Make Bazel's RAM estimate container aware #20435
Closed
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
github-actions
bot
added
team-Performance
meisterT
approved these changes
Dec 6, 2023
meisterT
added
awaiting-PR-merge
|
@bazel-io flag |
bazel-io
added
the
potential release blocker
|
@bazel-io fork 7.1.0 |
bazel-io
removed
the
potential release blocker
github-actions
bot
removed
the
awaiting-PR-merge
bazel-io
pushed a commit
to bazel-io/bazel
that referenced
this pull request
Dec 21, 2023
As of JDK 14, `OperatingSystemMXBean` provides information about system memory that is container-aware. Outside containers, it uses the same mechanisms as Bazel to determine available RAM (`/proc/meminfo` on Linux, `hw.memsize` on macOS) and can thus be used as a drop-in replacement for the custom implementation. A small caveat is that Bazel's macOS RAM estimate was based on converting bytes to "MB" via a divisor of `1000^2` instead of `1024^2`, resulting in a consistent overestimate compared to an identical Linux machine that is now corrected. This opportunity was missed in bazelbuild#16512 since `OperatingSystemMXBean` is based on a complete Java implementation of cgroups handling and doesn't go through the `os::total_memory` or `os::physical_memory` Hotspot functions. RELNOTES[INC]: * On Linux, Bazel's RAM estimate for the host machine is now aware of container resource limits. * On macOS, Bazel no longer consistently overestimates the total RAM by ~5% (`1024^2/1000^2`). * On Windows, Bazel's RAM estimate is now generally more accurate as it is no longer influenced by JVM heuristics. Fixes bazelbuild#3886 Closes bazelbuild#20435. PiperOrigin-RevId: 588718034 Change-Id: I2daafa0567740a1b149ca8756ec27f102129283c
github-merge-queue bot
pushed a commit
that referenced
this pull request
Jan 11, 2024
As of JDK 14, `OperatingSystemMXBean` provides information about system memory that is container-aware. Outside containers, it uses the same mechanisms as Bazel to determine available RAM (`/proc/meminfo` on Linux, `hw.memsize` on macOS) and can thus be used as a drop-in replacement for the custom implementation. A small caveat is that Bazel's macOS RAM estimate was based on converting bytes to "MB" via a divisor of `1000^2` instead of `1024^2`, resulting in a consistent overestimate compared to an identical Linux machine that is now corrected. This opportunity was missed in #16512 since `OperatingSystemMXBean` is based on a complete Java implementation of cgroups handling and doesn't go through the `os::total_memory` or `os::physical_memory` Hotspot functions. RELNOTES[INC]: * On Linux, Bazel's RAM estimate for the host machine is now aware of container resource limits. * On macOS, Bazel no longer consistently overestimates the total RAM by ~5% (`1024^2/1000^2`). * On Windows, Bazel's RAM estimate is now generally more accurate as it is no longer influenced by JVM heuristics. Fixes #3886 Closes #20435. Commit 2f3cdc5 PiperOrigin-RevId: 588718034 Change-Id: I2daafa0567740a1b149ca8756ec27f102129283c Co-authored-by: Fabian Meumertzheim <fabian@meumertzhe.im>
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
As of JDK 14,
OperatingSystemMXBeanprovides information about system memory that is container-aware. Outside containers, it uses the same mechanisms as Bazel to determine available RAM (/proc/meminfoon Linux,hw.memsizeon macOS) and can thus be used as a drop-in replacement for the custom implementation.A small caveat is that Bazel's macOS RAM estimate was based on converting bytes to "MB" via a divisor of
1000^2instead of1024^2, resulting in a consistent overestimate compared to an identical Linux machine that is now corrected.This opportunity was missed in #16512 since
OperatingSystemMXBeanis based on a complete Java implementation of cgroups handling and doesn't go through theos::total_memoryoros::physical_memoryHotspot functions.RELNOTES[INC]:
1024^2/1000^2).Fixes #3886