From: Leonardo Bras <leobras@redhat.com>
To: Sean Christopherson <seanjc@google.com>
Cc: Leonardo Bras <leobras@redhat.com>,
"Paul E. McKenney" <paulmck@kernel.org>,
Paolo Bonzini <pbonzini@redhat.com>,
Frederic Weisbecker <frederic@kernel.org>,
Neeraj Upadhyay <quic_neeraju@quicinc.com>,
Joel Fernandes <joel@joelfernandes.org>,
Josh Triplett <josh@joshtriplett.org>,
Boqun Feng <boqun.feng@gmail.com>,
Steven Rostedt <rostedt@goodmis.org>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
Lai Jiangshan <jiangshanlai@gmail.com>,
Zqiang <qiang.zhang1211@gmail.com>,
Marcelo Tosatti <mtosatti@redhat.com>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
rcu@vger.kernel.org
Subject: Re: [RFC PATCH v1 0/2] Avoid rcu_core() if CPU just left guest vcpu
Date: Fri, 10 May 2024 23:08:42 -0300 [thread overview]
Message-ID: <Zj7TKg9tHTwgWOIQ@LeoBras> (raw)
In-Reply-To: <ZjuFuZHKUy7n6-sG@google.com>
On Wed, May 08, 2024 at 07:01:29AM -0700, Sean Christopherson wrote:
> On Wed, May 08, 2024, Leonardo Bras wrote:
> > Something just hit me, and maybe I need to propose something more generic.
>
> Yes. This is what I was trying to get across with my complaints about keying off
> of the last VM-Exit time. It's effectively a broad stroke "this task will likely
> be quiescent soon" and so the core concept/functionality belongs in common code,
> not KVM.
>
Hello Sean,
Paul implemented the RCU patience cmdline option, that will help avoiding
rcuc waking up if the grace period is younger than X miliseconds, which
means the last quiescent state needs to be at least X miliseconds old.
With that I just have to add a quiescent state in guest_exit(), and we will
be able to get the same effect of last_guest_exit patch.
I sent this RFC patch doing that:
https://lore.kernel.org/all/20240511020557.1198200-1-leobras@redhat.com/
Please take a look.
Thanks!
Leo
next prev parent reply other threads:[~2024-05-11 2:08 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-28 17:19 [RFC PATCH v1 0/2] Avoid rcu_core() if CPU just left guest vcpu Leonardo Bras
2024-03-28 17:19 ` [RFC PATCH v1 1/2] kvm: Implement guest_exit_last_time() Leonardo Bras
2024-03-28 17:19 ` [RFC PATCH v1 2/2] rcu: Ignore RCU in nohz_full cpus if it was running a guest recently Leonardo Bras
2024-04-01 15:52 ` Paul E. McKenney
2024-04-01 20:21 ` [RFC PATCH v1 0/2] Avoid rcu_core() if CPU just left guest vcpu Sean Christopherson
2024-04-05 13:45 ` Marcelo Tosatti
2024-04-05 14:42 ` Sean Christopherson
2024-04-06 0:03 ` Paul E. McKenney
2024-04-08 17:16 ` Sean Christopherson
2024-04-08 18:42 ` Paul E. McKenney
2024-04-08 20:06 ` Sean Christopherson
2024-04-08 21:02 ` Paul E. McKenney
2024-04-08 21:56 ` Sean Christopherson
2024-04-08 22:35 ` Paul E. McKenney
2024-04-08 23:06 ` Sean Christopherson
2024-04-08 23:20 ` Paul E. McKenney
2024-04-10 2:39 ` Marcelo Tosatti
2024-04-15 19:47 ` Marcelo Tosatti
2024-04-15 21:29 ` Sean Christopherson
2024-04-16 12:36 ` Marcelo Tosatti
2024-04-16 14:07 ` Sean Christopherson
2024-04-17 16:14 ` Marcelo Tosatti
2024-04-17 17:22 ` Sean Christopherson
2024-05-03 20:44 ` Leonardo Bras
2024-05-06 18:47 ` Marcelo Tosatti
2024-05-07 18:05 ` Sean Christopherson
2024-05-07 22:36 ` Leonardo Bras
2024-05-03 18:42 ` Leonardo Bras
2024-05-03 19:09 ` Leonardo Bras
2024-05-03 21:29 ` Sean Christopherson
2024-05-03 22:00 ` Leonardo Bras
2024-05-03 22:00 ` Paul E. McKenney
2024-05-07 17:55 ` Sean Christopherson
2024-05-07 19:15 ` Paul E. McKenney
2024-05-07 21:00 ` Sean Christopherson
2024-05-07 21:37 ` Paul E. McKenney
2024-05-07 23:47 ` Sean Christopherson
2024-05-08 0:08 ` Sean Christopherson
2024-05-08 2:51 ` Leonardo Bras
2024-05-08 3:22 ` Paul E. McKenney
2024-05-08 6:19 ` Leonardo Bras
2024-05-08 14:01 ` Sean Christopherson
2024-05-09 3:32 ` Paul E. McKenney
2024-05-09 8:16 ` Leonardo Bras
2024-05-09 10:14 ` Leonardo Bras
2024-05-09 23:45 ` Paul E. McKenney
2024-05-10 16:06 ` Leonardo Bras
2024-05-10 16:21 ` Paul E. McKenney
2024-05-10 17:12 ` Leonardo Bras
2024-05-10 17:41 ` Paul E. McKenney
2024-05-10 19:50 ` Leonardo Bras
2024-05-10 21:15 ` Leonardo Bras
2024-05-10 21:38 ` Paul E. McKenney
2024-05-09 22:41 ` Paul E. McKenney
2024-05-09 23:07 ` Leonardo Bras Soares Passos
2024-05-11 2:08 ` Leonardo Bras [this message]
2024-05-08 3:20 ` Paul E. McKenney
2024-05-08 4:04 ` Paul E. McKenney
2024-05-08 14:36 ` Paul E. McKenney
2024-05-08 15:35 ` Sean Christopherson
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=Zj7TKg9tHTwgWOIQ@LeoBras \
--to=leobras@redhat.com \
--cc=boqun.feng@gmail.com \
--cc=frederic@kernel.org \
--cc=jiangshanlai@gmail.com \
--cc=joel@joelfernandes.org \
--cc=josh@joshtriplett.org \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mathieu.desnoyers@efficios.com \
--cc=mtosatti@redhat.com \
--cc=paulmck@kernel.org \
--cc=pbonzini@redhat.com \
--cc=qiang.zhang1211@gmail.com \
--cc=quic_neeraju@quicinc.com \
--cc=rcu@vger.kernel.org \
--cc=rostedt@goodmis.org \
--cc=seanjc@google.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 read-only IMAP folder(s) and NNTP newsgroup(s).