Should there be any difference in performance while writing to a memory as cached versus uncached mapping?
On Tue, Nov 4, 2014 at 2:16 PM, Konstantin Belousov <[email protected]> wrote: > On Mon, Nov 03, 2014 at 01:52:44PM -0500, John Baldwin wrote: > > On Saturday 01 November 2014 18:55:53 Sourish Mazumder wrote: > > > Hi John, > > > > > > I tried the pmap_mapdev() as suggested by you. Works perfectly. Thanks > for > > > the information. > > > > Sure. > > > > > What is required, If I want to add this nvram memory to VM pages? > > > > Hmm. If this is device memory you generally don't want that. I'm not > > actually sure how to do this at runtime. If you don't mind having a > local > > hack you can add a change in the MD startup code (e.g. in hammer_time() > > in sys/amd64/amd64/machdep.c) to adjust the ranges added to > > phys_avail[] and dump_avail[]. > > The facility exists to do this. It is OBJT_MGTDEVICE pager and > vm_phys_fictitious_reg_range(). This is used by i915 and TTM for > aperture, and seems XEN dom0 code uses it for mapping pages from > other domains into dom0. > -- Sourish Mazumder 9986309755 _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-amd64 To unsubscribe, send any mail to "[email protected]"
