From: Sean Christopherson <seanjc@google.com>
To: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: kvm@vger.kernel.org, Paolo Bonzini <pbonzini@redhat.com>,
Wanpeng Li <wanpengli@tencent.com>,
Jim Mattson <jmattson@google.com>,
"Dr. David Alan Gilbert" <dgilbert@redhat.com>,
Nitesh Narayan Lal <nitesh@redhat.com>,
Lai Jiangshan <jiangshanlai@gmail.com>,
Maxim Levitsky <mlevitsk@redhat.com>,
Eduardo Habkost <ehabkost@redhat.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v5 8/8] KVM: Make kvm_make_vcpus_request_mask() use pre-allocated cpu_kick_mask
Date: Fri, 3 Sep 2021 16:26:36 +0000 [thread overview]
Message-ID: <YTJMvI1GE5Ux7eVE@google.com> (raw)
In-Reply-To: <20210903075141.403071-9-vkuznets@redhat.com>
On Fri, Sep 03, 2021, Vitaly Kuznetsov wrote:
> kvm_make_vcpus_request_mask() already disables preemption so just like
> kvm_make_all_cpus_request_except() it can be switched to using
> pre-allocated per-cpu cpumasks. This allows for improvements for both
> users of the function: in Hyper-V emulation code 'tlb_flush' can now be
> dropped from 'struct kvm_vcpu_hv' and kvm_make_scan_ioapic_request_mask()
> gets rid of dynamic allocation.
>
> cpumask_available() checks in kvm_make_vcpu_request() and
> kvm_kick_many_cpus() can now be dropped as they checks for an impossible
> condition: kvm_init() makes sure per-cpu masks are allocated.
>
> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
> ---
Reviewed-by: Sean Christopherson <seanjc@google.com>
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index a4752dcc2a75..91c1e6c98b0f 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -9224,14 +9224,8 @@ static void process_smi(struct kvm_vcpu *vcpu)
> void kvm_make_scan_ioapic_request_mask(struct kvm *kvm,
> unsigned long *vcpu_bitmap)
> {
> - cpumask_var_t cpus;
> -
> - zalloc_cpumask_var(&cpus, GFP_ATOMIC);
> -
> kvm_make_vcpus_request_mask(kvm, KVM_REQ_SCAN_IOAPIC,
> - vcpu_bitmap, cpus);
> -
> - free_cpumask_var(cpus);
> + vcpu_bitmap);
Nit, this can all go on a single line.
> }
>
> void kvm_make_scan_ioapic_request(struct kvm *kvm)
next prev parent reply other threads:[~2021-09-03 16:26 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-03 7:51 [PATCH v5 0/8] KVM: Various fixes and improvements around kicking vCPUs Vitaly Kuznetsov
2021-09-03 7:51 ` [PATCH v5 1/8] KVM: Clean up benign vcpu->cpu data races when " Vitaly Kuznetsov
2021-09-04 0:52 ` Lai Jiangshan
2021-09-03 7:51 ` [PATCH v5 2/8] KVM: KVM: Use cpumask_available() to check for NULL cpumask " Vitaly Kuznetsov
2021-09-03 7:51 ` [PATCH v5 3/8] KVM: x86: hyper-v: Avoid calling kvm_make_vcpus_request_mask() with vcpu_mask==NULL Vitaly Kuznetsov
2021-09-03 7:51 ` [PATCH v5 4/8] KVM: Optimize kvm_make_vcpus_request_mask() a bit Vitaly Kuznetsov
2021-09-03 16:22 ` Sean Christopherson
2021-09-03 7:51 ` [PATCH v5 5/8] KVM: Drop 'except' parameter from kvm_make_vcpus_request_mask() Vitaly Kuznetsov
2021-09-03 7:51 ` [PATCH v5 6/8] KVM: x86: Fix stack-out-of-bounds memory access from ioapic_write_indirect() Vitaly Kuznetsov
2021-09-03 7:51 ` [PATCH v5 7/8] KVM: Pre-allocate cpumasks for kvm_make_all_cpus_request_except() Vitaly Kuznetsov
2021-09-03 16:24 ` Sean Christopherson
2021-09-03 7:51 ` [PATCH v5 8/8] KVM: Make kvm_make_vcpus_request_mask() use pre-allocated cpu_kick_mask Vitaly Kuznetsov
2021-09-03 16:26 ` Sean Christopherson [this message]
2021-09-06 7:23 ` Vitaly Kuznetsov
2021-09-20 14:48 ` [PATCH v5 0/8] KVM: Various fixes and improvements around kicking vCPUs Vitaly Kuznetsov
2021-09-20 18:04 ` Paolo Bonzini
2021-09-24 11:05 ` Paolo Bonzini
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=YTJMvI1GE5Ux7eVE@google.com \
--to=seanjc@google.com \
--cc=dgilbert@redhat.com \
--cc=ehabkost@redhat.com \
--cc=jiangshanlai@gmail.com \
--cc=jmattson@google.com \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mlevitsk@redhat.com \
--cc=nitesh@redhat.com \
--cc=pbonzini@redhat.com \
--cc=vkuznets@redhat.com \
--cc=wanpengli@tencent.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).