[Xen-ia64-devel] Re: [Xen-devel] Re: [PATCH] Disable auto-balloon on ia64
On 22 May 2006, at 10:37, Keir Fraser wrote: We just need to reverse the whole change for ia64, since both domU and domVTI are insert a hole by this auto-balloon patch. Due to missing balloon support on xen/ia64 as you said, both domU and domVTI failed due to this change. The first patch that you work around seems okay to me. That is, it seems correct that we make initial reservation exclude 'getDomainMemory headroom'. Shouldn't ia64 reserve extra memory as it needs it, as x86 does, rather than up front? The second bit of your workaround, which applies to getDomainMemory: I'll wait and see if Charles has anything to say, but otherwise I'll remove the code that adds the extra slack entirely. Thinking about it, that slack might have been added to give enough space for shadow page tables for live migration. Also, it shouldn't give you any problems if you weren't allocating headroom up front -- if you can fix ia64 to allocate the extra memory as needed then you shouldn't need either of your workarounds? -- Keir ___ Xen-ia64-devel mailing list Xen-ia64-devel@lists.xensource.com http://lists.xensource.com/xen-ia64-devel
[Xen-ia64-devel] RE: [Xen-devel] Re: [PATCH] Disable auto-balloon on ia64
From: Keir Fraser [mailto:[EMAIL PROTECTED] Sent: 2006年5月22日 17:51 To: Keir Fraser We just need to reverse the whole change for ia64, since both domU and domVTI are insert a hole by this auto-balloon patch. Due to missing balloon support on xen/ia64 as you said, both domU and domVTI failed due to this change. The first patch that you work around seems okay to me. That is, it seems correct that we make initial reservation exclude 'getDomainMemory headroom'. Shouldn't ia64 reserve extra memory as it needs it, as x86 does, rather than up front? The second bit of your workaround, which applies to getDomainMemory: I'll wait and see if Charles has anything to say, but otherwise I'll remove the code that adds the extra slack entirely. Thinking about it, that slack might have been added to give enough space for shadow page tables for live migration. Also, it shouldn't give you any problems if you weren't allocating headroom up front -- if you can fix ia64 to allocate the extra memory as needed then you shouldn't need either of your workarounds? -- Keir OK, the question by far is that ia64 describes the memory hierarchy presented to domain by d-max_pages. Before balloon is ready, we at least need to ensure all frames covered by d-max_pages allocated for target domain. Then there're two alternatives: - Keep the first piece of change on increase_reservation, which ensures all pages including extra spaces allocated immediately. - Pass the extra memory size to xen at arch_set_info_guest, and then change xen/ia64 to only tell domain maximum pfns as d-max_pages-extra_size Both need to be changed again later if balloon is ready. So I prefer to option I which is simpler and can help Alex to do sync quickly. How do you think? Thanks, Kevin ___ Xen-ia64-devel mailing list Xen-ia64-devel@lists.xensource.com http://lists.xensource.com/xen-ia64-devel
[Xen-ia64-devel] RE: [Xen-devel] Re: [PATCH] Disable auto-balloon on ia64
On Mon, 2006-05-22 at 21:33 +0800, Tian, Kevin wrote: OK, the question by far is that ia64 describes the memory hierarchy presented to domain by d-max_pages. Before balloon is ready, we at least need to ensure all frames covered by d-max_pages allocated for target domain. Then there're two alternatives: - Keep the first piece of change on increase_reservation, which ensures all pages including extra spaces allocated immediately. - Pass the extra memory size to xen at arch_set_info_guest, and then change xen/ia64 to only tell domain maximum pfns as d-max_pages-extra_size Both need to be changed again later if balloon is ready. So I prefer to option I which is simpler and can help Alex to do sync quickly. How do you think? I agree, I think we can get by with only the ia64 changes in the increase_reservation call. The other option seems more fragile. Keir, would you include the first chunk of Kevin's patch as a temporary solution until we have better ballooning support on xen/ia64 (should be soon)? Thanks, Alex -- Alex Williamson HP Linux Open Source Lab ___ Xen-ia64-devel mailing list Xen-ia64-devel@lists.xensource.com http://lists.xensource.com/xen-ia64-devel
