Linux tmpfs (Was: [OpenAFS] Solaris 10u6: ZFS cache?)

[Brandon S. Allbery KF8NH]

On 2008 Nov 14, at 7:18, Chas Williams (CONTRACTOR) wrote:
> In message <5FB03AFA-8CA1-4B39- 
> A743-188E5DBF4666@ece.cmu.edu>,"Brandon S. Allbe
> ry KF8NH" writes:
>> It used to be said (back when warlord was maintaining linux-afs and
>> Transarc 3.4a was the main release) that the memcache was much less
>> efficient than the disk cache and that it was better to use disk  
>> cache
>> in a ramdisk.  Both have been pretty thoroughly overhauled since  
>> then,
>> though.
>
> "efficient" isnt meaningful without context.  memcache does use quite
> a bit of host memory.  if your system is short on memory, memcache is
> not for you.  however, memcache outperforms diskcache is most cases
> (ignoring say rereads over a link with high latency).

At the time memcache was an unoptimized linked list, IIRC, and  
performance simply stank.  It was worse than disk cache.

-- 
brandon s. allbery [solaris,freebsd,perl,pugs,haskell] allbery@kf8nh.com
system administrator [openafs,heimdal,too many hats] allbery@ece.cmu.edu
electrical and computer engineering, carnegie mellon university    KF8NH