Dan Magenheimer
2009-Jun-16 18:02 UTC
[Xen-devel] [PATCH] [linux-2.6.18-xen] (take 3) transcendent memory ("tmem") linux-side changes
(take 3: no anonymous unions; match Jan''s xen-side patch) Transcendent memory ("tmem") for Linux Tmem, when called from a tmem-capable (paravirtualized) guest, makes use of otherwise unutilized ("fallow") memory to create and manage pools of pages that can be accessed from the guest either as "ephemeral" pages or as "persistent" pages. In either case, the pages are not directly addressible by the guest, only copied to and fro via the tmem interface. Ephemeral pages are a nice place for a guest to put recently evicted clean pages that it might need again; these pages can be reclaimed synchronously by Xen for other guests or other uses. Persistent pages are a nice place for a guest to put "swap" pages to avoid sending them to disk. These pages retain data as long as the guest lives, but count against the guest memory allocation. This patch contains the Linux paravirtualization changes to complement the tmem Xen patch (xen-unstable c/s 19646). It implements "precache" (ext3 only as of now), "preswap", and limited "shared precache" (ocfs2 only as of now) support. CONFIG options are required to turn on the support (but in this patch they default to "y"). If the underlying Xen does not have tmem support or has it turned off, this is sensed early to avoid nearly all hypercalls. Lots of useful prose about tmem can be found at http://oss.oracle.com/projects/tmem Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com> _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Keir Fraser
2009-Jun-17 06:31 UTC
Re: [Xen-devel] [PATCH] [linux-2.6.18-xen] (take 3) transcendent memory ("tmem") linux-side changes
On 16/06/2009 19:02, "Dan Magenheimer" <dan.magenheimer@oracle.com> wrote:> (take 3: no anonymous unions; match Jan''s xen-side patch) > > Transcendent memory ("tmem") for LinuxI''ve now synced the Xen headers over to Linux 2.6.18, so please rebase the patch on that. This means you will not need to modify anything under include/xen/interface, and probably most of mm/tmem.h goes as well. -- Keir _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Dan Magenheimer
2009-Jun-17 16:11 UTC
RE: [Xen-devel] [PATCH] [linux-2.6.18-xen] (take 3) transcendent memory ("tmem") linux-side changes
Attached rebased against 906 in the staging tree.> -----Original Message----- > From: Keir Fraser [mailto:keir.fraser@eu.citrix.com] > Sent: Wednesday, June 17, 2009 12:32 AM > To: Dan Magenheimer; Xen-Devel (E-mail) > Cc: Jan Beulich > Subject: Re: [Xen-devel] [PATCH] [linux-2.6.18-xen] (take 3) > transcendent memory ("tmem") linux-side changes > > > On 16/06/2009 19:02, "Dan Magenheimer" > <dan.magenheimer@oracle.com> wrote: > > > (take 3: no anonymous unions; match Jan''s xen-side patch) > > > > Transcendent memory ("tmem") for Linux > > I''ve now synced the Xen headers over to Linux 2.6.18, so > please rebase the > patch on that. This means you will not need to modify anything under > include/xen/interface, and probably most of mm/tmem.h goes as well. > > -- Keir > > >_______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel