* Trond Myklebust <[email protected]> wrote:
> > the comment suggests that this is optimized for append writes (which is
> > quite common, but by far not the only write workload) - but the
> > worst-case behavior of this code is very bad. How about disabling this
> > sorting altogether and benchmarking the result? Maybe it would get
> > comparable coalescing (higher levels do coalesce after all), but wastly
> > improved CPU utilization on the client side. (Note that the server
> > itself will do sorting of any write IO anyway, if this is to hit any
> > persistent storage - and if not then sorting so agressively on the
> > client side makes little sense.)
>
> No. Coalescing on the client makes tons of sense. The overhead of
> sending 8 RPC requests for 4k writes instead of sending 1 RPC request
> for a single 32k write is huge: among other things, you end up tying up
> 8 RPC slots on the client + 8 nfsd threads on the server instead of just
> one of each.
yes - coalescing a few pages makes sense, but linearly scanning
thousands of entries is entirely pointless.
Ingo
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
