Isaku Yamahata
2006-Apr-28 06:32 UTC
[Xen-devel] [PATCH 2/2] balloon driver: don''t use apply_to_page_range for xenLinux/ia64
2 / 2 _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Keir Fraser
2006-Apr-28 07:00 UTC
Re: [Xen-devel] [PATCH 2/2] balloon driver: don''t use apply_to_page_range for xenLinux/ia64
The existing code should work on ia64, right? It''s not performance critical code. -- Keir On 28 Apr 2006, at 07:32, Isaku Yamahata wrote:> > 2 / 2 > <9879: > b5117df9f8ed_balloon_driver_ia64.patch>________________________________ > _______________ > Xen-devel mailing list > Xen-devel@lists.xensource.com > http://lists.xensource.com/xen-devel_______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Isaku Yamahata
2006-Apr-28 09:14 UTC
Re: [Xen-devel] [PATCH 2/2] balloon driver: don''t use apply_to_page_range for xenLinux/ia64
On Fri, Apr 28, 2006 at 08:00:30AM +0100, Keir Fraser wrote:> The existing code should work on ia64, right? It''s not performance > critical code.Unfortunately no. Roughly init_mm is only used to map vmalloc area on Linux/ia64. init_mm of Linux/ia64 doesn''t map the area of [PAGE_OFFSET, ...]. Traversing init_mm with a virtual address of the area gives a zero-filled pte entry. It also populates unnecessary pud/pmd/pte pages. Linux/ia64 resolves faults on the area [PAGE_OFFSET, ...] by tlb insert without init_mm traverse after checking faulted virtual address and its privilege. -- yamahata _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Keir Fraser
2006-Apr-28 13:57 UTC
Re: [Xen-devel] [PATCH 2/2] balloon driver: don''t use apply_to_page_range for xenLinux/ia64
On 28 Apr 2006, at 10:14, Isaku Yamahata wrote:> Unfortunately no. > Roughly init_mm is only used to map vmalloc area on Linux/ia64. > init_mm of Linux/ia64 doesn''t map the area of [PAGE_OFFSET, ...]. > Traversing init_mm with a virtual address of the area > gives a zero-filled pte entry. > It also populates unnecessary pud/pmd/pte pages. > > Linux/ia64 resolves faults on the area [PAGE_OFFSET, ...] > by tlb insert without init_mm traverse after checking > faulted virtual address and its privilege.Okay, but the ia64 ifdefs are unfortunate. Your new scheme will work for x86 autotranslated guests too (I''m pretty sure). How about we pick between the two schemes based on the autotranslate feature flag rather than ''ifdef ia64''? -- Keir _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Isaku Yamahata
2006-Apr-29 04:36 UTC
Re: [Xen-devel] [PATCH 2/2] balloon driver: don''t use apply_to_page_range for xenLinux/ia64
On Fri, Apr 28, 2006 at 02:57:17PM +0100, Keir Fraser wrote:> > On 28 Apr 2006, at 10:14, Isaku Yamahata wrote: > > >Unfortunately no. > >Roughly init_mm is only used to map vmalloc area on Linux/ia64. > >init_mm of Linux/ia64 doesn''t map the area of [PAGE_OFFSET, ...]. > >Traversing init_mm with a virtual address of the area > >gives a zero-filled pte entry. > >It also populates unnecessary pud/pmd/pte pages. > > > >Linux/ia64 resolves faults on the area [PAGE_OFFSET, ...] > >by tlb insert without init_mm traverse after checking > >faulted virtual address and its privilege. > > Okay, but the ia64 ifdefs are unfortunate. Your new scheme will work > for x86 autotranslated guests too (I''m pretty sure). How about we pick > between the two schemes based on the autotranslate feature flag rather > than ''ifdef ia64''?I attached the updated patch. I only tested on xen/ia64. -- yamahata _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel