689955 - startup perf- Investigate lazy initialization for nsDiskCacheMap

Status: RESOLVED WONTFIX

(Core :: Networking: Cache, defect)

Description

[David Teller [:Yoric] - still alive but not very active]

It is my understanding that nsDiskCacheMap is currently initialized during startup, by a thread. This initialization causes some I/O that could possibly be moved to a later stage, i.e. during the first actual access to the cache. This could make startup slightly faster, 

I am planning to investigate this.

Comment 1

[Brian Smith (:briansmith, :bsmith, use NEEDINFO?)]

(In reply to David Rajchenbach Teller [:Yoric] from comment #0)
> It is my understanding that nsDiskCacheMap is currently initialized during
> startup, by a thread. This initialization causes some I/O that could
> possibly be moved to a later stage, i.e. during the first actual access to
> the cache. This could make startup slightly faster, 

It would make the first access to the disk cache (the first network I/O) have huge latency if were were to make the first access wait for the disk cache to be initialized.

I think that we should have the disk cache return "not found" when the disk cache doesn't exist, and initialize the data structures on disk during the first write to (not read from the cache).

Comment 2

[David Teller [:Yoric] - still alive but not very active]

Releasing the bug as I don't have time to work on it right now.

Comment 3

[Atul Jangra [:atuljangra]]

Yoric, can you give me some pointers? Maybe I can work on this one :)

Comment 4

[David Teller [:Yoric] - still alive but not very active]

Actually, I am not sure whether this bug is useful. So I'm not going to encourage anyone to work on it right now :)