472368 - decide on a bfcache (sessionhistory.max_total_viewers) for the release version of fennec

Status: VERIFIED FIXED

(Firefox for Android Graveyard :: General, defect)

Description

[Joel Maher ( :jmaher ) (UTC -8)]

Currently we have browser.sessionhistory.max_total_viewers=0 which doesn't give us any cache for navigating back and forward.  This causes a few chrome tests to fail as documented in bugs: 472334 and 472341.  We are working around this in automation by setting the value to -1 (which will automatically determine the # of viewers based on available cache).

Here is a description of what possible values we have to choose from:
http://kb.mozillazine.org/Browser.sessionhistory.max_total_viewers

Comment 1

[timeless]

the number has to be fairly small. for microb someone set the number to 31 or something similarly insane. the result is the browser tries to kill itself (and succeeds), and then all the reliability people have to remember to set sane values :(.

I'd recommend a number not higher than 5.

I'd love to see a study which shows how a user could need more.

Comment 2

[Mark Finkle (:mfinkle) (use needinfo?)]

(In reply to comment #1)

> I'd recommend a number not higher than 5.

Using -1 should keep the number at 3 or less on an n810 (probably less) using the chart found here:
http://kb.mozillazine.org/Browser.sessionhistory.max_total_viewers

> I'd love to see a study which shows how a user could need more.

I'd agree that more than 5 would seem more than needed.

Comment 3

[Joel Maher ( :jmaher ) (UTC -8)]

I think the danger in using -1 is that we could consume all the free memory (making the device unresponsive).  Too bad we can't calculate the # of pages that -1 would give and take the lower of that number or a number like 3 or 5.

Comment 4

[Mark Finkle (:mfinkle) (use needinfo?)]

I am hoping that -1 does not actually use all available memory, but picks a number that only consumes a small fraction of available memory.

Testing will tell us that :)

Comment 5

[Stuart Parmenter]

lets go ahead and set it to 1, so at least if you click on the wrong thing you can go back easily

Comment 6

[Mark Finkle (:mfinkle) (use needinfo?)]

Attachment: patch

Try using a value of 1 to start

Comment 7

[Mark Finkle (:mfinkle) (use needinfo?)]

http://hg.mozilla.org/mobile-browser/rev/8147bc95c0a4

Comment 8

[Joel Maher ( :jmaher ) (UTC -8)]

verified fixed via mxr