SMB2 performance is worse than SMB1 while iometer 512byte transfer

[Simo]

On Sun, 2013-09-15 at 05:26 -0700, Volker Lendecke wrote:
> On Sun, Sep 15, 2013 at 06:21:27AM +0800, Jones wrote:
> > Hi Jeremy,
> > 
> > 2013/9/14 Jeremy Allison <jra at samba.org>
> > >
> > >
> > > talloc_chunk_from_ptr should be inlined, so I'm assuming
> > > inlined functions shouldn't show up on perf (I may be
> > > wrong here :-).
> > >
> > > How are you compiling smbd. Are you using -O<level> ?
> > >
> > 
> > You are right! It is my fault!
> > There is no optimization level is specified when I compiling samba4,
> > After re-run the configuration phase with CFLAGS="-O -g" and re-compiling,
> > perf top does not show talloc_chunk_from_ptr anymore.
> > 
> > With samba-3.6, though -O is not specified in configuration phase,
> > source3/Makefile could see this
> > CFLAGS= -O -D_REENTRANT -D_POSIX_PTHREAD_SEMANTICS $(FLAGS)
> > -D_SAMBA_BUILD_=3
> > 
> > With samba-4 series, it is likely -O should be explicit specified,
> > now samba4 is deployed with python-style waf so cannot found the Makefile
> > as expected.
> > 
> > Found following links but not get much hint to where add the optimize flags,
> > is ./configure CFLAGS="-O" sufficient?
> 
> I always do
> 
> CFLAGS=-O ./configure
> 
> Just one question: Does -O3 make a difference?
> 
> Volker
> 

For best results I use "-O0 -ggdb3"

Simo.