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deps: V8: cherry-pick b49206d fom upstream #20727

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@ofrobots ofrobots commented May 14, 2018

Ref: #20083

Original commit message:

ThreadDataTable: Change global linked list to per-Isolate hash map.

For use cases with a large number of threads or a large number of isolates (or
both), ThreadDataTable can be a major performance bottleneck due to O(n)
lookup time of the linked list. Switching to a hash map reduces this to O(1).

Example 1: Sandstorm.io, a Node.js app that utilizes "fibers", was observed
spending the majority of CPU time iterating over the ThreadDataTable.
See: https://sandstorm.io/news/2016-09-30-fiber-bomb-debugging-story

Example 2: Cloudflare's Workers engine, a high-multi-tenancy web server
framework built on V8 (but not Node), creates large numbers of threads and
isolates per-process. It saw a 34x improvement in throughput when we applied
this patch.

Cloudflare has been using a patch in production since the Workers launch which
replaces the linked list with a hash map -- but still global.

This commit builds on that but goes further and creates a separate hash map
and mutex for each isolate, with the table being a member of the Isolate
class. This avoids any globals and should reduce lock contention.

Bug: v8:5338
Change-Id: If0d11509afb2e043b888c376e36d3463db931b47
Reviewed-on: https://chromium-review.googlesource.com/1014407
Reviewed-by: Yang Guo yangguo@chromium.org
Commit-Queue: Yang Guo yangguo@chromium.org
Cr-Commit-Position: refs/heads/master@{#52753}

Checklist
  • make -j4 test (UNIX), or vcbuild test (Windows) passes
  • commit message follows commit guidelines

CI: https://ci.nodejs.org/job/node-test-pull-request/14871/
V8-CI: https://ci.nodejs.org/view/All/job/node-test-commit-v8-linux/1368/

@nodejs-github-bot nodejs-github-bot added build Issues and PRs related to build files or the CI. v8 engine Issues and PRs related to the V8 dependency. labels May 14, 2018
Original commit message:
  ThreadDataTable: Change global linked list to per-Isolate hash map.

  For use cases with a large number of threads or a large number of isolates (or
  both), ThreadDataTable can be a major performance bottleneck due to O(n)
  lookup time of the linked list. Switching to a hash map reduces this to O(1).

  Example 1: Sandstorm.io, a Node.js app that utilizes "fibers", was observed
  spending the majority of CPU time iterating over the ThreadDataTable.
  See: https://sandstorm.io/news/2016-09-30-fiber-bomb-debugging-story

  Example 2: Cloudflare's Workers engine, a high-multi-tenancy web server
  framework built on V8 (but not Node), creates large numbers of threads and
  isolates per-process. It saw a 34x improvement in throughput when we applied
  this patch.

  Cloudflare has been using a patch in production since the Workers launch which
  replaces the linked list with a hash map -- but still global.

  This commit builds on that but goes further and creates a separate hash map
  and mutex for each isolate, with the table being a member of the Isolate
  class. This avoids any globals and should reduce lock contention.

  Bug: v8:5338
  Change-Id: If0d11509afb2e043b888c376e36d3463db931b47
  Reviewed-on: https://chromium-review.googlesource.com/1014407
  Reviewed-by: Yang Guo <yangguo@chromium.org>
  Commit-Queue: Yang Guo <yangguo@chromium.org>
  Cr-Commit-Position: refs/heads/master@{nodejs#52753}

PR-URL: nodejs#20727
Ref: nodejs#20083
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LGTM. New CI because the previous one bombed on infrastructure issues:

https://ci.nodejs.org/job/node-test-pull-request/14877/

@BridgeAR BridgeAR added the author ready PRs that have at least one approval, no pending requests for changes, and a CI started. label May 15, 2018
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New CI was all green: https://ci.nodejs.org/job/node-test-commit/18544/. Landing.

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Landed in 0ebbd76.

@ofrobots ofrobots closed this May 17, 2018
@ofrobots ofrobots deleted the backport-v8-5338 branch May 17, 2018 18:25
ofrobots added a commit that referenced this pull request May 17, 2018
Original commit message:
  ThreadDataTable: Change global linked list to per-Isolate hash map.

  For use cases with a large number of threads or a large number of
  isolates (or both), ThreadDataTable can be a major performance
  bottleneck due to O(n) lookup time of the linked list. Switching to a
  hash map reduces this to O(1).

  Example 1: Sandstorm.io, a Node.js app that utilizes "fibers", was
  observed spending the majority of CPU time iterating over the
  ThreadDataTable.
  See: https://sandstorm.io/news/2016-09-30-fiber-bomb-debugging-story

  Example 2: Cloudflare's Workers engine, a high-multi-tenancy web
  server framework built on V8 (but not Node), creates large numbers of
  threads and isolates per-process. It saw a 34x improvement in
  throughput when we applied this patch.

  Cloudflare has been using a patch in production since the Worker
  launch which replaces the linked list with a hash map -- but still
  global.

  This commit builds on that but goes further and creates a separate
  hash map and mutex for each isolate, with the table being a member of
  the Isolate class. This avoids any globals and should reduce lock
  contention.

  Bug: v8:5338
  Change-Id: If0d11509afb2e043b888c376e36d3463db931b47
  Reviewed-on: https://chromium-review.googlesource.com/1014407
  Reviewed-by: Yang Guo <yangguo@chromium.org>
  Commit-Queue: Yang Guo <yangguo@chromium.org>
  Cr-Commit-Position: refs/heads/master@{#52753}

PR-URL: #20727
Ref: #20083

Refs: #20083
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: James M Snell <jasnell@gmail.com>
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KoenLav commented May 21, 2018

@ofrobots is there anything still needed to get this into Node.js 8?

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@KoenLav the process we follow is that a fix first has to be available on the current release line before it is considered for back-porting to LTS by the @nodejs/release team. I have attached the labels above which will make this fix show up on the list of potential back-ports to the LTS releases.

It is going to take a little while before you see it on 8 LTS – but the objective is to make sure we have adequate feedback from the current line to avoid disrupting the LTS lines.. /cc @nodejs/release in case I got anything wrong about the release process.

MylesBorins pushed a commit that referenced this pull request May 22, 2018
Original commit message:
  ThreadDataTable: Change global linked list to per-Isolate hash map.

  For use cases with a large number of threads or a large number of
  isolates (or both), ThreadDataTable can be a major performance
  bottleneck due to O(n) lookup time of the linked list. Switching to a
  hash map reduces this to O(1).

  Example 1: Sandstorm.io, a Node.js app that utilizes "fibers", was
  observed spending the majority of CPU time iterating over the
  ThreadDataTable.
  See: https://sandstorm.io/news/2016-09-30-fiber-bomb-debugging-story

  Example 2: Cloudflare's Workers engine, a high-multi-tenancy web
  server framework built on V8 (but not Node), creates large numbers of
  threads and isolates per-process. It saw a 34x improvement in
  throughput when we applied this patch.

  Cloudflare has been using a patch in production since the Worker
  launch which replaces the linked list with a hash map -- but still
  global.

  This commit builds on that but goes further and creates a separate
  hash map and mutex for each isolate, with the table being a member of
  the Isolate class. This avoids any globals and should reduce lock
  contention.

  Bug: v8:5338
  Change-Id: If0d11509afb2e043b888c376e36d3463db931b47
  Reviewed-on: https://chromium-review.googlesource.com/1014407
  Reviewed-by: Yang Guo <yangguo@chromium.org>
  Commit-Queue: Yang Guo <yangguo@chromium.org>
  Cr-Commit-Position: refs/heads/master@{#52753}

PR-URL: #20727
Ref: #20083

Refs: #20083
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: James M Snell <jasnell@gmail.com>
@addaleax addaleax mentioned this pull request May 22, 2018
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veered commented Jun 22, 2018

@ofrobots Any idea on when this might land in Node 8? It'll be a huge deal for the Meteor community :)

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@MylesBorins is this on track for a 8.x release?

@MylesBorins
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@ofrobots this is going to need a manual backport to 8.x

ping @nodejs/v8-update

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8.x backport: #21529

ofrobots added a commit to ofrobots/node that referenced this pull request Jun 28, 2018
This is the v8.x backport of nodejs#20727.

Original commit message:
  ThreadDataTable: Change global linked list to per-Isolate hash map.

  For use cases with a large number of threads or a large number of
  isolates (or both), ThreadDataTable can be a major performance
  bottleneck due to O(n) lookup time of the linked list. Switching to a
  hash map reduces this to O(1).

  Example 1: Sandstorm.io, a Node.js app that utilizes "fibers", was
  observed spending the majority of CPU time iterating over the
  ThreadDataTable.
  See: https://sandstorm.io/news/2016-09-30-fiber-bomb-debugging-story

  Example 2: Cloudflare's Workers engine, a high-multi-tenancy web
  server framework built on V8 (but not Node), creates large numbers of
  threads and isolates per-process. It saw a 34x improvement in
  throughput when we applied this patch.

  Cloudflare has been using a patch in production since the Worker
  launch which replaces the linked list with a hash map -- but still
  global.

  This commit builds on that but goes further and creates a separate
  hash map and mutex for each isolate, with the table being a member of
  the Isolate class. This avoids any globals and should reduce lock
  contention.

  Bug: v8:5338
  Change-Id: If0d11509afb2e043b888c376e36d3463db931b47
  Reviewed-on: https://chromium-review.googlesource.com/1014407
  Reviewed-by: Yang Guo <yangguo@chromium.org>
  Commit-Queue: Yang Guo <yangguo@chromium.org>
  Cr-Commit-Position: refs/heads/master@{nodejs#52753}

Backport-PR-URL: nodejs#21529
PR-URL: nodejs#20727
Refs: nodejs#20083
Refs: nodejs#20083
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: James M Snell <jasnell@gmail.com>
@MylesBorins MylesBorins mentioned this pull request Jul 9, 2018
rvagg pushed a commit that referenced this pull request Aug 16, 2018
This is the v8.x backport of #20727.

Original commit message:
  ThreadDataTable: Change global linked list to per-Isolate hash map.

  For use cases with a large number of threads or a large number of
  isolates (or both), ThreadDataTable can be a major performance
  bottleneck due to O(n) lookup time of the linked list. Switching to a
  hash map reduces this to O(1).

  Example 1: Sandstorm.io, a Node.js app that utilizes "fibers", was
  observed spending the majority of CPU time iterating over the
  ThreadDataTable.
  See: https://sandstorm.io/news/2016-09-30-fiber-bomb-debugging-story

  Example 2: Cloudflare's Workers engine, a high-multi-tenancy web
  server framework built on V8 (but not Node), creates large numbers of
  threads and isolates per-process. It saw a 34x improvement in
  throughput when we applied this patch.

  Cloudflare has been using a patch in production since the Worker
  launch which replaces the linked list with a hash map -- but still
  global.

  This commit builds on that but goes further and creates a separate
  hash map and mutex for each isolate, with the table being a member of
  the Isolate class. This avoids any globals and should reduce lock
  contention.

  Bug: v8:5338
  Change-Id: If0d11509afb2e043b888c376e36d3463db931b47
  Reviewed-on: https://chromium-review.googlesource.com/1014407
  Reviewed-by: Yang Guo <yangguo@chromium.org>
  Commit-Queue: Yang Guo <yangguo@chromium.org>
  Cr-Commit-Position: refs/heads/master@{#52753}

Backport-PR-URL: #21529
PR-URL: #20727
Refs: #20083
Refs: #20083
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: James M Snell <jasnell@gmail.com>
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9 participants