[pbs-devel] [PATCH proxmox-backup 2/3] RemoteChunkReader: add LRU cached variant

[Stefan Reiter]

On 28/04/2021 18:26, Dietmar Maurer wrote:
> 
>> +    /// Create a new instance.
>> +    ///
>> +    /// Chunks listed in ``cache_hint`` are cached and kept in RAM, as well as the last
>> +    /// 'cache_lru' accessed chunks (the latter via a mmap file).
> 
> Does that cache_hint really helps here?
> Have you tested without? If so, whats the difference?
> 

Again, performance testing is hard with this (I'll take a closer look at 
why as well), but in terms of hit rate the "hinted" cache is at about 
1-2% - we could probably reduce it's size.

Removing it entirely would probably not be good, as I think we use it to 
cache the zero-chunk as well IIRC?