port txg dtrace script to ebpf #31
Merged
+394
−4
Conversation
This file contains hidden or 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
|
Responding to an external discussion. I looked into using BPF.ksymname() as an alternative to the drgn approach to read zfs_max_data_dirty. The support in BPF appears to be only for functions. |
prakashsurya
approved these changes
Feb 13, 2020
grwilson
reviewed
Feb 13, 2020
sebroy
requested changes
Feb 14, 2020
bpf/standalone/txg.py
Outdated
| /* | ||
| * Collect data to know how much we're being throttled / delayed. If we're | ||
| * throttled on every tx we could hit these probes a lot (burning CPU), so we | ||
| * avoid using syntactic sugar in this section. |
There was a problem hiding this comment.
What syntactic sugar is this referring to?
There was a problem hiding this comment.
I wish I had some syntactic sugar.
The spirit of the dtrace comment, warning about not overburdening this probe seemed worth keeping.
sebroy
approved these changes
Feb 14, 2020
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Outdated suggestions cannot be applied.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.
This is a port of the dtrace script :
http://grok.delphix.com/xref/dlpx-app-5.3-stage/appliance/server/service/performance_playbook/txg.d
This is a little different than the existing estat scripts and there are a few new things to give extra scrutiny too.
Here sample output. I need to get on a loaded machine and verify the output when throttling and delays are an issue.
Thu Jan 23 16:21:41 2020 100482 5025ms 214ms (99 pass 1) 2MB ( 0) 0us 0ms 0ms
Thu Jan 23 16:21:46 2020 100483 4909ms 114ms (97 pass 1) 1MB ( 0) 0us 0ms 0ms
Thu Jan 23 16:21:51 2020 100484 5226ms 179ms (99 pass 1) 2MB ( 0) 0us 0ms 0ms
Thu Jan 23 16:21:56 2020 100485 4972ms 75ms (96 pass 1) 1MB ( 0) 0us 0ms 0ms
Thu Jan 23 16:22:02 2020 100486 5044ms 72ms (98 pass 1) 2MB ( 0) 0us 0ms 0ms
date txg time since last sync
| | | sync time
| | | | (%% pass 1)
| | | | | highest dirty (%%)
| | | | | | highest throttle delay
| | | | | | | | avg delay
v v v v v v v v v
Thu Jan 23 16:22:07 2020 100487 5047ms 66ms (97 pass 1) 2MB ( 0) 0us 0ms 0ms
Thu Jan 23 16:22:12 2020 100488 5053ms 83ms (98 pass 1) 1MB ( 0) 0us 0ms 0ms
Thu Jan 23 16:22:17 2020 100489 5036ms 49ms (95 pass 1) 2MB ( 0) 0us 0ms 0ms
Thu Jan 23 16:22:22 2020 100490 5099ms 71ms (95 pass 1) 3MB ( 0) 0us 0ms 0ms
Thu Jan 23 16:22:27 2020 100491 5019ms 55ms (97 pass 1) 2MB ( 0) 0us 0ms 0ms
Thu Jan 23 16:22:32 2020 100492 5064ms 260ms (99 pass 1) 1MB ( 0) 0us 0ms 0ms
Thu Jan 23 16:22:37 2020 100493 4859ms 78ms (95 pass 1) 2MB ( 0) 0us 0ms 0ms
Thu Jan 23 16:22:43 2020 100494 5041ms 778ms (99 pass 1) 3MB ( 0) 0us 0ms 0ms
Thu Jan 23 16:22:48 2020 100495 4341ms 142ms (98 pass 1) 3MB ( 0) 0us 0ms 0ms