Rob Ross wrote:
quoted text
>
> Regarding Peter Staubach's comments about no one ever using the 
> readdirplus() call; well, if people weren't performing this workload 
> in the first place, we wouldn't *need* this sort of call! This call is 
> specifically targeted at improving "ls -l" performance on large 
> directories, and Sage has pointed out quite nicely how that might work. 


I don't think that anyone has shown a *need* for this sort of call yet,
actually.  What application would actually benefit from this call and
where are the measurements?  Simply asserting that "ls -l" will benefit
is not enough without some measurements.  Or mention a different real
world application...

Having developed and prototyped the NFSv3 READDIRPLUS, I can tell you
that the wins were less than expected/hoped for and while it wasn't
all that hard to implement in a simple way, doing so in a high performance
fashion is much harder.  Many implementations that I have heard about
turn off READDIRPLUS when dealing with a large directory.

Caching is what makes things fast and caching means avoiding going
over the network.

       ps
-
To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html