Closed Bug 1379126 Opened 3 years ago Closed 3 years ago

Filtering in CachePerfStats::MMA::AddValue is too strict

Categories

(Core :: Networking: Cache, enhancement)

enhancement
Not set

Tracking

()

RESOLVED FIXED
mozilla56
Tracking Status
firefox56 --- fixed

People

(Reporter: michal, Assigned: michal)

References

(Blocks 1 open bug)

Details

(Whiteboard: [necko-active])

Attachments

(1 file, 1 obsolete file)

Filtering based on max difference avg/4 + 2*stddev seems to be too strict. It's applied only on high values, so any low value pulls the average down. We include values from events that spent up to 5 event cycles in the queue, so we need to be more flexible here.
Attached patch fix (obsolete) — Splinter Review
Filtering of the values is now more relaxed. Also, stats for IO_WRITE isn't used in CachePerfStats::IsCacheSlow for detecting slow cache. Writes have low priority and it's normal that they are delayed a lot, but this doesn't necessarily affect opening cache entries.
Attachment #8884263 - Flags: review?(valentin.gosu)
Comment on attachment 8884263 [details] [diff] [review]
fix

Review of attachment 8884263 [details] [diff] [review]:
-----------------------------------------------------------------

nit: It's worth adding comments on why we ignore the write operations from the cache speed estimation.
Attachment #8884263 - Flags: review?(valentin.gosu) → review+
Attachment #8884263 - Attachment is obsolete: true
Attachment #8885727 - Flags: review+
Pushed by mnovotny@mozilla.com:
https://hg.mozilla.org/integration/mozilla-inbound/rev/0c098eb60dd1
Filtering in CachePerfStats::MMA::AddValue is too strict, r=valentin
https://hg.mozilla.org/mozilla-central/rev/0c098eb60dd1
Status: NEW → RESOLVED
Closed: 3 years ago
Resolution: --- → FIXED
Target Milestone: --- → mozilla56
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