Fix linux filesystem cache calculation #73
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
Linux's "Cached" statistic in /proc/meminfo is highly misleading as it contains swap-backed shmem. This is hard to reclaim at best, and not at all reclaimable on systems without swap. It should be considered actual_used, not actual_free. A more reliable filesystem cache footprint can be calculated from the file LRUs and the reclaimable slab cache, which is mostly filesystem metadata like dentries and inodes.
lizhanyin
added a commit
to lizhanyin/sigar
that referenced
this pull request
Aug 28, 2024
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
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Outdated suggestions cannot be applied.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.
Linux's "Cached" statistic in /proc/meminfo is highly misleading as it
contains swap-backed shmem. This is hard to reclaim at best, and not
at all reclaimable on systems without swap. It should be considered
actual_used, not actual_free.
A more reliable filesystem cache footprint can be calculated from the
file LRUs and the reclaimable slab cache, which is mostly filesystem
metadata like dentries and inodes.