| Message ID | 1368706673-8530-9-git-send-email-xiaoguangrong@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Il 16/05/2013 14:17, Xiao Guangrong ha scritto: > Zap at lease 10 pages before releasing mmu-lock to reduce the overload > caused by requiring lock > > [ It improves kernel building 0.6% ~ 1% ] > > Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> > --- > arch/x86/kvm/mmu.c | 11 ++++++++--- > 1 files changed, 8 insertions(+), 3 deletions(-) > > diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c > index e12f431..9c27fda 100644 > --- a/arch/x86/kvm/mmu.c > +++ b/arch/x86/kvm/mmu.c > @@ -4216,10 +4216,12 @@ restart: > spin_unlock(&kvm->mmu_lock); > } > > +#define BATCH_ZAP_PAGES 10 > static void zap_invalid_pages(struct kvm *kvm) > { > struct kvm_mmu_page *sp, *node; > LIST_HEAD(invalid_list); > + int batch = 0; > > restart: > list_for_each_entry_safe(sp, node, &kvm->arch.active_mmu_pages, link) { > @@ -4256,11 +4258,14 @@ restart: > * Need not flush tlb since we only zap the sp with invalid > * generation number. > */ > - if (cond_resched_lock(&kvm->mmu_lock)) > + if ((batch >= BATCH_ZAP_PAGES) && > + cond_resched_lock(&kvm->mmu_lock)) { > + batch = 0; > goto restart; > + } > > - if (kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list)) > - goto restart; > + batch += kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list); > + goto restart; Would this look again and again at the same page if kvm_mmu_prepare_zap_page returns 0? Paolo > } > > /* > -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 05/16/2013 08:45 PM, Paolo Bonzini wrote: > Il 16/05/2013 14:17, Xiao Guangrong ha scritto: >> Zap at lease 10 pages before releasing mmu-lock to reduce the overload >> caused by requiring lock >> >> [ It improves kernel building 0.6% ~ 1% ] >> >> Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> >> --- >> arch/x86/kvm/mmu.c | 11 ++++++++--- >> 1 files changed, 8 insertions(+), 3 deletions(-) >> >> diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c >> index e12f431..9c27fda 100644 >> --- a/arch/x86/kvm/mmu.c >> +++ b/arch/x86/kvm/mmu.c >> @@ -4216,10 +4216,12 @@ restart: >> spin_unlock(&kvm->mmu_lock); >> } >> >> +#define BATCH_ZAP_PAGES 10 >> static void zap_invalid_pages(struct kvm *kvm) >> { >> struct kvm_mmu_page *sp, *node; >> LIST_HEAD(invalid_list); >> + int batch = 0; >> >> restart: >> list_for_each_entry_safe(sp, node, &kvm->arch.active_mmu_pages, link) { >> @@ -4256,11 +4258,14 @@ restart: >> * Need not flush tlb since we only zap the sp with invalid >> * generation number. >> */ >> - if (cond_resched_lock(&kvm->mmu_lock)) >> + if ((batch >= BATCH_ZAP_PAGES) && >> + cond_resched_lock(&kvm->mmu_lock)) { >> + batch = 0; >> goto restart; >> + } >> >> - if (kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list)) >> - goto restart; >> + batch += kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list); >> + goto restart; > > Would this look again and again at the same page if > kvm_mmu_prepare_zap_page returns 0? We skip the invalid page (sp->role.invalid) before call kvm_mmu_prepare_zap_page so that kvm_mmu_prepare_zap_page can not meet the same page. ;) -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index e12f431..9c27fda 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -4216,10 +4216,12 @@ restart: spin_unlock(&kvm->mmu_lock); } +#define BATCH_ZAP_PAGES 10 static void zap_invalid_pages(struct kvm *kvm) { struct kvm_mmu_page *sp, *node; LIST_HEAD(invalid_list); + int batch = 0; restart: list_for_each_entry_safe(sp, node, &kvm->arch.active_mmu_pages, link) { @@ -4256,11 +4258,14 @@ restart: * Need not flush tlb since we only zap the sp with invalid * generation number. */ - if (cond_resched_lock(&kvm->mmu_lock)) + if ((batch >= BATCH_ZAP_PAGES) && + cond_resched_lock(&kvm->mmu_lock)) { + batch = 0; goto restart; + } - if (kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list)) - goto restart; + batch += kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list); + goto restart; } /*
Zap at lease 10 pages before releasing mmu-lock to reduce the overload caused by requiring lock [ It improves kernel building 0.6% ~ 1% ] Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> --- arch/x86/kvm/mmu.c | 11 ++++++++--- 1 files changed, 8 insertions(+), 3 deletions(-)