Re: Big performance improvements seen with cifs async write patcheseven over localhost

[Steve French]

On Fri, May 27, 2011 at 11:47 AM, Jeremy Allison <jra@xxxxxxxxx> wrote:
> On Fri, May 27, 2011 at 12:14:19AM -0500, Steve French wrote:
>> Did some informal testing of Jeff Layton's cifs async_write patch set
>> tonight (recent kernel). Copying 700MB sequentially was 20% faster
>> from cifs kernel client to Samba 3.6 with his patches - even mounted
>> over localhost (where network latency is a much smaller issue) and
>> with a slow laptop drive!
>>
>> I was simply doing
>>
>> time dd if=/dev/zero of=/mnt/null bs=1M count=700
>>
>> repeated 4 times each way (with old module, and with same code with
>> Jeff's cifs async write code builtin), deleting the target file in
>> between each run.
>>
>> I am looking forward to trying this over GigE tomorrow to servers with
>> faster disks.

Note that Samba defaults to negotiating a 128K write size but sending
"min receivefile size" in smb.conf to a larger value will allow larger
writes.   I see slightly better performance on the simple dd test over
localhost network interface with larger wsize of 512K than I do with
the default (128K).   I haven't measured the ideal wsize yet but
presumably it will vary depending on network and disk speed and server
load.

> Very nice ! Now where's my encrypted transport Steve ? :-) :-)

First cleanup patch is in (which gracefully handles failing mounts
when server requires encryption and client can't do it).    The 2nd
part - the NTLMSSP negotiation inside setfsunixinfo wasn't too bad and
I plan to send out for review within a few days.  I haven't written
the piece which uses these credentials to do the encryption yet.



-- 
Thanks,

Steve
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