Re: Slowdown on high-load machines with 3000 sockets

Christian Schmid
2005-02-28T00:09:01Z

No i am only using 4 tasks with Poll-API and non-blocking sockets. Every socket gets a 1 MB
read-ahead. This are 4000 MB Max on a 8 GB machine.... Shouldnt thrash.

Rik van Riel wrote:
> On Sun, 27 Feb 2005, Christian Schmid wrote:
>
>
>>>Christian, how big are the data blocks you sys_readahead, and
>>>how many do you have outstanding at a time ?
>>
>>I am reading 800000 bytes of data as soon as there is less than 200000
>>data in the cache. I do assume the cache doesnt kill itself. I have 8 GB
>>machine with 7,5 GB free for caching.
>
>
> OK, so you read 800kB with 4000 threads, or 3.2GB of
> readahead data. The inactive list is quite possibly
> smaller than that, at 1/3 of memory or around 2.6 GB.
>
> It looks like the cache might be killing itself, through
> readahead thrashing.
>