lkml.org 
[lkml]   [2012]   [Apr]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRE: swap on eMMC and other flash
Date
Hugh,

Great topics. As per one of Rik original points:

> 4) skip writeout of zero-filled pages - this can be a big help
> for KVM virtual machines running Windows, since Windows zeroes
> out free pages; simply discarding a zero-filled page is not
> at all simple in the current VM, where we would have to iterate
> over all the ptes to free the swap entry before being able to
> free the swap cache page (I am not sure how that locking would
> even work)
>
> with the extra layer of indirection, the locking for this scheme
> can be trivial - either the faulting process gets the old page,
> or it gets a new one, either way it'll be zero filled
>

Since it's KVMs realm here, can't KSM simply solve the zero-filled pages problem avoiding unnecessary burden for the Swap subsystem?

Cheers,
Luca


\
 
 \ /
  Last update: 2012-04-02 14:55    [W:0.258 / U:0.984 seconds]
©2003-2014 Jasper Spaans. Advertise on this site