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| author | Keir Fraser <keirf@google.com> | 2025-09-09 10:00:07 +0000 |
|---|---|---|
| committer | Marc Zyngier <maz@kernel.org> | 2025-09-15 10:55:23 +0100 |
| commit | 7d9a0273c45962e9a6bc06f3b87eef7c431c1853 (patch) | |
| tree | 163b60288a036257cfa8921cbd06537f4c084559 /include | |
| parent | KVM: Implement barriers before accessing kvm->buses[] on SRCU read paths (diff) | |
| download | linux-7d9a0273c45962e9a6bc06f3b87eef7c431c1853.tar.gz linux-7d9a0273c45962e9a6bc06f3b87eef7c431c1853.zip | |
KVM: Avoid synchronize_srcu() in kvm_io_bus_register_dev()
Device MMIO registration may happen quite frequently during VM boot,
and the SRCU synchronization each time has a measurable effect
on VM startup time. In our experiments it can account for around 25%
of a VM's startup time.
Replace the synchronization with a deferred free of the old kvm_io_bus
structure.
Tested-by: Li RongQing <lirongqing@baidu.com>
Signed-off-by: Keir Fraser <keirf@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/kvm_host.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index e7d6111cf254..103be35caf0d 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -206,6 +206,7 @@ struct kvm_io_range { struct kvm_io_bus { int dev_count; int ioeventfd_count; + struct rcu_head rcu; struct kvm_io_range range[]; }; |