lkml.org 
[lkml]   [2023]   [Jul]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH v4] xen: speed up grant-table reclaim
From
On 26.07.23 18:52, Demi Marie Obenour wrote:
> When a grant entry is still in use by the remote domain, Linux must put
> it on a deferred list. Normally, this list is very short, because
> the PV network and block protocols expect the backend to unmap the grant
> first. However, Qubes OS's GUI protocol is subject to the constraints
> of the X Window System, and as such winds up with the frontend unmapping
> the window first. As a result, the list can grow very large, resulting
> in a massive memory leak and eventual VM freeze.
>
> To partially solve this problem, make the number of entries that the VM
> will attempt to free at each iteration tunable. The default is still
> 10, but it can be overridden via a module parameter.
>
> This is Cc: stable because (when combined with appropriate userspace
> changes) it fixes a severe performance and stability problem for Qubes
> OS users.
>
> Cc: stable@vger.kernel.org
> Signed-off-by: Demi Marie Obenour <demi@invisiblethingslab.com>

Reviewed-by: Juergen Gross <jgross@suse.com>


Juergen

[unhandled content-type:application/pgp-keys][unhandled content-type:application/pgp-signature]
\
 
 \ /
  Last update: 2023-07-27 07:31    [W:0.045 / U:2.292 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site