From: "Denis V. Lunev" <den-lists@parallels.com>
To: Peter Maydell <peter.maydell@linaro.org>,
Tiejun Chen <tiejun.chen@intel.com>
Cc: QEMU Trivial <qemu-trivial@nongnu.org>,
Paolo Bonzini <pbonzini@redhat.com>,
QEMU Developers <qemu-devel@nongnu.org>,
kvm-devel <kvm@vger.kernel.org>
Subject: Re: [Qemu-trivial] [Qemu-devel] [PATCH] kvm_irqchip_assign_irqfd: just set irqfd in case of kvm_irqfds_enabled()
Date: Fri, 26 Dec 2014 13:16:10 +0300 [thread overview]
Message-ID: <549D356A.4050506@parallels.com> (raw)
In-Reply-To: <CAFEAcA9yR2FPUF-T_ehMS4Yd0SL91mVADYwhDAuxCbkhQnNZiA@mail.gmail.com>
On 26/12/14 13:00, Peter Maydell wrote:
> On 26 December 2014 at 08:05, Tiejun Chen <tiejun.chen@intel.com> wrote:
>> We should avoid to set irqfd{} unconditionally.
>>
>> Signed-off-by: Tiejun Chen <tiejun.chen@intel.com>
>
> Is there a hot path that we use this on such that the difference
> in code order matters at all?
>
> thanks
> -- PMM
>
IMHO the patch does not change anything even on hot-hot path.
the declaration 'struct kvm_irqfd irqfd = {};' will
result in memset inside.
Thus in order to achieve declared goal author should
declare
struct kvm_irqfd irqfd;
and perform
memset(&irqfd, 0, sizeof(irqfd));
later after the check.
Regards,
Den
WARNING: multiple messages have this Message-ID (diff)
From: "Denis V. Lunev" <den-lists@parallels.com>
To: Peter Maydell <peter.maydell@linaro.org>,
Tiejun Chen <tiejun.chen@intel.com>
Cc: QEMU Trivial <qemu-trivial@nongnu.org>,
Paolo Bonzini <pbonzini@redhat.com>,
QEMU Developers <qemu-devel@nongnu.org>,
kvm-devel <kvm@vger.kernel.org>
Subject: Re: [PATCH] kvm_irqchip_assign_irqfd: just set irqfd in case of kvm_irqfds_enabled()
Date: Fri, 26 Dec 2014 13:16:10 +0300 [thread overview]
Message-ID: <549D356A.4050506@parallels.com> (raw)
In-Reply-To: <CAFEAcA9yR2FPUF-T_ehMS4Yd0SL91mVADYwhDAuxCbkhQnNZiA@mail.gmail.com>
On 26/12/14 13:00, Peter Maydell wrote:
> On 26 December 2014 at 08:05, Tiejun Chen <tiejun.chen@intel.com> wrote:
>> We should avoid to set irqfd{} unconditionally.
>>
>> Signed-off-by: Tiejun Chen <tiejun.chen@intel.com>
>
> Is there a hot path that we use this on such that the difference
> in code order matters at all?
>
> thanks
> -- PMM
>
IMHO the patch does not change anything even on hot-hot path.
the declaration 'struct kvm_irqfd irqfd = {};' will
result in memset inside.
Thus in order to achieve declared goal author should
declare
struct kvm_irqfd irqfd;
and perform
memset(&irqfd, 0, sizeof(irqfd));
later after the check.
Regards,
Den
WARNING: multiple messages have this Message-ID (diff)
From: "Denis V. Lunev" <den-lists@parallels.com>
To: Peter Maydell <peter.maydell@linaro.org>,
Tiejun Chen <tiejun.chen@intel.com>
Cc: QEMU Trivial <qemu-trivial@nongnu.org>,
Paolo Bonzini <pbonzini@redhat.com>,
QEMU Developers <qemu-devel@nongnu.org>,
kvm-devel <kvm@vger.kernel.org>
Subject: Re: [Qemu-devel] [PATCH] kvm_irqchip_assign_irqfd: just set irqfd in case of kvm_irqfds_enabled()
Date: Fri, 26 Dec 2014 13:16:10 +0300 [thread overview]
Message-ID: <549D356A.4050506@parallels.com> (raw)
In-Reply-To: <CAFEAcA9yR2FPUF-T_ehMS4Yd0SL91mVADYwhDAuxCbkhQnNZiA@mail.gmail.com>
On 26/12/14 13:00, Peter Maydell wrote:
> On 26 December 2014 at 08:05, Tiejun Chen <tiejun.chen@intel.com> wrote:
>> We should avoid to set irqfd{} unconditionally.
>>
>> Signed-off-by: Tiejun Chen <tiejun.chen@intel.com>
>
> Is there a hot path that we use this on such that the difference
> in code order matters at all?
>
> thanks
> -- PMM
>
IMHO the patch does not change anything even on hot-hot path.
the declaration 'struct kvm_irqfd irqfd = {};' will
result in memset inside.
Thus in order to achieve declared goal author should
declare
struct kvm_irqfd irqfd;
and perform
memset(&irqfd, 0, sizeof(irqfd));
later after the check.
Regards,
Den
next prev parent reply other threads:[~2014-12-26 16:05 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-12-26 8:05 [Qemu-trivial] [PATCH] kvm_irqchip_assign_irqfd: just set irqfd in case of kvm_irqfds_enabled() Tiejun Chen
2014-12-26 8:05 ` [Qemu-devel] " Tiejun Chen
2014-12-26 8:05 ` Tiejun Chen
2014-12-26 10:00 ` [Qemu-trivial] [Qemu-devel] " Peter Maydell
2014-12-26 10:00 ` Peter Maydell
2014-12-26 10:00 ` Peter Maydell
2014-12-26 10:16 ` Denis V. Lunev [this message]
2014-12-26 10:16 ` Denis V. Lunev
2014-12-26 10:16 ` Denis V. Lunev
2014-12-26 17:59 ` [Qemu-trivial] [Qemu-devel] " Peter Maydell
2014-12-26 17:59 ` Peter Maydell
2014-12-26 17:59 ` Peter Maydell
2014-12-27 14:52 ` [Qemu-trivial] " Paolo Bonzini
2014-12-27 14:52 ` Paolo Bonzini
2014-12-27 14:52 ` Paolo Bonzini
2014-12-29 1:31 ` [Qemu-trivial] [Qemu-devel] " Chen, Tiejun
2014-12-29 1:31 ` Chen, Tiejun
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