RE: Protect syscache from bloating with negative cache entries

From: Ideriha, Takeshi [mailto:ideriha.takeshi@jp.fujitsu.com]
> number of tables   | 100  |1000    |10000
> -----------------------------------------------------------
> TPS (master)       |10966  |10654 |9099
> TPS (patch)        | 11137 (+1%) |10710 (+0%) |772 (-91%)
> 
> It seems that before cache exceeding the limit (no pruning at 100 and 1000),
> the results are almost same with master but after exceeding the limit (at
> 10000)
> the decline happens.

How many concurrent clients?

Can you show the perf's call graph sampling profiles of both the unpatched and patched version, to confirm that the
bottleneckis around catcache eviction and refill?
 


Regards
Takayuki Tsunakawa