75401 - memory cache not holding to assigned limit

Status: RESOLVED DUPLICATE of bug 72514

(Core :: Networking: Cache, defect)

Description

[ratman]

using win32 installer mtrunk build 2001040904.

1) go to edit->preferences
2) select the advanced->cache panel
3) set the disk cache and memory cache to the same size (i'm lazy, so i use 4096)
4) exit preferences
5) open a whole bunch of windows for different pages
6) in one window, open about:cache

expected behavior) the listed memory and disk cache sizes should be equal, and
both limits should be maintained

actual behavior) with the setting mentioned above of 4096 kb, the disk cache
correctly lists a maximum of 4194304 bytes and holds to it.  however, the memory
cache lists a max of 6291456 bytes, and with enough randomly loaded content,
bypasses the supposedly equal cache size max set for both caches.

regardless of whether the newcache disk cache is following its limits correctly,
memory cache shouldn't be off by this much.  the max size listed by about:cache
isn't even the default setting for mozilla to begin with.

i am unsure if this is related to the newcache landing, however; i only
discovered about:cache today.  what a concept!

Comment 1

[gordon]

I'm going to mark this as a duplicate of 72514 "add 2 level soft/hard cache size 
limits to preferences".  The preference you set in the cache pref panel for the 
memory cache is a "soft" limit, which the memory cache respects when it is in a 
quiescent state.  The "hard" limit is currently calculated to be the soft limit + 
2 Mb.  The hard limit exists to accomodate additional cache items that are in use 
by the current page.  The memory cache reports the hard limit in about:cache.

We really need to change the pref panel to allow the user to set both limits.
The soft limit can be exceeded temporarily, but the hard limit is absolute.


*** This bug has been marked as a duplicate of 72514 ***