[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH] [shadow] Disable higher level pagetables early unshadow only when the "process dying" hypercall is used.
This patch fixes a performance problem in fully virtualized guests. Should be backported to xen-4.0 and xen-4.1. This patch applies (with slightly different offsets) to all three versions. Signed-off-by: Gianluca Guida <gianluca.guida@xxxxxxxxxx> Tested-by: Jan Beulich <jbeulich@xxxxxxxx> diff -r 068d3d55ce6e xen/arch/x86/mm/shadow/multi.c --- a/xen/arch/x86/mm/shadow/multi.c Tue Nov 01 19:03:38 2011 +0000 +++ b/xen/arch/x86/mm/shadow/multi.c Wed Nov 16 14:30:57 2011 -0800 @@ -2723,8 +2723,9 @@ || ( !v->domain->arch.paging.shadow.pagetable_dying_op && v->arch.paging.shadow.last_emulated_mfn_for_unshadow == mfn_x(gmfn) ) ) && sh_mfn_is_a_page_table(gmfn) - && !(mfn_to_page(gmfn)->shadow_flags - & (SHF_L2_32|SHF_L2_PAE|SHF_L2H_PAE|SHF_L4_64)) ) + && (!v->domain->arch.paging.shadow.pagetable_dying_op || + !(mfn_to_page(gmfn)->shadow_flags + & (SHF_L2_32|SHF_L2_PAE|SHF_L2H_PAE|SHF_L4_64))) ) { perfc_incr(shadow_early_unshadow); sh_remove_shadows(v, gmfn, 1, 0 /* Fast, can fail to unshadow */ ); _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxxxxxxxx http://lists.xensource.com/xen-devel
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