
2021-11-03 15:59:11 +00:00
Bryan C. Mills c6a0b6f2de Revert "runtime: fix missing pprof labels"
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>
2021-11-02 16:15:22 +00:00
Felix Geisendörfer da7173a2ed runtime: fix missing pprof labels
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>
2021-11-02 15:15:09 +00:00
Michael Anthony Knyszek 3aecb3a8f7 runtime: fix sweep termination condition
Currently, there is a chance that the sweep termination condition could
flap, causing e.g. runtime.GC to return before all sweep work has not
only been drained, but also completed. CL 307915 and CL 307916 attempted
to fix this problem, but it is still possible that mheap_.sweepDrained is
marked before any outstanding sweepers are accounted for in
mheap_.sweepers, leaving a window in which a thread could observe
isSweepDone as true before it actually was (and after some time it would
revert to false, then true again, depending on the number of outstanding
sweepers at that point).

This change fixes the sweep termination condition by merging
mheap_.sweepers and mheap_.sweepDrained into a single atomic value.

This value is updated such that a new potential sweeper will increment
the oustanding sweeper count iff there are still outstanding spans to be
swept without an outstanding sweeper to pick them up. This design
simplifies the sweep termination condition into a single atomic load and
comparison and ensures the condition never flaps.

Updates #46500.
Fixes #45315.

Change-Id: I6d69aff156b8d48428c4cc8cfdbf28be346dbf04
Reviewed-on: https://go-review.googlesource.com/c/go/+/333389
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>
2021-10-29 17:12:47 +00:00
Russ Cox f229e7031a all: go fix -fix=buildtag std cmd (except for bootstrap deps, vendor)
When these packages are released as part of Go 1.18,
Go 1.16 will no longer be supported, so we can remove
the +build tags in these files.

Ran go fix -fix=buildtag std cmd and then reverted the bootstrapDirs
as defined in src/cmd/dist/buildtool.go, which need to continue
to build with Go 1.4 for now.

Also reverted src/vendor and src/cmd/vendor, which will need
to be updated in their own repos first.

Manual changes in runtime/pprof/mprof_test.go to adjust line numbers.

For #41184.

Change-Id: Ic0f93f7091295b6abc76ed5cd6e6746e1280861e
Reviewed-on: https://go-review.googlesource.com/c/go/+/344955
Trust: Russ Cox <rsc@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
2021-10-28 18:17:57 +00:00
Russ Cox 4d8db00641 all: use bytes.Cut, strings.Cut
Many uses of Index/IndexByte/IndexRune/Split/SplitN
can be written more clearly using the new Cut functions.
Do that. Also rewrite to other functions if that's clearer.

For #46336.

Change-Id: I68d024716ace41a57a8bf74455c62279bde0f448
Reviewed-on: https://go-review.googlesource.com/c/go/+/351711
Trust: Russ Cox <rsc@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2021-10-06 15:53:04 +00:00
Cherry Mui 7887313879 runtime/pprof: skip TestTimeVDSO on Android
The test is flaky on Android. VDSO may not be enabled so it may
not have the original problem anyway.

Change-Id: I73c2902c682a44d893e0d4e34f006c2377ef8816
Reviewed-on: https://go-review.googlesource.com/c/go/+/352509
Trust: Cherry Mui <cherryyz@google.com>
Run-TryBot: Cherry Mui <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
2021-09-27 21:53:31 +00:00
Rhys Hiltner 8cfd8c3db8 runtime: profile with per-thread timers on Linux
Using setitimer on Linux to request SIGPROF signal deliveries in
proportion to the process's on-CPU time results in under-reporting when
the program uses several goroutines in parallel. Linux calculates the
process's total CPU spend on a regular basis (often every 4ms); if the
process has spent enough CPU time since the last calculation to warrant
more than one SIGPROF (usually 10ms for the default sample rate of 100
Hz), the kernel is often able to deliver only one of them. With these
common settings, that results in Go CPU profiles being attenuated for
programs that use more than 2.5 goroutines in parallel.

To avoid in effect overflowing the kernel's process-wide CPU counter,
and relying on Linux's typical behavior of having the active thread
handle the resulting process-targeted signal, use timer_create to
request a timer for each OS thread that the Go runtime manages. Have
each timer track the CPU time of a single thread, with the resulting
SIGPROF going directly to that thread.

To continue tracking CPU time spent on threads that don't interact with
the Go runtime (such as those created and used in cgo), keep using
setitimer in addition to the new mechanism. When a SIGPROF signal
arrives, check whether it's due to setitimer or timer_create and filter
as appropriate: If the thread is known to Go (has an M) and has a
timer_create timer, ignore SIGPROF signals from setitimer. If the thread
is not known to Go (does not have an M), ignore SIGPROF signals that are
not from setitimer.

Counteract the new bias that per-thread profiling adds against
short-lived threads (or those that are only active on occasion for a
short time, such as garbage collection workers on mostly-idle systems)
by configuring the timers' initial trigger to be from a uniform random
distribution between "immediate trigger" and the full requested sample
period.

Updates #35057

Change-Id: Iab753c4e5101bdc09ef9132eec84a75478e05579
Reviewed-on: https://go-review.googlesource.com/c/go/+/324129
Run-TryBot: Rhys Hiltner <rhys@justin.tv>
TryBot-Result: Go Bot <gobot@golang.org>
Trust: David Chase <drchase@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
2021-09-27 18:58:29 +00:00
Cherry Mui 217507eb03 runtime: set vdsoSP to caller's SP consistently
m.vdsoSP should be set to the SP of the caller of nanotime1,
instead of the SP of nanotime1 itself, which matches m.vdsoPC.
Otherwise the unmatched vdsoPC and vdsoSP would make the stack
trace look like recursive.

We already do it correctly on AMD64, 386, and RISCV64. This CL
fixes the rest.

Fixes #47324.

Change-Id: I98b6fcfbe9fc6bdd28b8fe2a1299b7c505371dd4
Reviewed-on: https://go-review.googlesource.com/c/go/+/337590
Trust: Cherry Mui <cherryyz@google.com>
Trust: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2021-09-24 14:52:47 +00:00
Matthew Dempsky e4994e71fb [dev.typeparams] all: merge master (c8f4e61) into dev.typeparams
Conflicts:

- src/runtime/internal/sys/zgoarch_386.go
- src/runtime/internal/sys/zgoarch_amd64.go
- src/runtime/internal/sys/zgoarch_arm.go
- src/runtime/internal/sys/zgoarch_arm64.go
- src/runtime/internal/sys/zgoarch_arm64be.go
- src/runtime/internal/sys/zgoarch_armbe.go
- src/runtime/internal/sys/zgoarch_mips.go
- src/runtime/internal/sys/zgoarch_mips64.go
- src/runtime/internal/sys/zgoarch_mips64le.go
- src/runtime/internal/sys/zgoarch_mips64p32.go
- src/runtime/internal/sys/zgoarch_mips64p32le.go
- src/runtime/internal/sys/zgoarch_mipsle.go
- src/runtime/internal/sys/zgoarch_ppc.go
- src/runtime/internal/sys/zgoarch_ppc64.go
- src/runtime/internal/sys/zgoarch_ppc64le.go
- src/runtime/internal/sys/zgoarch_riscv.go
- src/runtime/internal/sys/zgoarch_riscv64.go
- src/runtime/internal/sys/zgoarch_s390.go
- src/runtime/internal/sys/zgoarch_s390x.go
- src/runtime/internal/sys/zgoarch_sparc.go
- src/runtime/internal/sys/zgoarch_sparc64.go
- src/runtime/internal/sys/zgoarch_wasm.go

  On dev.typeparams, CL 328336 moved these files to internal/goarch;
  whereas on master, CL 333909 reserved GOARCH=loong64. For this CL,
  I resolved the conflict by simply running "go generate internal/goarch".

Merge List:

+ 2021-07-19 c8f4e6152d spec: correct example comment in Conversions from slice to array
+ 2021-07-19 1d91551b73 time: correct typo in documentation for UnixMicro
+ 2021-07-19 404127c30f cmd/compile: fix off-by-one error in traceback argument counting
+ 2021-07-19 6298cfe672 cmd/compile: fix typo in fatal message of builtinCall
+ 2021-07-19 49402bee36 cmd/{compile,link}: fix bug in map.zero handling
+ 2021-07-18 a66190ecee test/bench/go1: fix size for RegexpMatchMedium_32
+ 2021-07-18 650fc2117a text/scanner: use Go convention in Position doc comment
+ 2021-07-16 aa4e0f528e net/http:  correct capitalization in cancelTimeBody comment
+ 2021-07-15 0941dbca6a testing: clarify in docs that TestMain is advanced
+ 2021-07-15 69728ead87 cmd/go: update error messages in tests to match CL 332573
+ 2021-07-15 c1cc9f9c3d cmd/compile: fix lookup package of redeclared dot import symbol
+ 2021-07-15 21a04e3335 doc/go1.17: mention GOARCH=loong64
+ 2021-07-14 2b00a54baf go/build, runtime/internal/sys: reserve GOARCH=loong64
+ 2021-07-14 60ddf42b46 cmd/go: change link in error message from /wiki to /doc.
+ 2021-07-13 d8f348a589 cmd/go: remove a duplicated word from 'go help mod graph'
+ 2021-07-12 a98589711d crypto/tls: test key type when casting
+ 2021-07-12 cfbd73ba33 doc/go1.17: editing pass over the "Compiler" section
+ 2021-07-09 ab4085ce84 runtime/pprof: call runtime.GC twice in memory profile test

Change-Id: I1490a4c7e4c560659c21a4eb67d243f35d1f908e
2021-07-20 14:34:09 -07:00
Michael Anthony Knyszek ab4085ce84 runtime/pprof: call runtime.GC twice in memory profile test
This change fixes #46500 by working around #45315 which may cause freed
objects to get missed in the heap profile published for the test.

By calling runtime.GC one more time this change ensures that all freed
objects are accounted for.

Fixes #46500.

Change-Id: Iedcd0b37dbaffa688b0ff8631a8b79f7a1169634
Reviewed-on: https://go-review.googlesource.com/c/go/+/333549
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>
2021-07-09 18:00:16 +00:00
Cuong Manh Le d626ba27bb [dev.typeparams] all: merge master (16e82be) into dev.typeparams
Merge List:

+ 2021-06-21 16e82be454 runtime: fix crash during VDSO calls on PowerPC
+ 2021-06-21 2e542c3c06 runtime/pprof: deflake TestMorestack more
+ 2021-06-21 ced0fdbad0 doc/go1.17: note deprecation of 'go get' for installing commands
+ 2021-06-21 7a5e7047a4 doc/go1.17: add Go 1.18 pre-announcements
+ 2021-06-21 85a2e24afd doc/go1.17: add security-related release notes
+ 2021-06-21 1de332996c doc/go1.17: document go/parser.SkipObjectResolution
+ 2021-06-21 117ebe0f52 cmd/go: do not require the module cache to exist for 'go mod edit'
+ 2021-06-20 460900a7b5 os/signal: test with a significantly longer fatal timeout
+ 2021-06-19 b73cc4b02b database/sql: do not rely on timeout for deadlock test
+ 2021-06-18 86743e7d86 image: add RGBA64Image interface
+ 2021-06-18 9401172166 runtime: clarify Frames.Next documentation
+ 2021-06-18 57aaa19aae runtime: disable CPU profiling before removing the SIGPROF handler
+ 2021-06-18 6f22d2c682 doc/go1.17: fix typo
+ 2021-06-17 45f251ad6c cmd/pprof,runtime/pprof: disable test on more broken platforms
+ 2021-06-17 ed834853ad cmd/go: replace a TODO with an explanatory comment
+ 2021-06-17 4dede02550 cmd/pprof: make ObjAddr a no-op
+ 2021-06-17 97cee43c93 testing: drop unusual characters from TempDir directory name
+ 2021-06-17 b0355a3e72 time: fix receiver for Time.IsDST method
+ 2021-06-17 881b6ea7ba doc/go1.17: fix redundant space
+ 2021-06-16 0e67ce3d28 cmd/go: in lazy modules, add transitive imports for 'go get' arguments
+ 2021-06-16 6ea2af0890 cmd/go: add a regression test for #45979
+ 2021-06-16 a294e4e798 math/rand: mention half-open intervals explicitly
+ 2021-06-16 a6a853f94c cmd/asm: restore supporting of *1 scaling on ARM64

Change-Id: Ifdcb817fd44b4fa9c477042b41da55d1d769b016
2021-06-22 00:35:08 +07:00
Cherry Mui 2e542c3c06 runtime/pprof: deflake TestMorestack more
Apparently, TestMorestack is still flaky on darwin/arm64 builder
after CL 307730. Let it spend more time in copying the stack.
With this CL, on my Apple M1 machine it passes reliably in short
mode for 1000 runs, and reliably gets 250+ samples in the 5-second
interval in long mode.

May fix #46755.

Change-Id: I07b36c1cf63ad35f7820e1f8e837e29376a37b2a
Reviewed-on: https://go-review.googlesource.com/c/go/+/329869
Trust: Cherry Mui <cherryyz@google.com>
Run-TryBot: Cherry Mui <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Michael Pratt <mpratt@google.com>
2021-06-21 16:48:36 +00:00
Michael Pratt 45f251ad6c cmd/pprof,runtime/pprof: disable test on more broken platforms
runtime/pprof has a more complete list of platforms with broken
profiling than I used in cmd/pprof in https://golang.org/cl/325809.
Duplicate that list in cmd/pprof and clean it up a bit in runtime/pprof
for easier reference.

Change-Id: I8f2580aac223de9b73cfff4355f49916f7b76493
Reviewed-on: https://go-review.googlesource.com/c/go/+/329149
Trust: Michael Pratt <mpratt@google.com>
Run-TryBot: Michael Pratt <mpratt@google.com>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
2021-06-17 21:58:54 +00:00
Cherry Mui cb80937bf6 Revert "doc/go1.17: mention block profile bias fix"
This reverts CL 324471 (commit 689f4c7415).

Reason for revert: break ~all builders. And it is not a doc-only change.

Change-Id: Iadbdda34d2ca476a9f5e6c2d3a28592ed7ccb067
Reviewed-on: https://go-review.googlesource.com/c/go/+/326170
Trust: Cherry Mui <cherryyz@google.com>
Run-TryBot: Cherry Mui <cherryyz@google.com>
Reviewed-by: Heschi Kreinick <heschi@google.com>
2021-06-08 20:39:45 +00:00
Felix Geisendörfer 689f4c7415 doc/go1.17: mention block profile bias fix
Change-Id: I76fd872b2d74704396f0683ffa9cec40b7027247
Reviewed-on: https://go-review.googlesource.com/c/go/+/324471
Reviewed-by: Heschi Kreinick <heschi@google.com>
Trust: Dmitri Shuralyov <dmitshur@golang.org>
2021-06-08 20:19:02 +00:00
Cherry Mui e0844acfc8 [dev.typeparams] runtime/pprof: replace funcPC with internal/abi.FuncPCABIInternal
All funcPC references are ABIInternal functions. Replace with the
intrinsics.

Change-Id: I2266bb6d2b713eb63b6a09846e9f9c423cab6e9b
Reviewed-on: https://go-review.googlesource.com/c/go/+/322349
Trust: Cherry Mui <cherryyz@google.com>
Run-TryBot: Cherry Mui <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
2021-05-24 21:05:06 +00:00
Felix Geisendörfer 0ae9c3b98b runtime/pprof: fix block profile bias
Block profiles were biased towards infrequent long events over frequent
short events. This fix corrects the bias by aggregating shorter events
as longer but less frequent in the profiles. As a result their
cumulative duration will be accurately represented in the profile
without skewing their sample mean (duration/count).

Credit to @dvyukov for suggesting to adjust the count in the
saveblockevent function.

Fixes #44192.

Change-Id: I71a99d7f6ebdb2d484d44890a2517863cceb4004
Reviewed-on: https://go-review.googlesource.com/c/go/+/299991
Trust: Michael Pratt <mpratt@google.com>
Trust: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Michael Pratt <mpratt@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Michael Pratt <mpratt@google.com>
2021-04-27 18:54:49 +00:00
Cherry Zhang 55bac87bd6 runtime/pprof: deflake TestMorestack
In TestMorestack, on macOS, for some reason it got most of the
samples in synchronization (e.g. pthread_cond_signal and
pthread_cond_wait) and sometimes in other "syscalls" (usleep,
nanotime1), and very few samples in stack copying, sometimes 0,
which causes the test to fail. Maybe synchronization is slower on
macOS? (It doesn't seem so to me.) Or it is the OS's accounting
problem, where it is more likely to trigger a profiling signal
at a syscall (or certain kinds of syscalls)?

As the test is really about whether it can connect stack copying
with the function that grows the stack, this CL makes it spend
more time in copying stack than synchronization. Now it's getting
~100 samples for stack copying on a 5 second interval on my
machine, and the test passes reliably.

Fixes #44418.

Change-Id: I3a462c8c39766f2d67d697598f8641bbe64f16ad
Reviewed-on: https://go-review.googlesource.com/c/go/+/307730
Trust: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Michael Pratt <mpratt@google.com>
2021-04-06 18:01:39 +00:00
Clément Chigot 7bfd681c2f runtime/pprof: skip tests for AIX
Most of the time, the pprof tests are passing, except
for the builder. The reason is still unknown but I'd rather release
the builder to avoid missing other more important bugs.

Updates #45170

Change-Id: I667543ee1ae309b7319c5b3676a0901b4d0ecf2e
Reviewed-on: https://go-review.googlesource.com/c/go/+/306489
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Trust: Lynn Boger <laboger@linux.vnet.ibm.com>
2021-04-04 12:04:33 +00:00
Elvina Yakubova 79d03ad739 runtime/pprof: move common code to writeProfileInternal function
This patch provides changes according to TODO. Since writeMutex and
writeBlock functions have a lot of code in common, it is better to
move this code to one function.

Change-Id: I81aaad067b0cb1647824909f3b5f6861add3a7ba
Reviewed-on: https://go-review.googlesource.com/c/go/+/280152
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Trust: Hyang-Ah Hana Kim <hyangah@gmail.com>
2021-03-18 21:10:31 +00:00
Russ Cox d4b2638234 all: go fmt std cmd (but revert vendor)
Make all our package sources use Go 1.17 gofmt format
(adding //go:build lines).

Part of //go:build change (#41184).
See https://golang.org/design/draft-gobuild

Change-Id: Ia0534360e4957e58cd9a18429c39d0e32a6addb4
Reviewed-on: https://go-review.googlesource.com/c/go/+/294430
Trust: Russ Cox <rsc@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2021-02-20 03:54:50 +00:00
Russ Cox a8942d2cff runtime/pprof: disable TestMorestack on darwin/arm64
Something is weird about darwin and TestMorestack,
but it is only manifesting on arm64 and race+amd64.
Disable for now.

Change-Id: I5862372fdd0b5ffae802fdefb65b2aa04e266fcc
Reviewed-on: https://go-review.googlesource.com/c/go/+/294409
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
Trust: Russ Cox <rsc@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
2021-02-20 00:54:44 +00:00
Russ Cox fa18f224c3 runtime/pprof: disable TestMorestack on macOS under race detector
This is failing but only under the race detector.
It doesn't really seem fair to expect pprof to find
specific profile events with the race detector slowing
everything down anyway.

Change-Id: I4b353d3d63944c87884d117e07d119b2c7bf4684
Reviewed-on: https://go-review.googlesource.com/c/go/+/294071
Trust: Russ Cox <rsc@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2021-02-19 15:31:06 +00:00
Russ Cox b445d6ea34 runtime/pprof: expect tests to pass on macOS
macOS tests have been disabled since CL 12429045 (Aug 2013).
At the time, macOS required a kernel patch to get a working profiler
(https://research.swtch.com/macpprof), which we didn't want
to require, of course.

macOS has improved - it no longer requires the kernel patch - but
we never updated the list of exceptions.

As far as I can tell, the builders have no problem passing the pprof test now.
(It is possible that the iOS builders have trouble, but that is now a different GOOS.)

Remove the exception for macOS. The test should now pass.

Fixes #6047.

Change-Id: Iab49036cacc1025e56f515bd19d084390c2f5357
Reviewed-on: https://go-review.googlesource.com/c/go/+/292229
Trust: Russ Cox <rsc@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2021-02-19 00:41:28 +00:00
Russ Cox 75e273fc2c runtime: fix windows/arm CONTEXT_CONTROL
The constant was wrong, and the “right” constant doesn't work either.
But with the actually-right constant (and possibly earlier fixes in this
stack as well), profiling now works.

Change-Id: If8caff1da556826db40961fb9bcfe2b1f31ea9f9
Reviewed-on: https://go-review.googlesource.com/c/go/+/288808
Trust: Russ Cox <rsc@golang.org>
Trust: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.com>
2021-02-19 00:03:36 +00:00
Russ Cox fbe74dbf42 runtime: use FuncInfo SPWRITE flag to identify untraceable profile samples
The old code was very clever about predicting whether a traceback was safe.
That cleverness has not aged well. In particular, the setsSP function is missing
a bunch of functions that write to SP and will confuse traceback.
And one such function - jmpdefer - was handled as a special case in
gentraceback instead of simply listing it in setsSP.

Throw away all the clever prediction about whether traceback will crash.
Instead, make traceback NOT crash, by checking whether the function
being walked writes to SP.

This CL is part of a stack adding windows/arm64
support (#36439), intended to land in the Go 1.17 cycle.
This CL is, however, not windows/arm64-specific.
It is cleanup meant to make the port (and future ports) easier.

Change-Id: I3d55fe257a22745e4919ac4dc9a9378c984ba0da
Reviewed-on: https://go-review.googlesource.com/c/go/+/288801
Trust: Russ Cox <rsc@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2021-02-19 00:02:40 +00:00
Russ Cox 4f1b0a44cb all: update to use os.ReadFile, os.WriteFile, os.CreateTemp, os.MkdirTemp
As part of #42026, these helpers from io/ioutil were moved to os.
(ioutil.TempFile and TempDir became os.CreateTemp and MkdirTemp.)

Update the Go tree to use the preferred names.

As usual, code compiled with the Go 1.4 bootstrap toolchain
and code vendored from other sources is excluded.

ReadDir changes are in a separate CL, because they are not a
simple search and replace.

For #42026.

Change-Id: If318df0216d57e95ea0c4093b89f65e5b0ababb3
Reviewed-on: https://go-review.googlesource.com/c/go/+/266365
Trust: Russ Cox <rsc@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2020-12-09 19:12:23 +00:00