Re: [PATCH 3/3] virtio-blk: Add bio-based IO path for virtio-blk

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 06/18/2012 06:05 PM, Rusty Russell wrote:
On Mon, 18 Jun 2012 16:03:23 +0800, Asias He <asias@xxxxxxxxxx> wrote:
On 06/18/2012 03:46 PM, Rusty Russell wrote:
On Mon, 18 Jun 2012 14:53:10 +0800, Asias He <asias@xxxxxxxxxx> wrote:
This patch introduces bio-based IO path for virtio-blk.

Why make it optional?

request-based IO path is useful for users who do not want to bypass the
IO scheduler in guest kernel, e.g. users using spinning disk. For users
using fast disk device, e.g. SSD device, they can use bio-based IO path.

Users using a spinning disk still get IO scheduling in the host though.
What benefit is there in doing it in the guest as well?

Merging in guest kernel's IO scheduling can reduce the number of requests guest fires to host side. For instance, with the same workload in guest side, the number of request drops to ~200K from ~4000K with guest kernel's merging in qemu.


Cheers,
Rusty.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/



--
Asias


_______________________________________________
Virtualization mailing list
Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx
https://lists.linuxfoundation.org/mailman/listinfo/virtualization


[Index of Archives]     [KVM Development]     [Libvirt Development]     [Libvirt Users]     [CentOS Virtualization]     [Netdev]     [Ethernet Bridging]     [Linux Wireless]     [Kernel Newbies]     [Security]     [Linux for Hams]     [Netfilter]     [Bugtraq]     [Yosemite Forum]     [MIPS Linux]     [ARM Linux]     [Linux RAID]     [Linux Admin]     [Samba]

  Powered by Linux