delta/go-git.git/src/runtime/pprof/testdata, branch dev.cmdgo

runtime/pprof: correctly encode inlined functions in CPU profile

2019-11-08T02:40:04+00:00

The pprof profile proto message expects inlined functions of a PC
to be encoded in one Location entry using multiple Line entries.
https://github.com/google/pprof/blob/5e96527/proto/profile.proto#L177-L184

runtime/pprof has encoded the symbolization information by creating
a Location for each PC found in the stack trace and including info
from all the frames expanded from the PC using runtime.CallersFrames.
This assumes inlined functions are represented as a single PC in the
stack trace. (https://go-review.googlesource.com/41256)

In the recent years, behavior around inlining and the traceback
changed significantly (e.g. https://golang.org/cl/152537,
https://golang.org/issue/29582, and many changes). Now the PCs
in the stack trace represent user frames even including inline
marks. As a result, the profile proto started to allocate a Location
entry for each user frame, lose the inline information (so pprof
presented incorrect results when inlined functions are involved),
and confuse the pprof tool with those PCs made up for inline marks.

This CL attempts to detect inlined call frames from the stack traces
of CPU profiles, and organize the Location information as intended.
Currently, runtime does not provide a reliable and convenient way to
detect inlined call frames and expand user frames from a given externally
recognizable PCs. So we use heuristics to recover the groups
  - inlined call frames have nil Func field
  - inlined call frames will have the same Entry point
  - but must be careful with recursive functions that have the
    same Entry point by definition, and non-Go functions that
    may lack most of the fields of Frame.

The followup CL will address the issue with other profile types.

Change-Id: I0c9667ab016a3e898d648f31c3f82d84c15398db
Reviewed-on: https://go-review.googlesource.com/c/go/+/204636
Reviewed-by: Keith Randall

all: shorten some tests

2019-05-22T12:54:00+00:00

Shorten some of the longest tests that run during all.bash.
Removes 7r 50u 21s from all.bash.

After this change, all.bash is under 5 minutes again on my laptop.

For #26473.

Change-Id: Ie0460aa935808d65460408feaed210fbaa1d5d79
Reviewed-on: https://go-review.googlesource.com/c/go/+/177559
Run-TryBot: Russ Cox 
TryBot-Result: Gobot Gobot 
Reviewed-by: Ian Lance Taylor

runtime/pprof: set HasFunctions of mapping entries

2018-06-13T14:04:38+00:00

The pprof tool utilizes attributes of mapping entries
such as HasFunctions to determine whether the profile
includes necessary symbol information.
If none of the attributes is set, pprof tool tries to
read the corresponding binary to use for local symbolization.
If the binary doesn't exist, it prints out error messages.

Go runtime generated profiles without any of the attributes
set so the pprof tool always printed out the error messages.
The error messages became more obvious with the new
terminal support that uses red color for error messages.

Go runtime can symbolize all Go symbols and generate
self-contained profile for pure Go program. Thus, there
is no reason for the pprof tool to look for the copy of
the binary. So, this CL sets one of the attributes
(HasFunctions) true if all PCs in samples look fully
symbolized.

For non-pure Go program, however, it's possible that
symbolization of non-Go PCs is incomplete. In this case,
we need to leave the attributes all false so pprof can attempt
to symbolize using the local copy of the binary if available.
It's hard to determine whether a mapping includes non-Go
code. Instead, this CL checks PCs from collected samples.
If unsuccessful symbolization is observed, it skips setting
the HasFunctions attribute.

Fixes #25743

Change-Id: I5108be45bbc37ab486d145fa03e7ce37d88fad50
Reviewed-on: https://go-review.googlesource.com/118275
Run-TryBot: Hyang-Ah Hana Kim 
TryBot-Result: Gobot Gobot 
Reviewed-by: Brad Fitzpatrick

runtime/pprof: add GNU build IDs to Mappings recorded from /proc/self/maps

2017-03-08T01:09:18+00:00

This helps systems that maintain an external database mapping
build ID to symbol information for the given binary, especially
in the case where /proc/self/maps lists many different files
(for example, many shared libraries).

Avoid importing debug/elf to avoid dragging in that whole
package (and its dependencies like debug/dwarf) into the
build of every program that generates a profile.

Fixes #19431.

Change-Id: I6d4362a79fe23e4f1726dffb0661d20bb57f766f
Reviewed-on: https://go-review.googlesource.com/37855
Run-TryBot: Russ Cox 
TryBot-Result: Gobot Gobot 
Reviewed-by: Ian Lance Taylor