Re: [RFC][CFT] GEOM direct dispatch and fine-grained CAM locking

On Saturday, September 07, 2013 2:32:45 am Alexander Motin wrote:
> On 07.09.2013 02:02, Jeremie Le Hen wrote:
> > On Fri, Sep 06, 2013 at 11:29:11AM +0300, Alexander Motin wrote:
> >> On 06.09.2013 11:06, Jeremie Le Hen wrote:
> >>> On Fri, Sep 06, 2013 at 12:46:27AM +0200, Olivier Cochard-Labbé wrote:
> >>>> On Thu, Sep 5, 2013 at 11:38 PM, Alexander Motin <mav_at_freebsd.org> 
wrote:
> >>>>> I've found and fixed possible double request completion, that could 
cause
> >>>>> such symptoms if happened. Updated patch located as usual:
> >>>>> http://people.freebsd.org/~mav/camlock_patches/camlock_20130905.patch
> >>>>>
> >>> With this new one I cannot boot any more (I also updated the source
> >>> tree).  This is a hand transcripted version:
> >>>
> >>> Trying to mount root from zfs:zroot/root []...
> >>> panic: Batch flag already set
> >>> cpuid = 1
> >>> KDB: stack backtrace:
> >>> db_trace_self_wrapper()
> >>> kdb_backtrace()
> >>> vpanic()
> >>> kassert_panic()
> >>> xpt_batch_start()
> >>> ata_interrupt()
> >>> softclock_call_cc()
> >>> softclock()
> >>> ithread_loop()
> >>> fork_exit()
> >>> fork_trampoline()
> >>
> >> Thank you for the report. I see my fault. It is probably specific to
> >> ata(4) driver only. I've workarounded that in new patch version, but
> >> probably that area needs some rethinking.
> >>
> >> http://people.freebsd.org/~mav/camlock_patches/camlock_20130906.patch
> >
> > I'm not sure you needed a confirmation, but it boots.  Thanks :).
> >
> > I didn't quite understand the thread; is direct dispatch enabled for
> > amd64?  ISTR you said only i386 but someone else posted the macro for
> > amd64.
> 
> Yes, it is enabled for amd64. I've said x86, meaning both i386 and amd64.

FYI, I tested mfi with this patch set and mfid worked fine for handling g_up
directly:

Index: dev/mfi/mfi_disk.c
===================================================================
--- dev/mfi/mfi_disk.c  (revision 257407)
+++ dev/mfi/mfi_disk.c  (working copy)
_at__at_ -162,6 +162,7 _at__at_
        sc->ld_disk->d_unit = sc->ld_unit;
        sc->ld_disk->d_sectorsize = secsize;
        sc->ld_disk->d_mediasize = sectors * secsize;
+       sc->ld_disk->d_flags = DISKFLAG_DIRECT_COMPLETION;
        if (sc->ld_disk->d_mediasize >= (1 * 1024 * 1024)) {
                sc->ld_disk->d_fwheads = 255;
                sc->ld_disk->d_fwsectors = 63;
                                                                                

-- 
John Baldwin