The DWARF inline info generation hooks weren't properly
handling unused auto vars in certain cases, triggering an assert (now
fixed). Also with this change, introduce a new autom "flavor" to
use for autom entries that are added to insure that a specific
auto type makes it into the linker (this is a follow-on to the fix
for 22941).
Fixes#22962.
Change-Id: I7a2d8caf47f6ca897b12acb6a6de0eb25f5cac8f
Reviewed-on: https://go-review.googlesource.com/81557
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
The iOS test harness dumps the output of its lldb session to stdout,
but only if the lldb session was successfully started.
Make sure the log is always dumpede, so that lldb startup failures
such as
lldb setup error: exited (lldb start: exit status 253)
can be diagnosed.
For the iOS builders.
Change-Id: Ie0e3341dd8f84a88d26509c34816668d3ebbfaa0
Reviewed-on: https://go-review.googlesource.com/76195
Run-TryBot: Elias Naur <elias.naur@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
The whole GOROOT/pkg tree is installed using the GOHOSTOS/GOHOSTARCH
toolchain (installed in GOROOT/pkg/tool/GOHOSTOS_GOHOSTARCH).
The testgo.exe we run during the cmd/go test will be built
for GOOS/GOARCH, which means it will use the GOOS/GOARCH toolchain
(installed in GOROOT/pkg/tool/GOOS_GOARCH).
If these are not the same toolchain, then the entire standard library
will look out of date to testgo.exe (the compilers in those two different
tool directories are built for different architectures and have different
buid IDs), which will cause many tests to do unnecessary rebuilds
and some tests to attempt to overwrite the installed standard library,
which will in turn make it look out of date to whatever runs after the
cmd/go test exits.
Bail out entirely in this case instead of destroying the world.
The changes outside TestMain are checks that might have caught
this a bit earlier and made it much less confusing to debug.
Fixes#22709.
Fixes#22965.
Change-Id: Ibf28fa19e29a1f1b8f17875f446d3474dd04a924
Reviewed-on: https://go-review.googlesource.com/81516
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
If we're using -covermode=atomic with -coverpkg, to add coverage
to more than just the package being tested, then we need to make sure
to make sync/atomic available to the compiler for every package
being recompiled for coverage.
Fixes#22728.
Change-Id: I27f88f6a62e37d4a7455554cd03c8ca2b21f81a4
Reviewed-on: https://go-review.googlesource.com/81497
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This change updates runtime.semasleep to no longer call
runtime.nanotime and instead calls lwp_park with a duration to sleep
relative to the monotonic clock, so the nanotime is never called.
(This requires updating to a newer version of the lwp_park system
call, which is safe, because Go 1.10 will require the unreleased
NetBSD 8+ anyway)
Additionally, this change makes the nanotime function use the
monotonic clock for netbsd/arm, which was forgotten from
https://golang.org/cl/81135 which updated netbsd/amd64 and netbsd/386.
Because semasleep previously depended on nanotime, the past few days
of netbsd have likely been unstable because lwp_park was then mixing
the monotonic and wall clocks. After this CL, lwp_park no longer
depends on nanotime.
Original patch submitted at:
https://www.netbsd.org/~christos/go-lwp-park-clock-monotonic.diff
This commit message (any any mistakes therein) were written by Brad
Fitzpatrick. (Brad migrated the patch to Gerrit and checked CLAs)
Updates #6007Fixes#22968
Also updates netbsd/arm to use monotonic time for
Change-Id: If77ef7dc610b3025831d84cdfadfbbba2c52acb2
Reviewed-on: https://go-review.googlesource.com/81715
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Note that Interrupt will compile but not work on Windows.
Fixes#22454
Change-Id: If011c32211f4bb45d458317e113b9794d5b4a4b1
Reviewed-on: https://go-review.googlesource.com/81035
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The full truth seems too complicated to write in this method's doc, so
I'm going with a simple half truth.
The full truth is that Fd returns the descriptor in blocking mode,
because that is historically how it worked, and existing programs
would be surprised if the descriptor is suddenly non-blocking. On Unix
systems whether a file is non-blocking or not is a property of the
underlying file description, not of a particular file descriptor, so
changing the returned descriptor to blocking mode also changes the
existing File to blocking mode. Blocking mode works fine, althoug I/O
operations now take up a thread. SetDeadline and friends rely on the
runtime poller, and the runtime poller only works if the descriptor is
non-blocking. So it's correct that calling Fd disables SetDeadline.
The other half of the truth is that if the program is willing to work
with a non-blocking descriptor, it could call
syscall.SetNonblock(descriptor, true) to change the descriptor, and
the original File, to non-blocking mode. At that point SetDeadline
would start working again. I tried to write that in a way that is
short and comprehensible but failed. Since deadlines mostly work on
pipes, and there isn't much reason to call Fd on a pipe, and few
people use SetDeadline, I decided to punt.
Fixes#22934
Change-Id: I2e49e036f0bcf71f5365193831696f9e4120527c
Reviewed-on: https://go-review.googlesource.com/81636
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
That Parse doesn't parse ("foo.com/path" or "foo.com:443/path") has
become something of a FAQ.
Updates #19779
Updates #21415
Updates #22955
Change-Id: Ib68efddb67f59b1374e8ed94effd4a326988dee7
Reviewed-on: https://go-review.googlesource.com/81436
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Simply choose an extremely unlikely path name in the test is fine.
Fixes#21013.
Change-Id: I56c0a1986b5ef5d618c7fe2b14701f584fe81c37
Reviewed-on: https://go-review.googlesource.com/81578
Run-TryBot: Robert Griesemer <gri@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
MAP_ANON is the deprecated but more portable spelling of
MAP_ANONYMOUS. Use MAP_ANON to un-break the Darwin 10.10 builder.
Updates #22930.
Change-Id: Iedd6232b94390b3b2a7423c45cdcb25c1a5b3323
Reviewed-on: https://go-review.googlesource.com/81615
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
The test binaries accept -timeout=0 to mean no timeout,
but then the backup timer in cmd/go kills the test after 1 minute.
Make cmd/go understand this special case and change
behavior accordingly.
Fixes#14780.
Change-Id: I66bf517173a4ad21d53a5ee88d163f04b8929fb6
Reviewed-on: https://go-review.googlesource.com/81499
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Also be clear that go test output is not suitable for piping into test2json.
Fixes#22710.
Fixes#22789.
Change-Id: I3d850c8a2288be7f9a27d638bbf847cb8707dcce
Reviewed-on: https://go-review.googlesource.com/81555
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
1. Apply JSON conversion when -bench is in use.
2. Apply JSON conversion to "no test files" result.
3. Apply JSON conversion to test case-ending SKIP status.
Fixes#22769.
Fixes#22790.
Change-Id: I67ad656fc58bacae8c51d23b1e6d543cad190f08
Reviewed-on: https://go-review.googlesource.com/81535
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The cover variable indices could vary from build to build,
but they were not included in the build ID hash, so that
reusing the previously built package was not safe.
Make the indices no longer vary from build to build,
so that caching is safe.
Fixes#22652.
Change-Id: Ie26d73c648aadd285f97e0bf39619cabc3da54f2
Reviewed-on: https://go-review.googlesource.com/81515
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
For Go 1.10, works around a go/types bug that can't typecheck
a corner-case type cycle. Once we are confident that bugs like
this are gone from go/types then we can stop ignoring these
failures.
For #22890.
Change-Id: I38da57e01a0636323e1af4484c30871786125df3
Reviewed-on: https://go-review.googlesource.com/81500
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Earlier versions of Go were not very picky about leading spaces
in the -gcflags values. Make the new pattern-enhanced parser
equally lax.
Fixes#22943.
Change-Id: I5cf4d3e81412e895a4b52af325853ed48d0b73f4
Reviewed-on: https://go-review.googlesource.com/81498
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
It's not safe to do p+x with unsafe if that would point past the
end of the object. (Valid in C, not safe in Go.)
Pass a "whySafe" reason (compiled away) to explain at each
call site why it's safe.
Fixes#21733.
Change-Id: I5da8c25bde66f5c9beac232f2135dcab8e8bf3b1
Reviewed-on: https://go-review.googlesource.com/80738
Reviewed-by: Austin Clements <austin@google.com>
The number of threads in syscall presented by execution tracer's
trace view includes not only the threads calling system calls on behalf
of user created goroutines, but also those running on behalf of system
goroutines.
When the number of such system goroutines was small, the graph was
useful when examining where a program was saturating the CPU.
But as more and more system goroutines are invloved the graph became
less useful for the purpose - for example, after golang.org/cl/34784,
the timer goroutines dominate in the graph with large P
because the runtime creates per-P timer goroutines.
This change excludes the threads in syscall on behalf of runtime (system
goroutines) from the visualization. Alternatively, I could visualize the
count of such threads in a separate counter but in the same graph.
Given that many other debug endpoints (e.g. /debug/pprof/goroutine) hide
the system goroutines, including them in the same graph can confuse users.
Update #22574
Change-Id: If758cd6b9ed0596fde9a471e846b93246580b9d5
Reviewed-on: https://go-review.googlesource.com/81315
Reviewed-by: Austin Clements <austin@google.com>
Run-TryBot: Hyang-Ah Hana Kim <hyangah@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Minor.
Makes reading failing runtime test stacktraces easier (by having fewer
goroutines to read) on machines where these gdb tests wouldn't have
ever run anyway.
Change-Id: I3fab0667e017f20ef3bf96a8cc4cfcc614d25b5c
Reviewed-on: https://go-review.googlesource.com/81575
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This adds logging for the expected duration of a growStack, plus
progress information on the growStack that timed out.
Updates #19381.
Change-Id: Ic358f8350f499ff22dd213b658aece7d1aa62675
Reviewed-on: https://go-review.googlesource.com/81556
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Per the decision for #14844, index expressions that are non-constant
shifts where the LHS operand is representable as an int are now valid.
Fixes#21693.
Change-Id: Ifafad2c0c65975e0200ce7e28d1db210e0eacd9d
Reviewed-on: https://go-review.googlesource.com/81277
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
I think of "sending" a signal as calling kill, but sigsend is involved
in handling a signal and, specifically delivering it to the internal
signal queue. The term "delivery" is already used in
signalWaitUntilIdle, so this CL also uses it in the documentation for
sigsend.
Change-Id: I86e171f247f525ece884a680bace616fa9a3c7bd
Reviewed-on: https://go-review.googlesource.com/81235
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Currently, when we minit on a thread that already has an alternate
signal stack (e.g., because the M was an extram being used for a cgo
callback, or to handle a signal on a C thread, or because the
platform's libc always allocates a signal stack like on Android), we
simply drop the Go-allocated gsignal stack on the floor.
This is a problem for Ms on the extram list because those Ms may later
be reused for a different thread that may not have its own alternate
signal stack. On tip, this manifests as a crash in sigaltstack because
we clear the gsignal stack bounds in unminit and later try to use
those cleared bounds when we re-minit that M. On 1.9 and earlier, we
didn't clear the bounds, so this manifests as running more than one
signal handler on the same signal stack, which could lead to arbitrary
memory corruption.
This CL fixes this problem by saving the Go-allocated gsignal stack in
a new field in the m struct when overwriting it with a system-provided
signal stack, and then restoring the original gsignal stack in
unminit.
This CL is designed to be easy to back-port to 1.9. It won't quite
cherry-pick cleanly, but it should be sufficient to simply ignore the
change in mexit (which didn't exist in 1.9).
Now that we always have a place to stash the original signal stack in
the m struct, there are some simplifications we can make to the signal
stack handling. We'll do those in a later CL.
Fixes#22930.
Change-Id: I55c5a6dd9d97532f131146afdef0b216e1433054
Reviewed-on: https://go-review.googlesource.com/81476
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
If package strings has a particular set of gcflags, then the strings_test
pseudo-package built as part of the test binary should inherit the same flags.
Fixes#22831.
Change-Id: I0e896b6c0f1063454300b7323f577feffbd6650b
Reviewed-on: https://go-review.googlesource.com/81496
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
If the build of the test binary failed, the go command correctly
avoided running the binary, but the -x output indicated otherwise.
Fixes#22659.
Change-Id: Ib4d262bf1735f057c994a45fc23c499d4ebe3246
Reviewed-on: https://go-review.googlesource.com/81495
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The CL introducing merged handling of cover profiles
did not correctly account for the fact that the file name argument
to -coverprofile is required to be interpreted relative to
the -outputdir argument.
Fixes#22804.
Change-Id: I804774013c12187313b8fd2044302978bdbb6697
Reviewed-on: https://go-review.googlesource.com/81455
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The code that generates the list of DWARF variables for a function
(params and autos) will emit a "no-location" entry in the DWARF for a
user var that appears in the original pre-optimization version of the
function but is no longer around when optimization is complete. The
intent is that if a GDB user types "print foo" (where foo has been
optimized out), the response will be "<optimized out>" as opposed to
"there is no such variable 'foo'). This change fixes said code to
include vars on the autom list for the function, to insure that the
type symbol for the variable makes it to the linker.
Fixes#22941.
Change-Id: Id29f1f39d68fbb798602dfd6728603040624fc41
Reviewed-on: https://go-review.googlesource.com/81415
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Values must not be copied after the first use.
Using noCopy makes vet complain about copies
even before the first use, which is incorrect
and very frustrating.
Drop it.
Fixes#21504.
Change-Id: Icd3a5ac3fe11e84525b998e848ed18a5d996f45a
Reviewed-on: https://go-review.googlesource.com/80836
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Call is meant to mirror the language semantics, which allow:
var r io.ReadWriter
f := func(io.Reader){}
f(r)
even though the conversion from io.ReadWriter to io.Reader is
being applied to a nil interface. This is different from an explicit
conversion:
_ = r.(io.Reader)
f(r.(io.Reader))
Both of those lines panic, but the implicit conversion does not.
By using E2I, which is the implementation of the explicit conversion,
the reflect.Call equivalent of f(r) was inadvertently panicking.
Avoid the panic.
Fixes#22143.
Change-Id: I6b2f5b808e0cd3b89ae8bc75881e307bf1c25558
Reviewed-on: https://go-review.googlesource.com/80736
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The ssa backend is aggressive about placing constants and
certain other values in the Entry block. It's implausible
that the original line numbers for these constants makes
any sort of sense when it appears to a user stepping in a
debugger, and they're also not that useful in dumps since
entry-block instructions tend to be constants (i.e.,
unlikely to be the cause of a crash).
Therefore, use src.NoXPos for any values that are explicitly
inserted into a function's entry block.
Passes all tests, including ssa/debug_test.go with both
gdb and a fairly recent dlv. Hand-verified that it solves
the reported problem; constructed a test that reproduced
a problem, and fixed it.
Modified test harness to allow injection of slightly more
interesting inputs.
Fixes#22558.
Change-Id: I4476927067846bc4366da7793d2375c111694c55
Reviewed-on: https://go-review.googlesource.com/81215
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Fixes#19293
Change-Id: I35f2f786e2e3972eda21ba5a948433bfcd621269
Reviewed-on: https://go-review.googlesource.com/81355
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This reverts commit 08f19bbde1.
Reason for revert:
The changed transformation takes effect on a larger set
of code snippets than expected.
For example, this:
func foo() {
// Comment
bar()
}
becomes:
func foo() {
// Comment
bar()
}
This is an unintended consequence.
Change-Id: Ifca88d6267dab8a8170791f7205124712bf8ace8
Reviewed-on: https://go-review.googlesource.com/81335
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Joe Tsai <joetsai@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
GOEXPERIMENT is only set during make.bash, so checking the environment
variable isn't effectual. Instead, check the values exposed by objabi.
These experiments look potentially safe, but it seems too late in the
release cycle to try to assuage that. The one exception is frame
pointer experiment, which is trivially safe: it just amounts to
incrementing some stack offsets by PtrSize.
Fixes#22223.
Change-Id: I46dc7c54b1347143d02d6b9635038230cda6d164
Reviewed-on: https://go-review.googlesource.com/80760
Reviewed-by: Russ Cox <rsc@golang.org>
It's not safe (it crashes), and it's also useless: if you run
multiple benchmarks in parallel you will not get reliable
timing results from any of them.
Fixes#18603.
Change-Id: I00e5a72f7c98151543cf7d5573c38383276e391a
Reviewed-on: https://go-review.googlesource.com/80841
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The build tags already prevent the tests from being run on windows or
plan9, so there is no need to check GOOS again.
Change-Id: I74d3c3b7756d9c50f6e5fd4c3e8b0db618fdebbb
Reviewed-on: https://go-review.googlesource.com/81295
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Otherwise we may delay the delivery of these signals for an arbitrary
length of time. We are already careful to not block signals that the
program has asked to see.
Also make sure that we don't miss a signal delivery if a thread
decides to stop for a while while executing the signal handler.
Also clean up the TestAtomicStop output a little bit.
Fixes#21433
Change-Id: Ic0c1a4eaf7eba80d1abc1e9537570bf4687c2434
Reviewed-on: https://go-review.googlesource.com/79581
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Dim performance has regressed by 14% vs 1.9 on amd64.
Current pure go version of Dim is faster and,
what is even more important for performance, is inlinable, so
instead of tweaking asm implementation, just remove it.
I had to update BenchmarkDim, because it was simply reloading
constant(answer) in a loop.
Perf data below:
name old time/op new time/op delta
Dim-6 6.79ns ± 0% 1.60ns ± 1% -76.39% (p=0.000 n=7+10)
If I modify benchmark to be the same as in this CL results are even better:
name old time/op new time/op delta
Dim-6 10.2ns ± 0% 1.6ns ± 1% -84.27% (p=0.000 n=8+10)
Updates #21913
Change-Id: I00e23c8affc293531e1d9f0e0e49f3a525634f53
Reviewed-on: https://go-review.googlesource.com/80695
Run-TryBot: Ilya Tocar <ilya.tocar@intel.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
In nat.divLarge (having signature (z nat).divLarge(u, uIn, v nat)),
we check whether z aliases uIn or v, but aliasing is currently not
checked for the u parameter.
Unfortunately, z and u aliasing each other can in some cases cause
errors in the computation.
The q return parameter (which will hold the result's quotient), is
unconditionally initialized as
q = z.make(m + 1)
When cap(z) ≥ m+1, z.make() will reuse z's backing array, causing q
and z to share the same backing array. If then z aliases u, setting q
during the quotient computation will then corrupt u, which at that
point already holds computation state.
To fix this, we add an alias(z, u) check at the beginning of the
function, taking care of aliasing the same way we already do for uIn
and v.
Fixes#22830
Change-Id: I3ab81120d5af6db7772a062bb1dfc011de91f7ad
Reviewed-on: https://go-review.googlesource.com/78995
Run-TryBot: Alberto Donizetti <alb.donizetti@gmail.com>
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
The trace command computes IO, Schedule, Block, and Syscall profiles
by following the unblocking links in the execution trace and summing
up the duration. This change offers variations of those profiles
that include only selected goroutine types. The id parameter takes the
goroutine type - i.e. pc of the goroutine.
The output is available from the /goroutine view. So, users can see
where the goroutines of interest typically block.
Also, these profiles are available for download so users can use
pprof or other tools to interpret the output. This change adds links
for download of global profile in the main page.
Change-Id: I35699252056d164e60de282b0406caf96d629c85
Reviewed-on: https://go-review.googlesource.com/75710
Reviewed-by: Sameer Ajmani <sameer@golang.org>
