[Stgt-devel] sg_turs on stgt iscsi drive is very slow

[Ming Zhang]

On Sun, 2006-12-24 at 18:07 +0900, FUJITA Tomonori wrote:
> From: FUJITA Tomonori <fujita.tomonori at lab.ntt.co.jp>
> Subject: Re: [Stgt-devel] sg_turs on stgt iscsi drive is very slow
> Date: Thu, 14 Dec 2006 11:41:27 +0900
> 
> > From: Ming Zhang <mingz at ele.uri.edu>
> > Subject: Re: [Stgt-devel] sg_turs on stgt iscsi drive is very slow
> > Date: Tue, 12 Dec 2006 11:13:33 -0500
> > 
> > > same as yesterday. i think that EPOLL should have problem.
> > 
> > I did some performance tests. I wrongly use EPOLL_WAIT or EPOLL_WAIT
> > is much slower than AIO queue (try r616 if you are interested).
> > 
> > I'll try kevent in -mm kernel shortly (probably, after 2.6.20-rc1).
> 
> Seems that it might takes months to have kevent in mainline. So I
> added tweaked the EPOLL_WAIT patch.
> 
> The latest patch (aioepoll-2.6.20-rc2.diff), I've just put into the
> svn repository, should provide much better performances.

unfortunately i did not get much better performance at my side.

dl 2.6.19, patch -rc2 patch, patch aioepoll-2.6.20-rc2.diff.
enable scsi target support in kernel and disable all kernel debug
option, compile and boot with new kernel.
make KERNELSRC=<rc2> ISCSI=1
export same 4 disk raid0.


results similar to last time.

Ming