On 07/30/2012 09:44 PM, Christoph Hellwig wrote:
On Mon, Jul 30, 2012 at 09:31:06AM +0200, Paolo Bonzini wrote:
You only need to add REQ_FLUSH support. The virtio-blk protocol does
not support REQ_FUA, because there's no easy way to do it in userspace.
A bio-based driver needs to handle both
On 07/30/2012 09:43 PM, Christoph Hellwig wrote:
On Mon, Jul 30, 2012 at 12:43:12PM +0800, Asias He wrote:
I think we can add REQ_FLUSH & REQ_FUA support to bio path and that
deserves another patch.
Adding it is a requirement for merging the code.
OK. Will add that.
--
Asias
--
To unsubscr
On Mon, Jul 30, 2012 at 12:43:12PM +0800, Asias He wrote:
> I think we can add REQ_FLUSH & REQ_FUA support to bio path and that
> deserves another patch.
Adding it is a requirement for merging the code.
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to
On Mon, Jul 30, 2012 at 09:31:06AM +0200, Paolo Bonzini wrote:
> You only need to add REQ_FLUSH support. The virtio-blk protocol does
> not support REQ_FUA, because there's no easy way to do it in userspace.
A bio-based driver needs to handle both REQ_FLUSH and REQ_FUA as it does
not get the sequ
Il 30/07/2012 06:43, Asias He ha scritto:
>>
>
> Yes. Something like this:
>
> qemu -drive file=foo.img,cache=writeback/unsafe
>
> is not safe against power losses also?
cache=writeback and cache=none are safe, cache=unsafe isn't.
> I think we can add REQ_FLUSH & REQ_FUA support to bio path
On 07/28/2012 02:42 PM, Paolo Bonzini wrote:
I'm not sure what the correct behavior for bio & cacheflush is, if
any.
REQ_FLUSH is not supported in the bio path.
Ouch, that's correct:
@@ -414,7 +529,7 @@ static void virtblk_update_cache_mode(struct virtio_device
*vdev)
u8 writeback =
On 07/29/2012 08:59 PM, Michael S. Tsirkin wrote:
On Sat, Jul 28, 2012 at 10:38:41AM +0800, Asias He wrote:
On 07/27/2012 08:33 AM, Rusty Russell wrote:
On Fri, 13 Jul 2012 16:38:51 +0800, Asias He wrote:
Add 'virtio_blk.use_bio=1' to kernel cmdline or 'modprobe virtio_blk
use_bio=1' to enabl
On Sat, Jul 28, 2012 at 10:38:41AM +0800, Asias He wrote:
> On 07/27/2012 08:33 AM, Rusty Russell wrote:
> >On Fri, 13 Jul 2012 16:38:51 +0800, Asias He wrote:
> >>Add 'virtio_blk.use_bio=1' to kernel cmdline or 'modprobe virtio_blk
> >>use_bio=1' to enable ->make_request_fn() based I/O path.
> >
> > I'm not sure what the correct behavior for bio & cacheflush is, if
> > any.
>
> REQ_FLUSH is not supported in the bio path.
Ouch, that's correct:
@@ -414,7 +529,7 @@ static void virtblk_update_cache_mode(struct virtio_device
*vdev)
u8 writeback = virtblk_get_cache_mode(vdev);
On 07/27/2012 08:33 AM, Rusty Russell wrote:
On Fri, 13 Jul 2012 16:38:51 +0800, Asias He wrote:
Add 'virtio_blk.use_bio=1' to kernel cmdline or 'modprobe virtio_blk
use_bio=1' to enable ->make_request_fn() based I/O path.
This patch conflicts with Paolo's Bonzini's 'virtio-blk: allow togglin
On Fri, 13 Jul 2012 16:38:51 +0800, Asias He wrote:
> This patch introduces bio-based IO path for virtio-blk.
Acked-by: Rusty Russell
I just hope we can do better than a module option in future.
Thanks,
Rusty.
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a m
On Fri, 13 Jul 2012 16:38:51 +0800, Asias He wrote:
> Add 'virtio_blk.use_bio=1' to kernel cmdline or 'modprobe virtio_blk
> use_bio=1' to enable ->make_request_fn() based I/O path.
This patch conflicts with Paolo's Bonzini's 'virtio-blk: allow toggling
host cache between writeback and writethrou
This patch introduces bio-based IO path for virtio-blk.
Compared to request-based IO path, bio-based IO path uses driver
provided ->make_request_fn() method to bypasses the IO scheduler. It
handles the bio to device directly without allocating a request in block
layer. This reduces the IO path in
13 matches
Mail list logo