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Adapt cache based on io rates

Assigned to



Networking: Cache
6 years ago
13 days ago


(Reporter: (dormant account), Assigned: michal)


Firefox Tracking Flags

(Not tracked)


(Whiteboard: [snappy:p2][necko-backlog])



6 years ago
On a lenovo x120e, deleting the cache directory takes about an hour. I don't remember the exact cache size, it was around 1gb(120gb of disk free).
We should restrict the size of cache on devices with extremely slow disks.
Cache performance also changes depending on whether other stuff is running on the computer. We should detect if cache entries are taking >100ms on average and disable disk cache completely in those cases.
This laptop consistently takes 500-800ms for HTTP_PAGE_CACHE_READ_TIME and is worse when other disk activity is present. Similar conditions happen on android phones.

Comment 1

6 years ago
here is comment from my blog that shows another weird case of a need to adapt our cache to disk speed:

I have to limit my network cache to 100MB, otherwise shutdown times (and unclean startup times) explode beyond all belief.

I have my profile directory (including the cache) encrypted on Windows using EFS. Shutting down Firefox takes up to a minute, and after a process terminate a startup takes up to a minute.

It used to be beyond ridiculous before I reduced the network cache size. I mean, seriously ridiculous, I'd terminate Firefox while it was still starting up because I thought it was crashed.

Note: EFS is single-threaded on Windows. So even though I have 8 cores it could be using, it only uses one. Also running on SSD with 12GB ram.

Comment 2

6 years ago
We'll be considering something like this as part of our Q1 cache performance work. Assigning to Nick Hurley as he's leading that effort.
Assignee: nobody → hurley


6 years ago
Duplicate of this bug: 647479


6 years ago
Whiteboard: [snappy] → [snappy:p2]


5 years ago
Assignee: hurley → michal.novotny
See Also: → bug 725423
Whiteboard: [snappy:p2] → [snappy:p2][necko-backlog]
Duplicate of this bug: 725423
Bulk change to priority: https://bugzilla.mozilla.org/show_bug.cgi?id=1399258
Priority: -- → P1
Bulk change to priority: https://bugzilla.mozilla.org/show_bug.cgi?id=1399258
Priority: P1 → P3
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