Re: FIO for MIPS

[Jens Axboe <jens.axboe@oracle.com>]

Hi,

Yes, if you can live with O_DIRECT, libaio performs a lot better than
posixaio. Nobody should use posixaio in their apps if they care just a
bit about performance, it just doesn't work very well. Using CLONE_IO
would help, but even with that it's still pretty suboptimal.


On Tue, Sep 01 2009, Learner Study wrote:
> Hi Jens:
> 
> Thanks - it works well.
> 
> I'm using FIO with posixaio ioengine and performance is pretty bad. I'm
> trying to get libaio to work  in my MIPS environment. Based on my tests in
> previous x86 env, I had seen libaio to give better performance with FIO as
> compared to posixaio.
> 
> Again, thanks for your prompt help.
> 
> On Mon, Aug 31, 2009 at 10:38 PM, Jens Axboe <jens.axboe@oracle.com> wrote:
> 
> > On Mon, Aug 31 2009, Learner Study wrote:
> > > Hello:
> > >
> > > I checked README for FIO and apparently it isn't yet supported on MIPS64
> > > platform yet (atleast until version 1.30)
> > > Does someone have a patch I could use to do this? Any other ideas...
> >
> > I just checked in the below patch. I haven't checked the memory ordering
> > defines yet, not sure if any of the mips cpus are weaker ordered. I'll
> > check that later, this should at least get you started.
> >
> > commit c28b912f77c3dafbdcdcf4def2c8c1f9c127100c
> > Author: Jens Axboe <jens.axboe@oracle.com>
> > Date:   Tue Sep 1 07:23:57 2009 +0200
> >
> >    MIPS support
> >
> >    Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
> >
> > diff --git a/arch/arch-mips.h b/arch/arch-mips.h
> > new file mode 100644
> > index 0000000..759d3a9
> > --- /dev/null
> > +++ b/arch/arch-mips.h
> > @@ -0,0 +1,25 @@
> > +#ifndef ARCH_MIPS64_H
> > +#define ARCH_MIPS64_H
> > +
> > +#define ARCH   (arch_mips)
> > +
> > +#ifndef __NR_ioprio_set
> > +#define __NR_ioprio_set                314
> > +#define __NR_ioprio_get                315
> > +#endif
> > +
> > +#ifndef __NR_fadvise64
> > +#define __NR_fadvise64         215
> > +#endif
> > +
> > +#ifndef __NR_sys_splice
> > +#define __NR_sys_splice                263
> > +#define __NR_sys_tee           265
> > +#define __NR_sys_vmsplice      266
> > +#endif
> > +
> > +#define read_barrier()         __asm__ __volatile__("": : :"memory")
> > +#define write_barrier()                __asm__ __volatile__("": :
> > :"memory")
> > +#define nop                    __asm__ __volatile__("": : :"memory")
> > +
> > +#endif
> > diff --git a/arch/arch.h b/arch/arch.h
> > index 28c6632..87db222 100644
> > --- a/arch/arch.h
> > +++ b/arch/arch.h
> > @@ -31,6 +31,8 @@ enum {
> >  #include "arch-sparc64.h"
> >  #elif defined(__arm__)
> >  #include "arch-arm.h"
> > +#elif defined(__mips__) || defined(__mips64__)
> > +#include "arch-mips.h"
> >  #else
> >  #error "Unsupported arch"
> >  #endif
> >
> > --
> > Jens Axboe
> >
> >

-- 
Jens Axboe