Bugzilla

(In reply to Doug Thayer [:dthayer] from comment #3)
> Yeah - my Windows machine is not available this second, but I wanted to take a look at what the file system cache looks like for xul.dll when we preload it vs not. I remember seeing interesting things when looking at it in RAMMap for the warmup service (i.e., significant differences in the standby column for xul.dll when preloading vs just loading and using the dll as normal). 

Update on this:

After clearing the cache, opening Firefox and opening a few web pages (for the cases where we actually load xul.dll), RAMMap's numbers look like this:

```                                      Total        Standby      Active
ReadAhead + Load       .../xul.dll       148300 K     103008 K     45292 K
Just Load              .../xul.dll       68424 K      19488 K      48936 K
Just ReadAhead         .../xul.dll       96868 K      96868 K      0 K
```

`ReadAhead + Load` is what we currently do. `Just Load` is where we load the DLL with no ReadAhead, and `Just ReadAhead` is where we just do the ReadAhead on the dll file and then exit the program.

This suggests that we are unnecessarily reading about 80 MB, as that's the excess Standby file cache we're left with.

(In reply to Doug Thayer [:dthayer] from comment #3)
> Yeah - my Windows machine is not available this second, but I wanted to take a look at what the file system cache looks like for xul.dll when we preload it vs not. I remember seeing interesting things when looking at it in RAMMap for the warmup service (i.e., significant differences in the standby column for xul.dll when preloading vs just loading and using the dll as normal). 

Update on this:

After clearing the cache, opening Firefox and opening a few web pages (for the cases where we actually load xul.dll), RAMMap's numbers look like this:

```
                                         Total        Standby      Active
ReadAhead + Load       .../xul.dll       148300 K     103008 K     45292 K
Just Load              .../xul.dll       68424 K      19488 K      48936 K
Just ReadAhead         .../xul.dll       96868 K      96868 K      0 K
```

`ReadAhead + Load` is what we currently do. `Just Load` is where we load the DLL with no ReadAhead, and `Just ReadAhead` is where we just do the ReadAhead on the dll file and then exit the program.

This suggests that we are unnecessarily reading about 80 MB, as that's the excess Standby file cache we're left with.