[RFC] Multiple QEMU AIO implementations

[Anthony Liguori <aliguori@us.ibm.com>]

[-- Attachment #1: Type: text/plain, Size: 745 bytes --]

This isn't fully cooked yet, but pretty close.  The basic idea is to 
make the aio usage in block-raw go to a set of function pointers and 
allow multiple simultaneous AIO implementations.

I converted the posix-aio support to this, and also introduced a "unix" 
aio which just uses O_NONBLOCK and select().  The later only supports 1 
simultaneous request per-fd but currently posix-aio is limited to that 
too.  At least with my QEMU testing, the unix aio implementation 
outperforms posix-aio by a factor of 2.

And it uses no signals...

I'm inclined to suggest that we use signalfd with posix-aio, and for 
older guests, just fall back to unix aio.  We can also introduce a 
linux-aio and use that when possible.

Regards,

Anthony Liguori

[-- Attachment #2: qemu-block-aio-unix.patch --]
[-- Type: application/mbox, Size: 27260 bytes --]

[-- Attachment #3: Type: text/plain, Size: 320 bytes --]

-------------------------------------------------------------------------
This SF.net email is sponsored by the 2008 JavaOne(SM) Conference 
Don't miss this year's exciting event. There's still time to save $100. 
Use priority code J8TL2D2. 
http://ad.doubleclick.net/clk;198757673;13503038;p?http://java.sun.com/javaone

[-- Attachment #4: Type: text/plain, Size: 158 bytes --]

_______________________________________________
kvm-devel mailing list
kvm-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/kvm-devel