699410 - Add telemetry for memory used by active disk cache entries

Status: NEW

(Core :: Networking: Cache, defect, P5)

Description

[u408661]

We would like to know how much memory overhead we have in the disk cache caused by entries that are in use in some way or another (reading, writing, not-yet-deactivated). Not 100% sure WHEN to probe this number, and whether to do the actual memory calculation or just count the number of active entries and extrapolate as best as possible from there.

Comment 1

[Nicholas Nethercote [inactive]]

Please use moz_malloc_usable_size() if you can -- see bug 669409 comment 5.

Comment 2

[u408661]

Attachment: patch

This patch builds on the one for bug 699951, so just requesting feedback for now, but it's in the final form that I'd like it to be in barring any problems.

Comment 3

[Jason Duell]

Comment on attachment 575903 [details] [diff] [review]
patch

Review of attachment 575903 [details] [diff] [review]:
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Looks fine to me, but I'm not familiar with the "gather-telemetry" event, so asking Taras to glance at it too.

Comment 4

[(dormant account)]

Comment on attachment 575903 [details] [diff] [review]
patch

gather-telemetry is an event we fire to give stuff a chance to gather one-off (and possibly async+expensive) telemetry data.

Comment 5

[u408661]

Reassigning to default owner, 'cause this will all change when we get our new cache, and someone else will likely be more appropriate to do this then.

Comment 6

[Firefox Bug Husbandry Bot]

Bulk change to priority: https://bugzilla.mozilla.org/show_bug.cgi?id=1399258