| commit | e2ca417ee797e1e80d8d395e0f4760416b8346d9 | [log] [tgz] |
|---|---|---|
| author | Than McIntosh <thanm@google.com> | Wed Jan 25 10:46:08 2023 -0500 |
| committer | Than McIntosh <thanm@google.com> | Mon Feb 06 20:56:47 2023 +0000 |
| tree | 76799335473fa94b98c4abec7b9d350b32487687 | |
| parent | b46e44a399045d0177dd063dc192168f0b5b3f55 [diff] |
cmd/link: linker portion of dead map removal
This patch contains the linker changes needed to enable deadcoding of
large unreferenced map variables, in combination with a previous
compiler change. We add a new cleanup function that runs just after
deadcode that looks for relocations in "init" funcs that are weak, of
type R_CALL (and siblings), and are targeting an unreachable function.
If we find such a relocation, after checking to make sure it targets a
map.init.XXX helper, we redirect the relocation to a point to a no-op
routine ("mapinitnoop") in the runtime.
Compilebench results for this change:
│ out.base.txt │ out.wrap.txt │
│ sec/op │ sec/op vs base │
Template 218.6m ± 2% 221.1m ± 1% ~ (p=0.129 n=39)
Unicode 180.5m ± 1% 178.9m ± 1% -0.93% (p=0.006 n=39)
GoTypes 1.162 ± 1% 1.156 ± 1% ~ (p=0.850 n=39)
Compiler 143.6m ± 1% 142.6m ± 1% ~ (p=0.743 n=39)
SSA 8.698 ± 1% 8.719 ± 1% ~ (p=0.145 n=39)
Flate 142.6m ± 1% 143.9m ± 3% ~ (p=0.287 n=39)
GoParser 247.7m ± 1% 248.8m ± 1% ~ (p=0.265 n=39)
Reflect 588.0m ± 1% 590.4m ± 1% ~ (p=0.269 n=39)
Tar 198.5m ± 1% 201.3m ± 1% +1.38% (p=0.005 n=39)
XML 259.1m ± 1% 260.0m ± 1% ~ (p=0.376 n=39)
LinkCompiler 746.8m ± 2% 747.8m ± 1% ~ (p=0.706 n=39)
ExternalLinkCompiler 1.906 ± 0% 1.902 ± 1% ~ (p=0.207 n=40)
LinkWithoutDebugCompiler 522.4m ± 21% 471.1m ± 1% -9.81% (p=0.000 n=40)
StdCmd 21.32 ± 0% 21.39 ± 0% +0.32% (p=0.035 n=40)
geomean 609.2m 606.0m -0.53%
│ out.base.txt │ out.wrap.txt │
│ user-sec/op │ user-sec/op vs base │
Template 401.9m ± 3% 406.9m ± 2% ~ (p=0.291 n=39)
Unicode 191.9m ± 6% 196.1m ± 3% ~ (p=0.052 n=39)
GoTypes 3.967 ± 3% 4.056 ± 1% ~ (p=0.099 n=39)
Compiler 171.1m ± 3% 173.4m ± 3% ~ (p=0.415 n=39)
SSA 30.04 ± 4% 30.25 ± 4% ~ (p=0.106 n=39)
Flate 246.3m ± 3% 248.9m ± 4% ~ (p=0.499 n=39)
GoParser 518.7m ± 1% 520.6m ± 2% ~ (p=0.531 n=39)
Reflect 1.670 ± 1% 1.656 ± 2% ~ (p=0.137 n=39)
Tar 352.7m ± 2% 360.3m ± 2% ~ (p=0.117 n=39)
XML 528.8m ± 2% 521.1m ± 2% ~ (p=0.296 n=39)
LinkCompiler 1.128 ± 2% 1.140 ± 2% ~ (p=0.324 n=39)
ExternalLinkCompiler 2.165 ± 2% 2.147 ± 2% ~ (p=0.537 n=40)
LinkWithoutDebugCompiler 484.2m ± 4% 490.7m ± 3% ~ (p=0.897 n=40)
geomean 818.5m 825.1m +0.80%
│ out.base.txt │ out.wrap.txt │
│ text-bytes │ text-bytes vs base │
HelloSize 766.0Ki ± 0% 766.0Ki ± 0% ~ (p=1.000 n=40) ¹
CmdGoSize 10.02Mi ± 0% 10.02Mi ± 0% -0.03% (n=40)
geomean 2.738Mi 2.738Mi -0.01%
¹ all samples are equal
│ out.base.txt │ out.wrap.txt │
│ data-bytes │ data-bytes vs base │
HelloSize 14.17Ki ± 0% 14.17Ki ± 0% ~ (p=1.000 n=40) ¹
CmdGoSize 308.3Ki ± 0% 298.5Ki ± 0% -3.19% (n=40)
geomean 66.10Ki 65.04Ki -1.61%
¹ all samples are equal
│ out.base.txt │ out.wrap.txt │
│ bss-bytes │ bss-bytes vs base │
HelloSize 197.3Ki ± 0% 197.3Ki ± 0% ~ (p=1.000 n=40) ¹
CmdGoSize 228.2Ki ± 0% 228.1Ki ± 0% -0.01% (n=40)
geomean 212.2Ki 212.1Ki -0.01%
¹ all samples are equal
│ out.base.txt │ out.wrap.txt │
│ exe-bytes │ exe-bytes vs base │
HelloSize 1.192Mi ± 0% 1.192Mi ± 0% +0.00% (p=0.000 n=40)
CmdGoSize 14.85Mi ± 0% 14.83Mi ± 0% -0.09% (n=40)
geomean 4.207Mi 4.205Mi -0.05%
Also tested for any linker changes by benchmarking relink of k8s
"kubelet"; no changes to speak of there.
Updates #2559.
Updates #36021.
Updates #14840.
Change-Id: I4cc5370b3f20679a1065aaaf87bdf2881e257631
Reviewed-on: https://go-review.googlesource.com/c/go/+/463395
Run-TryBot: Than McIntosh <thanm@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
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