> -----Original Message----- > From: Jan Beulich <jbeul...@suse.com> > Sent: 06 March 2020 13:46 > To: Paul Durrant <xadimg...@gmail.com> > Cc: sstabell...@kernel.org; jul...@xen.org; volodymyr_babc...@epam.com; > w...@xen.org; > konrad.w...@oracle.com; andrew.coop...@citrix.com; ian.jack...@eu.citrix.com; > george.dun...@citrix.com; xen-devel@lists.xenproject.org; 'David Woodhouse' > <dw...@infradead.org> > Subject: Re: [PATCH 2/2] domain: use PGC_extra domheap page for shared_info > > On 06.03.2020 14:41, Paul Durrant wrote: > >> -----Original Message----- > >> From: Jan Beulich <jbeul...@suse.com> > >> Sent: 06 March 2020 13:36 > >> To: Paul Durrant <xadimg...@gmail.com> > >> Cc: sstabell...@kernel.org; jul...@xen.org; volodymyr_babc...@epam.com; > >> w...@xen.org; > >> konrad.w...@oracle.com; andrew.coop...@citrix.com; > >> ian.jack...@eu.citrix.com; > >> george.dun...@citrix.com; xen-devel@lists.xenproject.org; 'David > >> Woodhouse' <dw...@infradead.org> > >> Subject: Re: [PATCH 2/2] domain: use PGC_extra domheap page for shared_info > >> > >> On 06.03.2020 14:26, Paul Durrant wrote: > >>>> From: Xen-devel <xen-devel-boun...@lists.xenproject.org> On Behalf Of > >>>> Jan Beulich > >>>> Sent: 06 March 2020 13:24 > >>>> > >>>> On 06.03.2020 14:13, Paul Durrant wrote: > >>>>> My aim is to make the separation abundantly obvious by getting rid > >>>>> of shared xenheap pages (for non-system domains at least) but I > >>>>> can't do that before converting shared_info and grant shared/status > >>>>> frames to domheap. > >>>> > >>>> Following David's various replies - instead of going this route of > >>>> replacing the sharing of xenheap pages by different logic, the > >>>> same ought to be achievable by making the backing allocations come > >>>> from the correct pool? > >>>> > >>> > >>> I still prefer the simplification of not having to clean up the > >>> shared xenheap page list in domain_kill() so IMO it is still worth > >>> it for that alone. > >> > >> I don't see anything very special with the cleaning up in > >> domain_kill() / domain_relinquish_resources(). What I'd view as > >> more desirable in this regard is the general fact of needing > >> two lists. But you realize there's a downside to this as well? > >> dump_pageframe_info() will reliably show _all_ Xen heap pages > >> associated with a domain, but it will only ever show up to 10 > >> pages on ->page_list for a domain that's not already being > >> cleaned up. > > > > That's not much of a downside though I don't think. The xenheap > > (or PGC_extra domheap pages) are 'special' and so info about > > them ought to be available via an alternate dump function anyway > > (and if not already, it can be added). > > Whatever you'd add, the logic would need to either traverse the > entire ->page_list (can take very long) or have/use out of band > information where such pages may have a record (fragile). >
But the shared xenheap pages in question are only shared info, or grant table, so their information can be dumped separately. I guess it makes more sense to add another patch into the series to do explicit dump of shared_info and then exclude 'special' pages from dump_pageframe_info(). Paul > Jan _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
