From: Keir Fraser Date: Thu, 12 Jun 2008 15:11:39 +0000 (+0100) Subject: x86: add perf counter for pointless updates of writable pages through a hypercall X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~14192^2~87 X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=ce095724dd15a17215a4e04453dc322dac77d8db;p=xen.git x86: add perf counter for pointless updates of writable pages through a hypercall Signed-off-by: Jan Beulich --- diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c index 9ab765da86..514d667715 100644 --- a/xen/arch/x86/mm.c +++ b/xen/arch/x86/mm.c @@ -2602,6 +2602,8 @@ int do_mmu_update( if ( unlikely(!get_page_type(page, PGT_writable_page)) ) break; + perfc_incr(writable_mmu_updates); + okay = paging_write_guest_entry(v, va, req.val, _mfn(mfn)); put_page_type(page); diff --git a/xen/include/asm-x86/perfc_defn.h b/xen/include/asm-x86/perfc_defn.h index 0bc2515b91..6012db35d2 100644 --- a/xen/include/asm-x86/perfc_defn.h +++ b/xen/include/asm-x86/perfc_defn.h @@ -23,6 +23,7 @@ PERFCOUNTER(calls_to_mmuext_op, "calls to mmuext_op") PERFCOUNTER(num_mmuext_ops, "mmuext ops") PERFCOUNTER(calls_to_mmu_update, "calls to mmu_update") PERFCOUNTER(num_page_updates, "page updates") +PERFCOUNTER(writable_mmu_updates, "mmu_updates of writable pages") PERFCOUNTER(calls_to_update_va, "calls to update_va_map") PERFCOUNTER(page_faults, "page faults") PERFCOUNTER(copy_user_faults, "copy_user faults")