src: use __executable_start for linux hugepages #31547

bnoordhuis · 2020-01-28T10:12:58Z

__executable_start is provided by GNU's and LLVM's default linker
scripts, obviating the need to plug in a custom linker script.

The problem with our bespoke linker script is that it works with ld.bfd
but not ld.gold and cannot easily be ported because the latter linker
doesn't understand the INSERT BEFORE directive.

The /proc/self/maps scanner is updated to account for the fact that
there are a number of sections between &__executable_start and
the start of the .text section.

Fortunately, those sections are all mapped into the same memory segment
so we only need to look at the next line to find the start of our text
segment.

Fixes: #31520

`__executable_start` is provided by GNU's and LLVM's default linker scripts, obviating the need to plug in a custom linker script. The problem with our bespoke linker script is that it works with ld.bfd but not ld.gold and cannot easily be ported because the latter linker doesn't understand the `INSERT BEFORE` directive. The /proc/self/maps scanner is updated to account for the fact that there are a number of sections between `&__executable_start` and the start of the .text section. Fortunately, those sections are all mapped into the same memory segment so we only need to look at the next line to find the start of our text segment. Fixes: nodejs#31520

nodejs-github-bot · 2020-01-28T10:15:12Z

CI: https://ci.nodejs.org/job/node-test-pull-request/28726/

bnoordhuis · 2020-01-28T10:23:35Z

https://ci.nodejs.org/job/node-test-commit-linux-containered/nodes=ubuntu1804_sharedlibs_shared_x64/17715/console

05:17:03 /home/iojs/build/workspace/node-test-commit-linux-containered/./node: symbol lookup error: /home/iojs/build/workspace/node-test-commit-linux-containered/out/Release/lib.target/libnode.so.81: undefined symbol: __executable_start
05:17:03 /home/iojs/build/workspace/node-test-commit-linux-containered/./node: symbol lookup error: /home/iojs/build/workspace/node-test-commit-linux-containered/out/Release/lib.target/libnode.so.81: undefined symbol: __executable_start
05:17:03 ./node: symbol lookup error: /home/iojs/build/workspace/node-test-commit-linux-containered/out/Release/lib.target/libnode.so.81: undefined symbol: __executable_start

I'm 99% sure this is caused by node.gyp adding node_large_page.cc to the wrong target. It should only be added to the target that builds the binary, not libnode.so.

nodejs-github-bot · 2020-01-28T10:44:12Z

CI: https://ci.nodejs.org/job/node-test-pull-request/28728/

nodejs-github-bot · 2020-01-28T14:35:24Z

CI: https://ci.nodejs.org/job/node-test-pull-request/28729/

devsnek · 2020-01-28T16:06:27Z

I believe this also fixes #31249

bnoordhuis · 2020-01-28T18:39:36Z

@devnexen Can you take a look at the last commit? That check makes me think that large pages aren't actually working on freebsd.

I believe this also fixes #31249

@devsnek You're right, it does.

devnexen

LGTM but will probably break other platforms.

bnoordhuis · 2020-01-31T08:32:12Z

@devnexen It shouldn't. The linker scripts weren't used outside of linux and there have been no functional changes to the non-linux code.

(Small white lie, I made a tiny bug fix. Before, r.from == &MoveTextRegionToLargePages bailed out. As that's the only symbol in .lpstub it seems like a likely condition.)

The reason I think it doesn't work on freebsd (with or without this patch) is that it wants .lpstub mapped below .text, but the binary seems to crash without the aforementioned guard, suggesting that .text <= .lpstub.

Trott · 2020-02-01T02:57:49Z

@bnoordhuis Seems OK to land this? Or did you want to gather more information about what is or isn't going on with FreeBSD first?

nodejs-github-bot · 2020-02-01T02:58:16Z

CI: https://ci.nodejs.org/job/node-test-pull-request/28831/ ✔️

bnoordhuis · 2020-02-01T09:39:31Z

@Trott Yep, this is good to go. The works/works not thing on freebsd was more of a heads-up for @devnexen.

`__executable_start` is provided by GNU's and LLVM's default linker scripts, obviating the need to plug in a custom linker script. The problem with our bespoke linker script is that it works with ld.bfd but not ld.gold and cannot easily be ported because the latter linker doesn't understand the `INSERT BEFORE` directive. The /proc/self/maps scanner is updated to account for the fact that there are a number of sections between `&__executable_start` and the start of the .text section. Fortunately, those sections are all mapped into the same memory segment so we only need to look at the next line to find the start of our text segment. Fixes: #31520 PR-URL: #31547 Reviewed-By: Anna Henningsen <[email protected]> Reviewed-By: Gus Caplan <[email protected]> Reviewed-By: James M Snell <[email protected]> Reviewed-By: Rich Trott <[email protected]> Reviewed-By: David Carlier <[email protected]>

addaleax · 2020-02-01T10:38:59Z

Landed in 938abd9

addaleax · 2020-02-01T22:38:03Z

Any chance this CI failure is related? I haven't seen it before.

AssertionError [ERR_ASSERTION]: Expected values to be strictly equal:

null !== 0

    at Object.<anonymous> (/home/iojs/build/workspace/node-test-commit-linux/nodes/alpine-latest-x64/test/parallel/test-startup-large-pages.js:13:10)
    at Module._compile (internal/modules/cjs/loader.js:1208:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1228:10)
    at Module.load (internal/modules/cjs/loader.js:1057:32)
    at Function.Module._load (internal/modules/cjs/loader.js:952:14)
    at Function.executeUserEntryPoint [as runMain] (internal/modules/run_main.js:71:12)
    at internal/main/run_main_module.js:17:47 {
  generatedMessage: true,
  code: 'ERR_ASSERTION',
  actual: null,
  expected: 0,
  operator: 'strictEqual'
}

(from https://ci.nodejs.org/job/node-test-commit-linux/32614/nodes=alpine-latest-x64/testReport/junit/(root)/test/parallel_test_startup_large_pages/)

bnoordhuis · 2020-02-02T01:40:11Z

Yes, it's possible. I'll open a PR that adds logging to the test. I suspect the binary is crashing but the test hides that.

The test starts child processes. A recent change is suspected of causing flaky crashes on one of the alpine buildbots but we can't know for sure because the test hides the child's stderr. Refs: nodejs#31547 (comment)

The test starts child processes. A recent change is suspected of causing flaky crashes on one of the alpine buildbots but we can't know for sure because the test hides the child's stderr. Refs: #31547 (comment) PR-URL: #31612 Reviewed-By: Rich Trott <[email protected]> Reviewed-By: Colin Ihrig <[email protected]> Reviewed-By: Anna Henningsen <[email protected]>

bnoordhuis · 2020-02-09T10:59:47Z

I've been going through the CI runs for the alpine buildbots since last week and that test failure doesn't seem to have happened again. 🤷‍♂

`__executable_start` is provided by GNU's and LLVM's default linker scripts, obviating the need to plug in a custom linker script. The problem with our bespoke linker script is that it works with ld.bfd but not ld.gold and cannot easily be ported because the latter linker doesn't understand the `INSERT BEFORE` directive. The /proc/self/maps scanner is updated to account for the fact that there are a number of sections between `&__executable_start` and the start of the .text section. Fortunately, those sections are all mapped into the same memory segment so we only need to look at the next line to find the start of our text segment. Fixes: #31520 PR-URL: #31547 Reviewed-By: Anna Henningsen <[email protected]> Reviewed-By: Gus Caplan <[email protected]> Reviewed-By: James M Snell <[email protected]> Reviewed-By: Rich Trott <[email protected]> Reviewed-By: David Carlier <[email protected]>

The test starts child processes. A recent change is suspected of causing flaky crashes on one of the alpine buildbots but we can't know for sure because the test hides the child's stderr. Refs: #31547 (comment) PR-URL: #31612 Reviewed-By: Rich Trott <[email protected]> Reviewed-By: Colin Ihrig <[email protected]> Reviewed-By: Anna Henningsen <[email protected]>

`__executable_start` is provided by GNU's and LLVM's default linker scripts, obviating the need to plug in a custom linker script. The problem with our bespoke linker script is that it works with ld.bfd but not ld.gold and cannot easily be ported because the latter linker doesn't understand the `INSERT BEFORE` directive. The /proc/self/maps scanner is updated to account for the fact that there are a number of sections between `&__executable_start` and the start of the .text section. Fortunately, those sections are all mapped into the same memory segment so we only need to look at the next line to find the start of our text segment. Fixes: nodejs#31520 PR-URL: nodejs#31547 Reviewed-By: Anna Henningsen <[email protected]> Reviewed-By: Gus Caplan <[email protected]> Reviewed-By: James M Snell <[email protected]> Reviewed-By: Rich Trott <[email protected]> Reviewed-By: David Carlier <[email protected]>

targos · 2020-04-18T08:51:39Z

depends on large pages change to land on v12.x

`__executable_start` is provided by GNU's and LLVM's default linker scripts, obviating the need to plug in a custom linker script. The problem with our bespoke linker script is that it works with ld.bfd but not ld.gold and cannot easily be ported because the latter linker doesn't understand the `INSERT BEFORE` directive. The /proc/self/maps scanner is updated to account for the fact that there are a number of sections between `&__executable_start` and the start of the .text section. Fortunately, those sections are all mapped into the same memory segment so we only need to look at the next line to find the start of our text segment. Fixes: nodejs#31520 Backport-PR-URL: nodejs#32092 PR-URL: nodejs#31547 Reviewed-By: Anna Henningsen <[email protected]> Reviewed-By: Gus Caplan <[email protected]> Reviewed-By: James M Snell <[email protected]> Reviewed-By: Rich Trott <[email protected]> Reviewed-By: David Carlier <[email protected]>

The test starts child processes. A recent change is suspected of causing flaky crashes on one of the alpine buildbots but we can't know for sure because the test hides the child's stderr. Refs: nodejs#31547 (comment) PR-URL: nodejs#31612 Reviewed-By: Rich Trott <[email protected]> Reviewed-By: Colin Ihrig <[email protected]> Reviewed-By: Anna Henningsen <[email protected]>

`__executable_start` is provided by GNU's and LLVM's default linker scripts, obviating the need to plug in a custom linker script. The problem with our bespoke linker script is that it works with ld.bfd but not ld.gold and cannot easily be ported because the latter linker doesn't understand the `INSERT BEFORE` directive. The /proc/self/maps scanner is updated to account for the fact that there are a number of sections between `&__executable_start` and the start of the .text section. Fortunately, those sections are all mapped into the same memory segment so we only need to look at the next line to find the start of our text segment. Fixes: #31520 Backport-PR-URL: #32092 PR-URL: #31547 Reviewed-By: Anna Henningsen <[email protected]> Reviewed-By: Gus Caplan <[email protected]> Reviewed-By: James M Snell <[email protected]> Reviewed-By: Rich Trott <[email protected]> Reviewed-By: David Carlier <[email protected]>

The test starts child processes. A recent change is suspected of causing flaky crashes on one of the alpine buildbots but we can't know for sure because the test hides the child's stderr. Refs: #31547 (comment) PR-URL: #31612 Reviewed-By: Rich Trott <[email protected]> Reviewed-By: Colin Ihrig <[email protected]> Reviewed-By: Anna Henningsen <[email protected]>

richardlau · 2020-07-01T16:11:34Z

Removing the lts-watch-v10.x label as we decided not to backport the hugepages changes to 10.x: #31105

nodejs-github-bot added build Issues and PRs related to build files or the CI. c++ Issues and PRs that require attention from people who are familiar with C++. labels Jan 28, 2020

bnoordhuis mentioned this pull request Jan 28, 2020

nodejs-13.7.0 fails with ld.gold linker #31520

Closed

fixup! enable large pages only for executable

569c1e0

addaleax approved these changes Jan 28, 2020

View reviewed changes

fixup! reinstate freebsd check

6d38519

devsnek approved these changes Jan 28, 2020

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jasnell approved these changes Jan 30, 2020

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Trott approved these changes Jan 30, 2020

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devnexen approved these changes Jan 31, 2020

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addaleax closed this Feb 1, 2020

bnoordhuis mentioned this pull request Feb 2, 2020

test: show child stderr output in largepages test #31612

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gabrielschulhof added the lts-watch-v12.x label Feb 12, 2020

bnoordhuis mentioned this pull request Feb 13, 2020

unable to build master, linking fails #31249

Closed

This was referenced Feb 13, 2020

ESM issue on 12.x requires a quick 12.16.1 nodejs/Release#532

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v12.16.1 proposal #31781

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richardlau added the lts-watch-v10.x label Feb 15, 2020

richardlau mentioned this pull request Feb 15, 2020

[v10.x] Backport large pages to v10.x #31105

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codebytere mentioned this pull request Feb 17, 2020

v13.9.0 proposal #31837

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v12.16.0 post-mortem nodejs/Release#536

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BethGriggs added baking-for-lts PRs that need to wait before landing in a LTS release. and removed baking-for-lts PRs that need to wait before landing in a LTS release. labels Feb 27, 2020

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targos added backported-to-v12.x and removed backport-blocked-v12.x labels Apr 25, 2020

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v12.17.0 release proposal #33197

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src: use __executable_start for linux hugepages #31547

src: use __executable_start for linux hugepages #31547

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src: use __executable_start for linux hugepages #31547

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