[REGRESSION][BISECTED] virtio-blk serial attribute causes guest to hang [Was: Re: [PATCH UPDATED 4/5] dm: implement REQ_FLUSH/FUA support for request-based dm]

2010-09-09 Thread Mike Snitzer
On Wed, Sep 01 2010 at 11:22pm -0400, Mike Snitzer snit...@redhat.com wrote: On Wed, Sep 01 2010 at 2:59pm -0400, Mike Snitzer snit...@redhat.com wrote: My hope was that the request-based deadlock I'm seeing would disappear if that relaxed ordering patch wasn't applied. Unfortunately, I

Re: [REGRESSION][BISECTED] virtio-blk serial attribute causes guest to hang [Was: Re: [PATCH UPDATED 4/5] dm: implement REQ_FLUSH/FUA support for request-based dm]

2010-09-09 Thread Ryan Harper
* Mike Snitzer snit...@redhat.com [2010-09-09 10:29]: On Wed, Sep 01 2010 at 11:22pm -0400, Mike Snitzer snit...@redhat.com wrote: On Wed, Sep 01 2010 at 2:59pm -0400, Mike Snitzer snit...@redhat.com wrote: My hope was that the request-based deadlock I'm seeing would disappear if

Re: [REGRESSION][BISECTED] virtio-blk serial attribute causes guest to hang [Was: Re: [PATCH UPDATED 4/5] dm: implement REQ_FLUSH/FUA support for request-based dm]

2010-09-09 Thread Mike Snitzer
On Thu, Sep 09 2010 at 11:44am -0400, Ryan Harper ry...@us.ibm.com wrote: * Mike Snitzer snit...@redhat.com [2010-09-09 10:29]: On Wed, Sep 01 2010 at 11:22pm -0400, Mike Snitzer snit...@redhat.com wrote: On Wed, Sep 01 2010 at 2:59pm -0400, Mike Snitzer snit...@redhat.com wrote:

Re: [REGRESSION][BISECTED] virtio-blk serial attribute causes guest to hang [Was: Re: [PATCH UPDATED 4/5] dm: implement REQ_FLUSH/FUA support for request-based dm]

2010-09-09 Thread Ryan Harper
* Mike Snitzer snit...@redhat.com [2010-09-09 10:58]: On Thu, Sep 09 2010 at 11:44am -0400, Ryan Harper ry...@us.ibm.com wrote: * Mike Snitzer snit...@redhat.com [2010-09-09 10:29]: On Wed, Sep 01 2010 at 11:22pm -0400, Mike Snitzer snit...@redhat.com wrote: On Wed, Sep 01 2010

Re: [REGRESSION][BISECTED] virtio-blk serial attribute causes guest to hang [Was: Re: [PATCH UPDATED 4/5] dm: implement REQ_FLUSH/FUA support for request-based dm]

2010-09-09 Thread Mike Snitzer
On Thu, Sep 09 2010 at 12:03pm -0400, Ryan Harper ry...@us.ibm.com wrote: * Mike Snitzer snit...@redhat.com [2010-09-09 10:58]: I'm using virtio-blk w/ cache=none for the root device. virtio-blk isn't used for any other devices in the guest. And you don't have any other disks in the

Re: [REGRESSION][BISECTED] virtio-blk serial attribute causes guest to hang [Was: Re: [PATCH UPDATED 4/5] dm: implement REQ_FLUSH/FUA support for request-based dm]

2010-09-09 Thread Ryan Harper
* Mike Snitzer snit...@redhat.com [2010-09-09 12:56]: On Thu, Sep 09 2010 at 12:03pm -0400, Ryan Harper ry...@us.ibm.com wrote: * Mike Snitzer snit...@redhat.com [2010-09-09 10:58]: I'm using virtio-blk w/ cache=none for the root device. virtio-blk isn't used for any other devices

Re: [REGRESSION][BISECTED] virtio-blk serial attribute causes guest to hang [Was: Re: [PATCH UPDATED 4/5] dm: implement REQ_FLUSH/FUA support for request-based dm]

2010-09-09 Thread Mike Snitzer
On Thu, Sep 09 2010 at 2:35pm -0400, Ryan Harper ry...@us.ibm.com wrote: * Mike Snitzer snit...@redhat.com [2010-09-09 12:56]: I have verified that I no longer get the hang if I switch the root device from virtio to ide. And in the failing case, do you see: /sys/block/vda/serial

Re: [REGRESSION][BISECTED] virtio-blk serial attribute causes guest to hang [Was: Re: [PATCH UPDATED 4/5] dm: implement REQ_FLUSH/FUA support for request-based dm]

2010-09-09 Thread Mike Snitzer
On Thu, Sep 09 2010 at 3:15pm -0400, Mike Snitzer snit...@redhat.com wrote: On Thu, Sep 09 2010 at 2:35pm -0400, Ryan Harper ry...@us.ibm.com wrote: * Mike Snitzer snit...@redhat.com [2010-09-09 12:56]: I have verified that I no longer get the hang if I switch the root device from

Re: [REGRESSION][BISECTED] virtio-blk serial attribute causes guest to hang [Was: Re: [PATCH UPDATED 4/5] dm: implement REQ_FLUSH/FUA support for request-based dm]

2010-09-09 Thread Mike Snitzer
On Thu, Sep 09 2010 at 3:43pm -0400, Mike Snitzer snit...@redhat.com wrote: Interestingly, just this loop: while true ; do cat /sys/block/vda/serial date sleep 1 ; done Thu Sep 9 15:29:30 EDT 2010 ... Thu Sep 9 15:31:19 EDT 2010 caused the following hang: ... So it seems like the

Re: [REGRESSION][BISECTED] virtio-blk serial attribute causes guest to hang [Was: Re: [PATCH UPDATED 4/5] dm: implement REQ_FLUSH/FUA support for request-based dm]

2010-09-09 Thread Ryan Harper
* Mike Snitzer snit...@redhat.com [2010-09-09 15:15]: On Thu, Sep 09 2010 at 3:43pm -0400, Mike Snitzer snit...@redhat.com wrote: Interestingly, just this loop: while true ; do cat /sys/block/vda/serial date sleep 1 ; done Thu Sep 9 15:29:30 EDT 2010 ... Thu Sep 9 15:31:19