From: Zdenek Kaspar <zkaspar82@gmail.com>
To: "kvm@vger.kernel.org" <kvm@vger.kernel.org>
Subject: Bad performance since 5.9-rc1
Date: Thu, 19 Nov 2020 04:05:26 +0100 [thread overview]
Message-ID: <20201119040526.5263f557.zkaspar82@gmail.com> (raw)
Hi,
in my initial report (https://marc.info/?l=kvm&m=160502183220080&w=2 -
now fixed by c887c9b9ca62c051d339b1c7b796edf2724029ed) I saw degraded
performance going back somewhere between v5.8 - v5.9-rc1.
OpenBSD 6.8 (GENERIC.MP) guest performance (time ./test-build.sh)
good: 0m13.54s real 0m10.51s user 0m10.96s system
bad : 6m20.07s real 11m42.93s user 0m13.57s system
bisected to first bad commit: 6b82ef2c9cf18a48726e4bb359aa9014632f6466
git bisect log:
# bad: [e47c4aee5bde03e7018f4fde45ba21028a8f8438] KVM: x86/mmu: Rename
page_header() to to_shadow_page() # good:
[01c3b2b5cdae39af8dfcf6e40fdf484ae0e812c5] KVM: SVM: Rename
svm_nested_virtualize_tpr() to nested_svm_virtualize_tpr() git bisect
start 'e47c4aee5bde' '01c3b2b5cdae' # bad:
[ebdb292dac7993425c8e31e2c21c9978e914a676] KVM: x86/mmu: Batch zap MMU
pages when shrinking the slab git bisect bad
ebdb292dac7993425c8e31e2c21c9978e914a676 # good:
[fb58a9c345f645f1774dcf6a36fda169253008ae] KVM: x86/mmu: Optimize MMU
page cache lookup for fully direct MMUs git bisect good
fb58a9c345f645f1774dcf6a36fda169253008ae # bad:
[6b82ef2c9cf18a48726e4bb359aa9014632f6466] KVM: x86/mmu: Batch zap MMU
pages when recycling oldest pages git bisect bad
6b82ef2c9cf18a48726e4bb359aa9014632f6466 # good:
[f95eec9bed76d42194c23153cb1cc8f186bf91cb] KVM: x86/mmu: Don't put
invalid SPs back on the list of active pages git bisect good
f95eec9bed76d42194c23153cb1cc8f186bf91cb # first bad commit:
[6b82ef2c9cf18a48726e4bb359aa9014632f6466] KVM: x86/mmu: Batch zap MMU
pages when recycling oldest pages
Host machine is old Intel Core2 without EPT (TDP).
TIA, Z.
next reply other threads:[~2020-11-19 3:05 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-19 3:05 Zdenek Kaspar [this message]
2020-12-01 6:35 ` Bad performance since 5.9-rc1 Zdenek Kaspar
2020-12-18 19:33 ` Zdenek Kaspar
2020-12-21 19:41 ` Sean Christopherson
2020-12-21 21:13 ` Zdenek Kaspar
2020-12-22 17:07 ` Sean Christopherson
2020-12-22 21:26 ` Zdenek Kaspar
2021-01-12 11:18 ` Zdenek Kaspar
2021-01-13 20:17 ` Sean Christopherson
2021-01-13 22:17 ` Zdenek Kaspar
2020-12-02 0:31 ` Sean Christopherson
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