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Date:   Thu, 27 Oct 2022 00:17:41 +0000
From:   Sean Christopherson <seanjc@google.com>
To:     Wei Wang <wei.w.wang@intel.com>
Cc:     pbonzini@redhat.com, dmatlack@google.com, vipinsh@google.com,
        ajones@ventanamicro.com, eric.auger@redhat.com,
        kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v1 09/18] KVM: selftests/steal_time: vcpu related code
 consolidation and cleanup
Message-ID: <Y1nOJQWys3gUp+oB@google.com>
References: <20221024113445.1022147-1-wei.w.wang@intel.com>
 <20221024113445.1022147-10-wei.w.wang@intel.com>
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In-Reply-To: <20221024113445.1022147-10-wei.w.wang@intel.com>
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On Mon, Oct 24, 2022, Wei Wang wrote:
> Remove the unnecessary definition of array of the vcpu pointers and
> re-use the one from the kvm_vm struct (i.e. vm->vcpus[]). Use the helper
> function to create the time stealing thread with name.

One thing per patch.

> Also add a check of the pthread_join return value.
> 
> Signed-off-by: Wei Wang <wei.w.wang@intel.com>
> ---
>  tools/testing/selftests/kvm/steal_time.c | 15 +++++++++------
>  1 file changed, 9 insertions(+), 6 deletions(-)
> 
> diff --git a/tools/testing/selftests/kvm/steal_time.c b/tools/testing/selftests/kvm/steal_time.c
> index db8967f1a17b..857ed2c073fc 100644
> --- a/tools/testing/selftests/kvm/steal_time.c
> +++ b/tools/testing/selftests/kvm/steal_time.c
> @@ -8,7 +8,6 @@
>  #include <stdio.h>
>  #include <time.h>
>  #include <sched.h>
> -#include <pthread.h>
>  #include <linux/kernel.h>
>  #include <asm/kvm.h>
>  #include <asm/kvm_para.h>
> @@ -241,7 +240,7 @@ static void run_vcpu(struct kvm_vcpu *vcpu)
>  
>  int main(int ac, char **av)
>  {
> -	struct kvm_vcpu *vcpus[NR_VCPUS];
> +	struct kvm_vcpu **vcpus;
>  	struct kvm_vm *vm;
>  	pthread_attr_t attr;
>  	pthread_t thread;
> @@ -250,7 +249,7 @@ int main(int ac, char **av)
>  	long stolen_time;
>  	long run_delay;
>  	bool verbose;
> -	int i;
> +	int i, r;
>  
>  	verbose = ac > 1 && (!strncmp(av[1], "-v", 3) || !strncmp(av[1], "--verbose", 10));
>  
> @@ -262,7 +261,8 @@ int main(int ac, char **av)
>  	pthread_setaffinity_np(pthread_self(), sizeof(cpu_set_t), &cpuset);
>  
>  	/* Create a VM and an identity mapped memslot for the steal time structure */
> -	vm = vm_create_with_vcpus(NR_VCPUS, guest_code, vcpus);
> +	vm = vm_create_with_vcpus(NR_VCPUS, guest_code, NULL);
> +	vcpus = vm->vcpus;

Just use vm->vcpus directly and drop the local variable, it's not that much more
churn and this looks quite odd.