mem: populate Cached from bcachestats on OpenBSD#2029
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shirou merged 2 commits intoshirou:masterfrom Mar 21, 2026
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On OpenBSD, Cached was hardcoded to 0 with the comment "not available", while Buffers was populated from bcachestats.Numbufpages (buffer cache pages). Since the buffer cache is the closest OpenBSD equivalent to Linux cached memory, populate Cached from the same source. This fixes the Available memory calculation which includes Cached: Available = Inactive + Cached + Free Previously, Available was understated because Cached was always 0. Ref: influxdata/telegraf#18469
shirou
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LGTM! Clean and well-motivated fix.
The reordering so that the bcachestats syscall happens before constructing ret is a nice improvement — no more partially-populated struct on error paths.
One minor suggestion: it might be worth adding a brief comment explaining why Cached and Buffers share the same value, to help future maintainers understand this is intentional and not a copy-paste mistake. Something like:
// On OpenBSD, the buffer cache is the closest equivalent to both
// Linux's Buffers and Cached memory.
bcache := uint64(bcs.Numbufpages) * p
Not a blocker though. But if you have time, it'd be great if you could update the PR to add that comment. Thanks for the fix and the clear PR description!
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Thank you for the update! |
This was referenced Apr 23, 2026
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On OpenBSD,
VirtualMemoryStat.Cachedwas hardcoded to0whileBufferswas populated frombcachestats.Numbufpages. Since the buffer cache is the closest OpenBSD equivalent to Linux cached memory, this change populatesCachedfrom the same source.This fixes the
Availablememory calculation:Previously,
Availablewas understated on OpenBSD becauseCachedwas always0, affecting downstream consumers (e.g. influxdata/telegraf#18469).