On Tue, Sep 15, 2009 at 10:39 AM, Vladislav Bolkhovitin <v...@vlnb.net> wrote: > Chris Worley, on 09/15/2009 03:03 AM wrote: >> >> On Mon, Sep 14, 2009 at 12:51 PM, Vladislav Bolkhovitin <v...@vlnb.net> >> wrote: >>> >>> Chris Worley, on 09/11/2009 11:50 PM wrote: >>>> >>>> I've definitely removed the switch/firmware from being the cause. >>>> >>>> I'm thinking the reason you can't repeat the test may be latency >>>> related. We get ~50usecs average latency (on small block sizes), >>>> which can't be achieved using regular SSD's (and rotating drives are >>>> nowhere close). Maybe a ramdisk would help repeat the issue. >>> >>> I think you should try to reproduce the problem with ramdisk or nullio. >>> By >>> so you will eliminate possible influence of the SSD backend. >> >> W/ 12GB RAM in the target, I created a 7GB ramdisk: >> >> mount -t ramfs -o size=7g ramfs /mnt/ >> dd if=/dev/zero of=/mnt/foo bs=1024k count=7000 >> echo "open ramdisk /mnt/foo" > /proc/scsi_tgt/vdisk/vdisk >> echo "add ramdisk 2" >/proc/scsi_tgt/groups/Default/devices >> >> Then, on the initiator, I tested it... and it hung during sequential >> 8KB block reads: >> >> fio --rw=read --bs=8k --numjobs=64 --iodepth=64 --sync=0 --direct=1 >> --randrepeat=0 \ >> --group_reporting --ioengine=libaio --filename=/dev/sde --name=test >> --loops=10000 --runtime=600 >> >> Note that I was running the SM on the target this time too. > > Should you try then with iSCSI with IPoIB? It will eliminate the SRP stack.
I don't see this issue w/ iSCSI over IPoIB... I also don't see the performance. Chris > >> Thanks, >> >> Chris >>> >>> Vlad >>> >> >> >> ------------------------------------------------------------------------------ >> Come build with us! The BlackBerry® Developer Conference in SF, CA >> is the only developer event you need to attend this year. Jumpstart your >> developing skills, take BlackBerry mobile applications to market and stay >> ahead of the curve. Join us from November 9-12, 2009. Register now! >> http://p.sf.net/sfu/devconf >> _______________________________________________ >> Scst-devel mailing list >> scst-de...@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/scst-devel >> > > -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html