From: Avi Kivity <avi@redhat.com>
To: Marcelo Tosatti <mtosatti@redhat.com>
Cc: kvm@vger.kernel.org, Gregory Haskins <gregory.haskins@gmail.com>
Subject: Re: [patch 2/4] KVM: move coalesced_mmio locking to its own device
Date: Tue, 26 May 2009 16:27:59 +0300 [thread overview]
Message-ID: <4A1BEE5F.2000207@redhat.com> (raw)
In-Reply-To: <20090526131547.GB19383@amt.cnet>
Marcelo Tosatti wrote:
>>
>> Why not use slots_lock to protect the entire iodevice list (rcu one
>> day), and an internal spinlock for coalesced mmio?
>>
>
> Don't like using slots_lock to protect the entire iodevice list, its
> reverse progress in my opinion. The PIO/MMIO device lists are data
> structures used in hot path, they are not directly related to the
> memslots, and therefore deserve a separate lock. Whenever slots_lock
> becomes an issue, you'll have to entangle the mess, so better start
> doing it now.
>
It's a reader/writer lock, so you'll never have contention.
I'm okay with a new lock though.
> Sure can switch to a internal spinlock for coalesced_mmio, but breaking
> out if spin_trylock fails. You're OK with that?
>
Why not do a normal spin_lock()? It's not like you'll wait years for
the store to complete.
--
error compiling committee.c: too many arguments to function
next prev parent reply other threads:[~2009-05-26 13:28 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-05-18 16:56 [patch 0/4] move irq protection role to separate kvm->irq_lock Marcelo Tosatti
2009-05-18 16:56 ` [patch 1/4] KVM: x86: grab pic lock in kvm_pic_clear_isr_ack Marcelo Tosatti
2009-05-18 16:56 ` [patch 2/4] KVM: move coalesced_mmio locking to its own device Marcelo Tosatti
2009-05-20 12:06 ` Avi Kivity
2009-05-20 14:09 ` Marcelo Tosatti
2009-05-20 14:29 ` Avi Kivity
2009-05-20 15:13 ` Marcelo Tosatti
2009-05-20 15:22 ` Marcelo Tosatti
2009-05-20 15:22 ` Avi Kivity
2009-05-20 18:48 ` [patch 0/4] move irq protection role to separate lock v2 Marcelo Tosatti
2009-05-20 18:48 ` [patch 1/4] KVM: x86: grab pic lock in kvm_pic_clear_isr_ack Marcelo Tosatti
2009-05-20 18:48 ` [patch 2/4] KVM: move coalesced_mmio locking to its own device Marcelo Tosatti
2009-05-24 14:04 ` Avi Kivity
2009-05-25 11:04 ` Marcelo Tosatti
2009-05-26 11:24 ` Avi Kivity
2009-05-26 13:15 ` Marcelo Tosatti
2009-05-26 13:27 ` Avi Kivity [this message]
2009-05-20 18:48 ` [patch 3/4] KVM: introduce irq_lock, use it to protect ioapic Marcelo Tosatti
2009-05-24 14:10 ` Avi Kivity
2009-05-25 11:11 ` Marcelo Tosatti
2009-05-26 11:33 ` Avi Kivity
2009-05-28 4:45 ` [patch 0/4] move irq protection role to separate lock v3 Marcelo Tosatti
2009-05-28 4:45 ` [patch 1/4] KVM: x86: grab pic lock in kvm_pic_clear_isr_ack Marcelo Tosatti
2009-05-28 4:45 ` [patch 2/4] KVM: move coalesced_mmio locking to its own device Marcelo Tosatti
2009-05-31 12:14 ` Avi Kivity
2009-06-01 21:23 ` Marcelo Tosatti
2009-06-01 21:43 ` Avi Kivity
2009-06-04 18:08 ` [patch 0/4] move irq protection role to separate lock v4 Marcelo Tosatti
2009-06-04 18:08 ` [patch 1/4] KVM: x86: grab pic lock in kvm_pic_clear_isr_ack Marcelo Tosatti
2009-06-04 18:08 ` [patch 2/4] KVM: move coalesced_mmio locking to its own device Marcelo Tosatti
2009-06-04 18:08 ` [patch 3/4] KVM: introduce irq_lock, use it to protect ioapic Marcelo Tosatti
2009-06-04 18:08 ` [patch 4/4] KVM: switch irq injection/acking data structures to irq_lock Marcelo Tosatti
2009-06-08 9:18 ` [patch 0/4] move irq protection role to separate lock v4 Avi Kivity
2009-05-28 4:45 ` [patch 3/4] KVM: introduce irq_lock, use it to protect ioapic Marcelo Tosatti
2009-05-28 4:45 ` [patch 4/4] KVM: switch irq injection/acking data structures to irq_lock Marcelo Tosatti
2009-05-20 18:48 ` [patch 4/4] KVM: switch irq injection/acking " Marcelo Tosatti
2009-05-21 4:50 ` [patch 0/4] move irq protection role to separate lock v2 Marcelo Tosatti
2009-05-21 6:55 ` Christian Bornträger
2009-05-21 7:26 ` Avi Kivity
2009-05-21 14:32 ` Marcelo Tosatti
2009-05-21 15:02 ` Avi Kivity
2009-05-18 16:56 ` [patch 3/4] KVM: introduce irq_lock, use it protect ioapic Marcelo Tosatti
2009-05-20 12:11 ` Avi Kivity
2009-05-20 14:11 ` Marcelo Tosatti
2009-05-20 14:29 ` Avi Kivity
2009-05-18 16:56 ` [patch 4/4] KVM: switch irq injection/acking to irq_lock Marcelo Tosatti
2009-05-20 12:15 ` Gregory Haskins
2009-05-20 14:16 ` Marcelo Tosatti
2009-05-24 14:53 ` Avi Kivity
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=4A1BEE5F.2000207@redhat.com \
--to=avi@redhat.com \
--cc=gregory.haskins@gmail.com \
--cc=kvm@vger.kernel.org \
--cc=mtosatti@redhat.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.