988011 - HTTP cache v2: minimize number of posts in the payload read code path

Status: RESOLVED DUPLICATE of bug 999383

(Core :: Networking: Cache, defect)

Description

[Honza Bambas (:mayhemer)]

In the past I discovered we do a lot of reposts while reading chunks of payload from the cache.  It has major bad influence on reading performance.  I was hoping we would need to fix this as one of optimizations after the new cache is turned on, but seems like this is too much of a regression.

Attached is a detailed log snippet from a cache2 enabled talos run.

I'd like to try to at least slightly increase performance here with good gain/risk ratio.

Comment 1

[Honza Bambas (:mayhemer)]

Talos results shows enlarging the chunk is enough for now.

Also, I now recall I was playing with removing/minimizing the number of posts before we have the prioritization in the IO thread and I also found low influence of it to my page load tests when the IO prioritization was in the tree.

Lowering impact rate here.