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Groups > linux.kernel > #1211413
| Path | csiph.com!news.mixmin.net!aioe.org!bofh.it!news.nic.it!robomod |
|---|---|
| From | Paolo Bonzini <pbonzini@redhat.com> |
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH v3 2/5] KVM: add KVM_REQ_EXIT request for userspace exit |
| Date | Sat, 22 Aug 2015 09:10:02 +0200 |
| Message-ID | <q0b6a-3oF-3@gated-at.bofh.it> (permalink) |
| References | <pXkfD-7xK-3@gated-at.bofh.it> <pXkfE-7xK-25@gated-at.bofh.it> <pZpbb-1nR-1@gated-at.bofh.it> |
| X-Original-To | Wanpeng Li <wanpeng.li@hotmail.com>, Radim Krčmář <rkrcmar@redhat.com>, linux-kernel@vger.kernel.org |
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| Sender | robomod@news.nic.it |
| List-ID | <linux-kernel.vger.kernel.org> |
| X-Mailing-List | linux-kernel@vger.kernel.org |
| Approved | robomod@news.nic.it |
| Lines | 24 |
| Organization | linux.* mail to news gateway |
| X-Original-Cc | kvm@vger.kernel.org, Christian Borntraeger <borntraeger@de.ibm.com> |
| X-Original-Date | Sat, 22 Aug 2015 00:04:55 -0700 |
| X-Original-Message-ID | <55D81F17.8000907@redhat.com> |
| X-Original-References | <1439546917-17391-1-git-send-email-rkrcmar@redhat.com> <1439546917-17391-3-git-send-email-rkrcmar@redhat.com> <BLU436-SMTP2157250AAE5CAE1E256309080660@phx.gbl> |
| X-Original-Sender | linux-kernel-owner@vger.kernel.org |
| Xref | csiph.com linux.kernel:1211413 |
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On 19/08/2015 20:55, Wanpeng Li wrote: >> The disadvantage is that it adds an overhead of one bit check for all >> kernel exits. A quick tracing shows that the ratio of userspace exits >> after boot is about 1/5 and in subsequent run of nmap and kernel compile >> has about 1/60, so the check should not regress global performance. >> >> All signal_pending() calls are userspace exit requests, so we add a >> check for KVM_REQ_EXIT there. There is one omitted call in kvm_vcpu_run >> because KVM_REQ_EXIT is implied in earlier check for requests. > > Actually I see more SIGUSR1 signals are intercepted by signal_pending() > in vcpu_enter_guest() and vcpu_run() w/ win7 guest and kernel_irqchip=off. You need more patches on the QEMU side. I tested a version that is mostly okay but not ready for upstream inclusion. Paolo -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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Re: [PATCH v3 2/5] KVM: add KVM_REQ_EXIT request for userspace exit Wanpeng Li <wanpeng.li@hotmail.com> - 2015-08-20 06:00 +0200 Re: [PATCH v3 2/5] KVM: add KVM_REQ_EXIT request for userspace exit Paolo Bonzini <pbonzini@redhat.com> - 2015-08-22 09:10 +0200
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